SCYON Abstract

Received on March 6 2013

The Snapshot Hubble U-Band Cluster Survey (SHUCS). I. Survey Description and First Application to the Mixed Star Cluster Population of NGC 4041

AuthorsI.S. Konstantopoulos (1,2), L.J. Smith (3), A. Adamo (4), E. Silva-Villa (5), J.S. Gallagher (6), N. Bastian (7,8), J.E. Ryon (6), M.S. Westmoquette (9), E. Zackrisson (10), S.S. Larsen (11), D.R. Weisz (12), and J.C. Charlton (2)
Affiliation(1) Australian Astronomical Observatory, PO Box 915, North Ryde NSW 1670, Australia;
(2) Department of Astronomy \& Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA
(3) Space Telescope Science Institute and European Space Agency, 3700 San Martin Drive, Baltimore, MD 21218, USA
(4) Max-Planck-Institut for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
(5) Departement de Physique, de Genie Physique et d'Optique, and Centre de Recherche en Astrophysique du Quebec (CRAQ), Universite Laval, Quebec, Canada
(6) Department of Astronomy, University of Wisconsin-Madison, 5534 Sterling, 475 North Charter Street, Madison WI 53706, USA
(7 Excellence Cluster Universe, Boltzmann-Strasse 2, 85748 Garching bei München, Germany
(8) Astrophysics Research Institute, Liverpool John Moores University, Egerton Wharf, Birkenhead, CH41 1LD, UK
(9) European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
(10) Department of Astronomy, Stockholm University, Oscar Klein Centre, AlbaNova, Stockholm SE-106 91, Sweden
(11) Department of Astrophysics/IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands
(12) Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195, USA
Accepted byAstronomical Journal


We present the Snapshot Hubble U-band Cluster Survey (SHUCS), a project aimed at characterizing the star cluster populations of ten nearby galaxies (d<23Mpc, half within ≈12Mpc) through new F336W (U band equivalent) imaging from Wide Field Camera 3, and archival BVI-equivalent data with the Hubble Space Telescope. Completing the UBVI baseline reduces the age-extinction degeneracy of optical colours, thus enabling the measurement of reliable ages and masses for the thousands of clusters covered by our survey. The sample consists chiefly of face-on spiral galaxies at low inclination, in various degrees of isolation (isolated, in group, merging), and includes two AGN hosts. This first paper outlines the survey itself, the observational datasets, the analysis methods, and presents a proof-of-concept study of the large-scale properties and star cluster population of NGC 4041, a massive SAbc galaxy at a distance of ≈23Mpc, and part of a small grouping of six giant members. We resolve two structural components with distinct stellar populations, a morphology more akin to merging and interacting systems. We also find strong evidence of a truncated, Schechter-type mass function, and a similarly segmented luminosity function. These results indicate that binning must erase much of the substructure present in the mass and luminosity functions, and might account for the conflicting reports on the intrinsic shape of these functions in the literature. We also note a tidal feature in the outskirts of the galaxy in GALEX UV imaging, and follow it up with a comprehensive multi-wavelength study of NGC 4041 and its parent group. We deduce a minor merger as a likely cause of its segmented structure and the observed pattern of a radially decreasing star formation rate. We propose that combining the study of star cluster populations with broad-band metrics is not only advantageous, but often easily achievable thorough archival datasets.