Ivana Barišić

Dust Properties of C ii Detected z ∼ 5.5 Galaxies: New HST/WFC3 Near-IR Observations

We examine the rest-frame ultraviolet (UV) properties of 10 [C II]λ158 μm-detected galaxies at z ~ 5.5 in COSMOS using new Hubble Space Telescope/Wide Field Camera 3 near-infrared imaging. Together with pre-existing 158 μm continuum and [C II] line measurements by the Atacama Large Millimeter/submillimeter Array, we study their dust attenuation properties on the IRX–β diagram, which connects the total dust emission (∝ IRX = log(L_(FIR)/L_(1600)) to the line-of-sight dust column (∝ β). We find systematically bluer UV continuum spectral slopes (β) compared to previous low-resolution ground-based measurements, which relieves some of the tension between models of dust attenuation and observations at high redshifts. While most of the galaxies are consistent with local starburst or Small Magellanic Cloud–like dust properties, we find galaxies with low IRX values and a large range in β that cannot be explained by models of a uniform dust distribution well mixed with stars. A stacking analysis of Keck/DEIMOS optical spectra indicates that these galaxies are metal-poor with young stellar populations that could significantly alter their spatial dust distribution.

Are High-redshift Galaxies Hot? Temperature of z > 5 Galaxies and Implications for Their Dust Properties

Recent studies have found a significant evolution and scatter in the relationship between the UV spectral slope (β_(UV)) and the infrared excess (IRX; L_(IR)/L_(UV)) at z > 4, suggesting different dust properties of these galaxies. The total far-infrared (FIR) luminosity is key for this analysis, but it is poorly constrained in normal (main-sequence) star-forming z > 5 galaxies, where often only one single FIR point is available. To better inform estimates of the FIR luminosity, we construct a sample of local galaxies and three low-redshift analogues of z > 5 systems. The trends in this sample suggest that normal high-redshift galaxies have a warmer infrared (IR) spectral energy distribution (SED) compared to average z 5. Despite this, some galaxies still fall below the minimum IRX−β relation derived with standard dust cloud models. We propose that radiation pressure in these highly star-forming galaxies causes a spatial offset between dust clouds and young star-forming regions within the lifetime of O/B stars. These offsets change the radiation balance and create viewing-angle effects that can change UV colors at fixed IRX. We provide a modified model that can explain the location of these galaxies on the IRX−β diagram.

Spatially Resolved Stellar Kinematics from LEGA-C: Increased Rotational Support in z ∼ 0.8 Quiscent Galaxies

We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at

Molecular Gas Contents and Scaling Relations for Massive, Passive Galaxies at Intermediate Redshifts from the LEGA-C Survey

z=0.6-1

Stellar Populations of over 1000 z ∼ 0.8 Galaxies from LEGA-C: Ages and Star Formation Histories from D n 4000 and Hδ

from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10-20kpc, or to an average of 2.7

Stellar Dynamics and Star Formation Histories of z ˜ 1 Radio-loud Galaxies

{rm R_e}

SFHs OF

. Combined with central stellar velocity dispersions (

Z\sim1

sigma_0

Galaxies in LEGA-C.

) this provides the first determination of the dynamical state of a sample selected by a lack of star formation activity at large lookback time. The most massive galaxies (

Fast and slow paths to quiescence : ages and sizes of 400 quiescent galaxies from the LEGA-C survey

M_{star}>2times10^{11},M_{odot}