Physical Sciences and Mathematics Commons^™

Stellar Metallicity Gradients In Sdss Galaxies, Benjamin Roig, Michael R. Blanton, Renbin Yan

Physics and Astronomy Faculty Publications

We infer stellar metallicity and abundance ratio gradients for a sample of red galaxies in the Sloan Digital Sky Survey (SDSS) Main galaxy sample. Because this sample does not have multiple spectra at various radii in a single galaxy, we measure these gradients statistically. We separate galaxies into stellar mass bins, stack their spectra in redshift bins, and calculate the measured absorption-line indices in projected annuli by differencing spectra in neighboring redshift bins. After determining the line indices, we use stellar population modeling from the EZ_Ages software to calculate ages, metallicities, and abundance ratios within each annulus. Our data cover …

Metal-Poor, Strongly Star-Forming Galaxies In The Deep2 Survey: The Relationship Between Stellar Mass, Temperature-Based Metallicity, And Star Formation Rate, Chun Ly, Jane R. Rigby, Michael Cooper, Renbin Yan

Physics and Astronomy Faculty Publications

We report on the discovery of 28 z ≈ 0.8 metal-poor galaxies in DEEP2.

For the remainder of the abstract, please download this article or visit https://doi.org/10.1088/0004-637X/805/1/45.

Bootstrapping Dielectronic Recombination From Second-Row Elements And The Orion Nebula, N. R. Badnell, Gary J. Ferland, T. W. Gorczyca, D. Nikolić, Gururaj Anil Wagle

Physics and Astronomy Faculty Publications

Dielectronic recombination (DR) is the dominant recombination process for most heavy elements in photoionized clouds. Accurate DR rates for a species can be predicted when the positions of autoionizing states are known. Unfortunately such data are not available for most third- and higher-row elements. This introduces an uncertainty that is especially acute for photoionized clouds, where the low temperatures mean that DR occurs energetically through very low-lying autoionizing states. This paper discusses S²⁺ → S⁺ DR, the process that is largely responsible for establishing the [S iii]/[S ii] ratio in nebulae. We derive an empirical rate coefficient using …

Atomic Data For Zn Ɪɪ: Improving Spectral Diagnostics Of Chemical Evolution In High-Redshift Galaxies, Romas Kisielius, Varsha P. Kulkarni, Gary J. Ferland, Pavel Bogdanovich, Debopam Som, Matt L. Lykins

Physics and Astronomy Faculty Publications

Damped Lyα (DLA) and sub-DLA absorbers in quasar spectra provide the most sensitive tools for measuring the element abundances of distant galaxies. The estimation of abundances from absorption lines depends sensitively on the accuracy of the atomic data used. We have started a project to produce new atomic spectroscopic parameters for optical and UV spectral lines using state-of-the-art computer codes employing a very broad configuration interaction (CI) basis. Here we report our results for Zn ii, an ion used widely in studies of the interstellar medium (ISM) as well as DLAs and sub-DLAs. We report new calculations of many …

P-Manga Galaxies: Emission-Lines Properties – Gas Ionization And Chemical Abundances From Prototype Observations, F. Belfiore, R. Maiolino, K. Bundy, D. Thomas, C. Maraston, D. Wilkinson, S. F. Sánchez, M. Bershady, G. A. Blanc, M. Bothwell, S. L. Cales, L. Coccato, N. Drory, E. Emsellem, H. Fu, J. Gelfand, D. Law, K. Masters, J. Parejko, C. Tremonti, D. Wake, A. Weijmans, Renbin Yan, T. Xiao, K. Zhang, T. Zheng, K. Bizyaev, K. Kinemuchi, D. Oravetz, A. Simmons

Physics and Astronomy Faculty Publications

MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-yr Sloan Digital Sky Survey (SDSS-IV) survey that will obtain spatially resolved spectroscopy from 3600 to 10 300 Å for a representative sample of over 10 000 nearby galaxies. In this paper, we present the analysis of nebular emission-line properties using observations of 14 galaxies obtained with P-MaNGA, a prototype of the MaNGA instrument. By using spatially resolved diagnostic diagrams, we find extended star formation in galaxies that are centrally dominated by Seyfert/LINER-like emission, which illustrates that galaxy characterizations based on single fibre spectra are necessarily incomplete. We observe extended …