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تسجيل مستخدم جديدWitnessing the active assembly phase of massive galaxies since z = 1
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We present an analysis of ~60 000 massive (stellar mass M_star > 10^{11} M_sun) galaxies out to z = 1 drawn from 55.2 deg2 of the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) and the Sloan Digital Sky Survey (SDSS) II Supernova Survey. This is by far the largest survey of massive galaxies with robust mass estimates, based on infrared (K-band) photometry, reaching to the Universe at about half its present age. We find that the most massive (M_star > 10^{11.5} M_sun) galaxies have experienced rapid growth in number since z = 1, while the number densities of the less massive systems show rather mild evolution. Such a hierarchical trend of evolution is consistent with the predictions of the current semi-analytic galaxy formation model based on Lambda CDM theory. While the majority of massive galaxies are red-sequence populations, we find that a considerable fraction of galaxies are blue star-forming galaxies. The blue fraction is smaller in more massive systems and decreases toward the local Universe, leaving the red, most massive galaxies at low redshifts, which would support the idea of active bottom-up formation of these populations during 0 < z < 1.
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We present a clustering analysis of ~60,000 massive (stellar mass Mstar > 10^{11} Msun) galaxies out to z = 1 drawn from 55.2 deg2 of the UKIRT Infrared Deep Sky Survey (UKIDSS) and the Sloan Digital Sky Survey (SDSS) II Supernova Survey. Strong clus
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Using deep infrared observations conducted with the MOIRCS on the Subaru Telescope in GOODS-N combined with public surveys in GOODS-S, we investigate the dependence on stellar mass, M_*, and galaxy type of the close pair fraction (5 kpc < r < 20 kpc)
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Using new spectroscopic observations obtained as part of the VIMOS Ultra-Deep Survey (VUDS), we perform a systematic search for overdense environments in the early universe ($z>2$) and report here on the discovery of Cl J0227-0421, a massive protoclu
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