CaltechAUTHORS
Published August 21, 2018 | Version Submitted + Published
Journal Article Open

Search for star cluster age gradients across spiral arms of three LEGUS disc galaxies

Creators

  • 1. ROR icon Heidelberg University
  • 2. ROR icon University of Wisconsin–Madison
  • 3. ROR icon Stockholm University
  • 4. ROR icon IBM Research - Thomas J. Watson Research Center
  • 5. ROR icon University of Exeter
  • 6. ROR icon Max Planck Institute for Astronomy
  • 7. ROR icon University of Massachusetts Amherst
  • 8. ROR icon Vassar College
  • 9. ROR icon University of Pisa
  • 10. ROR icon University of Wyoming
  • 11. ROR icon Space Telescope Science Institute
  • 12. ROR icon Johns Hopkins University
  • 13. ROR icon California Institute of Technology
  • 14. ROR icon SUNY Geneseo

Abstract

One of the main theories for explaining the formation of spiral arms in galaxies is the stationary density wave theory. This theory predicts the existence of an age gradient across the arms. We use the stellar cluster catalogues of the galaxies NGC 1566, M51a, and NGC 628 from the Legacy ExtraGalactic UV Survey (LEGUS) program. In order to test for the possible existence of an age sequence across the spiral arms, we quantified the azimuthal offset between star clusters of different ages in our target galaxies. We found that NGC 1566, a grand-design spiral galaxy with bisymmetric arms and a strong bar, shows a significant age gradient across the spiral arms that appear to be consistent with the prediction of the stationary density wave theory. In contrast, M51a with its two well-defined spiral arms and a weaker bar does not show an age gradient across the arms. In addition, a comparison with non-LEGUS star cluster catalogues for M51a yields similar results. We believe that the spiral structure of M51a is not the result of a stationary density wave with a fixed pattern speed. Instead, tidal interactions could be the dominant mechanism for the formation of spiral arms. We also found no offset in the azimuthal distribution of star clusters with different ages across the weak spiral arms of NGC 628.

Additional Information

© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices). Accepted 2018 May 11. Received 2018 April 23; in original form 2018 January 13. Published: 16 May 2018. This work is based on observations made with the NASA/ESA HST, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 13364. Support for Program 13364 was provided by NASA through a grant from the Space Telescope Science Institute. This research has made use of the NED, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. AA acknowledges the support of the Swedish Research Council (Vetenskapsrådet) and the Swedish National Space Board. DAG kindly acknowledges financial support by the German Research Foundation (DFG) through programme GO 1659/3-2.

Attached Files

Published - sty1277.pdf

Submitted - 1805.05643.pdf

Files

1805.05643.pdf

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Additional details

Identifiers

Eprint ID
89278
Resolver ID
CaltechAUTHORS:20180829-111309165

Related works

Describes
https://arxiv.org/abs/1805.05643 (URL)

Funding

NASA
NAS 5-26555
Space Telescope Science Institute
NASA/JPL/Caltech
Vetenskapsrådet
Swedish National Space Board (SNSB)
Deutsche Forschungsgemeinschaft (DFG)
GO 1659/3-2

Dates

Created
2018-08-29
Created from EPrint's datestamp field
Updated
2023-03-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)