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Title: Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems

Abstract

We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxy defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems thatmore » are recorded in the spectra of distant quasars and gamma-ray burst afterglows.« less

Authors:
 [1];  [2]
  1. Princeton University Observatory, Princeton, NJ 08544-1001 (United States)
  2. University of Washington, Seattle, Dept. of Astronomy, Seattle, WA 98195-1580 (United States)
Publication Date:
OSTI Identifier:
22661221
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 838; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; COSMIC GAMMA BURSTS; DUSTS; ELEMENT ABUNDANCE; GAMMA RADIATION; INTERSTELLAR SPACE; MAGELLANIC CLOUDS; MASS; METALLICITY; MILKY WAY; POLYCYCLIC AROMATIC HYDROCARBONS; QUASARS; SPECTRA; STARS; SUBSTRATES; ULTRAVIOLET RADIATION

Citation Formats

Jenkins, Edward B., and Wallerstein, George, E-mail: ebj@astro.princeton.edu, E-mail: walleg@u.washington.edu. Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA64D4.
Jenkins, Edward B., & Wallerstein, George, E-mail: ebj@astro.princeton.edu, E-mail: walleg@u.washington.edu. Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems. United States. doi:10.3847/1538-4357/AA64D4.
Jenkins, Edward B., and Wallerstein, George, E-mail: ebj@astro.princeton.edu, E-mail: walleg@u.washington.edu. Sat . "Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems". United States. doi:10.3847/1538-4357/AA64D4.
@article{osti_22661221,
title = {Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems},
author = {Jenkins, Edward B. and Wallerstein, George, E-mail: ebj@astro.princeton.edu, E-mail: walleg@u.washington.edu},
abstractNote = {We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxy defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems that are recorded in the spectra of distant quasars and gamma-ray burst afterglows.},
doi = {10.3847/1538-4357/AA64D4},
journal = {Astrophysical Journal},
number = 2,
volume = 838,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}