J/A+A/561/A89 Optical spectroscopy of 24 Ly-alpha emitters (Atek+, 2014)
Influence of physical galaxy properties on Lyman-alpha escape in
star-forming galaxies.
Atek H., Kunth D., Schaerer D., Mas-Hesse J.M., Hayes M., Ostlin G.,
Kneib J.P.
<Astron. Astrophys. 561, A89 (2014)>
=2014A&A...561A..89A 2014A&A...561A..89A
ADC_Keywords: Galaxies, spectra ; Ultraviolet
Keywords: galaxies: starburst - ultraviolet: galaxies - galaxies: star formation
Abstract:
Among the different observational techniques used to select
high-redshift galaxies, the hydrogen recombination line Lyman-alpha
(Lyα) is of particular interest because it gives access to the
measurement of cosmological quantities such as the star formation rate
(SFR) of distant galaxy populations. However, interpreting this line
and calibrating such observables are still subject to serious
uncertainties.
In this context, it important to understand the mechanisms responsible
for the attenuation of Lyα emission, and under what conditions
the Lyα emission line can be used as a reliable star formation
diagnostic tool.
We used a sample of 24 Lyα emitters at z∼0.3 with an optical
spectroscopic follow-up to calculate the Lyα escape fraction and
its dependence upon different physical properties. We also examined
the reliability of Lyα as a SFR indicator. We combined these
observations with a compilation of Lyα emitters selected at
z=0-0.3 from the literature to assemble a larger sample.
Description:
We obtained optical spectra for 24 galaxies in the Chandra Deep Field
South (CDFS) and ELAIS-S1, which have been first presented in Atek et
al. (2009A&A...506L...1A 2009A&A...506L...1A).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 116 24 Target information and emission line measurements
for the GALEX sample
phot/* . 16 Individual photometric files
spect/* . 23 Individual spectroscopic files
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See also:
J/ApJ/680/1072 : Lyα-emitting galaxies at 0.2<z<0.35 (Deharveng+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Object name (1)
15- 21 F7.4 deg RAdeg Right ascension (J2000)
23- 30 F8.4 deg DEdeg Declination (J2000)
32- 36 F5.3 --- z Redshift (2)
38- 42 F5.2 aW/m2 Lya Lymanα line flux (10-15erg/cm2/s) (3)
44- 47 F4.2 aW/m2 [OII] ?=- [OII]3727 line flux (10-15erg/cm2/s)
49- 52 F4.2 aW/m2 e_[OII] ? rms uncertainty on [OII]
54- 57 F4.2 aW/m2 Hb Hβ line flux (10-15erg/cm2/s)
59- 62 F4.2 aW/m2 e_Hb rms uncertainty on Hb
64- 67 F4.2 aW/m2 [OIII] ?=- [OIII]5007 line flux (10-15erg/cm2/s)
69- 72 F4.2 aW/m2 e_[OIII] ?=- rms uncertainty on [OIII]
74- 77 F4.2 aW/m2 Ha Hα line flux (10-15erg/cm2/s)
79- 82 F4.2 aW/m2 e_Ha rms uncertainty on Ha
84- 87 F4.2 aW/m2 [NII] ?=- [NII]6583 line flux (10-15erg/cm2/s)
89- 92 F4.2 aW/m2 e_[NII] ? rms uncertainty on [NII]
94-104 A11 --- spFile Name of the file with spectrum in
subdirectory spect
106-116 A11 --- phFile Name of the file with photometry in
subdirectory phot
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Note (1): Target names follow Deharveng et al. (2008, Cat. J/ApJ/680/1072)
nomenclature:
CDFS-NNNN = <[DSB2008] NNNNN> in Simbad,
ELAISS1-NNNNN = <[DSB2008] NNNNN> in Simbad
Note (2): The redshift is based on the mean position of optical lines with at
least 3σ significance.
Note (3): Measured in the GALEX spectra by Deharveng et al.
(2008, Cat. J/ApJ/680/1072).
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Byte-by-byte Description of file: phot/* spect/*
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Bytes Format Units Label Explanations
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8- 16 F9.4 0.1nm lambda [4227/9319] Observed wavelength
18- 29 E12.6 cW/m2/nm Fluxw 1D spectrum with weighted extraction
(erg/cm2/s/Å)
31- 42 E12.6 cW/m2/nm Flux 1D spectrum (no weights) (erg/cm2/s/Å)
44- 55 E12.6 cW/m2/nm Fsky Sky spectrum (erg/cm2/s/Å)
58- 68 E11.6 cW/m2/nm e_Flux Error Spectrum (erg/cm2/s/Å)
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Acknowledgements:
Hakim Atek, hakim.atek(at)epfl.ch
(End) Patricia Vannier [CDS] 30-Aug-2013