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The G305 star-forming complex: The central star clusters Danks 1 and Danks 2

Davies, B., Clark, J.S., Trombley, C., Figer, D.F., Najarro, F., Crowther, P.A., Kudritzki, R.-P., Thompson, M., Urquhart, J.S., Hindson, L. and others. (2012) The G305 star-forming complex: The central star clusters Danks 1 and Danks 2. Monthly Notices of the Royal Astronomical Society, 419 (3). pp. 1871-1886. ISSN 0035-8711. (doi:10.1111/j.1365-2966.2011.19736.x) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1111/j.1365-2966.2011.19736.x

Abstract

The G305 Hii complex (G305.4+0.1) is one of the most massive star-forming structures yet identified within the Galaxy. It is host to many massive stars at all stages of formation and evolution, from embedded molecular cores to post-main-sequence stars. Here, we present a detailed near-infrared analysis of the two central star clusters Danks 1 and Danks 2, using Hubble Space Telescope+NICMOS imaging and Very Large Telescope+ISAAC spectroscopy. We find that the spectrophotometric distance to the clusters is consistent with the kinematic distance to the G305 complex, an average of all measurements giving a distance of 3.8 ± 0.6kpc. From analysis of the stellar populations and the pre-main-sequence stars, we find that Danks 2 is the elder of the two clusters, with an age of 3 +3 - 1Myr. Danks 1 is clearly younger with an age of 1.5 +1.5 - 0.5Myr, and is dominated by three very luminous H-rich Wolf-Rayet stars which may have masses ?100M ?. The two clusters have mass functions consistent with the Salpeter slope, and total cluster masses of 8000 ± 1500 and 3000 ± 800M ? for Danks 1 and Danks 2, respectively. Danks 1 is significantly the more compact cluster of the two, and is one of the densest clusters in the Galaxy with log(?/M ?pc -3) = 5.5 +0.5 - 0.4. In addition to the clusters, there is a population of apparently isolated Wolf-Rayet stars within the molecular cloud's cavity. Our results suggest that the star-forming history of G305 began with the formation of Danks 2, and subsequently Danks 1, with the origin of the diffuse evolved population currently uncertain. Together, the massive stars at the centre of the G305 region appear to be clearing away what is left of the natal cloud, triggering a further generation of star formation at the cloud's periphery.

Item Type: Article
DOI/Identification number: 10.1111/j.1365-2966.2011.19736.x
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Mon. Not. R. Astron. Soc. [Field not mapped to EPrints] AD - Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, United Kingdom [Field not mapped to EPrints] AD - School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom [Field not mapped to EPrints] AD - Center for Detectors, Rochester Institute of Technology, 54 Memorial Drive, Rochester, NY 14623, United States [Field not mapped to EPrints] AD - Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom [Field not mapped to EPrints] AD - Centro de Astrobiología (CSIC-INTA), Ctra. de Torrejón a Ajalvir km-4, 28850 Torrejón de Ardoz, Madrid, Spain [Field not mapped to EPrints] AD - Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH, United Kingdom [Field not mapped to EPrints] AD - Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, United States [Field not mapped to EPrints] AD - Max Planck Institute for Astrophysics, Karl-Schwarzchild-Str. 1, 85748 Garching, Germany [Field not mapped to EPrints] AD - Centre for Astrophysics Research, STRI, University of Hertfordshire, College Lane, Hatfield AL10 9AB, United Kingdom [Field not mapped to EPrints] AD - Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: Hii regions, ISM: clouds, Open clusters and associations: general, Open clusters and associations: individual: Danks 1, Danks 2, Stars: formation, Stars: Wolf-Rayet
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: James Urquhart
Date Deposited: 30 Nov 2015 15:47 UTC
Last Modified: 29 May 2019 16:28 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/52215 (The current URI for this page, for reference purposes)
Urquhart, J.S.: https://orcid.org/0000-0002-1605-8050
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