scholarly journals The VHE γ-Ray View of the FSRQ PKS 1510-089

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 41 ◽  
Author(s):  
Michael Zacharias ◽  
Dijana Dominis Prester ◽  
Felix Jankowsky ◽  
Elina Lindfors ◽  
Manuel Meyer ◽  
...  
Keyword(s):  
High Energy ◽  
High Variability ◽  
Energy Bands ◽  
Current State ◽  
Spectrum Radio ◽  
Very High Energy ◽  
Monitoring Effort ◽  
Γ Ray ◽  
Radio Quasar ◽  
Very High

The flat spectrum radio quasar PKS 1510-089 is a monitored target in many wavelength bands due to its high variability. It was detected as a very-high-energy (VHE) γ-ray emitter with H.E.S.S. in 2009, and has since been a regular target of VHE observations by the imaging Cherenkov observatories H.E.S.S. and MAGIC. In this paper, we summarize the current state of results focusing on the monitoring effort with H.E.S.S. and the discovery of a particularly strong VHE flare in 2016 with H.E.S.S. and MAGIC. While the source has now been established as a weak, but regular emitter at VHE, no correlation with other energy bands has been established. This is underlined by the 2016 VHE flare, where the detected optical and high-energy γ-ray counterparts evolve differently than the VHE flux.

scholarly journals Long-term multiwavelength view of the blazar 1ES 1218+304

2019 ◽  
Vol 489 (4) ◽  
pp. 5076-5086 ◽  
Author(s):  
K K Singh ◽  
B Bisschoff ◽  
B van Soelen ◽  
A Tolamatti ◽  
J P Marais ◽  
...  
Keyword(s):  
High Energy ◽  
Host Galaxy ◽  
Energy Bands ◽  
X Ray ◽  
Very High Energy ◽  
Γ Ray ◽  
Activity State ◽  
Low Activity ◽  
Very High

ABSTRACT In this work, we present a multiwavelength study of the blazar 1ES 1218+304 using near simultaneous observations over 10 yr during the period 2008 September 1 to 2018 August 31 (MJD 54710–58361). We have analysed data from Swift-UVOT, Swift-XRT, and Fermi-LAT to study the long term behaviour of 1ES 1218+304 in different energy bands over the last decade. We have also used the archival data from OVRO, MAXI, and Swift-BAT available during the above period. The near simultaneous data on 1ES 1218+304 suggest that the long term multiwavelength emission from the source is steady and does not show any significant change in the source activity. The optical/UV fluxes are found to be dominated by the host galaxy emission and can be modelled using the pegase code. However, the time averaged X-ray and γ-ray emissions from the source are reproduced using a single zone leptonic model with log-parabolic distribution for the radiating particles. The intrinsic very high energy γ-ray emission during a low activity state of the source is broadly consistent with the predictions of the leptonic model for blazars. We have investigated the physical properties of the jet and the mass of the supermassive black hole at the centre of the host galaxy using long term X-ray observations from the Swift-XRT which is in agreement with the value derived using blackbody approximation of the host galaxy. We also discuss the extreme nature of the source on the basis of X-ray and γ-ray observations.

scholarly journals Very high energy γ-radiation from the radio quasar 4C 21.35

2011 ◽  
Vol 7 (S284) ◽  
pp. 414-416
Author(s):  
Josefa Becerra González ◽  
Laura Maraschi ◽  
Daniel Mazin ◽  
Elisa Prandini ◽  
Koji Saito ◽  
...  
Keyword(s):  
High Energy ◽  
Γ Radiation ◽  
Cherenkov Telescopes ◽  
Spectrum Radio ◽  
Hard Spectrum ◽  
Very High Energy ◽  
Γ Rays ◽  
Radio Quasar ◽  
Fast Variation ◽  
Very High

AbstractA very high energy (VHE) γ-radiation was detected from a flat spectrum radio quasar (FSRQ) 4C 21.35 (PKS1222+21) by MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes on June 17th 2010. 4C 21.35 is only the 3rd FSRQ detected in VHE γ-rays. With its hard spectrum (Γ = 2.72±0.34) with no apparent cut-off at energies below 130 GeV and an extremely fast variation of flux (doubling in 8.6+1.1−0.9 minutes), this detection poses a challenge to existing models of VHE γ-radiation from FSRQs. The most important results of observations performed by MAGIC telescopes are presented here, as well as some possible explanations of those results.

scholarly journals PKS 1510-089: a rare example of a flat spectrum radio quasar with a very high-energy emission

2014 ◽  
Vol 567 ◽  
pp. A113 ◽  
Author(s):  
Anna Barnacka ◽  
Rafal Moderski ◽  
Bagmeet Behera ◽  
Pierre Brun ◽  
Stefan Wagner
Keyword(s):  
High Energy ◽  
Energy Emission ◽  
Spectrum Radio ◽  
Very High Energy ◽  
High Energy Emission ◽  
Radio Quasar ◽  
Very High

scholarly journals Multiwavelength observations in 2019-2020 of a new very-high-energy gamma-ray emitter: the flat spectrum radio quasar QSO B1420+326

2021 ◽  
Author(s):  
Filippo D’Ammando ◽  
Roberto Angioni ◽  
Monica Orienti ◽  
Julian Sitarek ◽  
Seiya Nozaki ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
High Energy Gamma ◽  
Spectrum Radio ◽  
Very High Energy ◽  
Energy Gamma ◽  
Radio Quasar ◽  
Very High ◽  
Multiwavelength Observations

Particle Acceleration by Pulsars

1981 ◽  
Vol 94 ◽  
pp. 175-204 ◽  
Author(s):  
Jonathan Arons
Keyword(s):  
High Energy ◽  
Rotational Energy ◽  
Pair Creation ◽  
X Ray ◽  
Current State ◽  
Very High Energy ◽  
Γ Ray ◽  
High Energy Particles ◽  
Relativistic Particles ◽  
Very High

The evidence that pulsars accelerate relativistic particles is reviewed, with emphasis on the γ-ray observations. The current state of knowledge of acceleration in strong waves is summarized, with emphasis on the inability of consistent theories to accelerate very high energy particles without converting too much energy into high energy photons. The state of viable models for pair creation by pulsars is summarized, with the conclusion that pulsars very likely lose rotational energy in winds instead of in superluminous strong waves. The relation of the pair creation models to γ-ray observations and to soft X-ray observations of pulsars is outlined, with the conclusion that energetically viable models may exist, but none have yet yielded useful agreement with the extant data. Some paths for overcoming present problems are discussed.

scholarly journals Fermi LARGE AREA TELESCOPE DETECTION OF TWO VERY-HIGH-ENERGY ( E > 100 GeV) γ-RAY PHOTONS FROM THE z = 1.1 BLAZAR PKS 0426–380

2013 ◽  
Vol 777 (1) ◽  
pp. L18 ◽  
Author(s):  
Y. T. Tanaka ◽  
C. C. Cheung ◽  
Y. Inoue ◽  
Ł. Stawarz ◽  
M. Ajello ◽  
...  
Keyword(s):  
High Energy ◽  
Large Area ◽  
Very High Energy ◽  
Γ Ray ◽  
Very High

scholarly journals A Very High Energy γ-Ray Survey toward the Cygnus Region of the Galaxy

2018 ◽  
Vol 861 (2) ◽  
pp. 134 ◽  
Author(s):  
A. U. Abeysekara ◽  
A. Archer ◽  
T. Aune ◽  
W. Benbow ◽  
R. Bird ◽  
...  
Keyword(s):  
High Energy ◽  
The Galaxy ◽  
Very High Energy ◽  
Γ Ray ◽  
Very High

scholarly journals The Making of Catalogues of Very-High-Energy γ-ray Sources

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 421
Author(s):  
Mathieu de Naurois
Keyword(s):  
Galactic Plane ◽  
Population Studies ◽  
High Energy ◽  
Cherenkov Telescopes ◽  
Background Rejection ◽  
Fine Grained ◽  
Very High Energy ◽  
Advanced Analysis ◽  
Γ Ray ◽  
Very High

Thirty years after the discovery of the first very-high-energy γ-ray source by the Whipple telescope, the field experienced a revolution mainly driven by the third generation of imaging atmospheric Cherenkov telescopes (IACTs). The combined use of large mirrors and the invention of the imaging technique at the Whipple telescope, stereoscopic observations, developed by the HEGRA array and the fine-grained camera, pioneered by the CAT telescope, led to a jump by a factor of more than ten in sensitivity. The advent of advanced analysis techniques led to a vast improvement in background rejection, as well as in angular and energy resolutions. Recent instruments already have to deal with a very large amount of data (petabytes), containing a large number of sources often very extended (at least within the Galactic plane) and overlapping each other, and the situation will become even more dramatic with future instruments. The first large catalogues of sources have emerged during the last decade, which required numerous, dedicated observations and developments, but also made the first population studies possible. This paper is an attempt to summarize the evolution of the field towards the building up of the source catalogues, to describe the first population studies already made possible, and to give some perspectives in the context of the upcoming, new generation of instruments.

scholarly journals DISCOVERY OF HIGH-ENERGY AND VERY HIGH ENERGY γ-RAY EMISSION FROM THE BLAZAR RBS 0413

2012 ◽  
Vol 750 (2) ◽  
pp. 94 ◽  
Author(s):  
E. Aliu ◽  
S. Archambault ◽  
T. Arlen ◽  
T. Aune ◽  
M. Beilicke ◽  
...  
Keyword(s):  
High Energy ◽  
Very High Energy ◽  
Γ Ray ◽  
Very High
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