تقرير
Constraints on the merging channel of massive galaxies since z~1
| العنوان: | Constraints on the merging channel of massive galaxies since z~1 |
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| المؤلفون: | Ferreras, I., Trujillo, I., Mármol-Queraltó, E., Pérez-González, P., Cava, A., Barro, G., Cenarro, J., Hernán-Caballero, A., Cardiel, N., Rodríguez-Zaurín, J., Cebrián, M. |
| سنة النشر: | 2013 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Cosmology and Nongalactic Astrophysics |
| الوصف: | (Abridged) We probe the merging channel of massive galaxies over the z=0.3-1.3 redshift window by studying close pairs in a sample of 238 galaxies with stellar mass >1E11Msun, from the deep (m<26.5AB, 3 sigma) SHARDS survey. SHARDS provides medium band photometry equivalent to low-resolution optical spectra (R~50), allowing us to obtain extremely accurate photometric redshifts (|Dz|/(1+z)~0.55%) and to improve the constraints on the age distribution of the stellar populations. A strong correlation is found between the age difference of central and satellite galaxy and stellar mass ratio, from negligible age differences in major mergers to age differences ~4 Gyr for 1:100 minor mergers. However, this correlation is simply a reflection of the mass-age trend in the general population. The dominant contributor to the growth of massive galaxies corresponds to mass ratios mu=Msat/Mcen>0.3, followed by a decrease in the fractional mass growth rate linearly proportional to log mu, at least down to mu~0.01, suggesting a decreasing role of mergers involving low-mass satellites, especially if dynamical friction timescales are taken into account. A simple model results in an upper limit for the average mass growth rate of massive galaxies of DM/M/Dt~ 0.08+-0.02 per Gyr, over the z<1 range, with a ~70% fractional contribution from (major) mergers with mu>0.3. The majority of the stellar mass contributed by mergers does not introduce significantly younger populations, in agreement with the small radial age gradients observed in present-day early-type galaxies. Comment: MNRAS in press, 14 pages, 10+1 figures, 3 tables |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stu1425 |
| URL الوصول: | http://arxiv.org/abs/1312.5317 |
| رقم الأكسشن: | edsarx.1312.5317 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stu1425 |
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