Issue |
A&A
Volume 612, April 2018
|
|
---|---|---|
Article Number | A81 | |
Number of page(s) | 46 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/201730738 | |
Published online | 01 May 2018 |
Gathering dust: A galaxy-wide study of dust emission from cloud complexes in NGC 300★,★★
1
Max Planck Institute for Astronomy,
Königstuhl 17,
69117
Heidelberg, Germany
e-mail: riener@mpia.de
2
Institute for Astronomy (IfA), University of Vienna,
Türkenschanzstrasse 17,
1180
Vienna, Austria
3
Harvard-Smithsonian Center for Astrophysics,
60 Garden Street,
Cambridge,
MA
02138, USA
4
University of Hertfordshire, Centre for Astrophysics Research,
Hatfield
AL10 9AB, UK
Received:
6
March
2017
Accepted:
3
November
2017
Aims. We use multi-band observations by the Herschel Space Observatory to study the dust emission properties of the nearby spiral galaxy NGC 300. We compile a first catalogue of the population of giant dust clouds (GDCs) in NGC 300, including temperature and mass estimates, and give an estimate of the total dust mass of the galaxy.
Methods. We carried out source detection with the multiwavelength source extraction algorithm getsources. We calculated physical properties, including mass and temperature, of the GDCs from five-band Herschel PACS and SPIRE observations from 100 to 500 μm; the final size and mass estimates are based on the observations at 250 μm that have an effective spatial resolution of ~170 pc. We correlated our final catalogue of GDCs to pre-existing catalogues of HII regions to infer the number of GDCs associated with high-mass star formation and determined the Hα emission of the GDCs.
Results. Our final catalogue of GDCs includes 146 sources, 90 of which are associated with known HII regions. We find that the dust masses of the GDCs are completely dominated by the cold dust component and range from ~1.1 × 103 to 1.4 × 104 M⊙. The GDCs have effective temperatures of ~13–23 K and show a distinct cold dust effective temperature gradient from the centre towards the outer parts of the stellar disk. We find that the population of GDCs in our catalogue constitutes ~16% of the total dust mass of NGC 300, which we estimate to be about 5.4 × 106 M⊙. At least about 87% of our GDCs have a high enough average dust mass surface density to provide sufficient shielding to harbour molecular clouds. We compare our results to previous pointed molecular gas observations in NGC 300 and results from other nearby galaxies and also conclude that it is very likely that most of our GDCs are associated with complexes of giant molecular clouds.
Key words: methods: observational / galaxies: star formation / ISM: clouds
The catalogue is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A81
© ESO 2018
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.