Examining the Tightness of the Red Sequence with the RESOLVE Survey
Abstract
Galaxies in groups and clusters are typically quenched of star formation and fall on a red sequence in color vs. stellar mass. The tightness of the red sequence of galaxies has astrophysical implications for galaxy evolution as well as practical implications for cluster finding algorithms and photo-z estimation. The red sequence has usually been described as tight, implying that these galaxies have similar star formation histories. For the REsolved Spectroscopy of a Local VolumE (RESOLVE) survey, a volume-limited survey of the nearby universe, we have previously used total, extrapolated galaxy magnitudes that do not suppress color gradients (unlike commonly used SDSS model magnitudes) to show that the red sequence is less tight than commonly reported, suggesting greater variety in star formation histories. To further investigate the tightness of the red sequence, we measure aperture colors using the zeroth order moment of the Fourier transform of RESOLVE galaxy images. This technique allows for both psf deconvolution and accurate centering across imaging bands. Measuring galaxy color for different galaxy radii, we first evaluate the choice of radial aperture that defines the tightest red sequence for application to cluster finding algorithms and photo-z estimation in large photometric surveys. We then analyze how environment, quantified by group mass, central/satellite designation, and group centric radius, affects the tightness of the red sequence and the corresponding degree of similarity of star formation histories in red sequence galaxies.
- Publication:
-
American Astronomical Society Meeting Abstracts #231
- Pub Date:
- January 2018
- Bibcode:
- 2018AAS...23135428E