Details

Autor(en) / Beteiligte

• Moorman, Crystal M.
• Vogeley, Michael S.
• Hoyle, Fiona
• Pan, Danny C.
• Haynes, Martha P.
• Giovanelli, Riccardo

Titel

THE OPTICAL LUMINOSITY FUNCTION OF VOID GALAXIES IN THE SDSS AND ALFALFA SURVEYS

Ist Teil von

• The Astrophysical journal, 2015-09, Vol.810 (2), p.1-11

Ort / Verlag

The American Astronomical Society

Erscheinungsjahr

2015

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT We measure the r-band galaxy luminosity function (LF) across environments over the redshift range 0 < z < 0.107 using the Sloan Digital Sky Survey (SDSS). We divide our sample into galaxies residing in large-scale voids (void galaxies) and those residing in denser regions (wall galaxies). The best-fitting Schechter parameters for void galaxies are log(Mpc−3), = −19.88 0.05, and = −1.20 0.02. For wall galaxies, the best-fitting parameters are log(Mpc−3), = −20.80 0.03, and = −1.16 0.01. We find a shift in the characteristic magnitude, , toward fainter magnitudes for void galaxies and find no significant difference between the faint-end slopes of the void and wall galaxy LFs. We investigate how low-surface-brightness selection effects can affect the galaxy LF. To attempt to examine a sample of galaxies that is relatively free of surface-brightness selection effects, we compute the optical galaxy LF of galaxies detected by the blind H i survey Arecibo Legacy Fast ALFA (ALFALFA). We find that the global LF of the ALFALFA sample is not well fit by a Schechter function because of the presence of a wide dip in the LF around Mr = −18 and an upturn at fainter magnitudes ( ∼ −1.47). We compare the H i selected r-band LF to various LFs of optically selected populations to determine where the H i selected optical LF obtains its shape. We find that sample selection plays a large role in determining the shape of the LF.