{"id":611113,"date":"2026-09-09T21:48:11","date_gmt":"2026-09-09T21:48:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/611113\/"},"modified":"2026-09-09T21:48:11","modified_gmt":"2026-09-09T21:48:11","slug":"hypersoft-x-ray-sources-as-a-low-energy-class-of-luminous-cosmic-emitter","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/611113\/","title":{"rendered":"Hypersoft X-ray sources as a low-energy class of luminous cosmic emitter"},"content":{"rendered":"<p class=\"c-article-references__text\" id=\"ref-CR1\">Drake, J. J., Kashyap, V. L., Wargelin, B. J. &amp; Wolk, S. J. Pointing Chandra toward the extreme ultraviolet fluxes of very low mass stars. Astrophys. J. 893, 137 (2020).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.3847\/1538-4357\/ab7b5c\" data-track-item_id=\"10.3847\/1538-4357\/ab7b5c\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.3847%2F1538-4357%2Fab7b5c\" aria-label=\"Article reference 1\" data-doi=\"10.3847\/1538-4357\/ab7b5c\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2020ApJ...893..137D\" aria-label=\"ADS reference 1\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 1\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Pointing%20Chandra%20toward%20the%20extreme%20ultraviolet%20fluxes%20of%20very%20low%20mass%20stars&amp;journal=Astrophys.%20J.&amp;doi=10.3847%2F1538-4357%2Fab7b5c&amp;volume=893&amp;publication_year=2020&amp;author=Drake%2CJJ&amp;author=Kashyap%2CVL&amp;author=Wargelin%2CBJ&amp;author=Wolk%2CSJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR2\">McCammon, D. &amp; Sanders, W. T. The soft X-ray background and its origins. Annu. Rev. Astron. Astrophys. 28, 657\u2013688 (1990).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1146\/annurev.aa.28.090190.003301\" data-track-item_id=\"10.1146\/annurev.aa.28.090190.003301\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1146%2Fannurev.aa.28.090190.003301\" aria-label=\"Article reference 2\" data-doi=\"10.1146\/annurev.aa.28.090190.003301\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1990ARA%26A..28..657M\" aria-label=\"ADS reference 2\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 2\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20soft%20X-ray%20background%20and%20its%20origins&amp;journal=Annu.%20Rev.%20Astron.%20Astrophys.&amp;doi=10.1146%2Fannurev.aa.28.090190.003301&amp;volume=28&amp;pages=657-688&amp;publication_year=1990&amp;author=McCammon%2CD&amp;author=Sanders%2CWT\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR3\">Jelinsky, P., Vallerga, J. V. &amp; Edelstein, J. First spectral observations of the diffuse background with the extreme ultraviolet explorer. Astrophys. J. 442, 653 (1995).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/175469\" data-track-item_id=\"10.1086\/175469\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F175469\" aria-label=\"Article reference 3\" data-doi=\"10.1086\/175469\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1995ApJ...442..653J\" aria-label=\"ADS reference 3\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 3\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=First%20spectral%20observations%20of%20the%20diffuse%20background%20with%20the%20extreme%20ultraviolet%20explorer&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F175469&amp;volume=442&amp;publication_year=1995&amp;author=Jelinsky%2CP&amp;author=Vallerga%2CJV&amp;author=Edelstein%2CJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR4\">Kahabka, P. &amp; van den Heuvel, E. P. J. Luminous supersoft X-ray sources. Annu. Rev. Astron. Astrophys. 35, 69\u2013100 (1997).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1146\/annurev.astro.35.1.69\" data-track-item_id=\"10.1146\/annurev.astro.35.1.69\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1146%2Fannurev.astro.35.1.69\" aria-label=\"Article reference 4\" data-doi=\"10.1146\/annurev.astro.35.1.69\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1997ARA%26A..35...69K\" aria-label=\"ADS reference 4\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 4\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Luminous%20supersoft%20X-ray%20sources&amp;journal=Annu.%20Rev.%20Astron.%20Astrophys.&amp;doi=10.1146%2Fannurev.astro.35.1.69&amp;volume=35&amp;pages=69-100&amp;publication_year=1997&amp;author=Kahabka%2CP&amp;author=Heuvel%2CEPJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR5\">Greiner, J., Hasinger, G. &amp; Kahabka, P. ROSAT observation of two supersoft sources in the Large Magellanic Cloud. Astron. Astrophys. 246, 17\u201320 (1991).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1991A%26A...246L..17G\" aria-label=\"ADS reference 5\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 5\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=ROSAT%20observation%20of%20two%20supersoft%20sources%20in%20the%20Large%20Magellanic%20Cloud&amp;journal=Astron.%20Astrophys.&amp;volume=246&amp;pages=17-20&amp;publication_year=1991&amp;author=Greiner%2CJ&amp;author=Hasinger%2CG&amp;author=Kahabka%2CP\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR6\">Tr\u00fcmper, J. et al. X-ray survey of the Large Magellanic Cloud by ROSAT. Nature 349, 579\u2013583 (1991).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1038\/349579a0\" data-track-item_id=\"10.1038\/349579a0\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1038%2F349579a0\" aria-label=\"Article reference 6\" data-doi=\"10.1038\/349579a0\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1991Natur.349..579T\" aria-label=\"ADS reference 6\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 6\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20survey%20of%20the%20Large%20Magellanic%20Cloud%20by%20ROSAT&amp;journal=Nature&amp;doi=10.1038%2F349579a0&amp;volume=349&amp;pages=579-583&amp;publication_year=1991&amp;author=Tr%C3%BCmper%2CJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR7\">Rappaport, S., Di Stefano, R. &amp; Smith, J. D. Formation and evolution of luminous supersoft X-ray sources. Astrophys. J. 426, 692 (1994).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/174106\" data-track-item_id=\"10.1086\/174106\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F174106\" aria-label=\"Article reference 7\" data-doi=\"10.1086\/174106\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1994ApJ...426..692R\" aria-label=\"ADS reference 7\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 7\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Formation%20and%20evolution%20of%20luminous%20supersoft%20X-ray%20sources&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F174106&amp;volume=426&amp;publication_year=1994&amp;author=Rappaport%2CS&amp;author=Stefano%2CR&amp;author=Smith%2CJD\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR8\">Orio, M., Covington, J. &amp; \u00d6gelman, H. X-ray emission from classical and recurrent novae observed with ROSAT. Astron. Astrophys. 373, 542\u2013554 (2001).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361:20010537\" data-track-item_id=\"10.1051\/0004-6361:20010537\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%3A20010537\" aria-label=\"Article reference 8\" data-doi=\"10.1051\/0004-6361:20010537\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2001A%26A...373..542O\" aria-label=\"ADS reference 8\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 8\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20emission%20from%20classical%20and%20recurrent%20novae%20observed%20with%20ROSAT&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%3A20010537&amp;volume=373&amp;pages=542-554&amp;publication_year=2001&amp;author=Orio%2CM&amp;author=Covington%2CJ&amp;author=%C3%96gelman%2CH\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR9\">Henze, M. et al. X-ray monitoring of classical novae in the central region of M 31. II. Autumn and winter 2007\/2008 and 2008\/2009. Astron. Astrophys. 533, 52 (2011).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361\/201015887\" data-track-item_id=\"10.1051\/0004-6361\/201015887\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%2F201015887\" aria-label=\"Article reference 9\" data-doi=\"10.1051\/0004-6361\/201015887\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 9\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20monitoring%20of%20classical%20novae%20in%20the%20central%20region%20of%20M%2031.%20II.%20Autumn%20and%20winter%202007%2F2008%20and%202008%2F2009&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%2F201015887&amp;volume=533&amp;publication_year=2011&amp;author=Henze%2CM\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR10\">Henze, M. et al. X-ray monitoring of classical novae in the central region of M 31 III. Autumn and winter 2009\/10, 2010\/11, and 2011\/12. Astron. Astrophys. 563, 2 (2014).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361\/201322426\" data-track-item_id=\"10.1051\/0004-6361\/201322426\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%2F201322426\" aria-label=\"Article reference 10\" data-doi=\"10.1051\/0004-6361\/201322426\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 10\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20monitoring%20of%20classical%20novae%20in%20the%20central%20region%20of%20M%2031%20III.%20Autumn%20and%20winter%202009%2F10%2C%202010%2F11%2C%20and%202011%2F12&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%2F201322426&amp;volume=563&amp;publication_year=2014&amp;author=Henze%2CM\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR11\">Kaaret, P. et al. Direct detection of an ultraluminous ultraviolet source. Astrophys. J. Lett. 714, L167\u2013L170 (2010).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/2041-8205\/714\/1\/L167\" data-track-item_id=\"10.1088\/2041-8205\/714\/1\/L167\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F2041-8205%2F714%2F1%2FL167\" aria-label=\"Article reference 11\" data-doi=\"10.1088\/2041-8205\/714\/1\/L167\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2010ApJ...714L.167K\" aria-label=\"ADS reference 11\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 11\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Direct%20detection%20of%20an%20ultraluminous%20ultraviolet%20source&amp;journal=Astrophys.%20J.%20Lett.&amp;doi=10.1088%2F2041-8205%2F714%2F1%2FL167&amp;volume=714&amp;pages=L167-L170&amp;publication_year=2010&amp;author=Kaaret%2CP\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR12\">Werner, K. &amp; Rauch, T. Analysis of HST\/COS spectra of the bare C-O stellar core H1504+65 and a high-velocity twin in the Galactic halo. Astron. Astrophys. 584, 19 (2015).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361\/201527261\" data-track-item_id=\"10.1051\/0004-6361\/201527261\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%2F201527261\" aria-label=\"Article reference 12\" data-doi=\"10.1051\/0004-6361\/201527261\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2015A%26A...584A..19W\" aria-label=\"ADS reference 12\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 12\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Analysis%20of%20HST%2FCOS%20spectra%20of%20the%20bare%20C-O%20stellar%20core%20H1504%2B65%20and%20a%20high-velocity%20twin%20in%20the%20Galactic%20halo&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%2F201527261&amp;volume=584&amp;publication_year=2015&amp;author=Werner%2CK&amp;author=Rauch%2CT\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR13\">Gonz\u00e1lez-Riestra, R. et al. AG Draconis observed with XMM-Newton. Astron. Astrophys. 481, 725\u2013734 (2008).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361:20078593\" data-track-item_id=\"10.1051\/0004-6361:20078593\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%3A20078593\" aria-label=\"Article reference 13\" data-doi=\"10.1051\/0004-6361:20078593\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2008A%26A...481..725G\" aria-label=\"ADS reference 13\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 13\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=AG%20Draconis%20observed%20with%20XMM-Newton&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%3A20078593&amp;volume=481&amp;pages=725-734&amp;publication_year=2008&amp;author=Gonz%C3%A1lez-Riestra%2CR\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR14\">Fabbiano, G. Populations of X-ray sources in galaxies. Annu. Rev. Astron. Astrophys. 44, 323\u2013366 (2006).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1146\/annurev.astro.44.051905.092519\" data-track-item_id=\"10.1146\/annurev.astro.44.051905.092519\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1146%2Fannurev.astro.44.051905.092519\" aria-label=\"Article reference 14\" data-doi=\"10.1146\/annurev.astro.44.051905.092519\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2006ARA%26A..44..323F\" aria-label=\"ADS reference 14\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 14\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Populations%20of%20X-ray%20sources%20in%20galaxies&amp;journal=Annu.%20Rev.%20Astron.%20Astrophys.&amp;doi=10.1146%2Fannurev.astro.44.051905.092519&amp;volume=44&amp;pages=323-366&amp;publication_year=2006&amp;author=Fabbiano%2CG\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR15\">Paolillo, M. et al. Probing the GC-LMXB connection in NGC 1399: a wide-field study with the Hubble Space Telescope and Chandra. Astrophys. J. 736, 90 (2011).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/0004-637X\/736\/2\/90\" data-track-item_id=\"10.1088\/0004-637X\/736\/2\/90\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F0004-637X%2F736%2F2%2F90\" aria-label=\"Article reference 15\" data-doi=\"10.1088\/0004-637X\/736\/2\/90\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2011ApJ...736...90P\" aria-label=\"ADS reference 15\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 15\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Probing%20the%20GC-LMXB%20connection%20in%20NGC%201399%3A%20a%20wide-field%20study%20with%20the%20Hubble%20Space%20Telescope%20and%20Chandra&amp;journal=Astrophys.%20J.&amp;doi=10.1088%2F0004-637X%2F736%2F2%2F90&amp;volume=736&amp;publication_year=2011&amp;author=Paolillo%2CM\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR16\">Joseph, T. D., Maccarone, T. J., Kraft, R. P. &amp; Sivakoff, G. R. A deeper look at the X-ray point source population of NGC 4472. Mon. Not. R. Astron. Soc. 470, 4133\u20134144 (2017).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1093\/mnras\/stx1383\" data-track-item_id=\"10.1093\/mnras\/stx1383\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1093%2Fmnras%2Fstx1383\" aria-label=\"Article reference 16\" data-doi=\"10.1093\/mnras\/stx1383\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2017MNRAS.470.4133J\" aria-label=\"ADS reference 16\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 16\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=A%20deeper%20look%20at%20the%20X-ray%20point%20source%20population%20of%20NGC%204472&amp;journal=Mon.%20Not.%20R.%20Astron.%20Soc.&amp;doi=10.1093%2Fmnras%2Fstx1383&amp;volume=470&amp;pages=4133-4144&amp;publication_year=2017&amp;author=Joseph%2CTD&amp;author=Maccarone%2CTJ&amp;author=Kraft%2CRP&amp;author=Sivakoff%2CGR\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR17\">Ford, H. A. &amp; Bregman, J. N. Direct detections of young stars in nearby elliptical galaxies. Astrophys. J. 770, 137 (2013).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/0004-637X\/770\/2\/137\" data-track-item_id=\"10.1088\/0004-637X\/770\/2\/137\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F0004-637X%2F770%2F2%2F137\" aria-label=\"Article reference 17\" data-doi=\"10.1088\/0004-637X\/770\/2\/137\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2013ApJ...770..137F\" aria-label=\"ADS reference 17\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 17\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Direct%20detections%20of%20young%20stars%20in%20nearby%20elliptical%20galaxies&amp;journal=Astrophys.%20J.&amp;doi=10.1088%2F0004-637X%2F770%2F2%2F137&amp;volume=770&amp;publication_year=2013&amp;author=Ford%2CHA&amp;author=Bregman%2CJN\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR18\">Pietsch, W. et al. Optical novae: the major class of supersoft X-ray sources in M 31. Astron. Astrophys. 442, 879\u2013894 (2005).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361:20053127\" data-track-item_id=\"10.1051\/0004-6361:20053127\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%3A20053127\" aria-label=\"Article reference 18\" data-doi=\"10.1051\/0004-6361:20053127\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2005A%26A...442..879P\" aria-label=\"ADS reference 18\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 18\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Optical%20novae%3A%20the%20major%20class%20of%20supersoft%20X-ray%20sources%20in%20M%2031&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%3A20053127&amp;volume=442&amp;pages=879-894&amp;publication_year=2005&amp;author=Pietsch%2CW\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR19\">Avdan, H. &amp; Avdan, S. Exploring the nature of an ultraluminous X-ray source in NGC 628. Astron. Astrophys. 690, 335 (2024).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361\/202449509\" data-track-item_id=\"10.1051\/0004-6361\/202449509\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%2F202449509\" aria-label=\"Article reference 19\" data-doi=\"10.1051\/0004-6361\/202449509\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2024A%26A...690A.335A\" aria-label=\"ADS reference 19\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 19\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Exploring%20the%20nature%20of%20an%20ultraluminous%20X-ray%20source%20in%20NGC%20628&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%2F202449509&amp;volume=690&amp;publication_year=2024&amp;author=Avdan%2CH&amp;author=Avdan%2CS\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR20\">Panurach, T. et al. Do neutron star ultraluminous X-ray sources masquerade as intermediate-mass black holes in radio and X-ray? Astrophys. J. 977, 211 (2024).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.3847\/1538-4357\/ad8b9c\" data-track-item_id=\"10.3847\/1538-4357\/ad8b9c\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.3847%2F1538-4357%2Fad8b9c\" aria-label=\"Article reference 20\" data-doi=\"10.3847\/1538-4357\/ad8b9c\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2024ApJ...977..211P\" aria-label=\"ADS reference 20\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 20\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Do%20neutron%20star%20ultraluminous%20X-ray%20sources%20masquerade%20as%20intermediate-mass%20black%20holes%20in%20radio%20and%20X-ray%3F&amp;journal=Astrophys.%20J.&amp;doi=10.3847%2F1538-4357%2Fad8b9c&amp;volume=977&amp;publication_year=2024&amp;author=Panurach%2CT\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR21\">Walton, D. J., Roberts, T. P., Mateos, S. &amp; Heard, V. 2XMM ultraluminous X-ray source candidates in nearby galaxies. Mon. Not. R. Astron. Soc. 416, 1844\u20131861 (2011).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1111\/j.1365-2966.2011.19154.x\" data-track-item_id=\"10.1111\/j.1365-2966.2011.19154.x\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1111%2Fj.1365-2966.2011.19154.x\" aria-label=\"Article reference 21\" data-doi=\"10.1111\/j.1365-2966.2011.19154.x\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2011MNRAS.416.1844W\" aria-label=\"ADS reference 21\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 21\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=2XMM%20ultraluminous%20X-ray%20source%20candidates%20in%20nearby%20galaxies&amp;journal=Mon.%20Not.%20R.%20Astron.%20Soc.&amp;doi=10.1111%2Fj.1365-2966.2011.19154.x&amp;volume=416&amp;pages=1844-1861&amp;publication_year=2011&amp;author=Walton%2CDJ&amp;author=Roberts%2CTP&amp;author=Mateos%2CS&amp;author=Heard%2CV\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR22\">Hoyle, F. &amp; Fowler, W. A. Nucleosynthesis in supernovae. Astrophys. J. 132, 565 (1960).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/146963\" data-track-item_id=\"10.1086\/146963\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F146963\" aria-label=\"Article reference 22\" data-doi=\"10.1086\/146963\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1960ApJ...132..565H\" aria-label=\"ADS reference 22\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 22\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Nucleosynthesis%20in%20supernovae&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F146963&amp;volume=132&amp;publication_year=1960&amp;author=Hoyle%2CF&amp;author=Fowler%2CWA\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR23\">Whelan, J. &amp; Iben, I. Jr. Binaries and supernovae of type I. Astrophys. J. 186, 1007\u20131014 (1973).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/152565\" data-track-item_id=\"10.1086\/152565\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F152565\" aria-label=\"Article reference 23\" data-doi=\"10.1086\/152565\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1973ApJ...186.1007W\" aria-label=\"ADS reference 23\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 23\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Binaries%20and%20supernovae%20of%20type%20I&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F152565&amp;volume=186&amp;pages=1007-1014&amp;publication_year=1973&amp;author=Whelan%2CJ&amp;author=Iben%2CIJr\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR24\">Di Stefano, R., Primini, F. A., Liu, J., Kong, A. &amp; Patel, B. Populations of supersoft X-ray sources: novae, tidal disruption, type Ia supernovae, accretion-induced collapse, ionization, and intermediate-mass black holes? Astron. Nachr. 331, 205\u2013211 (2010).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1002\/asna.200911328\" data-track-item_id=\"10.1002\/asna.200911328\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1002%2Fasna.200911328\" aria-label=\"Article reference 24\" data-doi=\"10.1002\/asna.200911328\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2010AN....331..205D\" aria-label=\"ADS reference 24\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 24\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Populations%20of%20supersoft%20X-ray%20sources%3A%20novae%2C%20tidal%20disruption%2C%20type%20Ia%20supernovae%2C%20accretion-induced%20collapse%2C%20ionization%2C%20and%20intermediate-mass%20black%20holes%3F&amp;journal=Astron.%20Nachr.&amp;doi=10.1002%2Fasna.200911328&amp;volume=331&amp;pages=205-211&amp;publication_year=2010&amp;author=Stefano%2CR&amp;author=Primini%2CFA&amp;author=Liu%2CJ&amp;author=Kong%2CA&amp;author=Patel%2CB\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR25\">Gilfanov, M. &amp; Bogd\u00e1n, \u00c1. Progenitors of type Ia supernovae in elliptical galaxies. AIP Conf. Proc. 1379, 17\u201322 (2011).<\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR26\">Greiner, J. &amp; Di Stefano, R. X-ray off states and optical variability in CAL 83. Astron. Astrophys. 387, 944\u2013954 (2002).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361:20020463\" data-track-item_id=\"10.1051\/0004-6361:20020463\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%3A20020463\" aria-label=\"Article reference 26\" data-doi=\"10.1051\/0004-6361:20020463\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2002A%26A...387..944G\" aria-label=\"ADS reference 26\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 26\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20off%20states%20and%20optical%20variability%20in%20CAL%2083&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%3A20020463&amp;volume=387&amp;pages=944-954&amp;publication_year=2002&amp;author=Greiner%2CJ&amp;author=Stefano%2CR\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR27\">Rappaport, S., Podsiadlowski, P., Joss, P. C., Di Stefano, R. &amp; Han, Z. The relation between white dwarf mass and orbital period in wide binary radio pulsars. Mon. Not. R. Astron. Soc. 273, 731\u2013741 (1995).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1093\/mnras\/273.3.731\" data-track-item_id=\"10.1093\/mnras\/273.3.731\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1093%2Fmnras%2F273.3.731\" aria-label=\"Article reference 27\" data-doi=\"10.1093\/mnras\/273.3.731\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1995MNRAS.273..731R\" aria-label=\"ADS reference 27\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 27\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20relation%20between%20white%20dwarf%20mass%20and%20orbital%20period%20in%20wide%20binary%20radio%20pulsars&amp;journal=Mon.%20Not.%20R.%20Astron.%20Soc.&amp;doi=10.1093%2Fmnras%2F273.3.731&amp;volume=273&amp;pages=731-741&amp;publication_year=1995&amp;author=Rappaport%2CS&amp;author=Podsiadlowski%2CP&amp;author=Joss%2CPC&amp;author=Stefano%2CR&amp;author=Han%2CZ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR28\">Triani, D. P., Di Stefano, R., Hsiao, T. Y.-Y. &amp; Kewley, L. J. The significant contribution of supersoft X-ray sources to nebular He II line emission. Astrophys. J. 993, 117 (2025).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.3847\/1538-4357\/ae057d\" data-track-item_id=\"10.3847\/1538-4357\/ae057d\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.3847%2F1538-4357%2Fae057d\" aria-label=\"Article reference 28\" data-doi=\"10.3847\/1538-4357\/ae057d\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2025ApJ...993..117T\" aria-label=\"ADS reference 28\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 28\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20significant%20contribution%20of%20supersoft%20X-ray%20sources%20to%20nebular%20He%20II%20line%20emission&amp;journal=Astrophys.%20J.&amp;doi=10.3847%2F1538-4357%2Fae057d&amp;volume=993&amp;publication_year=2025&amp;author=Triani%2CDP&amp;author=Stefano%2CR&amp;author=Hsiao%2CTY-Y&amp;author=Kewley%2CLJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR29\">Shirazi, M. &amp; Brinchmann, J. Strongly star forming galaxies in the local Universe with nebular He II\u03bb4686 emission. Mon. Not. R. Astron. Soc. 421, 1043\u20131063 (2012).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1111\/j.1365-2966.2012.20439.x\" data-track-item_id=\"10.1111\/j.1365-2966.2012.20439.x\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1111%2Fj.1365-2966.2012.20439.x\" aria-label=\"Article reference 29\" data-doi=\"10.1111\/j.1365-2966.2012.20439.x\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2012MNRAS.421.1043S\" aria-label=\"ADS reference 29\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 29\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Strongly%20star%20forming%20galaxies%20in%20the%20local%20Universe%20with%20nebular%20He%20II%CE%BB4686%20emission&amp;journal=Mon.%20Not.%20R.%20Astron.%20Soc.&amp;doi=10.1111%2Fj.1365-2966.2012.20439.x&amp;volume=421&amp;pages=1043-1063&amp;publication_year=2012&amp;author=Shirazi%2CM&amp;author=Brinchmann%2CJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR30\">Heintz, K. E. et al. Strong damped Lyman-\u03b1 absorption in young star-forming galaxies at redshifts 9 to 11. Science 384, 890\u2013894 (2024).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1126\/science.adj0343\" data-track-item_id=\"10.1126\/science.adj0343\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1126%2Fscience.adj0343\" aria-label=\"Article reference 30\" data-doi=\"10.1126\/science.adj0343\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2024Sci...384..890H\" aria-label=\"ADS reference 30\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 30\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Strong%20damped%20Lyman-%CE%B1%20absorption%20in%20young%20star-forming%20galaxies%20at%20redshifts%209%20to%2011&amp;journal=Science&amp;doi=10.1126%2Fscience.adj0343&amp;volume=384&amp;pages=890-894&amp;publication_year=2024&amp;author=Heintz%2CKE\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR31\">Freeman, P. E., Kashyap, V., Rosner, R. &amp; Lamb, D. Q. A wavelet-based algorithm for the spatial analysis of Poisson data. Astrophys. J. Suppl. Ser. 138, 185\u2013218 (2002).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/324017\" data-track-item_id=\"10.1086\/324017\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F324017\" aria-label=\"Article reference 31\" data-doi=\"10.1086\/324017\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2002ApJS..138..185F\" aria-label=\"ADS reference 31\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 31\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=A%20wavelet-based%20algorithm%20for%20the%20spatial%20analysis%20of%20Poisson%20data&amp;journal=Astrophys.%20J.%20Suppl.%20Ser.&amp;doi=10.1086%2F324017&amp;volume=138&amp;pages=185-218&amp;publication_year=2002&amp;author=Freeman%2CPE&amp;author=Kashyap%2CV&amp;author=Rosner%2CR&amp;author=Lamb%2CDQ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR32\">Vikhlinin, A. et al. Evolution of cluster X-ray luminosities and radii: results from the 160 square degree ROSAT survey. Astrophys. J. 498, 21\u201325 (1998).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/311305\" data-track-item_id=\"10.1086\/311305\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F311305\" aria-label=\"Article reference 32\" data-doi=\"10.1086\/311305\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 32\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Evolution%20of%20cluster%20X-ray%20luminosities%20and%20radii%3A%20results%20from%20the%20160%20square%20degree%20ROSAT%20survey&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F311305&amp;volume=498&amp;pages=21-25&amp;publication_year=1998&amp;author=Vikhlinin%2CA\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR33\">Gaia Collaboration. Gaia Data Release 3. Summary of the content and survey properties. Astron. Astrophys. 674, A1 (2023).<\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR34\">Pietsch, W. et al. X-ray monitoring of optical novae in M 31 from July 2004 to February 2005. Astron. Astrophys. 465, 375\u2013392 (2007).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361:20066812\" data-track-item_id=\"10.1051\/0004-6361:20066812\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%3A20066812\" aria-label=\"Article reference 34\" data-doi=\"10.1051\/0004-6361:20066812\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2007A%26A...465..375P\" aria-label=\"ADS reference 34\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 34\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20monitoring%20of%20optical%20novae%20in%20M%2031%20from%20July%202004%20to%20February%202005&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%3A20066812&amp;volume=465&amp;pages=375-392&amp;publication_year=2007&amp;author=Pietsch%2CW\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR35\">Arnaud, K. A. In Astronomical Data Analysis Software and Systems V Vol. 101 (eds Jacoby, G. H. &amp; Barnes, J.) 17\u201320 (ASP, 1996).<\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR36\">Lee, H. et al. Accounting for calibration uncertainties in X-ray analysis: effective areas in spectral fitting. Astrophys. J. 731, 126 (2011).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/0004-637X\/731\/2\/126\" data-track-item_id=\"10.1088\/0004-637X\/731\/2\/126\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F0004-637X%2F731%2F2%2F126\" aria-label=\"Article reference 36\" data-doi=\"10.1088\/0004-637X\/731\/2\/126\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2011ApJ...731..126L\" aria-label=\"ADS reference 36\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 36\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Accounting%20for%20calibration%20uncertainties%20in%20X-ray%20analysis%3A%20effective%20areas%20in%20spectral%20fitting&amp;journal=Astrophys.%20J.&amp;doi=10.1088%2F0004-637X%2F731%2F2%2F126&amp;volume=731&amp;publication_year=2011&amp;author=Lee%2CH\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR37\">Henze, M. et al. X-ray monitoring of classical novae in the central region of M 31. I. June 2006\u2013March 2007. Astron. Astrophys. 523, 89 (2010).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361\/201014710\" data-track-item_id=\"10.1051\/0004-6361\/201014710\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%2F201014710\" aria-label=\"Article reference 37\" data-doi=\"10.1051\/0004-6361\/201014710\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 37\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=X-ray%20monitoring%20of%20classical%20novae%20in%20the%20central%20region%20of%20M%2031.%20I.%20June%202006%E2%80%93March%202007&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%2F201014710&amp;volume=523&amp;publication_year=2010&amp;author=Henze%2CM\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR38\">Greiner, J. et al. In Supersoft X-Ray Sources (ed. Greiner, J.) 267\u2013278 (Springer, 1996).<\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR39\">Mitsuda, K. et al. Energy spectra of low-mass binary X-ray sources observed from Tenma. Publ. Astron. Soc. Jpn 36, 741\u2013759 (1984).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1093\/pasj\/36.4.741\" data-track-item_id=\"10.1093\/pasj\/36.4.741\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1093%2Fpasj%2F36.4.741\" aria-label=\"Article reference 39\" data-doi=\"10.1093\/pasj\/36.4.741\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1984PASJ...36..741M\" aria-label=\"ADS reference 39\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 39\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Energy%20spectra%20of%20low-mass%20binary%20X-ray%20sources%20observed%20from%20Tenma&amp;journal=Publ.%20Astron.%20Soc.%20Jpn&amp;doi=10.1093%2Fpasj%2F36.4.741&amp;volume=36&amp;pages=741-759&amp;publication_year=1984&amp;author=Mitsuda%2CK\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR40\">Kraft, R. P., Burrows, D. N. &amp; Nousek, J. A. Determination of confidence limits for experiments with low numbers of counts. Astrophys. J. 374, 344 (1991).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/170124\" data-track-item_id=\"10.1086\/170124\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F170124\" aria-label=\"Article reference 40\" data-doi=\"10.1086\/170124\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1991ApJ...374..344K\" aria-label=\"ADS reference 40\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 40\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Determination%20of%20confidence%20limits%20for%20experiments%20with%20low%20numbers%20of%20counts&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F170124&amp;volume=374&amp;publication_year=1991&amp;author=Kraft%2CRP&amp;author=Burrows%2CDN&amp;author=Nousek%2CJA\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR41\">Park, T. et al. Bayesian estimation of hardness ratios: modeling and computations. Astrophys. J. 652, 610\u2013628 (2006).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/507406\" data-track-item_id=\"10.1086\/507406\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F507406\" aria-label=\"Article reference 41\" data-doi=\"10.1086\/507406\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2006ApJ...652..610P\" aria-label=\"ADS reference 41\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 41\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Bayesian%20estimation%20of%20hardness%20ratios%3A%20modeling%20and%20computations&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F507406&amp;volume=652&amp;pages=610-628&amp;publication_year=2006&amp;author=Park%2CT\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR42\">Chandra X-ray Center. Chandra Data Collection 395. Chandra Data Archive <a href=\"https:\/\/doi.org\/10.25574\/cdc.395\" data-track=\"click_references\" data-track-action=\"external reference\" data-track-value=\"external reference\" data-track-label=\"10.25574\/cdc.395\" rel=\"nofollow noopener\" target=\"_blank\">https:\/\/doi.org\/10.25574\/cdc.395<\/a> (2025).<\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR43\">Muhibullah, M., Irwin, J. &amp; Di Stefano, R. Hypersoft X-ray sources as a new class of luminous cosmic emitters. Zenodo <a href=\"https:\/\/doi.org\/10.5281\/zenodo.20534943\" data-track=\"click_references\" data-track-action=\"external reference\" data-track-value=\"external reference\" data-track-label=\"10.5281\/zenodo.20534943\" rel=\"nofollow noopener\" target=\"_blank\">https:\/\/doi.org\/10.5281\/zenodo.20534943<\/a> (2026).<\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR44\">Makarov, D., Prugniel, P., Terekhova, N., Courtois, H. &amp; Vauglin, I. HyperLEDA. III. The catalogue of extragalactic distances. Astron. Astrophys. 570, 13 (2014).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1051\/0004-6361\/201423496\" data-track-item_id=\"10.1051\/0004-6361\/201423496\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1051%2F0004-6361%2F201423496\" aria-label=\"Article reference 44\" data-doi=\"10.1051\/0004-6361\/201423496\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2014A%26A...570A..13M\" aria-label=\"ADS reference 44\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 44\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=HyperLEDA.%20III.%20The%20catalogue%20of%20extragalactic%20distances&amp;journal=Astron.%20Astrophys.&amp;doi=10.1051%2F0004-6361%2F201423496&amp;volume=570&amp;publication_year=2014&amp;author=Makarov%2CD&amp;author=Prugniel%2CP&amp;author=Terekhova%2CN&amp;author=Courtois%2CH&amp;author=Vauglin%2CI\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR45\">Riess, A. G., Fliri, J. &amp; Valls-Gabaud, D. Cepheid period-luminosity relations in the near-infrared and the distance to M31 from the Hubble Space Telescope wide field camera 3. Astrophys. J. 745, 156 (2012).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/0004-637X\/745\/2\/156\" data-track-item_id=\"10.1088\/0004-637X\/745\/2\/156\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F0004-637X%2F745%2F2%2F156\" aria-label=\"Article reference 45\" data-doi=\"10.1088\/0004-637X\/745\/2\/156\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2012ApJ...745..156R\" aria-label=\"ADS reference 45\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 45\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Cepheid%20period-luminosity%20relations%20in%20the%20near-infrared%20and%20the%20distance%20to%20M31%20from%20the%20Hubble%20Space%20Telescope%20wide%20field%20camera%203&amp;journal=Astrophys.%20J.&amp;doi=10.1088%2F0004-637X%2F745%2F2%2F156&amp;volume=745&amp;publication_year=2012&amp;author=Riess%2CAG&amp;author=Fliri%2CJ&amp;author=Valls-Gabaud%2CD\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR46\">Beaton, R. L. et al. The Carnegie-Chicago Hubble Program. VII. The distance to M101 via the optical tip of the red giant branch method. Astrophys. J. 885, 141 (2019).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.3847\/1538-4357\/ab4263\" data-track-item_id=\"10.3847\/1538-4357\/ab4263\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.3847%2F1538-4357%2Fab4263\" aria-label=\"Article reference 46\" data-doi=\"10.3847\/1538-4357\/ab4263\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2019ApJ...885..141B\" aria-label=\"ADS reference 46\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 46\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20Carnegie-Chicago%20Hubble%20Program.%20VII.%20The%20distance%20to%20M101%20via%20the%20optical%20tip%20of%20the%20red%20giant%20branch%20method&amp;journal=Astrophys.%20J.&amp;doi=10.3847%2F1538-4357%2Fab4263&amp;volume=885&amp;publication_year=2019&amp;author=Beaton%2CRL\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR47\">Tonry, J. L. et al. The SBF survey of galaxy distances. IV. SBF magnitudes, colors, and distances. Astrophys. J. 546, 681\u2013693 (2001).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/318301\" data-track-item_id=\"10.1086\/318301\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F318301\" aria-label=\"Article reference 47\" data-doi=\"10.1086\/318301\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2001ApJ...546..681T\" aria-label=\"ADS reference 47\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 47\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20SBF%20survey%20of%20galaxy%20distances.%20IV.%20SBF%20magnitudes%2C%20colors%2C%20and%20distances&amp;journal=Astrophys.%20J.&amp;doi=10.1086%2F318301&amp;volume=546&amp;pages=681-693&amp;publication_year=2001&amp;author=Tonry%2CJL\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR48\">Brassington, N. J. et al. The spectral and temporal properties of transient sources in early-type galaxies. Astrophys. J. 755, 162 (2012).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/0004-637X\/755\/2\/162\" data-track-item_id=\"10.1088\/0004-637X\/755\/2\/162\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F0004-637X%2F755%2F2%2F162\" aria-label=\"Article reference 48\" data-doi=\"10.1088\/0004-637X\/755\/2\/162\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2012ApJ...755..162B\" aria-label=\"ADS reference 48\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 48\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20spectral%20and%20temporal%20properties%20of%20transient%20sources%20in%20early-type%20galaxies&amp;journal=Astrophys.%20J.&amp;doi=10.1088%2F0004-637X%2F755%2F2%2F162&amp;volume=755&amp;publication_year=2012&amp;author=Brassington%2CNJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR49\">Cappellari, M. et al. The ATLAS3D project. I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria. Mon. Not. R. Astron. Soc. 413, 813\u2013836 (2011).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1111\/j.1365-2966.2010.18174.x\" data-track-item_id=\"10.1111\/j.1365-2966.2010.18174.x\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1111%2Fj.1365-2966.2010.18174.x\" aria-label=\"Article reference 49\" data-doi=\"10.1111\/j.1365-2966.2010.18174.x\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2011MNRAS.413..813C\" aria-label=\"ADS reference 49\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 49\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20ATLAS3D%20project.%20I.%20A%20volume-limited%20sample%20of%20260%20nearby%20early-type%20galaxies%3A%20science%20goals%20and%20selection%20criteria&amp;journal=Mon.%20Not.%20R.%20Astron.%20Soc.&amp;doi=10.1111%2Fj.1365-2966.2010.18174.x&amp;volume=413&amp;pages=813-836&amp;publication_year=2011&amp;author=Cappellari%2CM\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR50\">Blakeslee, J. P. et al. The ACS Fornax cluster survey. V. Measurement and recalibration of surface brightness fluctuations and a precise value of the Fornax-Virgo relative distance. Astrophys. J. 694, 556\u2013572 (2009).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1088\/0004-637X\/694\/1\/556\" data-track-item_id=\"10.1088\/0004-637X\/694\/1\/556\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1088%2F0004-637X%2F694%2F1%2F556\" aria-label=\"Article reference 50\" data-doi=\"10.1088\/0004-637X\/694\/1\/556\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2009ApJ...694..556B\" aria-label=\"ADS reference 50\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 50\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20ACS%20Fornax%20cluster%20survey.%20V.%20Measurement%20and%20recalibration%20of%20surface%20brightness%20fluctuations%20and%20a%20precise%20value%20of%20the%20Fornax-Virgo%20relative%20distance&amp;journal=Astrophys.%20J.&amp;doi=10.1088%2F0004-637X%2F694%2F1%2F556&amp;volume=694&amp;pages=556-572&amp;publication_year=2009&amp;author=Blakeslee%2CJP\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR51\">Dickey, J. M. &amp; Lockman, F. J. H I in the Galaxy. Annu. Rev. Astron. Astrophys. 28, 215\u2013261 (1990).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1146\/annurev.aa.28.090190.001243\" data-track-item_id=\"10.1146\/annurev.aa.28.090190.001243\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1146%2Fannurev.aa.28.090190.001243\" aria-label=\"Article reference 51\" data-doi=\"10.1146\/annurev.aa.28.090190.001243\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=1990ARA%26A..28..215D\" aria-label=\"ADS reference 51\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 51\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=H%20I%20in%20the%20Galaxy&amp;journal=Annu.%20Rev.%20Astron.%20Astrophys.&amp;doi=10.1146%2Fannurev.aa.28.090190.001243&amp;volume=28&amp;pages=215-261&amp;publication_year=1990&amp;author=Dickey%2CJM&amp;author=Lockman%2CFJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR52\">Evans, I. N. et al. The Chandra Source Catalog Release 2 Series. Astrophys. J. Suppl. Ser. 274, 22 (2024).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.3847\/1538-4365\/ad6319\" data-track-item_id=\"10.3847\/1538-4365\/ad6319\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.3847%2F1538-4365%2Fad6319\" aria-label=\"Article reference 52\" data-doi=\"10.3847\/1538-4365\/ad6319\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2024ApJS..274...22E\" aria-label=\"ADS reference 52\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 52\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=The%20Chandra%20Source%20Catalog%20Release%202%20Series&amp;journal=Astrophys.%20J.%20Suppl.%20Ser.&amp;doi=10.3847%2F1538-4365%2Fad6319&amp;volume=274&amp;publication_year=2024&amp;author=Evans%2CIN\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n<p class=\"c-article-references__text\" id=\"ref-CR53\">Brassington, N. J. et al. Deep Chandra monitoring observations of NGC 3379: catalog of source properties. Astrophys. J. Suppl. Ser. 179, 142\u2013165 (2008).<\/p>\n<p class=\"c-article-references__links u-hide-print\"><a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"10.1086\/591527\" data-track-item_id=\"10.1086\/591527\" data-track-value=\"article reference\" data-track-action=\"article reference\" href=\"https:\/\/doi.org\/10.1086%2F591527\" aria-label=\"Article reference 53\" data-doi=\"10.1086\/591527\" target=\"_blank\">Article<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" rel=\"nofollow noopener\" data-track-label=\"link\" data-track-item_id=\"link\" data-track-value=\"ads reference\" data-track-action=\"ads reference\" href=\"http:\/\/adsabs.harvard.edu\/cgi-bin\/nph-data_query?link_type=ABSTRACT&amp;bibcode=2008ApJS..179..142B\" aria-label=\"ADS reference 53\" target=\"_blank\">ADS<\/a>\u00a0<br \/>\n    <a data-track=\"click_references\" data-track-action=\"google scholar reference\" data-track-value=\"google scholar reference\" data-track-label=\"link\" data-track-item_id=\"link\" rel=\"nofollow noopener\" aria-label=\"Google Scholar reference 53\" href=\"http:\/\/scholar.google.com\/scholar_lookup?&amp;title=Deep%20Chandra%20monitoring%20observations%20of%20NGC%203379%3A%20catalog%20of%20source%20properties&amp;journal=Astrophys.%20J.%20Suppl.%20Ser.&amp;doi=10.1086%2F591527&amp;volume=179&amp;pages=142-165&amp;publication_year=2008&amp;author=Brassington%2CNJ\" target=\"_blank\"><br \/>\n                    Google Scholar<\/a>\u00a0\n                <\/p>\n","protected":false},"excerpt":{"rendered":"Drake, J. J., Kashyap, V. L., Wargelin, B. J. &amp; Wolk, S. J. Pointing Chandra toward the extreme&hellip;\n","protected":false},"author":2,"featured_media":611114,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[1409,21155,128596,10003,3181,164423,85,46,370,141],"class_list":["post-611113","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-astronomy","tag-astrophysics-and-cosmology","tag-compact-astrophysical-objects","tag-galaxies-and-clusters","tag-general","tag-high-energy-astrophysics","tag-il","tag-israel","tag-physics","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/611113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=611113"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/611113\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/611114"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=611113"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=611113"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=611113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}