Bibcode
Sánchez-Gallego, J. R.; Knapen, J. H.; Wilson, C. D.; Barmby, P.; Azimlu, M.; Courteau, S.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 422, Issue 4, pp. 3208-3248.
Advertised on:
6
2012
Citations
25
Refereed citations
22
Description
We present Hα fluxes, star formation rates (SFRs) and equivalent
widths (EWs) for a sample of 156 nearby galaxies observed in the
12CO J= 3-2 line as part of the James Clerk Maxwell Telescope
Nearby Galaxies Legacy Survey. These are derived from images and values
in the literature and from new Hα images for 72 galaxies which we
publish here. We describe the sample, observations and procedures to
extract the Hα fluxes and related quantities. We discuss the SFR
properties of our sample and confirm the well-known correlation with
galaxy luminosity, albeit with high dispersion. Our SFRs range from 0.1
to 11 M&sun; yr-1 with a median SFR value for the
complete sample of 0.2 M&sun; yr-1. This median
value is somewhat lower than similar published measurements, which we
attribute, in part, to our sample being H I selected and, thus, not
biased towards high SFRs as has frequently been the case in previous
studies. Additionally, we calculate internal absorptions for the
Hα line, A(Hα), which are lower than many of those used in
previous studies. Our derived EWs, which range from 1 to 880 Å
with a median value of 27 Å, show little dependence on luminosity
but rise by a factor of 5 from early- to late-type galaxies. This paper
is the first in a series aimed at comparing SFRs obtained from Hα
imaging of galaxies with information derived from other tracers of star
formation and atomic and molecular gas.
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