تقرير
Conditional Quenching: A detailed look at the SFR-Density Relation at z ~ 0.9 from ORELSE
| العنوان: | Conditional Quenching: A detailed look at the SFR-Density Relation at z ~ 0.9 from ORELSE |
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| المؤلفون: | Tomczak, Adam R., Lemaux, Brian C., Lubin, Lori M., Pelliccia, Debora, Shen, Lu, Gal, Roy R., Hung, Denise, Kocevski, Dale D., Fevre, Olivier Le, Mei, Simona, Rumbaugh, Nicholas, Squires, Gordon K., Wu, Po-Feng |
| سنة النشر: | 2018 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We present a study of the star-formation rate (SFR)-density relation at z ~ 0.9 using data drawn from the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. We find that SFR does depend on environment, but only for intermediate-stellar mass galaxies (10^10.1 < M* / Msol < 10^10.8) wherein the median SFR at the highest densities is 0.2-0.3 dex less than at lower densities at a significance of 4 sigma. Interestingly, mass does not drive SFR; galaxies that are more/less massive have SFRs that vary at most by ~20% across all environments showing no statistically significant dependence. We further split galaxies into low-redshift (z ~ 0.8) and high-redshift (z ~ 1.05) subsamples and observe nearly identical behavior. We devise a simple toy model to explore possible star-formation histories (SFHs) for galaxies evolving between these redshifts. The key assumption in this model is that star-forming galaxies in a given environment-stellar mass bin can be described as a superposition of two exponential timescales (SFR ~ e^(-t/tau)): a long-tau timescale with tau = 4 Gyr to simulate "normal" star-forming galaxies, and a short-tau timescale with free tau (between 0.3 < tau/Gyr < 2) to simulate galaxies on a quenching trajectory. In general we find that galaxies residing in low/high environmental densities are more heavily weighted to the long-tau/short-tau pathways respectively, which we argue is a signature of environmental quenching. Furthermore, for intermediate-stellar mass galaxies this transition begins at intermediate-density environments suggesting that environmental quenching is relevant in group-like halos and/or cluster infall regions. Comment: 17 pages, 7 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stz342 |
| URL الوصول: | http://arxiv.org/abs/1812.04633 |
| رقم الأكسشن: | edsarx.1812.04633 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stz342 |
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