Bibcode
Kahre, L.; Walterbos, R. A.; Kim, H.; Thilker, D.; Calzetti, D.; Lee, J. C.; Sabbi, E.; Ubeda, L.; Aloisi, A.; Cignoni, M.; Cook, D. O.; Dale, D. A.; Elmegreen, B. G.; Elmegreen, D. M.; Fumagalli, M.; Gallagher, J. S., III; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Hunter, D. A.; Sacchi, E.; Smith, L. J.; Tosi, M.; Adamo, A.; Andrews, J. E.; Ashworth, G.; Bright, S. N.; Brown, T. M.; Chandar, R.; Christian, C.; de Mink, S. E.; Dobbs, C.; Evans, A. S.; Herrero, A.; Johnson, K. E.; Kennicutt, R. C.; Krumholz, M. R.; Messa, M.; Nair, P.; Nota, A.; Pellerin, A.; Ryon, J. E.; Schaerer, D.; Shabani, F.; Van Dyk, S. D.; Whitmore, B. C.; Wofford, A.
Referencia bibliográfica
The Astrophysical Journal, Volume 855, Issue 2, article id. 133, 16 pp. (2018).
Fecha de publicación:
3
2018
Revista
Número de citas
27
Número de citas referidas
27
Descripción
We present a study of the dust-to-gas ratios in five nearby galaxies:
NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305
(Holmberg II). Using Hubble Space Telescope broadband WFC3/UVIS UV and
optical images from the Treasury program Legacy ExtraGalactic UV Survey
(LEGUS) combined with archival HST/Advanced Camera for Surveys data, we
correct thousands of individual stars for extinction across these five
galaxies using an isochrone-matching (reddening-free Q) method. We
generate extinction maps for each galaxy from the individual stellar
extinctions using both adaptive and fixed resolution techniques and
correlate these maps with neutral H I and CO gas maps from the
literature, including the H I Nearby Galaxy Survey and the HERA CO-Line
Extragalactic Survey. We calculate dust-to-gas ratios and investigate
variations in the dust-to-gas ratio with galaxy metallicity. We find a
power-law relationship between dust-to-gas ratio and metallicity,
consistent with other studies of dust-to-gas ratio compared to
metallicity. We find a change in the relation when H2 is not
included. This implies that underestimation of
{N}{{{H}}2} in low-metallicity dwarfs from a
too-low CO-to-H2 conversion factor X CO could have
produced too low a slope in the derived relationship between dust-to-gas
ratio and metallicity. We also compare our extinctions to those derived
from fitting the spectral energy distribution (SED) using the Bayesian
Extinction and Stellar Tool for NGC 7793 and find systematically lower
extinctions from SED fitting as compared to isochrone matching.
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