Galaxies with Background QSOs: II. An Automated Search for Multiple Galaxy Emission Lines

Abstract

We have improved upon our previous search technique of systematically searching QSO spectra for narrow galactic H-alpha emission, which indicates a foreground galaxy within the Sloan Digital Sky Survey (SDSS) spectral fiber. We now search for H-alpha plus eight other galactic emission lines in the same manner. We have scanned the SDSS DR7 QSO catalog spectra searching for these emission lines. Here we present our sample which focuses on the redshift range z<0.401 where galactic H-alpha is detectable in the SDSS spectra. This has revealed 27 unique galaxies on top of QSOs (GOTOQs). We have deblended the QSOs from the respective galaxies and determined the photometric properties of these systems. We find upon deblending that most of the galaxies are primarily blue, late-type galaxies with colors in the range -0.71<(u-r)<2.07. We find a slight anti-correlation between reddening and impact parameter (E(B-V)_(g-i) vs. b). The galaxies have average star formation rates of 0.01 to 1 M_sun yr^-1, with an average of 0.6 M_sun} yr^-1. They range in z from 0 to 0.4 and in stellar luminosity from about 0.01 L* to 3.0 L*. They are foreground to QSOs of brightness 17.4 to 20.4 magnitudes (r-band) with impact parameters of 1 to 10 kpc. They represent a fair sample of typical galaxies for which it should be possible to determine accurately various quantities (e.g. abundances, dust extinction, Faraday rotation) using follow-up analysis of the background QSOs. [...]

9 pages, 8 figures

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Cited by in corpus (8)

• Multi-phase Circum-Galactic Medium probed with MUSE and ALMA
• HI 21-cm absorption survey of quasar-galaxy pairs: Distribution of cold gas around z<0.4 galaxies
• On the Kinematics of Cold, Metal-enriched Galactic Fountain Flows in Nearby Star-forming Galaxies
• Damped Ly-alpha Absorbers in Star-forming Galaxies at z < 0.15 Detected with the Hubble Space Telescope and Implications for Galaxy Evolution
• Galactic nebular lines in the fiber spectra of background QSOs: Reaching a hundred QSO-galaxy pairs with spectroscopic and photometric measurements
• HI 21-cm absorption from $z\sim 0.35$ strong MgII absorbers
• Nature of the Galaxies On Top Of Quasars producing MgII absorption
• HI 21-cm Absorption Associated with Foreground Galaxies on Top of Quasars