. | . |
NASA's Fermi satellite clocks 'cannonball' pulsar speeding through space by Francis Reddy for GSFC News Greenbelt MD (SPX) Mar 20, 2019
Astronomers found a pulsar hurtling through space at nearly 2.5 million miles an hour - so fast it could travel the distance between Earth and the Moon in just 6 minutes. The discovery was made using NASA's Fermi Gamma-ray Space Telescope and the National Science Foundation's Karl G. Jansky Very Large Array (VLA). Pulsars are superdense, rapidly spinning neutron stars left behind when a massive star explodes. This one, dubbed PSR J0002+6216 (J0002 for short), sports a radio-emitting tail pointing directly toward the expanding debris of a recent supernova explosion. "Thanks to its narrow dart-like tail and a fortuitous viewing angle, we can trace this pulsar straight back to its birthplace," said Frank Schinzel, a scientist at the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico. "Further study of this object will help us better understand how these explosions are able to 'kick' neutron stars to such high speed." Schinzel, together with his colleagues Matthew Kerr at the U.S. Naval Research Laboratory in Washington, and NRAO scientists Dale Frail, Urvashi Rau and Sanjay Bhatnagar presented the discovery at the High Energy Astrophysics Division meeting of the American Astronomical Society in Monterey, California. A paper describing the team's results has been submitted for publication in a future edition of The Astrophysical Journal Letters. Pulsar J0002 was discovered in 2017 by a citizen-science project called Einstein@Home, which uses time on the computers of volunteers to process Fermi gamma-ray data. Thanks to computer processing time collectively exceeding 10,000 years, the project has identified 23 gamma-ray pulsars to date. Located about 6,500 light-years away in the constellation Cassiopeia, J0002 spins 8.7 times a second, producing a pulse of gamma rays with each rotation. The pulsar lies about 53 light-years from the center of a supernova remnant called CTB 1. Its rapid motion through interstellar gas results in shock waves that produce the tail of magnetic energy and accelerated particles detected at radio wavelengths using the VLA. The tail extends 13 light-years and clearly points back to the center of CTB 1. Using Fermi data and a technique called pulsar timing, the team was able to measure how quickly and in what direction the pulsar is moving across our line of sight. "The longer the data set, the more powerful the pulsar timing technique is," said Kerr. "Fermi's lovely 10-year data set is essentially what made this measurement possible." The result supports the idea that the pulsar was kicked into high speed by the supernova responsible for CTB 1, which occurred about 10,000 years ago. J0002 is speeding through space five times faster than the average pulsar, and faster than 99 percent of those with measured speeds. It will eventually escape our galaxy. At first, the supernova's expanding debris would have moved outward faster than J0002, but over thousands of years the shell's interaction with interstellar gas produced a drag that gradually slowed this motion. Meanwhile, the pulsar, behaving more like a cannonball, steadily raced through the remnant, escaping it about 5,000 years after the explosion. Exactly how the pulsar was accelerated to such high speed during the supernova explosion remains unclear, and further study of J0002 will help shed light on the process. One possible mechanism involves instabilities in the collapsing star forming a region of dense, slow-moving matter that survives long enough to serve as a "gravitational tugboat," accelerating the nascent neutron star toward it.
Quasar jets confuse orbital telescope Moscow, Russia (SPX) Mar 14, 2019 Astrophysicists from the Moscow Institute of Physics and Technology, the Lebedev Physical Institute of the Russian Academy of Sciences (LPI RAS), and NASA have found an error in the coordinates of active galactic nuclei measured by the Gaia space telescope, and helped correct it. The findings, published in The Astrophysical Journal, also serve as an independent confirmation of the astrophysical model of these objects. "One of the key results of our work is a new and fairly unexpected way of indire ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |