Near-identical star formation rate densities from Hα and FUVat redshift zero. Issue 1 (12th June 2018)

• Record Type: Journal Article
• Authors: Audcent-Ross, Fiona M; Meurer, Gerhardt R; Wong, O I; Zheng, Z; Hanish, D; Zwaan, M A; Bland-Hawthorn, J; Elagali, A; Meyer, M; Putman, M E; Ryan-Weber, E V; Sweet, S M; Thilker, D A; Seibert, M; Allen, R; Dopita, M A; Doyle-Pegg, M T; Drinkwater, M; Ferguson, H C; Freeman, K C; Heckman, T M; Kennicutt, R C; Kilborn, V A; Kim, J H; Knezek, P M; Koribalski, B; Smith, R C; Staveley-Smith, L; Webster, R L; Werk, J K
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 480:Issue 1(2018)
• Page Start: 119
• Page End: 133
• Publication Date: 2018-06-12
• Subjects: surveys -- galaxies: luminosity function, mass function -- galaxies: star formation -- ultraviolet: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty1538
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: For the first time both H α and far-ultraviolet (FUV) observations from an H i -selected sample are used to determine the dust-corrected star formation rate density (SFRD: $\dot{\rho }$ ) in the local Universe. Applying the two star formation rate indicators on 294 local galaxies, we determine log($\dot{\rho } _{ {\rm H}\alpha }) = -1.68^{+0.13}_{-0.05}$ [M⊙ yr −1 Mpc −3 ] and log($\dot{\rho }_{ {\rm FUV}}$ ) $= -1.71^{+0.12}_{-0.13}$ [M⊙ yr −1 Mpc −3 ]. These values are derived from scaling H α and FUV observations to the H i mass function. Galaxies were selected to uniformly sample the full H i mass ($M_{\rm{H\, \small {I}}}$ ) range of the H i Parkes All-Sky Survey ($M_{\rm{H\, \small {I}}} \sim 10^{7}$ to ∼10 10.7 M⊙ ). The approach leads to relatively larger sampling of dwarf galaxies compared to optically selected surveys. The low H i mass, low luminosity, and low surface brightness galaxy populations have, on average, lower H α /FUV flux ratios than the remaining galaxy populations, consistent with the earlier results of Meurer. The near-identical H α - and FUV-derived SFRD values arise with the low H α /FUV flux ratios of some galaxies being offset by enhanced H α from the brightest and high mass galaxy populations. Our findings confirm the necessity to fully sample the H i mass range for a complete census of local star formation to include lower stellar mass galaxies which dominate the local Universe.