VizieR Online Data Catalog: Census of circumgalactic MgII at redshift z=<0.5 (Huang+, 2021)
Abstract
To investigate the correlation between galaxy properties and MgII absorbing gas at small projected distances, we need to obtain spectroscopic data of both galaxies and QSO absorbers along common sightlines. We utilize the MagE (Marshall et al. 2008SPIE.7014E..54M) on the Magellan Clay Telescope to conduct a survey of MgII absorbers at z<0.4. The high UV throughput of MagE from λ=3100Å enables searches of MgII absorbers at redshift as low as 0.11. Briefly, the QSO and galaxy pairs are selected from the SDSS DR6 catalogues (Adelman-McCarthy et al. 2008ApJS..175..297A, Cat. II/282). To maximize the efficiency of searching MgII absorbers, we consider galaxies at photometric redshifts of zphot=<0.4 that have background QSOs in close projected distance d<Rgas. Rgas=130kpc is the distinct boundary found by Chen & Tinker (2008ApJ...687..745C) using 23 galaxy-QSO pairs at intermediate redshifts of z~0.4, beyond which no MgII absorbers are found.
To establish a physical connection between galaxies and MgII absorbing systems along nearby QSO sightlines, it is essential to have medium to high resolution spectra to obtain precise and accurate redshift measurements of these galaxies. We have obtained optical spectra of 218 galaxies that satisfy the criteria described above using the MagE Spectrograph (Marshall et al. 2008SPIE.7014E..54M) at the Las Campanas Observatory and the Double Imaging Spectrograph (DIS; Lupton 1995) on the 3.5-m telescope at the Apache Point Observatory. Details about the spectroscopic observation setups and data reduction are presented in Chen et al. (2010ApJ...714.1521C, Cat. J/ApJ/714/1521). (4 data files).- Publication:
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VizieR Online Data Catalog
- Pub Date:
- October 2023
- Bibcode:
- 2023yCat..75024743H
- Keywords:
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- Galaxies;
- QSOs;
- Redshifts;
- Equivalent widths;
- Spectroscopy;
- Ultraviolet;
- Optical