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

1994 ◽  
Vol 47 (5) ◽  
pp. 615 ◽  
Author(s):  
DE Harris

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.

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

2020 ◽  
Vol 492 (3) ◽  
pp. 3156-3168
Author(s):  
Wenhao Liu ◽  
Ming Sun ◽  
Paul E J Nulsen ◽  
Diana M Worrall ◽  
Mark Birkinshaw ◽  
...  

ABSTRACT We present results from a deep (174 ks) Chandra observation of the FR-II radio galaxy 3C 220.1, the central brightest cluster galaxy (BCG) of a kT ∼ 4 keV cluster at z = 0.61. The temperature of the hot cluster medium drops from ∼5.9 to ∼3.9 keV at ∼35 kpc radius, while the temperature at smaller radii may be substantially lower. The central active galactic nucleus (AGN) outshines the whole cluster in X-rays, with a bolometric luminosity of 2.0 × 1046 erg s−1 (∼10 per cent of the Eddington rate). The system shows a pair of potential X-ray cavities ∼35 kpc east and west of the nucleus. The cavity power is estimated within the range of 1.0 × 1044 and 1.7 × 1045 erg s−1, from different methods. The X-ray enhancements in the radio lobes could be due to inverse Compton emission, with a total 2–10 keV luminosity of ∼8.0 × 1042 erg s−1. We compare 3C 220.1 with other cluster BCGs, including Cygnus A, as there are few BCGs in rich clusters hosting an FR-II galaxy. We also summarize the jet power of FR-II galaxies from different methods. The comparison suggests that the cavity power of FR-II galaxies likely underestimates the jet power. The properties of 3C 220.1 suggest that it is at the transition stage from quasar-mode feedback to radio-mode feedback.


1998 ◽  
Vol 504 (2) ◽  
pp. 743-748 ◽  
Author(s):  
M. J. Hardcastle ◽  
C. R. Lawrence ◽  
D. M. Worrall

2015 ◽  
Vol 808 (2) ◽  
pp. 154 ◽  
Author(s):  
Christopher S. Reynolds ◽  
Anne M. Lohfink ◽  
Patrick M. Ogle ◽  
Fiona A. Harrison ◽  
Kristin K. Madsen ◽  
...  

1999 ◽  
Vol 306 (2) ◽  
pp. 467-472 ◽  
Author(s):  
K. Iwasawa ◽  
S. W. Allen ◽  
A. C. Fabian ◽  
A. C. Edge ◽  
S. Ettori

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

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.


Author(s):  
L Hernández-García ◽  
F Panessa ◽  
L Bassani ◽  
G Bruni ◽  
F Ursini ◽  
...  

Abstract Mrk 1498 is part of a sample of galaxies with extended emission line regions (extended outwards up to a distance of ∼7 kpc) suggested to be photo-ionized by an AGN that has faded away or that is still active but heavily absorbed. Interestingly, the nucleus of Mrk 1498 is at the center of two giant radio lobes with a projected linear size of 1.1 Mpc. Our multi-wavelength analysis reveals a complex nuclear structure, with a young radio source (Giga-hertz Peaked Spectrum) surrounded by a strong X-ray nuclear absorption, a mid-infrared spectrum that is dominated by the torus emission, plus a circum-nuclear extended emission in the [OIII] image (with radius of ∼ 1 kpc), most likely related to the ionization of the AGN, aligned with the small and large scale radio jet and extended also at X-rays. In addition a large-scale extended emission (up to ∼ 10 kpc) is only visible in [OIII]. These data show conclusive evidence of a heavily absorbed nucleus and has recently restarted its nuclear activity. To explain its complexity, we propose that Mrk 1498 is the result of a merging event or secular processes, such as a minor interaction, that has triggered the nuclear activity and produced tidal streams. The large-scale extended emission that gives place to the actual morphology could either be explained by star formation or outflowing material from the AGN.


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