Open AccessA cosmic relation between extinction and star formation
Author(s) -
Zoran Oren,
Barkana Rennan,
Thompson Rodger I.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2006.00154.x
Subject(s) - physics , astrophysics , star formation , extinction (optical mineralogy) , redshift , galaxy , metallicity , astronomy , cosmic cancer database , optics
We study the relation between the star formation intensity of galaxies and the extinction by dust of their emitted light. We employ a detailed statistical analysis of Hubble Deep Field North data to show a clear positive correlation between the extinction and star formation intensity at all epochs from redshift 0.4 to 6.5. The extinction evidently increases with time for a given star formation intensity, consistent with the expected increase in the metallicity with time. Our observational results are well fitted at all epochs by a double‐power‐law model with a fixed shape that simply shifts with redshift. The correlation between the extinction and the star formation intensity can be interpreted by combining two other trends: the correlation between the star formation rate and the gas content of galaxies, and the evolution of the dust‐to‐gas ratio in galaxies. If we assume that Kennicutt's observed relation for the former is valid at each redshift, then our findings imply an interesting variation in the dust‐to‐gas ratio in galaxies within each epoch and with time, and suggest new ways to investigate the cosmic evolution of this quantity.