J/A+A/643/A172 Abell 2626 radio source LOFAR image at 144MHz (Ignesti+, 2020)
The great Kite in the sky:
A LOFAR observation of the radio source in Abell 2626.
Ignesti A., Shimwell T., Brunetti G., Gitti M., Intema H.,
van Weeren R.J., Hardcastle M.J., Clarke A.O., Botteon A., Di Gennaro G.,
Brueggen M., Browne I., Mandal S., Roettgering H.J.A., Cuciti V.,
de Gasperin F., Cassano R., Scaife A.M.M.
<Astron. Astrophys. 643, A172 (2020)>
=2020A&A...643A.172I 2020A&A...643A.172I (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Radio continuum
Keywords: galaxies: clusters: individual: Abell 2626 -
galaxies: individual: IC 5338 - galaxies: jets -
radio continuum: galaxies - radiation mechanisms: non-thermal -
methods: observational
Abstract:
We present new LOFAR data of the galaxy cluster Abell 2626. Weproduced
a new, resolved spectral index map of the source with a resolution of
7" and we studied the spatial correlation of radio and X-ray
emission to investigate the interplay between thermal and nonthermal
plasma. The new LOFAR data changed our view of the Kite because we
discovered two steep-spectrum (α←1.5) plumes of emission
connected to the arcs. On the basis of our results, we propose that the
Kite was originally an X-shaped radio galaxy whose fossil radio
plasma, after the end of the activity of the central active galactic
nucleus, has been compressed as a consequence of motions of the
thermal plasma encompassing the galaxy. The interplay between the
compression and advection of the fossil plasma, with the restarting of
the nuclear activity of the central galaxy,could have enhanced the
radio emission of the fossil plasma producing the arcs of the Kite. We
also present the first, low-frequency observation of a jellyfish galaxy
in the same field, in which we detect extended, low-frequency emission
without a counterpart at higher frequencies.
Description:
LOFAR image at 144MHz of the central radio source. The image was
produced with WSCLEAN with a BRIGSS weight robust =-0.75; the final
resolution is 6.7x5.6 arcsecond and the RMS is 120*10-6Jy/beam.
File Header description:
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BITPIX Floating point (32 bit) -32
BMAJ null 1.868321837678E-03
BMIN null 1.547679793258E-03
BPA null 7.954995839783E+01
BSCALE PHYSICAL = PIXEL*BSCALE + BZERO 1.000000000000E+00
BTYPE null Intensity
BUNIT Brightness (pixel) unit Jy/beam
BZERO null 0.000000000000E+00
CDELT1 null -4.166666666667E-04
CDELT2 null 4.166666666667E-04
CDELT3 null 4.687500000000E+07
CDELT4 null 1.000000000000E+00
CRPIX1 null 7.700000000000E+02
CRPIX2 null 7.700000000000E+02
CRPIX3 null 1.000000000000E+00
CRPIX4 null 1.000000000000E+00
CRVAL1 null -5.891875000000E+00
CRVAL2 null 2.111634722000E+01
CRVAL3 null 1.436508178711E+08
CRVAL4 null 1.000000000000E+00
CTYPE1 null RA---SIN
CTYPE2 null DEC--SIN
CTYPE3 null FREQ
CTYPE4 null STOKES
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Objects:
-----------------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------------
23 36 31.0 +21 09 36 Abell 2626 = ACO 2626
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 157 1 Information on fits image
fits/* . 1 Fits image
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Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 55 A26 "datime" Obs.date Observation date
57- 63 F7.3 MHz Freq Observed frequency
65- 68 I4 Kibyte size Size of FITS file
70-124 A55 --- FileName Name of FITS file, in subdirectory fits
126-157 A32 --- Title Title of the FITS file
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Acknowledgements:
Alessandro Ignesti, alessandro.ignesti2(at)unibo.it,
DIFA, University of Bologna
(End) Alessandro Ignesti [DIFA], Patricia Vannier [CDS] 05-Nov-2020