scholarly journals The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 34
Author(s):  
Michael Zacharias ◽  
Markus Böttcher ◽  
Felix Jankowsky ◽  
Jean-Philippe Lenain ◽  
Stefan Wagner ◽  
...  
Keyword(s):  
Light Curve ◽  
Gamma Ray ◽  
X Ray ◽  
Relativistic Jet ◽  
Spectrum Radio ◽  
Flux Level ◽  
Gas Cloud ◽  
Radio Quasar

The flat spectrum radio quasar CTA 102 ( z = 1 . 032 ) went through a tremendous phase of variability. Since early 2016 the gamma-ray flux level has been significantly higher than in previous years. It was topped by a four month long giant outburst, where peak fluxes were more than 100 times higher than the quiescence level. Similar trends are observable in optical and X-ray energies. We have explained the giant outburst as the ablation of a gas cloud by the relativistic jet that injects additional matter into the jet and can self-consistently explain the long-term light curve. Here, we argue that the cloud responsible for the giant outburst is part of a larger system that collides with the jet and is responsible for the years-long activity in CTA 102.

scholarly journals The picture of relativistic jet from Fermi-LAT and multi-band observations of blazar 3C 279

2010 ◽  
Vol 6 (S275) ◽  
pp. 155-159
Author(s):  
Masaaki Hayashida ◽  
Greg Madejski
Keyword(s):  
Gamma Ray ◽  
First Year ◽  
Energy Bands ◽  
X Ray ◽  
Relativistic Jet ◽  
Spectrum Radio ◽  
Successful Launch ◽  
Γ Ray ◽  
Radio Quasar ◽  
Multi Band

AbstractStrong and variable radiation detected over all accessible energy bands in blazar arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. Flat Spectrum Radio Quasar 3C 279 was one of the brightest γ-ray blazars in the sky at the time of the discovery with EGRET. Since the successful launch of the Fermi Gamma-ray Space telescope in 2008, we have organized extensive multi-band observational campaign of 3C 279 from radio to γ-ray bands, also including optical polarimetric observations. The uninterrupted monitoring in the γ-ray band by Fermi-LAT together with the multi-band data provide us with new insights of the relativistic jet of blazar. Here, we present the results of the first-year multi-band campaign of 3C 279 including the discovery of a γ-ray flare event associated with a dramatic change of the optical polarization - as well as a discovery of an “orphan” X-ray flare, unassociated with prominent outbursts in other bands.

scholarly journals On the Long-Term Light Curve Behaviour of the Intermediate Polar TX Col

1996 ◽  
Vol 158 ◽  
pp. 185-186
Author(s):  
D. A. H. Buckley
Keyword(s):  
Light Curve ◽  
High Flux ◽  
X Rays ◽  
X Ray ◽  
Beat Period ◽  
Spin Period ◽  
Flux Level

TX Col (1H0547–407; Porb = 5.72 h) is an intermediate polar (IP) with spin and synodic (beat) periods of 1911s and 2106 s respectively (Buckley & Tuohy 1989). EXOSAT observations (Tuohy et al. 1986) showed the beat period dominated at higher energies (ME; 1… 9keV), while the spin period was stronger in softer X-rays (LE1; 0.1… IkeV). The high flux level, and pulse fraction (>70%), of the soft X-rays were unique in an IP at that time. Now three other IPs, recently discovered from the ROSAT survey, have been found to show a true separate soft X-ray component, similar to the polars (Motch & Haberl 1994).The strength of the synodic X-ray period in TX Col was, until the recent discovery of the variable polarised IP, RX J1712.6–2414 (Buckley et al. 1995), unique. This was taken as evidence for direct accretion onto the magnetosphere (e.g. Mason, Rosen & Hellier 1988), through a component of the accretion stream overflowing the disc (Hellier 1992).

scholarly journals Broadband X-ray observations of four gamma-ray narrow-line Seyfert 1 galaxies

2019 ◽  
Vol 632 ◽  
pp. A120 ◽  
Author(s):  
M. Berton ◽  
V. Braito ◽  
S. Mathur ◽  
L. Foschini ◽  
E. Piconcelli ◽  
...  
Keyword(s):  
Accretion Disk ◽  
Gamma Ray ◽  
High Energy ◽  
Time Variability ◽  
X Rays ◽  
Narrow Line ◽  
X Ray ◽  
Relativistic Jet ◽  
Line Region ◽  
Spectrum Radio

Narrow-line Seyfert 1 galaxies (NLS1s) is one of the few classes of active galactic nuclei harboring powerful relativistic jets and detected in γ-rays. NLS1s are well-known X-ray sources. While in non-jetted sources the origin of this X-ray emission may be a hot corona surrounding the accretion disk, in jetted objects, especially beamed ones, the contribution of corona and relativistic jet is difficult to disentangle without a proper sampling of the hard X-ray emission. For this reason, we observed with NuSTAR the first four NLS1s detected at high energy γ-rays. These data, along with XMM-Newton and Swift/XRT observations, confirmed that X-rays originate both in the jet and in the accretion disk corona. Time variability in hard X-rays furthermore suggests that, as observed in flat-spectrum radio quasars, the dissipation region during flares could change its position from source to source, and it can be located both inside and outside the broad-line region. We find that jetted NLS1s, and other blazars as well, seem not to follow the classical fundamental plane of black hole (BH) activity, which therefore should be used as a BH mass estimator in blazars with extreme care only. Our results strengthen the idea according to which γ-NLS1s are smaller and younger version of flat-spectrum radio quasars, in which both a Seyfert and a blazar component co-exist.

scholarly journals Evidence for chromatic X-ray light-curve breaks in Swift gamma-ray burst afterglows and their theoretical implications

2006 ◽  
Vol 369 (4) ◽  
pp. 2059-2064 ◽  
Author(s):  
A. Panaitescu ◽  
P. Mészáros ◽  
D. Burrows ◽  
J. Nousek ◽  
N. Gehrels ◽  
...  
Keyword(s):  
Light Curve ◽  
Gamma Ray ◽  
Gamma Ray Burst ◽  
X Ray

scholarly journals An X-Ray All Sky Monitor for a Japanese Experimental Module on the Space Station

1990 ◽  
Vol 123 ◽  
pp. 463-468
Author(s):  
M. Matsuoka ◽  
N. Kawai ◽  
T. Imai ◽  
M. Yamauchi ◽  
A. Yoshida ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Space Station ◽  
Transient Phenomena ◽  
X Ray ◽  
Sky Monitor ◽  
Image Position ◽  
Japanese Experimental Module

AbstractWe propose an X-ray all sky monitor for Japanese Experimental Module (JEM) on the space station. Considering practical circumstances, we show as a case study that the all sky monitor with slit hole cameras is most promising for monitoring the short-term and long-term X-ray transients. We call this all sky monitor as MAXI (Monitor of All-sky X-ray Image). Position determination of gamma-ray bursts could be achieved with accuracy less than one degree observing the X-ray component of the burst. Weak X-ray sources such as active galactic nuclei could be also monitored with time resolution less than one day. The X-ray all sky monitor will work to discover X-ray novae and transient phenomena and give us the alarm for further detailed observations. The obtained data will be also used for archival study.

scholarly journals Gamma-ray and optical properties of the flat spectrum radio quasar 3C 279 flare in June 2015

2020 ◽  
Vol 26 ◽  
pp. 65-76
Author(s):  
K.K. Singh ◽  
P.J. Meintjes ◽  
B. Bisschoff ◽  
F.A. Ramamonjisoa ◽  
B. van Soelen
Keyword(s):  
Optical Properties ◽  
Gamma Ray ◽  
Spectrum Radio ◽  
Radio Quasar

scholarly journals Gamma-ray-emitting narrow-line Seyfert 1 galaxies: the Swift view

2020 ◽  
Vol 496 (2) ◽  
pp. 2213-2229 ◽  
Author(s):  
F D’Ammando
Keyword(s):  
Gamma Ray ◽  
Thermal Emission ◽  
Optical Emission ◽  
X Rays ◽  
Narrow Line ◽  
X Ray ◽  
Relativistic Jet ◽  
Photon Index ◽  
Γ Ray ◽  
Lower Variability

ABSTRACT We report the analysis of all Swift observations available up to 2019 April of γ-ray-emitting narrow-line Seyfert 1 galaxies (NLSy1). The distribution of X-ray luminosities (and fluxes) indicates that the jet radiation significantly contributes to their X-ray emission, with Doppler boosting making values higher than other radio-loud NLSy1. The 0.3–10 keV photon indices are on average harder with respect to radio-quiet and radio-loud NLSy1, confirming a dominant jet contribution in X-rays. However, the lower variability amplitude with respect to blazars and the softening of the spectrum in some periods suggests that also the corona radiation contributes to the X-ray emission. In optical and ultraviolet (UV) significant flux changes have been observed on daily, weekly, and monthly time-scale, providing a clear indication of the significant contribution of the jet radiation in this part of spectrum. A strong correlation between X-ray, UV, and optical emission and simultaneous flux variations have been observed in 1H 0323+342, SBS 0846+513, PMN J0948+0022 as expected in case the jet radiation is the dominant mechanism. Correlated multiband variability favours the jet-dominated scenario also in FBQS J1644+2619 and PKS 2004−447. The summed X-ray Telescope spectra of 1H 0323+342, SBS 0846+513, PMN J0948+0022, and FBQS J1644+2619 are well fitted by a broken power law with a break around 2 keV. The spectrum above 2 keV is dominated by the non-thermal emission from a beamed relativistic jet, as suggested by the hard photon index. A Seyfert-like feature like the soft X-ray excess has been observed below 2 keV, making these γ-ray-emitting NLSy1 different from typical blazars.

LONG-TERM MONITORING OF THE HARD X-RAY/GAMMA-RAY EMISSION FROM GALACTIC BLACK HOLES WITH BATSE

2008 ◽  
Author(s):  
G. L. CASE ◽  
E. ANZALONE ◽  
M.L. CHERRY ◽  
J. C. RODI ◽  
J. C. LING ◽  
...  
Keyword(s):  
Black Holes ◽  
Gamma Ray ◽  
X Ray ◽  
Long Term Monitoring ◽  
Gamma Ray Emission ◽  
Term Monitoring

scholarly journals Flat Spectrum Radio Quasar Evolution and the Gamma-ray Background

2013 ◽  
Vol 9 (S304) ◽  
pp. 149-152
Author(s):  
Jack Singal ◽  
Allan Ko ◽  
Vahe Petrosian
Keyword(s):  
Optical Spectroscopy ◽  
Spectral Index ◽  
Gamma Ray ◽  
Space Telescope ◽  
Spectrum Radio ◽  
Photon Index ◽  
The Universe ◽  
Radio Quasar

AbstractWe discuss an analysis of the redshift evolutions and distributions of the gamma-ray luminosity and photon spectral index of flat spectrum radio quasar (FSRQ) type blazars. We utilize data from the Fermi Gamma-ray Space Telescope, with redshfits as determined from optical spectroscopy by Shaw et al. We find that FSRQs have evolved significantly in luminosity but negligibly in photon index, and contribute in toto roughly 20% of the total gamma-ray output of the Universe.

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