Detection of X‐Ray Emission from the Eastern Radio Lobe of Pictor A

We would like to present early results from the EINSTEIN X-ray Observatory on three radio galaxies: Centaurus A, NGC 315 = DW0055+30, and Cygnus A = 3C405. We hope to demonstrate that imaging X-ray astronomy can provide important insights into the physics and environment of radio galaxies and their extended radio components.NGC 5128, the parent galaxy of the double-double radio source Centaurus A, is the nearest radio galaxy, providing the best testing ground for high resolution X-ray studies. The X-ray morphology has proved to be rich and varied. We detect four distinct components to the X-ray emission: (1) the strong, compact nucleus detected by earlier satellites; (2) extended emission around the nucleus; (3) emission from the inner radio lobes; and (4) a unique X-ray jet between the nucleus and the NE radio lobe. A detailed presentation of these observations can be found in Schreier et al. (1979).

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

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3067 ◽

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.

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Creation of the X‐Ray Cavity Jet and Its Radio Lobe in M87/Virgo with Cosmic Rays: Relevance to Relic Radio Sources

The Astrophysical Journal ◽

10.1086/527429 ◽

2008 ◽

Vol 676 (2) ◽

pp. 880-888 ◽

Cited By ~ 21

Author(s):

William G. Mathews ◽

Fabrizio Brighenti

Keyword(s):

Cosmic Rays ◽

Radio Sources ◽

X Ray ◽

Radio Lobe

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THE JET HEATED X-RAY FILAMENT IN THE CENTAURUS A NORTHERN MIDDLE RADIO LOBE

The Astrophysical Journal ◽

10.1088/0004-637x/698/2/2036 ◽

2009 ◽

Vol 698 (2) ◽

pp. 2036-2047 ◽

Cited By ~ 38

Author(s):

R. P. Kraft ◽

W. R. Forman ◽

M. J. Hardcastle ◽

M. Birkinshaw ◽

J. H. Croston ◽

...

Keyword(s):

X Ray ◽

Radio Lobe ◽

Centaurus A

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Radio and X-Ray Structure of Centaurus A

Symposium - International Astronomical Union ◽

10.1017/s0074180900027467 ◽

1982 ◽

Vol 97 ◽

pp. 107-114

Author(s):

Eric D. Feigelson

Keyword(s):

Radio Galaxy ◽

Hii Regions ◽

X Rays ◽

Active Nucleus ◽

Very Large Array ◽

X Ray ◽

Radio Lobe ◽

Inverse Compton ◽

Centaurus A

Recent studies of the nearby radio galaxy Centaurus A with the Very Large Array and the Einstein X-Ray Observatory reveal complex radio and X-ray structures. A prominent one-sided jet comprised of resolved knots located 0.2–6 kpc from the nucleus is seen in both radio and X-rays. The X-ray emission is probably synchrotron, requiring in situ reacceleration up to Γ ≃ 107. Inverse Compton emission is not a likely explanation though a thermal model in which the nucleus ejects dense 105M0 clouds cannot be excluded. An elongated X-ray region is also found near the “middle” radio lobe and optical HII regions ∼ 30 kpc NE of the nucleus. Conditions around the active nucleus, the absence of X-rays from the inner radio lobes, and X-ray evidence for a hot interstellar medium are briefly discussed.

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Hubble Space Telescope Observations of Synchrotron Jets

International Astronomical Union Colloquium ◽

10.1017/s0252921100078301 ◽

1994 ◽

Vol 142 ◽

pp. 909-916

Author(s):

W. B. Sparks ◽

J. A. Biretta ◽

F. Macchetto

Keyword(s):

Radio Emission ◽

Hubble Space Telescope ◽

Detailed Comparison ◽

Synchrotron Emission ◽

Space Telescope ◽

X Ray ◽

Radio Lobe ◽

First Time ◽

Relativistic Particles ◽

Single Power

AbstractThe Hubble Space Telescope for the first time enables optical and UV images of jets to be obtained with spatial resolution comparable to radio interferometric techniques. Because synchrotron emission at these wavelengths is a diagnostic of particles several orders of magnitude higher in energy and correspondingly shorter in lifetime than those probed by radio, the sites of particle acceleration may be more readily identified in the optical and UV. Short-lifetime optical synchrotron emission in the SE inner radio lobe of M87 argues strongly for the presence of an invisible counterjet. A detailed comparison of HST and VLA images of the M87 jet shows there are very strong similarities in overall morphology, but that there are also significant differences. The optical and UV radiation is more localized within the knots than the radio emission and appears more confined toward the jet center. These differences may arise from localized shocks, sited at the optical knots with diffusion of relativistic particles away from those knots, or else they may be due to nonuniform magnetic fields and distributed acceleration processes. The UV fluxes of the knots are consistent with a single power law from optical to X-ray. Optical jets in other radio galaxies show diverse properties—the jet of PKS 0521–36 is smoothly resolved by HST while that of 3C 66B shows previously unsuspected filmentary structure. Likewise, the jet of 3C 273 shows newly observed optical filaments and an intensity distribution quite unlike that of the radio emission. Like M87, the optical jet of 3C 273 is narrower than the radio jet. The serendipitous discovery of a new optical synchrotron jet in 3C 264 suggests that optical jets may be relatively common.Subject heading: galaxies: jets

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An All-Sky Atlas of Radio/X-ray Associations

Publications of the Astronomical Society of Australia ◽

10.1071/as09060 ◽

2010 ◽

Vol 27 (3) ◽

pp. 283-289 ◽

Cited By ~ 26

Author(s):

E. Flesch

Keyword(s):

Optical Data ◽

Radio Sources ◽

X Ray ◽

Object Selection ◽

Extant Literature ◽

Radio Lobe

AbstractAn all-sky comprehensive catalogue of calculated radio and X-ray associations to optical objects is presented. Included are X-ray sources from XMM-Newton, Chandra and ROSAT catalogues, radio sources from NVSS, FIRST and SUMSS catalogues, and optical data, identifications and redshifts from the APM, USNO-A, SDSS-DR7 and the extant literature. This ‘Atlas of Radio/X-ray Associations’ inherits many techniques from the predecessor Quasars.org (2004) catalogue, but object selection is changed and processing tweaked. Optical objects presented are those which are calculated with ≥40% confidence to be associated with radio/X-ray detections, totalling 602 570 objects in all, including 23 681 double radio lobe detections. For each of these optical objects I display the calculated percentage probabilities of its being a QSO, galaxy, star, or erroneous radio/X-ray association, plus any identification from the literature. The catalogue includes 105 568 uninvestigated objects listed as 40% to >99% likely to be a QSO. The catalogue is available at http://quasars.org/arxa.htm.

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Properties of the Medium Causing Asymmetric Depolarization in Strong Double Radio Sources with One Jet

Symposium - International Astronomical Union ◽

10.1017/s007418090019093x ◽

1990 ◽

Vol 140 ◽

pp. 482-482

Author(s):

A. Crusius-Wätzel ◽

P.L. Biermann ◽

I. Lerche ◽

R. Schlickeiser

Keyword(s):

Magnetic Field ◽

Faraday Rotation ◽

Magnetized Plasma ◽

Radio Sources ◽

Radio Waves ◽

X Ray ◽

Hot Gas ◽

Radio Lobe ◽

The One ◽

The Magnetic Field

Polarization data of strong double-lobed radio sources (Garrington et al., 1988a; Laing, 1988) in many cases show that one side is more depolarized than the other. Since a jet is seen only on the less depolarized side it can be concluded that this radio lobe is nearer to us, if the one-sidedness of the jet is interpreted by bulk relativistic motion. The effect is then due to random Faraday rotation where the RMS-rotation angle is larger than about π/2 for the longer wavelength. This suggests an intervening magnetized plasma which may be the hot gas in the halos of the (elliptical) galaxies or in the cluster. Comparing the effects of both, the intracluster medium (ICM) probably is the dominating component. Garrington (1988b) comes to the same conclusion. Considering the transport of polarized radio waves in a turbulent Faraday screen (cells of size l0) we further find that the coherence length of the magnetic field is of the order of l0 = 1–4 kpc. From EINSTEIN X-ray data (for 3C9, 4C01.11, 3C270.1, 3C275.1, 3C208) we find luminosities in the range Lx = 0.6–7 × 1045erg s−1, which can only be due to the cluster gas or an active galactic nucleus. If we assume that the total X-ray flux is produced by the ICM the electron core densities are n0 = 2–7 × 10−3 cm−3. Combining this with the values for l0 gives upper limits to the ratio of thermal to magnetic pressure (plasma-beta) of βp = 50–370 and lower limits to the core magnetic field strength of B0 = 3–9 μG. If the AGN contributes substantially to the X-ray emission the given limits would be even stronger, in the direction of equipartition of energy in the hot gas and in the magnetic field, since B0 has to be larger if n0 is smaller to account for the same dispersion in Faraday rotation. We plan to separate the diffuse and the pointlike emission by ROSAT observations. A more detailed version of this paper will be presented elsewhere (Crusius–Wätzel et al., 1989).

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