arXiv subjects

Shannon Osborne

Publications and source records attributed to Shannon Osborne.

2 recordsLinked to original sources

arXiv2024

CLusters in the Uv as EngineS (CLUES). II. Sub-kpc scale outflows driven by stellar feedback

We analyze the far-ultraviolet spectroscopy of 20 young and massive star clusters (YSCs) in 11 nearby star-forming galaxies. We probe the interstellar gas intervening along the line of sight, detecting several metal absorption lines of a wide range of ionization potentials, from 6.0 eV to 77.5 eV. Multiple-component Voigt fits to the absorption lines are used to study the kinematics of the gas. We find that nearly all targets in the sample feature gas outflowing from 30 up to 190 km per second, often both in the neutral and ionized phase. The outflow velocities correlate with the underlying stellar population properties directly linked to the feedback: the mass of the YSCs, the photon production rate and the instantaneous mechanical luminosity produced by stellar winds and SNe. We detect a neutral inflow in 4 targets, which we interpret as likely not associated with the star cluster but tracing larger scale gas kinematics. A comparison between the outflows energy and that produced by the associated young stellar populations suggests an average coupling efficiency of 10 per cent with a broad scatter. Our results extend the relation found in previous works between galactic outflows and the host galaxy star-formation rate to smaller scales, pointing towards the key role that clustered star formation and feedback play in regulating galaxy growth.

astro-ph.GA↗

arXiv2021

Mock Lightcones and Theory Friendly Catalogs for the CANDELS Survey

We present mock catalogs created to support the interpretation of the CANDELS survey. We extract halos along past lightcones from the Bolshoi Planck dissipationless N-body simulations and populate these halos with galaxies using two different independently developed semi-analytic models of galaxy formation and the empirical model UniverseMachine. Our mock catalogs have geometries that encompass the footprints of observations associated with the five CANDELS fields. In order to allow field-to-field variance to be explored, we have created eight realizations of each field. In this paper, we present comparisons with observable global galaxy properties, including counts in observed frame bands, luminosity functions, color-magnitude distributions and color-color distributions. We additionally present comparisons with physical galaxy parameters derived from SED fitting for the CANDELS observations, such as stellar masses and star formation rates. We find relatively good agreement between the model predictions and CANDELS observations for luminosity and stellar mass functions. We find poorer agreement for colors and star formation rate distributions. All of the mock lightcones as well as curated "theory friendly" versions of the observational CANDELS catalogs are made available through a web-based data hub.

astro-ph.GA↗