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A Statistical Study of Mg II Absorption-Selected Galaxies in the SDSS at 0.3<z<0.5. Brittney Curtis Astronomy 3350 Professor Donald Terndrup Ohio State University. (Credit: NASA; ESA; A. Feild , STScI ). We can use quasars to learn about the circumgalactic medium.
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A Statistical Study of Mg II Absorption-Selected Galaxies in the SDSS at 0.3<z<0.5 Brittney Curtis Astronomy 3350 Professor Donald Terndrup Ohio State University
(Credit: NASA; ESA; A. Feild, STScI) Brittney Curtis
We can use quasars to learn about the circumgalactic medium. Quasar light passes by galaxies on its way to us. The metal-enriched gas associated with the galaxy absorbs some of the quasar light. We can use the absorption lines in the quasar spectrum to determine the characteristics of the gas and associated galaxies. (Credit: NASA; ESA; A. Feild, STScI) Brittney Curtis
SDSS DR7 Sky Coverage Brittney Curtis
How can we tell which galaxy is the MgII Absorber? • SDSS only has photometric data for the galaxies in this redshift range • We can’t tell which galaxy is the MgII absorber because their redshifts are not well-constrained • Instead, we probe the environments of the MgII absorbers MgII Absorber Environments 1400 Quasars with MgII absorption at 0.3 < z < 0.5 3200 total Galaxies within 1 arcmin of the sightlines Background Sample 1400 Quasars without absorption at 0.3 < z < 0.5 2500 total Galaxies within 1 arcmin of the sightlines Brittney Curtis
Positive detection of excess galaxies around the lines of sight to quasars that are being absorbed. Brittney Curtis
Extinction-Corrected and K-Corrected Luminosity Distribution Brittney Curtis
Summary • We detect more galaxies around the sightlines to quasars that are being absorbed than around empty lines of sight. • The excess galaxies tend to be bright compared to a background sample. • Determining the properties of these galaxies will help us learn how having a metal-enriched halo affects the evolution of galaxies. Brittney Curtis