J/AJ/135/1311 Environments of moderate redshift radio galaxies (Auger+, 2008)
The environments of low- and high-luminosity radio galaxies at moderate
redshifts.
Auger M.W., Becker R.H., Fassnacht C.D.
<Astron. J., 135, 1311-1317 (2008)>
=2008AJ....135.1311A 2008AJ....135.1311A
ADC_Keywords: Galaxies, radio ; Redshifts ; Spectroscopy ; Photometry, SDSS
Keywords: galaxies: active
Abstract:
In the local universe, high-power radio galaxies live in lower-density
environments than low-luminosity radio galaxies. If this trend
continued to higher redshifts, powerful radio galaxies would serve as
efficient probes of moderate redshift groups and poor clusters.
Photometric studies of radio galaxies at 0.3≲z≲0.5 suggest that the
radio luminosity-environment correlation disappears at moderate
redshifts, though this could be the result of foreground/background
contamination affecting the photometric measures of environment. We
have obtained multi-object spectroscopy in the fields of 14 lower
luminosity (L1.4GHz<4x1024W/Hz) and higher luminosity
(L1.4GHz>1.2x1025W/Hz) radio galaxies at z∼0.3 to
spectroscopically investigate the link between the environment and the
radio luminosity of radio galaxies at moderate redshifts. Our results
support the photometric analyses; there does not appear to be a
correlation between the luminosity of a radio galaxy and its
environment at moderate redshifts. Hence, radio galaxies are not
efficient signposts for group environments at moderate redshifts.
Description:
Sources in the FIRST catalog (Cat. VIII/71) were matched against the
galaxies in the SDSS DR5 spectroscopic catalog (Cat. II/276,
superseded by II/294) with a conservative matching tolerance of 1".
Multi-object spectroscopy was obtained for the fields of the 14
targets with the Low-Resolution Imaging Spectrometer (LRIS) on the
Keck I telescope (see table2).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 72 14 *Radio galaxy group properties
table4.dat 90 161 *Group Member Properties
table12.dat 76 16 *Moderate redshift radio galaxy sub-sample
with LRIS MOS observations (14 targets)
(table1 and 2 of the paper)
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Note on table*.dat: 223616.932-100045.54 of table1 and 3 is identified to
223616.978-100046.06 in table2 and table4, and 232844.520+000134.32 of
table1 and 3 is identified to 232844.518+000133.64 in table2 and 4.
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See also:
VIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/AJ/123/3018 : Redshifts of radio-selected poor clusters (Miller+, 2002)
J/MNRAS/333/100 : Radio galaxies in the 2dFGRS (Magliocchetti+, 2002)
J/A+A/424/371 : 1.4GHz First Look Survey (FLS) (Morganti+, 2004)
J/MNRAS/390/819 : Combined NVSS-FIRST Galaxies (CoNFIG) sample (Gendre+, 2008)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Name of the sub-sample radio galaxy
(HHMMSS.sss+DDMMSS.ss) associated with the group
22- 23 I2 h RAh Group Hour of right ascension (J2000)
25- 26 I2 min RAm Group Minute of right ascension (J2000)
28- 32 F5.2 s RAs Group Second of right ascension (J2000)
34 A1 --- DE- Group Declination sign (J2000)
35- 36 I2 deg DEd Group Degree of declination (J2000)
38- 39 I2 arcmin DEm Group Arcminute of declination (J2000)
41- 44 F4.1 arcsec DEs Group Arcsecond of declination (J2000)
46- 47 I2 --- Nsp Number of spectroscopically confirmed group
members
49- 50 I2 --- N500 Number of photometrically estimated group
members within 500h-1kpc
52- 53 I2 --- N1000 Number of photometrically estimated group
members within 1h-1Mpc
55- 57 I3 arcsec off Offset of the sub-sample radio galaxy from the
spectroscopic group center
59- 64 F6.4 --- z Redshift of the group
66- 68 I3 km/s sigma Velocity dispersion of the group
70- 72 I3 km/s e_sigma Velocity dispersion of the group uncertainty
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Sub-sample radio galaxy name
(HHMMSS.sss+DDMMSS.ss)
22- 23 I2 h RAh Member Hour of Right Ascension (J2000)
25- 26 I2 min RAm Member Minute of Right Ascension (J2000)
28- 33 F6.3 s RAs Member Second of Right Ascension (J2000)
35 A1 --- DE- Sign of the Declination (J2000)
36- 37 I2 deg DEd Member Degree of Declination (J2000)
39- 40 I2 arcmin DEm Member Arcminute of Declination (J2000)
42- 47 F6.3 arcsec DEs Member Arcsecond of Declination (J2000)
49- 54 F6.4 --- z Redshift
56 A1 --- l_gmag Limit flag on gmag
58- 63 F6.3 mag gmag Member SDSS g band magnitude
65 A1 --- l_rmag Limit flag on rmag
67- 72 F6.3 mag rmag Member SDSS r band magnitude
74 A1 --- l_imag Limit flag on imag
76- 81 F6.3 mag imag Member SDSS i band magnitude
83 A1 --- l_zmag Limit flag on zmag
85- 90 F6.3 mag zmag Member SDSS z band magnitude
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Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Name of the radio galaxy
(HHMMSS.sss+DDMMSS.ss)
22- 23 I2 h RAh Hour of right ascension (J2000)
25- 26 I2 min RAm Minute of right ascension (J2000)
28- 32 F5.2 s RAs Second of right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Degree of declination (J2000)
38- 39 I2 arcmin DEm Arcminute of declination (J2000)
41- 44 F4.1 arcsec DEs Arcsecond of declination (J2000)
46- 51 F6.4 --- z Redshift of the galaxy
53- 57 F5.2 10+24W/Hz L1.4GHz Luminosity at 1.4GHz
59- 68 A10 "YYYY/MM/DD" Obsdate Observation date
70- 73 I4 s texp Exposure time
75- 76 I2 --- Nz Number of successful redshifts obtained
per mask (see section 3)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Aug-2010