Revealing the cold dust in low-metallicity environments: I. Photometry analysis of the Dwarf Galaxy Survey with Herschel

Simple item page
dc.contributor.authorRemy-Ruyer, A.
dc.contributor.authorMadden, S.C.
dc.contributor.authorGalliano, F.
dc.contributor.authorHony, S.
dc.contributor.authorSauvage, M.
dc.contributor.authorBendo, G.J.
dc.contributor.authorRoussel, H.
dc.contributor.authorPohlen, M.
dc.contributor.authorSmith, M.W.L.
dc.contributor.authorGalametz, M.
dc.contributor.authorCormier, D.
dc.contributor.authorLebouteiller, V.
dc.contributor.authorWu, R.
dc.contributor.authorBaes, M.
dc.contributor.authorBarlow, M.J.
dc.contributor.authorBoquien, M.
dc.contributor.authorBoselli, A.
dc.contributor.authorCiesla, L.
dc.contributor.authorDe Looze, I.
dc.contributor.authorKarczewski, O.L.
dc.contributor.authorPanuzzo, P.
dc.contributor.authorSpinoglio, L.
dc.contributor.authorVaccari, M.
dc.contributor.authorWilson, C.D.
dc.date.accessioned2017-02-20T09:57:34Z
dc.date.available2017-02-20T09:57:34Z
dc.date.issued2013
dc.description.abstractContext. We present new photometric data from our Herschel Guaranteed Time Key Programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in low-metallicity environments. A total of 48 dwarf galaxies were observed with the PACS and SPIRE instruments onboard the Herschel Space Observatory at 70, 100, 160, 250, 350, and 500 µm. Aims. The goal of this paper is to provide reliable far infrared (FIR) photometry for the DGS sample and to analyse the FIR/submillimetre (submm) behaviour of the DGS galaxies. We focus on a systematic comparison of the derived FIR properties (FIR luminosity, LFIR, dust mass, Mdust , dust temperature, T, emissivity index, β) with more metal-rich galaxies and investigate the detection of a potential submm excess. Methods. The data reduction method is adapted for each galaxy in order to derive the most reliable photometry from the final maps. The derived PACS flux densities are compared with the Spitzer MIPS 70 and 160 µm bands. We use colour-colour diagrams to analyse the FIR/submm behaviour of the DGS galaxies and modified blackbody fitting procedures to determine their dust properties. To study the variation in these dust properties with metallicity, we also include galaxies from the Herschel KINGFISH sample, which contains more metal-rich environments, totalling 109 galaxies. Results. The location of the DGS galaxies on Herschel colour-colour diagrams highlights the differences in dust grain properties and/or global environments of low-metallicity dwarf galaxies. The dust in DGS galaxies is generally warmer than in KINGFISH galaxies (TDGS ∼ 32 K and TKINGFIS H ∼ 23 K). The emissivity index, β, is ∼ 1.7 in the DGS, however metallicity does not make a strong effect on β. The proportion of dust mass relative to stellar mass is lower in low-metallicity galaxies: Mdust /Mstar ∼ 0.02% for the DGS versus 0.1% for KINGFISH. However, per unit dust mass, dwarf galaxies emit about six times more in the FIR/submm than higher metallicity galaxies. Out of the 22 DGS galaxies detected at 500 µm, about 41% present an excess in the submm beyond the explanation of our dust SED model, and this excess can go up to 150% above the prediction from the model. The excess mainly appears in lower metallicity galaxies (12+log(O/H) ;S 8.3), and the strongest excesses are detected in the most metal-poor galaxies. However, we so stress the need for observations longwards of the Herschel wavelengths to detect any submm excess appearing beyond 500 .en_US
dc.description.accreditationNorwegian List
dc.identifier.citationRemy-Ruyer, A. et al. (2013). Revealing the cold dust in low-metallicity environments: I - Photometry analysis of the Dwarf Galaxy Survey with Herschel. Astronomy & Astrophysics, 557 (A95)en_US
dc.identifier.issn0004-6361
dc.identifier.urihttp://hdl.handle.net/10566/2554
dc.identifier.urihttp://dx.doi.org/10.1051/0004-6361/201321602
dc.language.isoen_USen_US
dc.privacy.showsubmitterFALSE
dc.publisherEDP Sciencesen_US
dc.rightsArticles published in these journals will be freely and permanently accessible online. Authors retain the copyright to their work, licensing it under the Creative Commons Attribution License, and are free to reproduce and re-distribute it without restrictions, as long as the original work is correctly cited. This is the final version published online at http://dx.doi.org/10.1051/0004-6361/201321602
dc.status.ispeerreviewedTRUE
dc.subjectGalaxiesen_US
dc.subjectDwarfen_US
dc.subjectPhotometryen_US
dc.titleRevealing the cold dust in low-metallicity environments: I. Photometry analysis of the Dwarf Galaxy Survey with Herschelen_US
dc.typeArticleen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Remy-Ruyer_Cold dust_2013.pdf
Size:
5.64 MB
Format:
Adobe Portable Document Format
Description:
Download

Collections

Research Articles (Physics)