Gordon, KD;
Roman-Duval, J;
Bot, C;
Meixner, M;
Babler, B;
Bernard, J-P;
Bolatto, A;
... Skibba, R; + view all
(2014)
Dust and gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. I. Dust properties and insights into the origin of the submillimeter excess emission.
Astrophysical Journal
, 797
(2)
, Article 85. 10.1088/0004-637X/797/2/85.
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Dust and gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. I. Dust properties and insights into the origin of the submillimeter excess emission.pdf Download (3MB) | Preview |
Abstract
The dust properties in the Large and Small Magellanic clouds (LMC/SMC) are studied using the HERITAGE Herschel Key Project photometric data in five bands from 100 to 500 μm. Three simple models of dust emission were fit to the observations: a single temperature blackbody modified by a power-law emissivity (SMBB), a single temperature blackbody modified by a broken power-law emissivity (BEMBB), and two blackbodies with different temperatures, both modified by the same power-law emissivity (TTMBB). Using these models, we investigate the origin of the submillimeter excess, defined as the submillimeter emission above that expected from SMBB models fit to observations <200 μm. We find that the BEMBB model produces the lowest fit residuals with pixel-averaged 500 μm submillimeter excesses of 27% and 43% for the LMC and SMC, respectively. Adopting gas masses from previous works, the gas-to-dust ratios calculated from our fitting results show that the TTMBB fits require significantly more dust than are available even if all the metals present in the interstellar medium (ISM) were condensed into dust. This indicates that the submillimeter excess is more likely to be due to emissivity variations than a second population of colder dust. We derive integrated dust masses of (7.3 ± 1.7) × 105 and (8.3 ± 2.1) × 104 M ☉ for the LMC and SMC, respectively. We find significant correlations between the submillimeter excess and other dust properties; further work is needed to determine the relative contributions of fitting noise and ISM physics to the correlations.
| Type: | Article |
|---|---|
| Title: | Dust and gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. I. Dust properties and insights into the origin of the submillimeter excess emission |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1088/0004-637X/797/2/85 |
| Publisher version: | http://dx.doi.org/10.1088/0004-637X/797/2/85 |
| Language: | English |
| Additional information: | Copyright © 2014. The American Astronomical Society. All rights reserved. |
| Keywords: | infrared: galaxies, infrared: ISM, ISM: general, Magellanic clouds |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1459481 |
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