J/MNRAS/489/3403 A new sample of southern radio galaxies (Marubini+, 2019)
A new sample of southern radio galaxies: host-galaxy masses and star-formation
rates.
Marubini T., Jarvis M.J., Fine S., Mauch T., McAlpine K., Prescott M.
<Mon. Not. R. Astron. Soc., 489, 3403-3411 (2019)>
=2019MNRAS.489.3403M 2019MNRAS.489.3403M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Active gal. nuclei ; Redshifts ;
Radio sources ; Optical ; Infrared
Keywords: galaxies: active - galaxies: star formation -
radio continuum: galaxies
Abstract:
In this study we define a new sample of distant powerful radio
galaxies in order to study their host galaxy properties and provide
targets for future observations of HI absorption with new radio
telescopes and to understand the fuelling and feedback from such
sources. We have cross-matched the Sydney University Molonglo Sky
Survey (SUMSS) radio catalogue at 843MHz with the VISTA Hemisphere
Survey (VHS) near-infrared catalogue using the likelihood ratio
technique. Photometric redshifts from the Dark Energy Survey are then
used to assign redshifts to the radio source counterparts. We found a
total of 249 radio sources with photometric redshifts over a 148deg2
region. By fitting the optical and near-infrared photometry with
spectral synthesis models we determine the stellar mass and star
formation rates of the radio sources, finding typical stellar masses
of 1011-1012M☉ for the powerful high-redshift radio
galaxies. We also find a population of low-mass blue galaxies.
However, by comparing the derived star formation rates to the radio
luminosity, we suggest that these sources are false positives in our
likelihood ratio analysis. Follow-up, higher resolution (~<5arcsec)
radio imaging would help alleviate these mid-identifications, as the
limiting factor in our cross-identifications is the low resolution
(∼45arcsec) of the SUMSS radio imaging.
Description:
In order to create a new sample of powerful radio galaxies in the
Southern hemisphere, we first require a parent radio survey which
covers enough sky area that it provides a statistically significant
number of bright radio sources. The parent radio survey that we use in
this study is therefore SUMSS. SUMSS surveyed the sky below
δ←30° with |b|>10°, at a frequency of 843MHz using the
Molonglo Observatory Synthesis Telescope (MOST; Mills
1981PASA....4..156M 1981PASA....4..156M).
The Visible and Infrared Survey Telescope for Astronomy (VISTA)
Hemisphere Survey (VHS) is an NIR photometric survey of the southern
sky. It covers 18000deg2 with magnitude limits of H=19.8; J=20.6;
Ks=18.5 (Vega). The NIR photometric data, which have a resolution of
∼1.2arcsec, was accessed via the VISTA Science Archive
(http://www-wfau.roe.ac.uk/sss/) and we used the VHS Data Release 3.
The DES (Dark Energy Survey Collaboration 2016MNRAS.460.1270D 2016MNRAS.460.1270D) is an
optical survey that will eventually cover 5000deg2 in the SGP region
in the griz bands, using a dedicated camera (DECam) on the 4m Victor
M. Blanco Telescope at the Cerro Tololo Inter-American Observatory
(CTIO) in Chile (Flaugher et al. 2015AJ....150..150F 2015AJ....150..150F).
Of the 1195 DES+VHS sources cross-matched to the SUMSS data, we find
that 249 have good photometric information that allow the
determination of photometric redshifts (see Table 1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 161 249 The radio galaxy sample overlapping
SUMSS+VHS+DES defined in this paper
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See also:
VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)
II/367 : The VISTA Hemisphere Survey (VHS) catalog DR5 (McMahon+, 2020)
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/249] Galaxy identifier
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
29- 34 F6.3 mag gmag ? DES g-band magnitude
36- 41 F6.4 mag e_gmag ? Error on gmag
43- 48 F6.3 mag rmag ? DES r-band magnitude
50- 55 F6.4 mag e_rmag ? Error on rmag
57- 62 F6.3 mag imag DES i-band magnitude
64- 69 F6.4 mag e_imag Error on imag
71- 76 F6.3 mag zmag DES z-band magnitude
78- 83 F6.4 mag e_zmag Error on zmag
85- 90 F6.3 mag Jmag ? VHS J-band magnitude
92- 96 F5.3 mag e_Jmag ? Error on Jmag
98-103 F6.3 mag Hmag ? VHS H-band magnitude
105-109 F5.3 mag e_Hmag ? Error on Hmag
111-116 F6.3 mag Ksmag VHS Ks-band magnitude
118-122 F5.3 mag e_Ksmag Error on Ksmag
124-129 F6.1 mJy S843 SUMSS flux at 843MHz
131-134 F4.1 mJy e_S843 Error on S843
136-139 F4.2 --- zphot Photometric redshift
141-144 F4.2 --- b_zphot Lower bound on zphot
146-149 F4.2 --- B_zphot Upper bound on zphot
151-155 F5.2 [Msun] logM* Logarithm of stellar mass
157-161 F5.2 [Msun/yr] logSFR Logarithm of star formation rate
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 13-Jan-2023