High-Resolution Mapping of Dust via Extinction in the M31 Bulge

DOI: 
10.1093/mnras/stw778
Publication date: 
01/06/2016
Main author: 
Dong, Hui
IAA authors: 
Dong, Hui
Authors: 
Dong, Hui;Li, Zhiyuan;Wang, Q. D.;Lauer, Tod R.;Olsen, Knut A. G.;Saha, Abhijit;Dalcanton, Julianne J.;Groves, Brent A.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Pages: 
2262-2273
Abstract: 
We map the dust distribution in the central 180″ (̃680 pc) region of the M31 bulge, based on HST WFC3 and ACS observations in ten bands from near-ultraviolet (2700 Å) to near-infrared (1.5 μm). This large wavelength coverage gives us great leverage to detect not only dense dusty clumps, but also diffuse dusty molecular gas. We fit a pixel-by-pixel spectral energy distributions to construct a high-dynamic-range extinction map with unparalleled angular resolution (̃0.5″, i.e., ̃2 pc) and sensitivity (the extinction uncertainty, δA<SUB>V</SUB> ̃0.05). In particular, the data allow to directly fit the fractions of starlight obscured by individual dusty clumps, and hence their radial distances in the bulge. Most of these clumps seem to be located in a thin plane, which is tilted with respect to the M31 disk and appears face-on. We convert the extinction map into a dust mass surface density map and compare it with that derived from the dust emission as observed by Herschel. The dust masses in these two maps are consistent with each other, except in the low-extinction regions, where the mass inferred from the extinction tends to be underestimated. Further, we use simulations to show that our method can be used to measure the masses of dusty clumps in Virgo cluster early-type galaxies to an accuracy within a factor of ̃2.
Database: 
ADS
SCOPUS
WOK
URL: 
https://ui.adsabs.harvard.edu/#abs/2016MNRAS.459.2262D/abstract
ADS Bibcode: 
2016MNRAS.459.2262D
Keywords: 
Astrophysics - Astrophysics of Galaxies