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Title: Attenuation Modified by DIG and Dust as Seen in M31

Abstract

The spatial distribution of dust in galaxies affects the global attenuation, and hence inferred properties, of galaxies. We trace the spatial distribution of dust in five approximately kiloparsec fields of M31 by comparing optical attenuation with the total dust mass distribution. We measure the attenuation from the Balmer decrement using Integral Field Spectroscopy and the dust mass from Herschel far-IR observations. Our results show that M31's dust attenuation closely follows a foreground screen model, contrary to what was previously found in other nearby galaxies. By smoothing the M31 data, we find that spatial resolution is not the cause for this difference. Based on the emission-line ratios and two simple models, we conclude that previous models of dust/gas geometry need to include a weakly or non-attenuated diffuse ionized gas (DIG) component. Due to the variation of dust and DIG scale heights with galactic radius, we conclude that different locations in galaxies will have different vertical distributions of gas and dust and therefore different measured attenuation. The difference between our result in M31 with that found in other nearby galaxies can be explained by our fields in M31 lying at larger galactic radii than the previous studies that focused on the centersmore » of galaxies.« less

Authors:
; ;  [1];  [2];  [3];  [4];  [5];  [6]
  1. Max Planck Institute for Astronomy (MPIA), Königstuhl 17, 69117 Heidelberg (Germany)
  2. School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia)
  3. Center for Astrophysics and Space Sciences, Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States)
  4. Department of Astronomy, University of Cape Town, Republic of South Africa (South Africa)
  5. Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  6. Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
Publication Date:
OSTI Identifier:
22663306
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 844; 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; APPROXIMATIONS; ATTENUATION; COMPARATIVE EVALUATIONS; COSMIC DUST; EMISSION; GALAXIES; MASS; MASS DISTRIBUTION; SPATIAL RESOLUTION; SPECTROSCOPY; STARS; VARIABLE STARS

Citation Formats

Tomičić, Neven, Kreckel, Kathryn, Schinnerer, Eva, Groves, Brent, Sandstrom, Karin, Kapala, Maria, Blanc, Guillermo A., and Leroy, Adam, E-mail: tomicic@mpia-hd.mpg.de. Attenuation Modified by DIG and Dust as Seen in M31. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7B30.
Tomičić, Neven, Kreckel, Kathryn, Schinnerer, Eva, Groves, Brent, Sandstrom, Karin, Kapala, Maria, Blanc, Guillermo A., & Leroy, Adam, E-mail: tomicic@mpia-hd.mpg.de. Attenuation Modified by DIG and Dust as Seen in M31. United States. doi:10.3847/1538-4357/AA7B30.
Tomičić, Neven, Kreckel, Kathryn, Schinnerer, Eva, Groves, Brent, Sandstrom, Karin, Kapala, Maria, Blanc, Guillermo A., and Leroy, Adam, E-mail: tomicic@mpia-hd.mpg.de. Tue . "Attenuation Modified by DIG and Dust as Seen in M31". United States. doi:10.3847/1538-4357/AA7B30.
@article{osti_22663306,
title = {Attenuation Modified by DIG and Dust as Seen in M31},
author = {Tomičić, Neven and Kreckel, Kathryn and Schinnerer, Eva and Groves, Brent and Sandstrom, Karin and Kapala, Maria and Blanc, Guillermo A. and Leroy, Adam, E-mail: tomicic@mpia-hd.mpg.de},
abstractNote = {The spatial distribution of dust in galaxies affects the global attenuation, and hence inferred properties, of galaxies. We trace the spatial distribution of dust in five approximately kiloparsec fields of M31 by comparing optical attenuation with the total dust mass distribution. We measure the attenuation from the Balmer decrement using Integral Field Spectroscopy and the dust mass from Herschel far-IR observations. Our results show that M31's dust attenuation closely follows a foreground screen model, contrary to what was previously found in other nearby galaxies. By smoothing the M31 data, we find that spatial resolution is not the cause for this difference. Based on the emission-line ratios and two simple models, we conclude that previous models of dust/gas geometry need to include a weakly or non-attenuated diffuse ionized gas (DIG) component. Due to the variation of dust and DIG scale heights with galactic radius, we conclude that different locations in galaxies will have different vertical distributions of gas and dust and therefore different measured attenuation. The difference between our result in M31 with that found in other nearby galaxies can be explained by our fields in M31 lying at larger galactic radii than the previous studies that focused on the centers of galaxies.},
doi = {10.3847/1538-4357/AA7B30},
journal = {Astrophysical Journal},
number = 2,
volume = 844,
place = {United States},
year = {Tue Aug 01 00:00:00 EDT 2017},
month = {Tue Aug 01 00:00:00 EDT 2017}
}