The Radio-to-Submm Spectral Index as a Redshift Indicator

Details The Radio-to-Submm Spectral Index as a Redshift Indicator The Radio-to-Submm Spectral Index as a Redshift Indicator

1998-12-14

arxiv.org/abs/astro-ph/9812251v4

Astrophys.J. 513 (1999) L13-L16

Astronomy and Astrophysics

Astrophysics

standard LATEX file plus 1 postscript figure. Added references and revised figure. second figure revision. Final Proof version

Scientific paper

10.1086/311909

We present models of the 1.4 GHz to 350 GHz spectral index, alpha(350/1.4), for starburst galaxies as a function of redshift. The models include a semi-analytic formulation, based on the well quantified radio-to-far infrared correlation for low redshift star forming galaxies, and an empirical formulation, based on the observed spectrum of the starburst galaxies M82 and Arp 220. We compare the models to the observed values of alpha(350/1.4) for starburst galaxies at low and high redshift. We find reasonable agreement between the models and the observations, and in particular, that an observed spectral index of alpha(350/1.4) > +0.5 indicates that the target source is likely to be at high redshift, z > 1. The evolution of alpha(350/1.4) with redshift is mainly due to the very steep rise in the Raleigh-Jeans portion of the thermal dust spectrum shifting into the 350 GHz band with increasing redshift. We also discuss situations where this relationship could be violated. We then apply our models to examine the putative identifications of submm sources in the Hubble Deep Field, and conclude that the submm sources reported by Hughes et al. are likely to be at high redshifts, z > 1.5.

Affiliated with

Also associated with

No associations

Rating

The Radio-to-Submm Spectral Index as a Redshift Indicator does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Radio-to-Submm Spectral Index as a Redshift Indicator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Radio-to-Submm Spectral Index as a Redshift Indicator will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-317046