Evolution of Intrinsic Scatter in the SFR-Stellar Mass Correlation at 0.5 < z < 3
Abstract
We present estimates of intrinsic scatter in the star formation rate (SFR)-stellar mass (M*) correlation in the redshift range 0.5< z< 3.0 and in the mass range {10}7< {M}*< {10}11M⊙. We utilize photometry in the Hubble Ultradeep Field (HUDF12) and Ultraviolet Ultra Deep Field (UVUDF) campaigns and CANDELS/GOODS-S and estimate SFR, M* from broadband spectral energy distributions and the best-available redshifts. The maximum depth of the UDF photometry (F160W 29.9 AB, 5σ depth) probes the SFR-M* correlation down to {M}*\quad ∼ 107M⊙, a factor of 10-100× lower in M* than previous studies, and comparable to dwarf galaxies in the local universe. We find the slope of the SFR-M* relationship to be near unity at all redshifts and the normalization to decrease with cosmic time. We find a moderate increase in intrinsic scatter with cosmic time from 0.2 to 0.4 dex across the epoch of peak cosmic star formation. None of our redshift bins show a statistically significant increase in intrinsic scatter at low mass. However, it remains possible that intrinsic scatter increases at low mass on timescales shorter than ∼100 Myr. Our results are consistent with a picture of gradual and self-similar assembly of galaxies across more than three orders of magnitude in stellar mass from as low as 107M⊙.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2016
- DOI:
- 10.3847/2041-8205/820/1/L1
- arXiv:
- arXiv:1602.03909
- Bibcode:
- 2016ApJ...820L...1K
- Keywords:
-
- galaxies: dwarf;
- galaxies: evolution;
- galaxies: formation;
- galaxies: high-redshift;
- galaxies: statistics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 8 pages, 3 figures, 2 tables. Revised and resubmitted to ApJ Letters. Comments welcome