Sloan数字银河坐标系中星形成速率指示器
摘要
Sloan数字银河坐标系（SDSS）首次数据发布提供了106000个主星系样本中具有测量光谱的独立星系。从这些具有FIRST 1.4 GHz luminosities的3079个星系中，通过使用光学光谱诊断方法识别出星形成（SF）星系样本。以1.4 GHz luminosities作为不受遮蔽效应影响的参考星形成速率（SFR）估计器，比较了来自SDSS测量的Halpha、[OII]和u-band光度，以及来自IRAS的远红外光度所衍生的SFR。 established that straightforward corrections for obscuration and aperture effects reliably bring the SDSS emission line and photometric SFR estimates into agreement with those at 1.4 GHz, although considerable scatter (~60%) remains in the relations. It thus appears feasible to perform detailed investigations of star formation for large and varied samples of SF galaxies through the available spectroscopic and photometric measurements from the SDSS. We provide herein exact prescriptions for determining the SFR for SDSS galaxies. The expected strong correlation between [OII] and Halpha line fluxes for SF galaxies is seen, but with a median line flux ratio F_[OII]/F_Halpha=0.23, about a factor of two smaller than that found in the sample of Kennicutt (1992). This correlation, used in deriving the [OII] SFRs, is consistent with the luminosity-dependent relation found by Jansen et al. (2001). The median obscuration for the SDSS SF systems is found to be A_Halpha=1.2 mag, while for the radio detected sample the median obscuration is notably higher, 1.6 mag, and with a broader distribution.
关键词
引用
@article{arxiv.astro-ph/0306621,
title = {Star formation rate indicators in the Sloan Digital Sky Survey},
author = {A. M. Hopkins and C. J. Miller and R. C. Nichol and A. J. Connolly and M. Bernardi and P. L. Gomez and T. Goto and C. A. Tremonti and J. Brinkmann and Z. Ivezic and D. Q. Lamb},
journal= {arXiv preprint arXiv:astro-ph/0306621},
year = {2009}
}
备注
Accepted for publication in ApJ, 40 pages, 26 figures