Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-41826

Kranz, W D; Tran, K V H; Giordano, L; Saintonge, A (2010). The homogeneous properties of Hα-selected galaxies at (0.05 < z < 0.15). Astronomical Journal, 140(2):561-576.

[img]
Preview
Accepted Version
PDF
779kB

View at publisher

Abstract

We show that the Hα line (6563 Å) alone is an extremely effective criterion for identifying galaxies that are uniform in color (red), luminosity-weighted age (old), and morphology (bulge-dominated). By combining the Sloan Digital Sky Survey (Data Release 6) with the New York University Value-Added Galaxy Catalog, we have photometric and spectroscopic indices for over 180,000 galaxies at (0.05 < z < 0.15). We separate the galaxies into three samples: (1) galaxies with Hα equivalent width, EW <0 Å (i.e., no emission), (2) galaxies with morphological Sérsic index n > 2 (bulge-dominated), and (3) galaxies with n > 2 that are also red in (g' - r'). We find that the Hα-selected galaxies consistently have the smallest color scatter: for example, at z ~ 0.05 the intrinsic scatter in apparent (g' - r') for the Hα sample is only 0.0287 ± 0.0007 compared to 0.0682 ± 0.0014 for the Sérsic sample. Applying a color cut to the n > 2 sample does decrease the color scatter to 0.0313 ± 0.0007, but a measurable fraction of star-forming and/or active galactic nucleus galaxies (up to 9.3%) remain. All of the EW(Hα) <0 Å galaxies have n > 2, i.e., they are bulge-dominated systems. The spectra for the three samples confirm that the Hα-selected galaxies have the highest D4000 values and are, on average, nearly twice as old as the Sérsic-selected samples. With the advent of multi-object near-infrared spectrographs, Hα alone can be used to reliably isolate truly quiescent galaxies dominated by evolved stellar populations at any epoch from z ~ 0 up to z ~ 2.

Citations

Altmetrics

Downloads

30 downloads since deposited on 03 Mar 2011
3 downloads since 12 months

Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute for Computational Science
DDC:530 Physics
Language:English
Date:August 2010
Deposited On:03 Mar 2011 15:35
Last Modified:08 Dec 2013 03:25
Publisher:Institute of Physics Publishing
ISSN:0004-6256
Publisher DOI:10.1088/0004-6256/140/2/561
Related URLs:http://arxiv.org/abs/1006.2831

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page