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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Spectroscopic study of star-forming galaxies in filaments and the field at $z\sim$0.5
T2 - evidence for environmental dependence of electron density
AU - Darvish, Behnam
AU - Mobasher, Bahram
AU - Sobral, David
AU - Hemmati, Shoubaneh
AU - Nayyeri, Hooshang
AU - Shivaei, Irene
N1 - main figs. 1,7,8,9,10 and 13.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - We study the physical properties of a spectroscopic sample of 28 star-forming galaxies in a large filamentary structure in the COSMOS field at $z\sim$0.53, with spectroscopic data taken with the Keck/DEIMOS spectrograph, and compare them with a control sample of 30 field galaxies. We spectroscopically confirm the presence of a large galaxy filament ($\sim$ 8 Mpc), along which five confirmed X-ray groups exist. We show that within the uncertainties, the ionization parameter, equivalent width (EW), EW versus specific star-formation rate (sSFR) relation, EW versus stellar mass relation, line-of-sight velocity dispersion, dynamical mass, and stellar-to-dynamical mass ratio are similar for filament and field star-forming galaxies. However, we show that on average, filament star-forming galaxies are more metal-enriched ($\sim$ 0.1$-$0.15 dex), possibly due to the inflow of the already enriched intrafilamentary gas into filament galaxies. Moreover, we show that electron densities are significantly lower (a factor of $\sim$17) in filament star-forming systems compared to those in the field, possibly because of a longer star-formation timescale for filament star-forming galaxies. Our results highlight the potential pre-processing role of galaxy filaments and intermediate-density environments on the evolution of galaxies, which has been highly underestimated.
AB - We study the physical properties of a spectroscopic sample of 28 star-forming galaxies in a large filamentary structure in the COSMOS field at $z\sim$0.53, with spectroscopic data taken with the Keck/DEIMOS spectrograph, and compare them with a control sample of 30 field galaxies. We spectroscopically confirm the presence of a large galaxy filament ($\sim$ 8 Mpc), along which five confirmed X-ray groups exist. We show that within the uncertainties, the ionization parameter, equivalent width (EW), EW versus specific star-formation rate (sSFR) relation, EW versus stellar mass relation, line-of-sight velocity dispersion, dynamical mass, and stellar-to-dynamical mass ratio are similar for filament and field star-forming galaxies. However, we show that on average, filament star-forming galaxies are more metal-enriched ($\sim$ 0.1$-$0.15 dex), possibly due to the inflow of the already enriched intrafilamentary gas into filament galaxies. Moreover, we show that electron densities are significantly lower (a factor of $\sim$17) in filament star-forming systems compared to those in the field, possibly because of a longer star-formation timescale for filament star-forming galaxies. Our results highlight the potential pre-processing role of galaxy filaments and intermediate-density environments on the evolution of galaxies, which has been highly underestimated.
KW - galaxies: abundances
KW - galaxies: evolution
KW - galaxies: fundamental parameters
KW - galaxies: starburst
KW - large-scale structure of universe
KW - MASS-METALLICITY RELATION
KW - DIGITAL SKY SURVEY
KW - EMISSION-LINE GALAXIES
KW - TULLY-FISHER RELATION
KW - LARGE-SCALE STRUCTURE
KW - NEAR-INFRARED SPECTROSCOPY
KW - HOT INTERGALACTIC MEDIUM
KW - RAY LUMINOUS CLUSTERS
KW - VIRGO SPIRAL GALAXIES
KW - II EMITTING GALAXIES
U2 - 10.1088/0004-637X/814/2/84
DO - 10.1088/0004-637X/814/2/84
M3 - Journal article
VL - 814
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 84
ER -