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

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.

Download Full-text

MAXIINVESTIGATION INTO THE LONG-TERM X-RAY VARIABILITY FROM THE VERY-HIGH-ENERGY γ-RAY BLAZAR Mrk 421

The Astrophysical Journal ◽

10.1088/0004-637x/798/1/27 ◽

2014 ◽

Vol 798 (1) ◽

pp. 27 ◽

Cited By ~ 26

Author(s):

Naoki Isobe ◽

Ryosuke Sato ◽

Yoshihiro Ueda ◽

Masaaki Hayashida ◽

Megumi Shidatsu ◽

...

Keyword(s):

High Energy ◽

X Ray ◽

Very High Energy ◽

Γ Ray ◽

Very High

Download Full-text

A New Chapter in Hard X-rays of the M87 AGN

Proceedings ◽

10.3390/proceedings2019017009 ◽

2019 ◽

Vol 17 (1) ◽

pp. 9

Author(s):

Ka-Wah Wong ◽

Rodrigo S. Nemmen ◽

Jimmy A. Irwin ◽

Dacheng Lin

Keyword(s):

High Energy ◽

X Rays ◽

X Ray ◽

Accretion Flow ◽

Relativistic Jet ◽

Very High Energy ◽

Γ Ray ◽

High Energy Emission ◽

First Time ◽

Very High

The nearby M87 hosts an exceptional relativistic jet. It has been regularly monitored in radio to TeV bands, but little has been done in hard X-rays ≳10 keV. For the first time, we have successfully detected hard X-rays up to 40 keV from its X-ray core with joint Chandra and NuSTAR observations, providing important insights to the X-ray origins: from the unresolved jet or the accretion flow. We found that the hard X-ray emission is significantly lower than that predicted by synchrotron self-Compton models introduced to explain very-high-energy γ -ray emission above a GeV. We discuss recent models to understand these high energy emission processes.

Download Full-text

Nonthermal processes in microquasars

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310016066 ◽

2010 ◽

Vol 6 (S275) ◽

pp. 215-223

Author(s):

Valentí Bosch-Ramon

Keyword(s):

Thermal Emission ◽

High Energy ◽

Energy Bands ◽

X Ray ◽

Radio Jets ◽

Extended Radio ◽

Very High Energy ◽

X Ray Binaries ◽

Very High ◽

Negligible Contribution

AbstractMicroquasars are X-ray binaries that show extended radio jets. These jets can accelerate particles up to relativistic energies that produce non-thermal emission from radio to TeV, and could also make a non-negligible contribution to the galactic CRs in some energy ranges. The orbital motion and compactness of these sources allow the study of high-energy astrophysical phenomena in extreme conditions that change in accessible timescales. In this work, I briefly discuss the production of broadband non-thermal emission in microquasars, putting special emphasis on the high- and the very high-energy bands.

Download Full-text

OBSERVATIONS OF MICROQUASAR CANDIDATES WITH THE MAGIC TELESCOPE

International Journal of Modern Physics D ◽

10.1142/s0218271808013492 ◽

2008 ◽

Vol 17 (10) ◽

pp. 1859-1866

Author(s):

◽

J. RICO

Keyword(s):

Black Hole ◽

Experimental Evidence ◽

Energy Band ◽

High Energy ◽

Time Dependent ◽

X Ray ◽

Orbital Cycles ◽

Very High Energy ◽

Γ Ray ◽

Very High

We report on the results from the observations in very high energy band (VHE, Eγ ≥ 100 GeV ) of the γ-ray binary LS I +61 303 and the black hole X-ray binary (BHXB) Cygnus X-1. LS I +61 303 was recently discovered at VHE by MAGIC1 and here we present the preliminary results from an extensive observation campaign, comprising 112 observation hours covering 4 orbital cycles, aiming at determining the time-dependent features of the VHE emission. Cygnus X-1 was observed for a total of 40 hours during 26 nights, spanning the period between June and November 2006. We report on the results of the searches for steady and variable γ-ray signals from Cygnus X-1, including the first experimental evidence for an intense flare, of duration between 1.5 and 24 hours.

Download Full-text

Observation of the Gamma-Ray Binary HESS J0632+057 with the H.E.S.S., MAGIC, and VERITAS Telescopes

The Astrophysical Journal ◽

10.3847/1538-4357/ac29b7 ◽

2021 ◽

Vol 923 (2) ◽

pp. 241

Author(s):

C. B. Adams ◽

W. Benbow ◽

A. Brill ◽

J. H. Buckley ◽

M. Capasso ◽

...

Keyword(s):

Binary Systems ◽

Gamma Ray ◽

High Energy ◽

Energy Bands ◽

X Ray ◽

Cherenkov Telescopes ◽

Orbital Cycles ◽

Very High Energy ◽

Energy Gamma ◽

Very High

Abstract The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the Hα emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 ± 4.4 days is reported, consistent with the period of 317.3 ± 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical Hα parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.

Download Full-text

VHE GAMMA-RAYS FROM GALACTIC X-RAY BINARY SYSTEMS

International Journal of Modern Physics D ◽

10.1142/s0218271808013480 ◽

2008 ◽

Vol 17 (10) ◽

pp. 1849-1858 ◽

Cited By ~ 3

Author(s):

J. M. PAREDES

Keyword(s):

Gamma Rays ◽

Binary Systems ◽

High Energy ◽

X Ray ◽

Very High Energy ◽

Γ Rays ◽

Γ Ray ◽

Tev Gamma Rays ◽

X Ray Binaries ◽

Very High

The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR B1259–63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus X-1 by MAGIC, provides clear evidence of very efficient acceleration of particles to multi-TeV energies in X-ray binaries. These observations demonstrate the richness of nonthermal phenomena in compact galactic objects containing relativistic outflows or winds produced near black holes and neutron stars. I review here some of the main observational results on very high energy (VHE) γ-ray emission from X-ray binaries, as well as some of the proposed scenarios to explain the production of VHE γ-rays. I put special emphasis on the flare TeV emission, suggesting that the flaring activity might be a common phenomena in X-ray binaries.

Download Full-text

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

Galaxies ◽

10.3390/galaxies7010041 ◽

2019 ◽

Vol 7 (1) ◽

pp. 41 ◽

Cited By ~ 2

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.

Download Full-text

Very high energy γ-ray emission from X-ray transients during major outbursts

Astronomy and Astrophysics ◽

10.1051/0004-6361:20066238 ◽

2007 ◽

Vol 465 (3) ◽

pp. 703-709 ◽

Cited By ~ 6

Author(s):

M. Orellana ◽

G. E. Romero ◽

L. J. Pellizza ◽

S. Vidrih

Keyword(s):

High Energy ◽

X Ray ◽

Very High Energy ◽

Γ Ray ◽

Very High

Download Full-text

Particle Acceleration by Pulsars

Symposium - International Astronomical Union ◽

10.1017/s007418090007457x ◽

1981 ◽

Vol 94 ◽

pp. 175-204 ◽

Cited By ~ 2

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.

Download Full-text