Related papers: The Cosmic Microwave Background and the Stellar In…
We measure new estimates for the galaxy stellar mass function and star formation rates for samples of galaxies at $z \sim 4,~5,~6~\&~7$ using data in the CANDELS GOODS South field. The deep near-infrared observations allow us to construct…
We compare predictions of a number of empirical models and numerical simulations of galaxy formation to the conditional stellar mass functions (CSMF)of galaxies in groups of different masses obtained recently by Lan et al. to test how well…
The characteristic mass M_c and slope Gamma of the IMF are reviewed for clusters, field regions, galaxies, and regions formed during cosmological times. Local star formation has a somewhat uniform M_c and Gamma. Statistical variations in…
A universal stellar initial mass function (IMF) should not be expected from theoretical models of star formation, but little conclusive observational evidence for a variable IMF has been uncovered. In this paper, a parameterization of the…
The formation of the first generations of stars at redshifts z > 15-20 signaled the transition from the simple initial state of the universe to one of increasing complexity. We here review recent progress in understanding the assembly…
We investigate the effects of the Cosmic Microwave Background (CMB) radiation field on the collapse of prestellar clouds. Using a semi-analytic model to follow the thermal evolution of clouds with varying initial metallicities and dust…
We present a new determination of the star-forming main sequence (MS), obtained through stacking 100k K-band-selected galaxies in the far-infrared (FIR) Herschel and James Clerk Maxwell Telescope (JCMT) imaging. By fitting the dust emission…
The conditions that affect the formation of stars in radiatively and mechanically active environments are quite different than the conditions that apply to our local interstellar neighborhood. In such galactic environments, a variety of…
The characteristic mass of stars at early times may have been higher than today owing to the cosmic microwave background (CMB). This study proposes that (1) the testable predictions of this "CMB-IMF" hypothesis are an increase in the…
Using the self-consistent modeling of the conditional stellar mass functions across cosmic time by Yang et al. (2012), we make model predictions for the star formation histories (SFHs) of {\it central} galaxies in halos of different masses.…
We investigate the contribution of star formation to the growth of stellar mass in galaxies over the redshift range 0.5 < z < 1.1 by studying the redshift evolution of the specific star formation rate (SSFR), defined as the star formation…
Observations of normal galactic star-forming regions suggest there is widespread near-uniformity in the initial stellar mass function (IMF) in spite of diverse physical conditions. Fluctuations may come largely from statistical effects and…
For a mass-selected sample of 66544 galaxies with photometric redshifts from the Cosmic Evolution Survey (COSMOS), we examine the evolution of star formation activity as a function of stellar mass in galaxies. We estimate the cosmic star…
We study the connection between the observed star formation rate-stellar mass (SFR-$M_*$) relation and the evolution of the stellar mass function (SMF) by means of a subhalo abundance matching technique coupled to merger trees extracted…
We present models of the cosmological star formation and metal production history of (proto-)galaxies with varying axis ratios. More massive and/or roughly spherical systems reach the threshold-metallicity for a transition to a multi-phase…
At high red-shifts, the distribution of angular separations between galaxies in clusters is in tension with the standard cosmological model. The JWST data at even higher red-shifts have exacerbated this tension. However, Zwick Tired Light…
Theoretical arguments and indirect observational evidence suggest that the stellar initial mass function (IMF) may evolve with time, such that it is more weighted toward high mass stars at higher redshift. Here we test this idea by…
One of the key mysteries of star formation is the origin of the stellar initial mass function (IMF). The IMF is observed to be nearly universal in the Milky Way and its satellites, and significant variations are only inferred in extreme…
In these lectures I review observations of star-forming molecular clouds in our Galaxy and nearby galaxies to develop a physical intuition for understanding star formation in the local and high-redshift Universe. A lot of this material is…
Cosmic rays (CRs) drive ionization and influence gas dynamics in molecular clouds (MCs), potentially impacting the resulting star formation outcomes. Although previous simulations of individual star formation have included methods for…