J/AJ/144/16 Optical and HI properties of galaxies in voids (Kreckel+, 2012)
The Void Galaxy Survey: optical properties and HI morphology and kinematics.
Kreckel K., Platen E., Aragon-Calvo M.A., van Gorkom J.H.,
van de Weygaert R., van der Hulst J.M., Beygu B.
<Astron. J., 144, 16 (2012)>
=2012AJ....144...16K 2012AJ....144...16K
ADC_Keywords: H I data ; Redshifts ; Photometry, SDSS ; Photometry, RI ;
Galaxies, spectra ; Surveys
Keywords: galaxies: evolution - galaxies: formation -
galaxies: kinematics and dynamics - galaxies: structure -
large-scale structure of Universe - radio lines: galaxies
Abstract:
We have carefully selected a sample of 60 galaxies that reside in the
deepest underdensities of geometrically identified voids within the
Sloan Digital Sky Survey. HI imaging of 55 galaxies with the
Westerbork Synthesis Radio Telescope reveals morphological and
kinematic signatures of ongoing interactions and gas accretion. We
probe a total volume of 485Mpc3 within the voids, with an angular
resolution of 8kpc at an average distance of 85Mpc. We reach column
density sensitivities of 5x1019/cm-2, corresponding to an HI mass
limit of 3x108M☉. We detect HI in 41 galaxies, with total
masses ranging from 1.7x108 to 5.5x109M☉. The upper limits
on the 14 non-detections are not inconsistent with their luminosities,
given their expected HI mass-to-light ratios. We find that the void
galaxies are generally gas-rich, low-luminosity, blue disk galaxies,
with optical and HI properties that are not unusual for their
luminosity and morphology. The sample spans a range of absolute
magnitudes (-16.1>Mr>-20.4) and colors (0.06<g-r<0.87), and includes
disk and irregular galaxies. We also identify three as early-type
galaxies, all of which are not detected in HI. All galaxies have
stellar masses less than 3x1010M☉, and many have kinematic and
morphological signs of ongoing gas accretion, suggesting that the void
galaxy population is still in the process of assembling. The
small-scale clustering in the void, within 600kpc and 200km/s, is
similar to that in higher density regions, and we identify 18 HI-rich
neighboring galaxies in the voids. Most are within 100kpc and 100km/s
of the targeted galaxy, and we find no significant population of
HI-rich low-luminosity galaxies filling the voids, contrary to what is
predicted by simulations.
Description:
We have selected a sample of 60 galaxies using voids identified within
the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7, Cat. II/294,
superseded by Cat. V/139).
We observed a total of 55 of the 60 galaxies at the Westerbork
Synthesis Radio Telescope (WSRT) between 2006 and 2010, with a
velocity resolution of 8.6km/s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 60 Parameters of selected void galaxies taken from
the SDSS catalog
table3.dat 86 18 Companion galaxy parameters taken from the SDSS
catalog
table4.dat 76 78 HI properties of targeted void galaxies and
companions
table5.dat 29 60 Stellar and star formation parameters for void
galaxies
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
J/AJ/138/338 : Arecibo Legacy Fast ALFA Survey. IX. (Stierwalt+, 2009)
J/ApJS/183/214 : Arecibo Legacy Fast Alfa Survey (ALFALFA) VIII.
(Martin+, 2009)
J/AJ/136/713 : Arecibo legacy fast ALFA survey. VI. (Kent+, 2008)
J/AJ/135/588 : Arecibo legacy fast ALFA survey V. (Saintonge+, 2008)
J/AJ/133/2569 : Arecibo legacy fast ALFA survey III. (Giovanelli+, 2007)
J/A+A/370/765 : HI synthesis observations in UMa cluster (Verheijen+, 2001)
J/AJ/119/32 : Survey of galaxies within nearby voids. II (Grogin+, 2000)
J/AJ/118/2561 : Survey of galaxies within prominent nearby voids
(Grogin+, 1999)
J/A+A/319/67 : HI observations of dwarf galaxies in voids (Huchtmeier+ 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [VGS]
5- 6 I02 --- VGS [1/60] Void galaxy identifier
<[KPA2011] VGS NN> in Simbad
8- 26 A19 --- SDSS SDSS name (hhmmss.ss+ddmmss.s; J2000)
28- 29 I2 h RAh Hour of Right Ascension (J2000)
31- 32 I2 min RAm Minute of Right Ascension (J2000)
34- 37 F4.1 s RAs Second of Right Ascension (J2000)
39 A1 --- DE- Sign of the Declination
40- 41 I2 deg DEd Degree of Declination (J2000)
43- 44 I2 arcmin DEm Arcminute of Declination (J2000)
46- 47 I2 arcsec DEs Arcsecond of Declination (J2000)
49- 56 F8.6 --- z [0.01/0.03] Redshift
58- 62 F5.2 mag rmag [14.17/18.05] SDSS-DR7 magnitude in r filter
64- 67 F4.2 mag g-r Color index g-r (1)
69- 73 F5.1 mag RMag [-20.4/-16.2] Johnson-Cousins R-band absolute
magnitude (corrected for galactic extinction)
75- 79 F5.2 --- delta Filtered density contrast at Rf=1h-1Mpc
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Note (1): Drawn from the apparent model magnitudes as measured by the SDSS-DR7.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [VGS]
5- 6 I02 --- VGS [1/60] Void galaxy main identifier
7 A1 --- m_VGS [ab] Companion galaxy identifier
<[KPA2011] VGS NNa> in Simbad
9- 27 A19 --- SDSS SDSS name (hhmmss.ss+ddmmss.s; J2000)
29- 30 I2 h RAh Hour of Right Ascension (J2000)
32- 33 I2 min RAm Minute of Right Ascension (J2000)
35- 38 F4.1 s RAs Second of Right Ascension (J2000)
40 A1 --- DE- Sign of the Declination
41- 42 I2 deg DEd Degree of Declination (J2000)
44- 45 I2 arcmin DEm Arcminute of Declination (J2000)
47- 48 I2 arcsec DEs Arcsecond of Declination (J2000)
50- 54 F5.2 mag rmag [13.79/22.26] SDSS-DR7 magnitude in r filter
56- 60 F5.2 mag g-r Color index g-r (1)
62- 66 F5.1 mag RMag [-21/-11.4] Johnson-Cousins R-band absolute
magnitude (corrected for galactic extinction)
68- 71 F4.1 arcmin Dtheta Displacement from the beam center Δθ
between the target and companion galaxy
73- 75 I3 kpc Sep Projected sky separation Δd between the
target and companion galaxy
77- 80 I4 km/s DV Velocity separation Δv between the target
and companion galaxy
82- 86 F5.2 --- delta Filtered density contrast at Rf=1h-1Mpc
--------------------------------------------------------------------------------
Note (1): Drawn from the apparent model magnitudes as measured by the SDSS DR7.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [VGS]
5- 7 A3 --- VGS Void galaxy identifier
<[KPA2011] VGS NN> in Simbad or companion
galaxy identifier
<[KPA2011] VGS NNa> in Simbad
9- 12 F4.1 h Time Total integration time for each object
14 A1 --- l_MHI 3σ upper limit on MHI (non-detections)
16- 21 F6.2 10+8Msun MHI ? HI mass (see Section 3.1 for more details)
23- 27 F5.2 10+8Msun e_MHI ? Error in MHI
29- 32 I4 km/s Vsys ? Systemic HI velocity, using the optical
definition
34- 36 I3 Mpc Dist ? Distance to the target galaxy
38- 40 F3.1 kpc r90 Optical galaxy radius (containing 90% of the
light)
42 A1 --- l_rHI Upper limit on rHI (listed for poorly resolved
systems when possible)
44- 47 F4.1 kpc rHI ? HI radius
49- 51 I3 km/s W50 ? The 50% HI line widths, corrected for
instrumental broadening
53- 55 I3 km/s W20 ? The 20% HI line widths, corrected for
instrumental broadening
57- 58 I2 deg i ? Inclination angle, calculated such that
90° is edge-on (see Section 3.1 and
equation (1) for further details)
60- 62 I3 deg PA ? Position angle
64 A1 --- l_Mdyn Upper limit on Mdyn (listed for poorly
resolved systems when possible)
66- 70 F5.2 10+10Msun Mdyn ? Dynamical mass
72- 76 F5.2 Msun/Lsun MHI/L ? HI mass-to-light ratio
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [VGS]
5- 6 I02 --- VGS [1/60] Void galaxy identifier
<[KPA2011] VGS NN> in Simbad
8- 12 F5.1 10+8Msun Mass [0.2/213.4]? Stellar mass
14- 17 F4.2 Msun/yr SFR ? Star formation rate calculated from the
Hα emission-line feature
19- 23 F5.1 10-11yr-1 SFR/M* ? Hα star formation rate-to-stellar
mass ratio
25- 29 F5.1 10-11yr-1 SFR/MHI ? Hα star formation rate-to-HI mass ratio
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 06-Sep-2013