Bibcode
Knapen, J. H.; Cisternas, M.; Querejeta, M.
Bibliographical reference
From Interstellar Clouds to Star-Forming Galaxies: Universal Processes?, Proceedings of the International Astronomical Union, IAU Symposium, Volume 315, pp. 236-239
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2016
Citations
0
Refereed citations
0
Description
We investigate the influence of interactions on the star formation by
studying a sample of almost 1500 of the nearest galaxies, all within a
distance of ~45 Mpc. We define the massive star formation rate (SFR), as
measured from far-IR emission, and the specific star formation rate
(SSFR), which is the former quantity normalized by the stellar mass of
the galaxy, and explore their distribution with morphological type and
with stellar mass. We then calculate the relative enhancement of these
quantities for each galaxy by normalizing them by the median SFR and
SSFR values of individual control populations of similar non-interacting
galaxies. We find that both SFR and SSFR are enhanced in interacting
galaxies, and more so as the degree of interaction is higher. The
increase is, however, moderate, reaching a maximum of a factor of 1.9
for the highest degree of interaction (mergers). The SFR and SSFR are
enhanced statistically in the population, but in most individual
interacting galaxies they are not enhanced at all. We discuss how those
galaxies with the largest SFR and/or SSFR enhancement can be defined as
starbursts. We argue that this study, based on a representative sample
of nearby galaxies, should be used to place constraints on studies based
on samples of galaxies at larger distances.