scholarly journals Focusing on the extended X-ray emission in 3C 459 with a Chandra follow-up observation

2018 ◽  
Vol 619 ◽  
pp. A75 ◽  
Author(s):  
A. Maselli ◽  
R. P. Kraft ◽  
F. Massaro ◽  
M. J. Hardcastle
Keyword(s):  
Spectral Analysis ◽  
Radio Galaxy ◽  
Line Of Sight ◽  
X Ray ◽  
Hot Gas ◽  
Radio Jets ◽  
Absorbing Material ◽  
Radio Map ◽  
Powerful Radio Galaxy

Aims. We investigated the X-ray emission properties of the powerful radio galaxy 3C 459 revealed by a recent Chandra follow-up observation carried out in October 2014 with a 62 ks exposure. Methods. We performed an X-ray spectral analysis from a few selected regions on an image obtained from this observation and also compared the X-ray image with a 4.9 GHz VLA radio map available in the literature. Results. The dominant contribution comes from the radio core but significant X-ray emission is detected at larger angular separations from it, surrounding both radio jets and lobes. According to a scenario in which the extended X-ray emission is due to a plasma collisionally heated by jet-driven shocks and not magnetically dominated, we estimated its temperature to be ∼0.8 keV. This hot gas cocoon could be responsible for the radio depolarization observed in 3C 459, as recently proposed also for 3C 171 and 3C 305. On the other hand, our spectral analysis and the presence of an oxygen K edge, blueshifted at 1.23 keV, cannot exclude the possibility that the X-ray radiation originating from the inner regions of the radio galaxy could be intercepted by some outflow of absorbing material intervening along the line of sight, as already found in some BAL quasars.

scholarly journals A rare case of FR I interaction with a hot X-ray bridge in the A2384 galaxy cluster

2019 ◽  
Author(s):  
V Parekh ◽  
T F Laganá ◽  
K Thorat ◽  
K van der Heyden ◽  
A Iqbal ◽  
...  
Keyword(s):  
Radio Galaxy ◽  
Galaxy Cluster ◽  
Plasma Properties ◽  
X Ray ◽  
Hot Gas ◽  
Radio Jets ◽  
Radio Lobe ◽  
Unique System ◽  
Varying Mass ◽  
Two Bodies

Abstract Clusters of varying mass ratios can merge and the process significantly disturbs the cluster environments and alters their global properties. Active radio galaxies are another phenomenon that can also affect cluster environments. Radio jets can interact with the intra-cluster medium (ICM) and locally affect its properties. Abell 2384 (hereafter A2384) is a unique system that has a dense, hot X-ray filament or bridge connecting the two unequal mass clusters A2384(N) and A2384(S). The analysis of its morphology suggests that A2384 is a post-merger system where A2384(S) has already interacted with the A2384(N), and as a result hot gas has been stripped over a ∼1 Mpc region between the two bodies. We have obtained its 325 MHz GMRT data, and we detected a peculiar FR I type radio galaxy which is a part of the A2384(S). One of its radio lobes interacts with the hot X-ray bridge and pushes the hot gas in the opposite direction. This results in displacement in the bridge close to A2384(S). Based on Chandra and XMM-Newton X-ray observations, we notice a temperature and entropy enhancement at the radio lobe-X-ray plasma interaction site, which further suggests that the radio lobe is changing thermal plasma properties. We have also studied the radio properties of the FR I radio galaxy, and found that the size and radio luminosity of the interacting north lobe of the FR I galaxy are lower than those of the accompanying south lobe.

scholarly journals Interaction of Cygnus A with its environment

2014 ◽  
Vol 10 (S313) ◽  
pp. 236-241
Author(s):  
Paul E. J. Nulsen ◽  
Andrew J. Young ◽  
Ralph P. Kraft ◽  
Brian R. McNamara ◽  
Michael W. Wise
Keyword(s):  
Energy Flow ◽  
Radio Galaxy ◽  
Galaxy Cluster ◽  
Solar Mass ◽  
X Ray ◽  
Radio Jets ◽  
Cygnus A ◽  
Radio Lobe ◽  
Massive Galaxy ◽  
Powerful Radio Galaxy

AbstractCygnus A, the nearest truly powerful radio galaxy, resides at the centre of a massive galaxy cluster. Chandra X-ray observations reveal its cocoon shocks, radio lobe cavities and an X-ray jet, which are discussed here. It is argued that X-ray emission from the outer regions of the cocoon shocks is nonthermal. The X-ray jets are best interpreted as synchrotron emission, suggesting that they, rather than the radio jets, are the path of energy flow from the nucleus to the hotspots. In that case, a model shows that the jet flow is non-relativistic and carries in excess of one solar mass per year.

scholarly journals Radio and X-ray Observations of the Restarted Radio Galaxy in the Galaxy Cluster CL 0838+1948

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 108
Author(s):  
Simona Giacintucci ◽  
Tracy Clarke ◽  
Namir E. Kassim ◽  
Wendy Peters ◽  
Emil Polisensky
Keyword(s):  
Radio Source ◽  
Survey Data ◽  
Radio Galaxy ◽  
Galaxy Cluster ◽  
Gas Emission ◽  
Low Frequencies ◽  
Nuclear Activity ◽  
X Ray ◽  
Hot Gas ◽  
The Galaxy

We present VLA Low-band Ionosphere and Transient Experiment (VLITE) 338 MHz observations of the galaxy cluster CL 0838+1948. We combine the VLITE data with Giant Metrewave Radio Telescope 610 MHz observations and survey data. The central galaxy hosts a 250 kpc source whose emission is dominated by two large lobes at low frequencies. At higher frequencies, a pair of smaller lobes (∼30 kpc) is detected within the galaxy optical envelope. The observed morphology is consistent with a restarted radio galaxy. The outer lobes have a spectral index αout=1.6, indicating that they are old, whereas the inner lobes have αinn=0.6, typical for an active source. Spectral modeling confirms that the outer emission is a dying source whose nuclear activity switched off not more than 110 Myr ago. Using archival Chandra X-ray data, we compare the radio and hot gas emission. We find that the active radio source is contained within the innermost and X-ray brightest region, possibly a galactic corona. Alternatively, it could be the remnant of a larger cool core whose outer layers have been heated by the former epoch of activity that has generated the outer lobes.

THE 2008 MULTIWAVELENGTH CAMPAIGN OF THE TeV RADIO-GALAXY M 87

2009 ◽  
Vol 18 (10) ◽  
pp. 1493-1498
Author(s):  
◽  
PIERRE COLIN ◽  
MATTHIAS BEILICKE ◽  
FREDERICK DAVIES ◽  
D. E. HARRIS ◽  
...  
Keyword(s):  
High Resolution ◽  
Radio Galaxy ◽  
Time Correlation ◽  
Line Of Sight ◽  
Emission Process ◽  
X Ray ◽  
Cherenkov Telescopes ◽  
Extragalactic Object ◽  
Spatially Resolved ◽  
Radio Band

M 87 is the first and brightest radio galaxy detected in the TeV regime. It is the closest extragalactic object showing variability and the only one that does not have its jet pointing toward the line of sight. The structure of the M 87 jet is spatially resolved in X-ray, optical and radio observations. Time correlation between the TeV flux and emission at other wavelengths provides a unique opportunity to localize the VHE emission process occurring in active galaxy nuclei. For 10 years, M87 has been monitored in the TeV band by imaging air Cherenkov telescopes (IACT) as well as in X-ray, optical and radio bands. In 2008, the three main IACTs, H.E.S.S./MAGIC/VERITAS, coordinated their observations in a joint campaign. In February, high TeV activities with rapid flares have been detected. Contemporaneously, M 87 was observed with high resolution instruments in the X-ray (Chandra) and Radio band (VLBA).

scholarly journals The ASCA X-ray spectrum of the powerful radio galaxy 3C 109

1997 ◽  
Vol 286 (3) ◽  
pp. 765-770 ◽  
Author(s):  
S. W. Allen ◽  
A. C. Fabian ◽  
E. Idesawa ◽  
H. Inoue ◽  
T. Kii ◽  
...  
Keyword(s):  
Radio Galaxy ◽  
Powerful Radio ◽  
X Ray ◽  
Powerful Radio Galaxy

scholarly journals Probing the pc- and kpc-scale Environment of the Powerful Radio Galaxy Hercules A

2002 ◽  
Vol 19 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Nectaria A. B. Gizani ◽  
M. A. Garrett ◽  
J. P. Leahy
Keyword(s):  
Radio Source ◽  
Radio Galaxy ◽  
Angular Size ◽  
Position Angle ◽  
Extragalactic Radio Source ◽  
X Ray ◽  
Central Value ◽  
Intracluster Gas ◽  
Extended Emission ◽  
Powerful Radio Galaxy

AbstractWe present the kpc-scale behaviour of the powerful extragalactic radio source Hercules A and the behaviour of the intracluster gas in which the radio source is situated. We have found that Hercules A exhibits a strong Laing-Garrington effect. The X-ray observations have revealed an extended X-ray emission elongated along the radio galaxy axis. The estimated temperature of the cluster is kT=2.45 keV and the central electron density is n○≃7.8×10−3 cm−3 which reveals a hot, dense environment in which Hercules A is situated. From the combined study of the radio and X-ray data we have estimated a central value of 3 ≲ B○(μG)≲9.We also present the most recent results from the analysis of the radio data on the pc-scale structure of the radio galaxy, observed at 18 cm by the EVN–MERLIN array. A faint but compact radio source, coincident with the optical centre of Hercules A, was detected by the EVN at 18 mas resolution. The total flux density of the EVN core is 14.6 mJy. Its angular size is 18×7 mas with a position angle of ≃139°. There is also evidence for extended emission in the NW–SE direction, most probably from the eastern pc-scale jet. If this is true then there is a misalignment between the direction of the pc-eastern and the aligned kpc-scale jets of ≃35°.

scholarly journals Extended and Compact X‐Ray Emission from the Powerful Radio Galaxy 3C 220.1

1998 ◽  
Vol 504 (2) ◽  
pp. 743-748 ◽  
Author(s):  
M. J. Hardcastle ◽  
C. R. Lawrence ◽  
D. M. Worrall
Keyword(s):  
Radio Galaxy ◽  
Powerful Radio ◽  
X Ray ◽  
Powerful Radio Galaxy

scholarly journals IGR J17503–2636: a candidate supergiant fast X-ray transient

2019 ◽  
Vol 624 ◽  
pp. A142 ◽  
Author(s):  
C. Ferrigno ◽  
E. Bozzo ◽  
A. Sanna ◽  
G. K. Jaisawal ◽  
J. M. Girard ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Neutron Star ◽  
Energy Distribution ◽  
Power Law ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
X Ray ◽  
Broad Feature

The object IGR J17503–2636 is a hard X-ray transient discovered by INTEGRAL on 2018 August 11. This was the first ever reported X-ray emission from this source. Following the discovery, follow-up observations were carried out with Swift, Chandra, NICER, and NuSTAR. Here we report on the analysis of all of these X-ray data and the results obtained. Based on the fast variability in the X-ray domain, the spectral energy distribution in the 0.5–80 keV energy range, and the reported association with a highly reddened OB supergiant at ∼10 kpc, we conclude that IGR J17503–2636 is most likely a relatively faint new member of the supergiant fast X-ray transients. Spectral analysis of the NuSTAR data revealed a broad feature in addition to the typical power-law with exponential roll-over at high energy. This can be modeled either in emission or as a cyclotron scattering feature in absorption. If confirmed by future observations, this feature would indicate that IGR J17503–2636 hosts a strongly magnetized neutron star with B ∼ 2 × 1012 G.

scholarly journals Cygnus A ? John Bolton?s First Cosmic Source

1994 ◽  
Vol 47 (5) ◽  
pp. 615 ◽  
Author(s):  
DE Harris
Keyword(s):  
Radio Galaxy ◽  
Discrete Source ◽  
X Rays ◽  
Powerful Radio ◽  
X Ray ◽  
Cygnus A ◽  
Cosmic Source ◽  
Powerful Radio Galaxy

Using a sea interferometer, Bolton and Stanley isolated Cygnus A as a discrete source in 1948. It is a prime example� of a powerful radio galaxy and, in the last decade, has also been studied extensively in X-rays. In this paper I summarise the results from a ROSAT X-ray image.

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