J/ApJ/793/92 Global properties of z=1∼2 GMASS galaxies (Tang+, 2014)
Probing outflows in z=1∼2 galaxies through Fe II/Fe II* multiplets.
Tang Y., Giavalisco M., Guo Y., Kurk J.
<Astrophys. J., 793, 92 (2014)>
=2014ApJ...793...92T 2014ApJ...793...92T (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Redshifts ; Interstellar medium
Keywords: galaxies: evolution - galaxies: ISM - ISM: lines and bands
Abstract:
We report on a study of the 2300-2600 Å Fe II/Fe II* multiplets in
the rest-UV spectra of star-forming galaxies at 1.0<z<2.6 as
probes of galactic-scale outflows. We extracted a mass-limited sample
of 97 galaxies at z∼1.0-2.6 from ultra-deep spectra obtained during
the GMASS spectroscopic survey in the GOODS South field with the Very
Large Telescope and FORS2. We obtain robust measures of the rest
equivalent width of the Fe II absorption lines down to a limit of
Wr>1.5 Å and of the Fe II* emission lines to Wr>0.5 Å.
Whenever we can measure the systemic redshift of the galaxies from the
[O II] emission line, we find that both the Fe II and Mg II absorption
lines are blueshifted, indicating that both species trace gaseous
outflows. We also find, however, that the Fe II gas has generally
lower outflow velocity relative to that of Mg II. We investigate the
variation of Fe II line profiles as a function of the radiative
transfer properties of the lines, and find that transitions with
higher oscillator strengths are more blueshifted in terms of both line
centroids and line wings. We discuss the possibility that Fe II lines
are suppressed by stellar absorptions. The lower velocities of the Fe
II lines relative to the Mg II doublet, as well as the absence of
spatially extended Fe II* emission in two-dimensional stacked spectra,
suggest that most clouds responsible for Fe II absorption lie close
(3∼4 kpc) to the disks of galaxies. We show that the Fe II/Fe II*
multiplets offer unique probes of the kinematic structure of galactic
outflows.
Description:
The sample of galaxies discussed here is extracted from the Galaxy
Mass Assembly Spectroscopic Survey (GMASS) described by Kurk et al.
(2013, J/A+A/549/A63), a program of spectroscopic observations of a
mid-IR magnitude-limited (mAB of IRAC 4.5<23.0) sample selected from
a 6.8'x6.8' field in the GOODS-S field (Giavalisco et al.
2004ApJ...600L..93G 2004ApJ...600L..93G). The main scientific motivation of GMASS was to
investigate the mass assembly and evolution of galaxies within the
redshift range 1.3<z<2.6. The spectra were obtained at the ESO Very
Large Telescope (VLT) with the FORS2 instrument using two grisms, a
blue one (300V) covering the spectral range 3600-6000 Å and a red
one (300I) for the range 6000-10000 Å. A slit width of 1 arcsec
yielded a spectral resolution of 500 km/s with both grisms. The
observation are very deep, with typical exposure times on target of
>10 hr for the blue masks and 20-30 hr for the red masks.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 97 Global Properties of Galaxies
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See also:
J/A+A/549/A63 : GMASS photometry (Kurk+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Group [AB] Galaxy's group (1)
3- 6 I4 --- GMASS GMASS identifier (NNNN)
8- 16 F9.6 deg RAdeg Right Ascension in decimal degrees (J2000)
18- 27 F10.6 deg DEdeg Declination in decimal degrees (J2000)
29- 38 F10.8 --- z Redshift
40- 46 F7.2 Msun/yr SFR Star formation rate
48- 55 F8.2 Msun/yr e_SFR Error in SFR
57- 61 F5.2 Msun Mass Stellar mass
63- 66 F4.2 Msun e_Mass Error in Mass
68- 72 F5.2 mag E(B-V) The (B-V) color excess
74- 77 F4.2 mag e_E(B-V) Error in E(B-V)
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Note (1): Group as follows:
A = Galaxy has [O II] 3727 detection and therefore accurate determination of
systemic redshift ;
B = Galaxy has redshift determined from cross-correlation.
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History:
From electronic version of the journal
(End) Prepared by Tiphaine Pouvreau [CDS] 19-Apr-2017