TY - JOUR

T1 - The Geometry of Cold, Metal-enriched Gas around Galaxies at z similar to 1.2

AU - Lundgren, Britt F.

AU - Creech, Samantha

AU - Brammer, Gabriel

AU - Kirse, Nathan

AU - Peek, Matthew

AU - Wake, David

AU - York, Donald G.

AU - Chisholm, John

AU - Erb, Dawn K.

AU - Kulkarni, Varsha P.

AU - Straka, Lorrie

AU - Tremonti, Christy

AU - van Dokkum, Pieter

PY - 2021/5/24

Y1 - 2021/5/24

N2 - We present the first results from a Hubble Space Telescope Wide Field Camera 3/Infrared program, which obtained direct imaging and grism observations of galaxies near quasar sightlines with a high frequency of uncorrelated foreground Mg ii absorption. These highly efficient observations targeted 54 Mg ii absorbers along the line of sight to nine quasars at z ((qso) similar to 2. We find that 89% of the absorbers in the range of 0.64 < z < 1.6 can be spectroscopically matched to at least one galaxy with an impact parameter of less than 200 kpc and divide Delta z divide /(1 + z) < 0.006. We have estimated the star formation rates and measured structural parameters for all detected galaxies with impact parameters in the range of 7-200 kpc and star formation rates greater than 1.3 M (circle dot) yr(-1). We find that galaxies associated with Mg ii absorption have significantly higher mean star formation rates and marginally higher mean star formation rate surface densities compared to galaxies with no detected Mg ii. Nearly half of the Mg ii absorbers match more than one galaxy, and the mean equivalent width of the Mg ii absorption is found to be greater for groups, compared to isolated galaxies. Additionally, we observe a significant redshift evolution in the physical extent of Mg ii-absorbing gas around galaxies and evidence of an enhancement of Mg ii within 50 degrees of the minor axis, characteristic of outflows, which persists to 80 kpc around the galaxies, in agreement with recent predictions from simulations.

AB - We present the first results from a Hubble Space Telescope Wide Field Camera 3/Infrared program, which obtained direct imaging and grism observations of galaxies near quasar sightlines with a high frequency of uncorrelated foreground Mg ii absorption. These highly efficient observations targeted 54 Mg ii absorbers along the line of sight to nine quasars at z ((qso) similar to 2. We find that 89% of the absorbers in the range of 0.64 < z < 1.6 can be spectroscopically matched to at least one galaxy with an impact parameter of less than 200 kpc and divide Delta z divide /(1 + z) < 0.006. We have estimated the star formation rates and measured structural parameters for all detected galaxies with impact parameters in the range of 7-200 kpc and star formation rates greater than 1.3 M (circle dot) yr(-1). We find that galaxies associated with Mg ii absorption have significantly higher mean star formation rates and marginally higher mean star formation rate surface densities compared to galaxies with no detected Mg ii. Nearly half of the Mg ii absorbers match more than one galaxy, and the mean equivalent width of the Mg ii absorption is found to be greater for groups, compared to isolated galaxies. Additionally, we observe a significant redshift evolution in the physical extent of Mg ii-absorbing gas around galaxies and evidence of an enhancement of Mg ii within 50 degrees of the minor axis, characteristic of outflows, which persists to 80 kpc around the galaxies, in agreement with recent predictions from simulations.

KW - MG II ABSORPTION

KW - DIGITAL-SKY-SURVEY

KW - STAR-FORMING GALAXIES

KW - LUMINOUS RED GALAXIES

KW - HIGH-REDSHIFT SURVEY

KW - H-ALPHA EMITTERS

KW - CIRCUMGALACTIC MEDIUM

KW - GALACTIC OUTFLOWS

KW - HALO GAS

KW - PHYSICAL-PROPERTIES

U2 - 10.3847/1538-4357/abef6a

DO - 10.3847/1538-4357/abef6a

M3 - Journal article

VL - 913

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 50

ER -