{"id":275807,"date":"2025-11-06T20:03:07","date_gmt":"2025-11-06T20:03:07","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/275807\/"},"modified":"2025-11-06T20:03:07","modified_gmt":"2025-11-06T20:03:07","slug":"nearby-pulsar-offers-insights-into-emission-physics-near-the-death-line","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/275807\/","title":{"rendered":"Nearby pulsar offers insights into emission physics near the death line"},"content":{"rendered":"

\"Observations<\/p>\n

Pulse stacks of PSR J2129+4119 observed on September 29, 2024, showing three distinct behaviors: steady drifting (left), intermittent drifting with breaks (middle), and beat-like modulation (right). Credit: arXiv (2025). DOI: 10.48550\/arxiv.2510.26209<\/p>\n

Using the Five-hundred-meter Aperture Spherical Radio Telescope (FAST), astronomers from the Chinese Academy of Sciences (CAS) and elsewhere have observed a nearby pulsar known as PSR J2129+4119. Results of the observational campaign, published<\/a> October 30 on the arXiv pre-print server, deliver important insights into the behavior and properties of this pulsar.<\/p>\n

Radio emission from pulsars exhibits a variety of phenomena, including subpulse drifting, nulling, or mode changing. In the case of subpulse drifting, radio emission from a pulsar appears to drift in spin phase within the main pulse profile. When it comes to nulling, the emission from a pulsar ceases abruptly from a few to hundreds of pulse periods before it is restored.<\/p>\n

Discovered in 2017, PSR J2129+4119 is an old and nearby pulsar located some 7,500 light years away. It has a pulse period of 1.69 seconds, dispersion measure of 31 cm\/pc3, and characteristic age of 342.8 million years. The pulsar lies below the so-called “death line”\u2014a theoretical boundary in the period-period derivative diagram below which the coherent radio emission is sustained.<\/p>\n

Now, a team of astronomers led by Habtamu Menberu Tedila of CAS has inspected PSR J2129+4119 with high-sensitivity FAST observations, which revealed a plethora of emission phenomena from this pulsar.<\/p>\n

“We present a detailed single-pulse<\/a> study of the long-period pulsar PSR J2129+4119 using high-sensitivity FAST observations. Despite locating well below the traditional death line, the pulsar exhibits sustained and multi-modal emission behavior, including nulls, weak pulses, regular emission, and occasional bright pulses,” the researchers write in the paper.<\/p>\n

In particular, the observations reveal that PSR J2129+4119 showcases sustained and multi-modal emission behavior, including three distinct modes: nulls, weak pulses, and regular pulses. It also occasionally emits bright pulses, quasi-periodic microstructure, and displays clear subpulse modulation features. The nulling fraction was measured to be approximately 8.13%.<\/p>\n

Furthermore, the observations found that both regular and weak pulses of PSR J2129+4119 show high linear polarization. The collected data indicate a small impact angle of about -3 degrees, which is consistent with a near-tangential line of sight.<\/p>\n

It appears that post-null regular pulses of the pulsar display enhanced trailing components relative to pre-null pulses. This, according to the authors of the paper, suggests gradual magnetospheric reactivation rather than a purely geometric origin.<\/p>\n

The obtained data also show that microstructure is present in about 64% of the pulsar’s regular pulses, with mean periodicity of 4.57 milliseconds and mean width of 4.3 milliseconds.<\/p>\n

Therefore, all the new findings indicate that PSR J2129+4119 remains magnetospherically active and coherently emitting despite its low energy loss rate.<\/p>\n

“The pulsar’s diverse observational behavior, including beat-like modulation, emission asymmetries near nulls, and quasi-periodic microstructure, suggests that its magnetosphere operates near the threshold for coherent emission, providing valuable constraints on the physical conditions that enable or suppress pulsar<\/a> radio emission<\/a>,” the researchers conclude.<\/p>\n

\n Written for you by our author Tomasz Nowakowski<\/a>, edited by Sadie Harley<\/a>, and fact-checked and reviewed by Robert Egan<\/a>\u2014this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive.
\n If this reporting matters to you,
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\n You’ll get an ad-free account as a thank-you.\n <\/p>\n

More information:
\n\t\t\t\t\t\t\t\t\t\t\t\tHabtamu Menberu Tedila et al, Multi-Faceted Emission Properties of PSR J2129+4119 Observed with FAST, arXiv (2025). DOI: 10.48550\/arxiv.2510.26209<\/a><\/p>\n

\n\t\t\t\t\t\t\t\t\t\t\t\t\tJournal information:
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tarXiv<\/a>
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/p>\n

\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/p>\n

\n\t\t\t\t\t\t\t\t\t\t\t\t \u00a9 2025 Science X Network\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n

\n\t\t\t\t\t\t\t\t\t\t\t\tCitation:
\n\t\t\t\t\t\t\t\t\t\t\t\tNearby pulsar offers insights into emission physics near the death line (2025, November 6)
\n\t\t\t\t\t\t\t\t\t\t\t\tretrieved 6 November 2025
\n\t\t\t\t\t\t\t\t\t\t\t\tfrom https:\/\/phys.org\/news\/2025-11-nearby-pulsar-insights-emission-physics.html\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n

\n\t\t\t\t\t\t\t\t\t\t\t This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
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