J/MNRAS/436/3759 ECDFS sources optical/IR counterparts (Bonzini+, 2013)
The sub-mJy radio sky in the Extended Chandra Deep Field-South:
source population.
Bonzini M., Padovani P., Mainieri V., Kellermann K.I., Miller N.,
Rosati P., Tozzi P., Vattakunnel S.
<Mon. Not. R. Astron. Soc., 436, 3759-3771 (2013)>
=2013MNRAS.436.3759B 2013MNRAS.436.3759B (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Infrared sources ; X-ray sources ;
Radio sources
Keywords: catalogues - galaxies: active - galaxies: star formation
Abstract:
The sub-mJy radio population is a mixture of active systems, that is
star-forming galaxies (SFGs) and active galactic nuclei (AGNs). We
study a sample of 883 radio sources detected at 1.4GHz in a deep Very
Large Array survey of the Extended Chandra Deep Field-South that
reaches a best rms sensitivity of 6µJy. We have used a simple
scheme to disentangle SFGs, radio-quiet (RQ), and radio-loud (RL) AGNs
based on the combination of radio data with Chandra X-ray data and
mid-infrared observations from Spitzer. We find that at flux densities
between about 30 and 100µJy, the radio population is dominated by
SFGs (∼60%) and that RQ AGNs become increasingly important over RL
ones below 100 µJy. We also compare the host galaxy properties of
the three classes in terms of morphology, optical colours and stellar
masses. Our results show that both SFG and RQ AGN host galaxies have
blue colours and late-type morphology while RL AGNs tend to be hosted
by massive red galaxies with early-type morphology. This supports the
hypothesis that radio emission in SFGs and RQ AGNs mainly comes from
the same physical process: star formation in the host galaxy.
Description:
We consider a sample of 883 radio sources detected at 1.4GHz in a
deep Very Large Array (VLA) survey of the Extended Chandra Deep
Field-South (E-CDFS) that reaches a best rms sensitivity of 6uJy.
We used deep Spitzer InfraRed Array Camera (IRAC) and Multiband
Imaging Photometer for Spitzer (MIPS) data. The IRAC data were
obtained as part of the Spitzer IRAC/MUSYC Public Legacy Survey in the
Extended CDF-South (SIMPLE) survey (Damen et al., 2011ApJ...727....1D 2011ApJ...727....1D,
Cat. J/ApJ/727/1). It covers an area of about 1600 arcmin2 centred
on the E-CDFS. The typical 5σ flux density limits are 1.1, 1.3,
6.3 and 7.6uJy at 3.6, 4.5, 5.8 and 8.0um, respectively. We also use
MIPS 24um data from the Far-Infrared Deep Extragalactic Legacy
(FIDEL) survey (Dickinson & FIDEL Team, 2007AAS...211.5216D 2007AAS...211.5216D).
The E-CDFS has been mapped in the X-ray band by Chandra. A total of
129 radio sources have a counterpart in the 4 Ms observations of the
CDFS presented in Xue et al. (2011ApJS..195...10X 2011ApJS..195...10X, Cat. J/ApJS/195/10)
and another 99 in the main E-CDFS catalogue by Lehmer et al.
(2005ApJS..161...21L 2005ApJS..161...21L, Cat. J/ApJS/161/21) obtained with shallower
(250ks) observations in each of four pointings. The list of the X-ray
counterparts of the radio sources is given in Bonzini et al.
(2012ApJS..203...15B 2012ApJS..203...15B, Cat. J/ApJS/203/15).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 883 Classification of radio sources
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See also:
J/ApJS/161/21 : Extended Chandra Deep Field-South survey (Lehmer+, 2005)
J/ApJS/195/10 : The CDF-S survey: 4Ms source catalogs (Xue+, 2011)
J/ApJ/727/1 : IRAC/MUSYC SIMPLE survey (Damen+, 2011)
J/ApJS/203/15 : Counterparts to 1.4GHz sources in ECDF-S (Bonzini+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- RID Radio source ID, [MBF2013] NNN in Simbad (1)
5- 6 I2 h RAh ? Optical-IR counterpart
right ascension (J2000)
8- 9 I2 min RAm ? Optical-IR counterpart
right ascension (J2000)
11- 15 F5.2 s RAs ? Optical-IR counterpart
right ascension (J2000)
17 A1 --- DE- Optical-IR counterpart
declination sign (J2000)
18- 19 I2 deg DEd ? Optical-IR counterpart declination (J2000)
21- 22 I2 arcmin DEm ? Optical-IR counterpart declination (J2000)
24- 28 F5.2 arcsec DEs ? Optical-IR counterpart declination (J2000)
30- 35 A6 --- Class Classification of the source (2)
37- 40 F4.2 --- z ?=- Redshift
42- 46 F5.2 [W/Hz] logPr ?=- Radio power
48 A1 --- l_logLX Limit flag for 3σ upper limit
49- 53 F5.2 [10-7W] logLX ?=0 X-ray luminosity in the hard
band (2-10keV) (3)
55- 59 F5.2 --- logq24o ?=- Ratio of the observed 24um and 1.4GHz
luminosities
61- 65 F5.2 [-] log(S3/S1) ?=- log10 of the ratio of the flux density in
the 5.8 and 3.6um IRAC bands
67- 71 F5.2 [-] log(S4/S2) ?=- log10 of the ratio of the flux density in
the 8.0 and 4.5um IRAC bands
73- 76 F4.1 --- alphar ?=- Radio spectral index; alphar=0.7 if no
6cm observations are available
78- 83 F6.2 mag BMAG ?=- Rest frame absolute B magnitude
85 I1 --- QF [1/3] Quality flag of the classification:
from 3=secure to 1=insecure
87 I1 --- f_logq24o [0/1] Flag for the logq24o:
1 = upper limit on logq24o, 0 = detection
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Note (1): from Miller et al., 2013, Cat. J/ApJS/205/13 &
Bonzini et al., 2012, Cat. J/ApJS/203/15.
Note (2): Classification of the source as follows:
SFG = star forming galaxy
RQ AGN = radio quiet AGN
RL AGN = radio loud AGN
Note (3): sources without redshift have upper limits computed assuming z=1
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Oct-2015