Bibcode
Elmegreen, Debra Meloy; Elmegreen, Bruce G.; Sánchez-Almeida, J.; Muñoz-Tuñón, C.; Putko, Joseph; Dewberry, Janosz
Bibliographical reference
The Astrophysical Journal, Volume 750, Issue 2, article id. 95 (2012).
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5
2012
Journal
Citations
37
Refereed citations
32
Description
Tadpole galaxies have a giant star-forming region at the end of an
elongated intensity distribution. Here we use Sloan Digital Sky Survey
data to determine the ages, masses, and surface densities of the heads
and tails in 14 local tadpoles selected from the Kiso and Michigan
surveys of UV-bright galaxies, and we compare them to tadpoles
previously studied in the Hubble Ultra Deep Field. The young stellar
mass in the head scales linearly with rest-frame galaxy luminosity,
ranging from ~105 M &sun; at galaxy absolute
magnitude U = -13 mag to 109 M &sun; at U
= -20 mag. The corresponding head surface density increases from
several M &sun; pc-2 locally to 10-100 M
&sun; pc-2 at high redshift, and the star
formation rate (SFR) per unit area in the head increases from ~0.01 M
&sun; yr-1 kpc-2 locally
to ~1 M &sun; yr-1 kpc-2
at high z. These local values are normal for star-forming regions, and
the increases with redshift are consistent with other cosmological SFRs,
most likely reflecting an increase in gas abundance. The tails in the
local sample look like bulge-free galaxy disks. Their photometric ages
decrease from several Gyr to several hundred Myr with increasing z, and
their surface densities are more constant than the surface densities of
the heads. The far-outer intensity profiles in the local sample are
symmetric and exponential. We suggest that most local tadpoles are
bulge-free galaxy disks with lopsided star formation, perhaps from
environmental effects such as ram pressure or disk impacts, or from a
Jeans length comparable to half the disk size.
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Starbursts in Galaxies GEFE
Starsbursts play a key role in the cosmic evolution of galaxies, and thus in the star formation (SF) history of the universe, the production of metals, and the feedback coupling galaxies with the cosmic web. Extreme SF conditions prevail early on during the formation of the first stars and galaxies, therefore, the starburst phenomenon constitutes a
Casiana
Muñoz Tuñón