Hierarchical star formation across the grand-design spiral NGC 1566
Authors
Gouliermis, DA
Elmegreen, BG
Elmegreen, DM
Calzetti, D
Cignoni, M
Gallagher, JS
Klessen, RS
Sabbi, E
Thilker, D
Ubeda, L
Aloisi, A
Adamo, A
Cook, DO
Dale, D
Grasha, K
Grebel, EK
Johnson, KE
Sacchi, E
Shabani, F
Smith, LJ
Wofford, A
Publication Date
2017-06-11Journal Title
Monthly Notices of the Royal Astronomical Society
ISSN
0035-8711
Publisher
Oxford University Press
Volume
468
Issue
1
Pages
509-530
Language
English
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Gouliermis, D., Elmegreen, B., Elmegreen, D., Calzetti, D., Cignoni, M., Gallagher, J., Kennicutt, R., et al. (2017). Hierarchical star formation across the grand-design spiral NGC 1566. Monthly Notices of the Royal Astronomical Society, 468 (1), 509-530. https://doi.org/10.1093/mnras/stx445
Abstract
We investigate how star formation is spatially organized in the grand-design spiral NGC 1566 from deep $\textit{Hubble Space Telescope}$ photometry with the Legacy ExtraGalactic UV Survey. Our contour-based clustering analysis reveals 890 distinct stellar conglomerations at various levels of significance. These star-forming complexes are organized in a hierarchical fashion with the larger congregations consisting of smaller structures, which themselves fragment into even smaller and more compact stellar groupings. Their size distribution, covering a wide range in length-scales, shows a power law as expected from scale-free processes. We explain this shape with a simple ‘fragmentation and enrichment’ model. The hierarchical morphology of the complexes is confirmed by their mass–size relation that can be represented by a power law with a fractional exponent, analogous to that determined for fractal molecular clouds. The surface stellar density distribution of the complexes shows a lognormal shape similar to that for supersonic non-gravitating turbulent gas. Between 50 and 65 per cent of the recently formed stars, as well as about 90 per cent of the young star clusters, are found inside the stellar complexes, located along the spiral arms. We find an age difference between young stars inside the complexes and those in their direct vicinity in the arms of at least 10 Myr. This time-scale may relate to the minimum time for stellar evaporation, although we cannot exclude the $\textit{in situ}$ formation of stars. As expected, star formation preferentially occurs in spiral arms. Our findings reveal turbulent-driven hierarchical star formation along the arms of a grand-design galaxy.
Keywords
methods: statistical, stars: formation, galaxies: individual: NGC 1566, galaxies: spiral, galaxies: stellar content, galaxies: structure
Sponsorship
DAG kindly acknowledges financial support by the German Research Foundation (DFG) through programme GO 1659/3-2. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has also made use of the SIMBAD data base (Wenger et al. 2000), operated at CDS, Strasbourg, France. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute (STScI). STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. These observations are associated with programme GO-13364. Support for programme 13364 was provided by NASA through grants from STScI.
Funder references
SCIENCE & TECHNOLOGY FACILITIES COUNCIL (ST/N000927/1)
Embargo Lift Date
2100-01-01
Identifiers
External DOI: https://doi.org/10.1093/mnras/stx445
This record's URL: https://www.repository.cam.ac.uk/handle/1810/264049
Rights
Licence:
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