English

A controlled study of cold dust content in galaxies from $z=0-2$

Astrophysics of Galaxies 2017-07-19 v2

Abstract

At z=13z=1-3, the formation of new stars is dominated by dusty galaxies whose far-IR emission indicates they contain colder dust than local galaxies of a similar luminosity. We explore the reasons for the evolving IR emission of similar galaxies over cosmic time using: 1) Local galaxies from GOALS (LIR=10111012L)(L_{\rm IR}=10^{11}-10^{12}\,L_\odot); 2) Galaxies at z0.10.5z\sim0.1-0.5 from the 5MUSES (LIR=10101012LL_{\rm IR}=10^{10}-10^{12}\,L_\odot); 3) IR luminous galaxies spanning z=0.53z=0.5-3 from GOODS and Spitzer xFLS (LIR>1011LL_{\rm IR}>10^{11}\,L_\odot). All samples have Spitzer mid-IR spectra, and Herschel and ground-based submillimeter imaging covering the full IR spectral energy distribution, allowing us to robustly measure LIRSFL_{\rm IR}^{\rm\scriptscriptstyle SF}, TdustT_{\rm dust}, and MdustM_{\rm dust} for every galaxy. Despite similar infrared luminosities, z>0.5z>0.5 dusty star forming galaxies have a factor of 5 higher dust masses and 5K colder temperatures. The increase in dust mass is linked with an increase in the gas fractions with redshift, and we do not observe a similar increase in stellar mass or star formation efficiency. L160SF/L70SFL_{160}^{\rm\scriptscriptstyle SF}/L_{70}^{\rm\scriptscriptstyle SF}, a proxy for TdustT_{\rm dust}, is strongly correlated with LIRSF/MdustL_{\rm IR}^{\rm\scriptscriptstyle SF}/M_{\rm dust} independently of redshift. We measure merger classification and galaxy size for a subsample, and there is no obvious correlation between these parameters and LIRSF/MdustL_{\rm IR}^{\rm \scriptscriptstyle SF}/M_{\rm dust} or L160SF/L70SFL_{160}^{\rm\scriptscriptstyle SF}/L_{70}^{\rm\scriptscriptstyle SF}. In dusty star forming galaxies, the change in LIRSF/MdustL_{\rm IR}^{\rm\scriptscriptstyle SF}/M_{\rm dust} can fully account for the observed colder dust temperatures, suggesting that any change in the spatial extent of the interstellar medium is a second order effect.

Keywords

Cite

@article{arxiv.1705.10846,
  title  = {A controlled study of cold dust content in galaxies from $z=0-2$},
  author = {Allison Kirkpatrick and Alexandra Pope and Anna Sajina and Daniel A. Dale and Tanio Diaz-Santos and Christopher C. Hayward and Yong Shi and Rachel S. Somerville and Sabrina Stierwalt and Lee Armus and Jeyhan S. Kartaltepe and Dale D. Kocevski and Daniel H. McIntosh and David B. Sanders and Lin Yan},
  journal= {arXiv preprint arXiv:1705.10846},
  year   = {2017}
}

Comments

Accepted for publication in ApJ. 21 pages, 11 figures