We study the evolution of galactic conformity with redshift out to z = 2.5. Galactic conformity has been observed in the local universe as a correlation between the star formation activity of centrals and their satellites. The correlation is such that the quiescent fraction of satellites is higher around quiescent central galaxies than around star-forming […]
Tomczak et al. 2016 Summary: We explore star-formation histories (SFHs) of galaxies based on the evolution of the star-formation rate stellar mass relation (SFR-M*) at 0.5 < z < 4. We find that the SFR-M* relation is not consistent with a single power-law of the form SFR ~ M*a at any redshift; it has a power-law slope […]
Recently, with ZFOURGE we presented the discovery of a substantial population of massive quiescent galaxies at Z ~ 4, when the universe was only ~1.5 billion years old (http://zfourge.tamu.edu/publications/straatman-2014-summary/). At high redshift, quiescent galaxies are very different from the large elliptical early types that we observe in the universe today. In particular they have been […]
Allen et al. 2015 Summary: To investigate the differences in star-forming and quiescent galaxy properties as a function of environment at z=2.1, we create a mass-complete sample of 59 cluster galaxies (Spitler et al. 2012) and 478 field galaxies with log(M/M)>9 using photometric redshifts from the ZFOURGE survey. We compare the stellar mass-size relation of […]
Evolution of M* Galaxies over 11 billion years of cosmic history: Galaxies with stellar masses near M* contain the majority of stellar mass in the local universe, and are therefore of special interest in the study of galaxy evolution. The Milky Way (MW) and Andromeda (M31) both have present-day stellar masses near M*, at 5 […]
We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1< z < 3 using imaging from the FourStar Galaxy Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). The deep near-IR data select satellites down to M/Msol >10^9 at z < 3. Massive quiescent centrals (M/Msol […]
Our understanding of the redshift z>3 galaxy population relies largely on samples selected using the popular “dropout” technique, typically consisting of UV-bright galaxies with blue colors and prominent Lyman breaks. As it is currently unknown if these galaxies are representative of the massive galaxy population, we here use the FourStar Galaxy Evolution (ZFOURGE) Survey to […]
We report the likely identification of a substantial population of massive (M ~ 1011M☉) galaxies at redshift z ~ 4 with suppressed star formation rates, from the FourStar Galaxy Evolution Survey (ZFOURGE). We found a total of 15 quiescent galaxies in 3 fields: COSMOS, CDFS and UDS, by selecting on optical to near-IR colours. Learn […]
Using data from the FourStar Galaxy Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) we have measured the galaxy stellar mass function (SMF) to a substantial depth for a mass-selected sample of galaxies. We find evidence for a steepening slope at the low-mass end of the SMF as early as […]
We have discovered three robust candidate galaxies at redshift z~7 using deep near-infrared imaging from the ZFOURGE survey in the CANDELS/COSMOS field. The FourStar medium-band filters provide the equivalent of R∼10 spectroscopy, which cleanly distinguishes between z ∼ 7 galaxies and nearby brown dwarfs. FourStar medium-band filters provides a powerful tool to distinguish between compact […]