VERITAS OBSERVATIONS OF RELATIVISTIC JETS

Author(s):  
RESHMI MUKHERJEE

VERITAS is an array of four imaging atmospheric Cherenkov telescopes located in southern Arizona, and is now starting its fifth year of observations of the northern Sky at energies > 100 GeV. Observations of astrophysical objects in the TeV band are sensitive probes of highly energetic processes occurring in these sources. The majority of the active galaxies detected at TeV energies are blazars, sources where we view the jet nearly along its axis. TeV and multiwavelength observations of blazars help us to better understand the mechanisms of ultrarelativistic jet production by supermassive black holes, and constrain models of particle acceleration in blazar jets. Galactic sources at TeV energies include supernova remnants, pulsar wind nebulae, and binary systems, and TeV emission is a key diagnostic of highly energetic particles in these objects. This report presents recent results from VERITAS on Galactic and extragalactic sources.

2009 ◽  
Vol 5 (H15) ◽  
pp. 808-808
Author(s):  
Emma de Oña-Wilhelmi

AbstractThe H.E.S.S. Galactic Plane Survey (GPS) has revealed a large number of Galactic Sources, including Pulsar Wind Nebulae (PWN), Supernova Remnants (SNRs), giant molecular clouds, star formation regions and compact binary systems, as well as a number of unidentified objects, or dark sources, for which no obvious counterparts at other wavelengths have yet been found. We will review the latest results from the GPS observations and discuss the most interesting cases.


1986 ◽  
Vol 64 (4) ◽  
pp. 482-483
Author(s):  
R. H. Becker

Accreting neutron star or black holes in binary systems can, under appropriate circumstances, eject jets of particles into their environment. This is most readily observed in SS433, Sco X-1, and Cyg X-3. We infer the presence of the injection of relativistic particles in a number of other galactic sources where actual jets have not been observed. In some cases the energy imparted results in nonthermal radio sources comparable in size to supernova remnants.


2010 ◽  
Vol 27 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Kevin Heng

AbstractA concise and critical review of Balmer-dominated shocks (BDSs) is presented, summarizing the state of theory and observations, including models with/without shock precursors and their synergy with atomic physics. Observations of BDSs in supernova remnants are reviewed on an object-by-object basis. The relevance of BDSs towards understanding the acceleration of cosmic rays in shocks is emphasized. Probable and possible detections of BDSs in astrophysical objects other than supernova remnants, including pulsar wind nebulae and high-redshift galaxies, are described. The case for the continued future of studying BDSs in astrophysics is made, including their relevance towards understanding electron–ion temperature equilibration in collisionless shocks.


2004 ◽  
Vol 218 ◽  
pp. 221-224
Author(s):  
John R. Dickel ◽  
Shiya Wang

Several Crab-type supernova remnants appear to have very bright non-thermal X-ray cores just around the pulsar or expected pulsar. This X-ray brightness is often not matched by a corresponding increase in radio emission. The best example of this phenomenon is in N157B in the LMC. G21.5−0.9 and possibly 3C 58 also show it while the Crab Nebula and 0540−69.3 do not. Some method to enhance the higher energy particles must be present in these objects.


2018 ◽  
Vol 483 (1) ◽  
pp. 70-118 ◽  
Author(s):  
H Chawner ◽  
K Marsh ◽  
M Matsuura ◽  
H L Gomez ◽  
P Cigan ◽  
...  

2019 ◽  
Vol 623 ◽  
pp. A90 ◽  
Author(s):  
S. M. Straal ◽  
J. van Leeuwen

Pinpointing a pulsar in its parent supernova remnant (SNR) or resulting pulsar wind nebula (PWN) is key to understanding its formation history and the pulsar wind mechanism, yet only about half the SNRs and PWNe appear associated with a pulsar. Our aim was to find the pulsars in a sample of eight known and new SNRs and PWNe. Using the LOFAR radio telescope at 150 MHz, each source was observed for 3 h. We covered the entire remnants where needed, by employing many tied-array beams to tile out even the largest objects. For objects with a confirmed point source or PWN we constrained our search to those lines of sight. We identified a promising radio pulsar candidate towards PWN G141.2+5.0. The candidate, PSR J0337+61, has a period of 94 ms and a DM of 226 pc cm−3. We re-observed the source twice with increased sensitivities of 30% and 50%, but did not re-detect it. It thus remains unconfirmed. For our other sources we obtain very stringent upper limits of 0.8 − 3.1 mJy at 150 MHz. Generally, we can rule out that the pulsars travelled out of the remnant. From these strict limits we conclude our non-detections towards point sources and PWNe are the result of beaming and propagation effects. Some of the remaining SNRs should host a black hole rather than a neutron star.


2003 ◽  
Author(s):  
Ann E. Wehrle ◽  
Stephen C. Unwin ◽  
Dayton L. Jones ◽  
David L. Meier ◽  
B. G. Piner

2004 ◽  
Vol 423 (1) ◽  
pp. 253-265 ◽  
Author(s):  
N. Bucciantini ◽  
E. Amato ◽  
R. Bandiera ◽  
J. M. Blondin ◽  
L. Del Zanna

2018 ◽  
Vol 478 (1) ◽  
pp. 926-931 ◽  
Author(s):  
Yutaka Ohira ◽  
Shota Kisaka ◽  
Ryo Yamazaki

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