J/A+A/618/A152 Abell 1795 GMRT and Chandra maps (Kokotanekov+, 2018)
Signatures of multiple episodes of AGN activity in the core of Abell 1795.
Kokotanekov G., Wise M.W., de Vries M., Intema H.T.
<Astron. Astrophys. 618, A152 (2018)>
=2018A&A...618A.152K 2018A&A...618A.152K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Radio sources ; X-ray sources
Keywords: galaxies: clusters: general - galaxies: clusters: individual: A1795 -
galaxies: clusters: intracluster medium - radio continuum: general -
X-rays: galaxies: clusters - methods: observational
Abstract:
In this paper we analyze AGN activity signatures in the rich nearby
galaxy cluster Abell 1795 aiming to confirm and characterize the
long-term feedback history in the system. We combine radio
observations at 610 and 235MHz from the Giant Metrewave Radio
Telescope (GMRT) with 3.4Msec X-ray data from the Chandra Observatory.
Extracting radial temperature profiles, as well as Xray and radio
surface brightness profiles in three directions showing major
morphological disturbances, we highlight the signatures of activity in
the system. For the first time we observe radio emission corresponding
to the NW X-ray depression, which provides evidence in favor of the
classification of the depression as a cavity. We identify two other
X-ray cavities situated NW and SW of the AGN. While the central radio
emission corresponding to the inner cavities shows a flatter spectral
index, the radio extensions associated with the farthest X-ray
cavities consist of aged plasma. All observed signatures both in radio
and X-ray are consistent with several consecutive episodes of AGN
activity, which gave rise to the observed morphology NW and SW from
the core. In the southern region, we confirm the cooling wake
hypothesis for the origin of the long tail. The deep X-ray data also
allows us to distinguish significant distortions in the tail's inner
parts, which we attribute to the activity of the AGN.
Description:
We have extracted and reprocessed existing archival Chandra data for
A1795, which has been used extensively as a Chandra calibration and
reference target since launch and, consequently, has one of the
deepest accumulated exposures of any cluster target. In this work, we
analyze over 3.4Msec of Chandra data, consisting of 148 individual
ObsIDs taken between December 1999 and November 2016.
Objects:
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RA (2000) DE Designation(s)
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13 49 00.5 +26 35 07 A1795 = Abell 1795
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 126 6 List of fits files
fits/* . 6 Individual fits files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 I5 --- Nx Number of pixels along X-axis
26- 30 I5 --- Ny Number of pixels along Y-axis
32- 57 A26 "datime" Obs.date Observation date
59- 65 F7.3 MHz Obs.Freq ? Observed frequency
67- 72 I6 Kibyte size Size of FITS file
74- 89 A16 --- FileName Name of FITS file, in subdirectory fits
91-126 A36 --- Title Title of the FITS file
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Acknowledgements:
Georgi Kokotanekov, gkokotanekov(at)gmail.com
(End) Patricia Vannier [CDS] 15-Oct-2018