J/other/Galax/9.99 Giant Radio Galaxies in RACS (Andernach+, 2021)
Discovery of 178 Giant Radio Galaxies in 1059 deg2 of the Rapid ASKAP
Continuum Survey at 888 MHz.
Andernach H., Jimenez Andrade E.F., Willis A.G.
<Galaxies, vol. 9, 99 (2021)>
=2021Galax...9...99A 2021Galax...9...99A (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Radio sources ; Surveys ; Galaxies, radio
Keywords: galaxies: active - radio sources: radio galaxies
Abstract:
We report the results of a visual inspection of images of the Rapid
ASKAP Continuum Survey (RACS) in search of extended radio galaxies
(ERG) that reach or exceed linear sizes on the order of one
Megaparsec. We searched a contiguous area of 1059deg2 from
RA=20h20m to 06h20m, and -50°<Dec←40° which is covered by
deep multi-band optical images of the Dark Energy Survey (DES), and in
which previously only three ERGs larger than 1Mpc had been reported.
For over 1800 radio galaxy candidates inspected, our search in optical
and infrared images resulted in hosts for 1440 ERG, for which
spectroscopic and photometric redshifts from various references were
used to convert their largest angular size (LAS) to projected linear
size (LLS). This resulted in 178 newly discovered giant radio sources
(GRS) with LLS>1Mpc, of which 18 exceed 2Mpc and the largest one
is 3.4Mpc. Their redshifts range from 0.02 to about 2.0, but only 10
of the 178 new GRS have spectroscopic redshifts. For the 146 host
galaxies the median r-band magnitude and redshift are 20.9 and 0.64,
while for the 32 quasars or candidates these are 19.7 and 0.75.
Merging the six most recent large compilations of GRS results in 458
GRS larger than 1Mpc, so we were able to increase this number by
about 39 per cent to now 636.
Description:
We report radio and optical parameters of 181 giant radio sources
(GRS) with projected linear sizes larger than 1 Mpc in a high Galactic
latitude area between -50 and -40 degrees Declination (J2000), of
which 178 were newly discovered by us through visual inspection of the
Rapid ASKAP Continuum Survey (RACS) 888-MHz images.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 147 181 Radio and Optical data for 181
Giant Radio Galaxies
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See also:
J/A+A/635/A5 : LoTSS giant radio galaxies. I. (Dabhade+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Jname GRS object designation, JHHMM+DDMMC (1)
13 A1 --- Origin Survey in which the GRS was seen first (2)
15- 22 F8.4 deg RAdeg Right ascension (J2000) of GRS host
24- 31 F8.4 deg DEdeg Declination (J2000) of GRS host
34 A1 --- l_LAS [>] Limit flag on LAS
35- 39 F5.2 arcmin LAS Largest projected angular size of GRS
40 A1 --- u_LAS [?] Uncertainty flag on LAS
42 A1 --- l_z [>] Limit flag on redshift
43- 49 F7.5 --- z Redshift
51 A1 --- u_z [?] Uncertainty flag on redshift (3)
53 A1 --- ztype [spe] Type of redshift: s = spectroscopic,
p = photometric, e = estimated by us
55- 62 A8 --- r_z References used for redshifts (4)
64 A1 --- l_LLS [>] Limit flag on LLS
65- 68 F4.2 Mpc LLS Largest projected linear size (5)
70- 93 A24 --- Host Name of GRS host object (6)
95 A1 --- u_Host [?] Uncertainty flag on host (7)
97- 98 A2 --- Class Type of host of the GRS (8)
100-104 F5.2 mag rmag r-band magnitude of host from DES
105 A1 --- u_rmag [?] Uncertainty flag on rmag
107-113 F7.1 mJy S888 Integrated 888-MHz flux density
116-120 F5.2 W/Hz logP888 decimal log of 888-MHz spectral power
123-125 I3 deg RPA [0,179] Radio position angle (N through E)
128-147 A20 --- Rmorph Morphological type of radio emission
according to table 1 of the paper
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Note (1): in the format JHHMM+DDMMC (truncated J2000 host coordinates); a "C"
in byte 11 indicates that the object is a candidate, due to either uncertain
radio size, redshift or optical host identification or a combination thereof.
Note (2): Survey in which the GRS was seen first code as follows:
P = previously published (3 GRS)
A = ATESP (3 GRS),
E = EMU Pilot Survey (8 GRS)
S = SUMSS (45 GRS)
R = RACS (122 GRS)
Note (3): a '?' sign indicates inconsistencies between published photometric
redshifts or uncertainties in the estimation method
Note (4): References are coded with the following numbers:
1 = Zhou et al., 2021MNRAS.501.3309Z 2021MNRAS.501.3309Z (DESI DR9)
2 = Bilicki et al., 2016ApJS..225....5B 2016ApJS..225....5B (WISE-SuperCosmos)
3 = Bilicki et al., 2014ApJS..210....9B 2014ApJS..210....9B (2MPZ)
4 = Burgess & Hunstead, 2006AJ....131..114B 2006AJ....131..114B, Cat. J/AJ/131/114
5 = Colless et al., 2001MNRAS.328.1039C 2001MNRAS.328.1039C, Cat. VII/250 (2dF)
6 = Jones & Mcadam, 1992ApJS...80..137J 1992ApJS...80..137J, Cat. J/ApJS/80/137
7 = Jones et al., 2009MNRAS.399..683J 2009MNRAS.399..683J, cat. VII/259 (6dF)
8 = Krogager et al., 2018ApJS..235...10K 2018ApJS..235...10K
9 = Flesch, 2021arXiv210512985F 2021arXiv210512985F, Cat. VII/290 (Milliquas)
10 = Danziger et al., 1978MNRAS.184..341D 1978MNRAS.184..341D
11 = Danziger & Goss, 1983MNRAS.202..703D 1983MNRAS.202..703D
12 = Loveday et al., 1996ApJS..107..201L 1996ApJS..107..201L, Cat. J/ApJS/107/201
13 = Wisotzki et al., 2000A&A...358...77W 2000A&A...358...77W, Cat. J/A+A/358/77
14 = Shu et al., 2019MNRAS.489.4741S 2019MNRAS.489.4741S
Note (5): based on H0=70km/s/Mpc, Omegam=0.3, OmegaLambda=0.7; note
that the flags l_LAS, u_LAS, and l_z apply to LLS as well.
Note (6): one GRS (J0131-4901) has a recognizable host on DESI DR9 images,
but is too faint to be listed in the corresponding object catalogue
Note (7): a '?' indicates that this is the most likely host (see text)
Note (8): Type of host of the GRS as follows:
G = galaxy
GP = galaxy pair
Q = quasar
Qc = quasar candidate
G? = likely a galaxy
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Acknowledgements:
Heinz Andernach, heinz(at)ugto.mx
References:
McConnell et al., 2020PASA...37...48M 2020PASA...37...48M, The Rapid ASKAP Continuum Survey I
Hale et al., 2021arXiv21090095, The Rapid ASKAP Continuum Survey II
(End) Heinz Andernach [Univ. Guanajuato], Patricia Vannier [CDS] 31-Oct-2021