J/ApJ/708/1076 The WHIQII survey: compact blue galaxies (Tollerud+, 2010)
The WHIQII survey: metallicities and spectroscopic properties of luminous
compact blue galaxies.
Tollerud E.J., Barton E.J., van Zee L., Cooke J.
<Astrophys. J., 708, 1076-1091 (2010)>
=2010ApJ...708.1076T 2010ApJ...708.1076T
ADC_Keywords: Galaxies, spectra ; Abundances ; Redshifts ; Equivalent widths
Keywords: galaxies: abundances - galaxies: evolution - galaxies: high-redshift -
galaxies: starburst
Abstract:
As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey,
we present 123 spectra of faint emission-line galaxies, selected to
focus on intermediate redshift (0.4≲z≲0.8) galaxies with blue colors
that appear physically compact on the sky. The sample includes 15 true
Luminous Compact Blue Galaxies (LCBGs) and an additional 27 slightly
less extreme emission-line systems. These galaxies represent a highly
evolving class that may play an important role in the decline of star
formation since z∼1, but their exact nature and evolutionary pathways
remain a mystery. Here, we use emission lines to determine
metallicities and ionization parameters, constraining their intrinsic
properties and state of star formation. Some LCBG metallicities are
consistent with a "bursting dwarf" scenario, while a substantial
fraction of others are not, further confirming that LCBGs are a highly
heterogeneous population but are broadly consistent with the
intermediate redshift field. In agreement with previous studies, we
observe overall evolution in the luminosity-metallicity relation at
intermediate redshift. Our sample, and particularly the LCBGs,
occupies a region in the empirical R23-O32 plane that differs from
luminous local galaxies and is more consistent with dwarf irregulars
at the present epoch, suggesting that cosmic "downsizing" is
observable in even the most fundamental parameters that describe star
formation.
Description:
The WIYN High Image Quality Indiana-Irvine (WHIQII) survey aims to
address the question of the evolutionary paths of Luminous Compact
Blue Galaxies (LCBGs) by examining the metallicities of a large sample
derived using the strong [OII]3727, [OIII]5007, [OIII]4959, and
Hβ lines; primarily through the use of the
R23=([OII]3727+[OIII]4959,5007)/Hβ and
O32=[OIII]4959,5007/[OII]3727 indicators.
The BVRI imaging data for WHIQII was obtained from observations using
the Mini-Mosaic Imager (MiniMo) on the WIYN 3.5 m telescope over 25
nights from 2001 to 2004. Spectroscopic observations of 213 targets
were taken on the nights of 2005 February 11 and 2005 August 3-4 with
the dual-channel Low Resolution Imaging Spectrometer (LRIS) on the
Keck I telescope. Of the 213 spectra taken, 168 show strong enough
spectral features to be assigned a redshift, and 123 have unambiguous
emission lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 75 168 WIYN High Image Quality Indiana-Irvine (WHIQII):
photometric properties of objects with redshifts
table2.dat 63 168 WIYN High Image Quality Indiana-Irvine (WHIQII):
emission line ratios of objects with redshifts
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See also:
J/A+A/429/115 : JHK' photometry of Blue Compact Dwarf Galaxies (Noeske+, 2005)
J/A+A/434/887 : HI data of blue compact dwarf galaxies (Huchtmeier+, 2005)
J/A+A/425/417 : Star formation rates of blue compact galaxies (Kong+, 2004)
J/ApJS/147/29 : BRHalpha data of blue compact dwarf galaxies (Gil De Paz+,
2003)
J/A+A/396/503 : Spectra of blue compact galaxies (Kong+, 2002)
J/A+A/373/24 : Blue compact galaxies from SBS (Pustilnik+ 2001)
J/A+AS/137/419 : Dynamics of blue compact galaxies I. The data (Oestlin + 1999)
J/ApJ/511/639 : Abundances in blue compact galaxies (Izotov+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- WHIQII The WHIQII object number
7- 8 I2 h RAh Hour of Right Ascension (J2000)
10- 11 I2 min RAm Minute of Right Ascension (J2000)
13- 17 F5.2 s RAs Second of Right Ascension (J2000)
19 A1 --- DE- Sign of the Declination (J2000)
20- 21 I2 deg DEd Degree of Declination (J2000)
23- 24 I2 arcmin DEm Arcminute of Declination (J2000)
26- 30 F5.2 arcsec DEs Arcsecond of Declination (J2000)
32- 36 F5.1 mag BMag K-corrected B band absolute magnitude
38- 40 F3.1 mag e_BMag Uncertainty in BMag
42- 44 F3.1 mag B-V K-corrected (B-V) color index
46- 48 F3.1 mag e_B-V Uncertainty in B-V
50- 56 E7.2 Msun Mstar Stellar mass (1)
58- 61 F4.1 kpc rh Half-light radius
63- 68 F6.4 --- z Redshift from spectrum
70- 75 F6.4 --- e_z Uncertainty in z
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Note (1): As determined from the mean of the BVRI bands using the
Bell & de Jong (2001ApJ...550..212B 2001ApJ...550..212B) M/L relations.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- WHIQII The WHIQII object number
7- 11 F5.1 --- R23 ? The ([OII]3727+[OIII]4959,5007)/Hβ line
flux ratio
13- 17 F5.1 --- e_R23 ? Uncertainty in R23
19- 22 F4.1 --- O23 ? The [OIII]4959,5007/[OII]3727 line flux ratio
24- 26 F3.1 --- e_O23 ? Uncertainty in O23
28- 31 F4.1 [-] O/H ? Oxygen abundance; log(O/H)+12 (2)
33- 35 F3.1 [-] e_O/H ? Uncertainty in O/H
37- 40 F4.1 --- REW ? The ([OII]3727+[OIII]4959,5007)/Hβ
equivalent width ratio
42- 44 F3.1 --- e_REW ? Uncertainty in REW
46- 49 F4.1 --- OEW ? The [OIII]4959,5007/[OII]3727 equivalent
width ratio
51- 53 F3.1 --- e_OEW ? Uncertainty in OEW
55- 59 F5.1 [-] O/HEW ? Oxygen abundance from equivalent width;
log(O/H)+12 (2)
61- 63 F3.1 [-] e_O/HEW ? Uncertainty in O/HEW
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Note (2): From Kewley & Dopita (2002ApJS..142...35K 2002ApJS..142...35K) calibration.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 21-Feb-2012