The resolved stellar populations in the LEGUS galaxies
Abstract
The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the Hubble Space Telescope. It studied 50 nearby star-forming galaxies in five bands from the near UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. Photometric catalogs and mosaicked images for all filters are available for download. We present optical and near UV color-magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color-magnitude diagrams to identify stars more massive than 14 Mo, and compared their number with the number of massive stars expected from the GALEX FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the time scale for evaporation of unbound structures is comparable or longer than 10 Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems.
Keywords
Cite
@article{arxiv.1801.05467,
title = {The resolved stellar populations in the LEGUS galaxies},
author = {E. Sabbi and D. Calzetti and L. Ubeda and A. Adamo and M. Cignoni and D. Thilker and A. Aloisi and B. G. Elmegreen and D. M. Elmegreen and D. A. Gouliermis and E. K. Grebel and M. Messa and L. J. Smith and M. Tosi and A. Dolphin and J. E. Andrews and G. Ashworth and S. N. Bright and T. M. Brown and R. Chandar and C. Christian and G. C. Clayton and D. O. Cook and D. A. Dale and S. E. de Mink and C. Dobbs and A. S. Evans and M. Fumagalli and J. S. Gallagher and K. Grasha and A. Herrero and D. A. Hunter and K. E. Johnson and L. Kahre and R. C. Kennicutt and H. Kim and M. R. Krumholz and J. C. Lee and D. Lennon and C. Martin and P. Nair and A. Nota and G. Ostlin and A. Pellerin and J. Prieto and M. W. Regan and J. E. Ryon and E. Sacchi and D. Schaerer and D. Schiminovich and F. Shabani and S. D. Van Dyk and R. Walterbos and B. C. Whitmore and A. Wofford},
journal= {arXiv preprint arXiv:1801.05467},
year = {2018}
}
Comments
71 pages, 15 figures, 4 tables, Accpeted for publication on ApJS