تقرير
Exploring the links between star formation and minor companions around isolated galaxies
| العنوان: | Exploring the links between star formation and minor companions around isolated galaxies |
|---|---|
| المؤلفون: | Edman, Jacob P., Barton, Elizabeth J., Bullock, James S. |
| سنة النشر: | 2011 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics |
| الوصف: | Previous studies have shown that galaxies with minor companions exhibit an elevated star formation rate. We reverse this inquiry, constructing a volume-limited sample of \simL\star (Mr \leq -19.5 + 5 log h) galaxies from the Sloan Digital Sky Survey that are isolated with respect to other luminous galaxies. Cosmological simulations suggest that 99.8% of these galaxies are alone in their dark matter haloes with respect to other luminous galaxies. We search the area around these galaxies for photometric companions. Matching strongly star forming (EW(H{\alpha})\geq 35 \AA) and quiescent (EW(H{\alpha})< 35 \AA) samples for stellar mass and redshift using a Monte Carlo resampling technique, we demonstrate that rapidly star-forming galaxies are more likely to have photometric companions than other galaxies. The effect is relatively small; about 11% of quiescent, isolated galaxies have minor photometric companions at radii \leq 60 kpc h$^{-1}$ kpc while about 16% of strongly star-forming ones do. Though small, the cumulative difference in satellite counts between strongly star-forming and quiescent galaxies is highly statistically significant (PKS = 1.350 \times10$^{-3}$) out to to radii of \sim 100 h$^{-1}$ kpc. We discuss explanations for this excess, including the possibility that \sim 5% of strongly star-forming galaxies have star formation that is causally related to the presence of a minor companion. Comment: 7 pages, 6 figures, submitted to MNRAS |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1111/j.1365-2966.2012.21335.x |
| URL الوصول: | http://arxiv.org/abs/1110.2152 |
| رقم الأكسشن: | edsarx.1110.2152 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1111/j.1365-2966.2012.21335.x |
|---|