Bibcode
James, P. A.; Knapen, J. H.; Shane, N. S.; Baldry, I. K.; de Jong, R. S.
Bibliographical reference
Astronomy and Astrophysics, Volume 482, Issue 2, 2008, pp.507-516
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5
2008
Journal
Citations
41
Refereed citations
40
Description
Aims: We present an analysis of the star formation properties of field
galaxies within the local volume out to a recession velocity limit of
3000 km s-1. Methods: A parent sample of 863
star-forming galaxies is used to calculate a B-band luminosity function.
This is then populated with star formation information from a subsample
of 327 galaxies, for which we have Hα imaging, firstly by
calibrating a relationship between galaxy B-band luminosity and star
formation rate, and secondly by a Monte Carlo simulation of a
representative sample of galaxies, in which star formation information
is randomly sampled from the observed subset. Results: The total
star formation rate density of the local Universe is found to be between
0.016 and 0.023 M&sun; yr-1 Mpc-3 with
the uncertainties dominated by the internal extinction correction used
in converting measured Hα fluxes to star formation rates. If our
internally derived B-band luminosity function is replaced by one from
the Sloan Digital Sky Survey blue sequence, the star formation rate
densities are ~60% of the above values. We also calculate the
contribution to the total star formation rate density from galaxies of
different luminosities and Hubble T-types. The largest contribution
comes from bright galaxies with MB˜ -20 mag, and the
total contribution from galaxies fainter than MB= -15.5 mag
is less than 10%. Almost 60% of the star formation rate density comes
from galaxies of types Sb, Sbc or Sc; 9% from galaxies earlier than Sb
and 33% from galaxies later than Sc. Finally, 75-80% of the total star
formation in the local Universe is shown to be occurring in disk
regions, defined as being >1 kpc from the centres of galaxies. Conclusions: The star formation rate density estimates found here are
consistent with values from the recent literature using a range of
different star formation indicators. Even though they are numerous,
dwarf galaxies contribute little to the star formation in the local
Universe, and the bulk of the star formation takes place in
L* spirals.
Based on observations made with the Jacobus Kapteyn Telescope operated
on the island of La Palma by the Isaac Newton Group in the Spanish
Observatorio del Roque de los Muchachos of the Instituto de
Astrofísica de Canarias.
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