Bibcode
DOI
Bakos, Judit; Trujillo, I.; Pohlen, Michael
Bibliographical reference
The Astrophysical Journal, Volume 683, Issue 2, pp. L103-L106.
Advertised on:
8
2008
Journal
Citations
165
Refereed citations
148
Description
We have explored radial color and stellar surface mass density profiles
for a sample of 85 late-type spiral galaxies with deep (down to ~27 mag
arcsec-2) SDSS g'- and r'-band surface
brightness profiles. About 90% of the light profiles have been
classified as broken exponentials, exhibiting either truncations (Type
II galaxies) or antitruncations (Type III galaxies). The color profiles
of Type II galaxies show a ``U shape'' with a minimum of
(g'-r')=0.47+/-0.02 mag at the break radius.
Around the break radius, Type III galaxies have a plateau region with a
color of (g'-r')=0.57+/-0.02. Using the color to
calculate the stellar surface mass density profiles reveals a surprising
result. The breaks, well established in the light profiles of the
truncated galaxies, are almost gone, and the mass profiles now resemble
those of the pure exponential (Type I) galaxies. This result suggests
that the origin of the break in Type II galaxies is more likely due to a
radial change in stellar population than being associated with an actual
drop in the distribution of mass. Type III galaxies, however, seem to
preserve their shape in the stellar mass density profiles. We find that
the stellar surface mass density at the break for truncated galaxies is
13.6+/-1.6 Msolar pc-2 and for the antitruncated
ones is 9.9+/-1.3 Msolar pc-2. We estimate that
the fraction of stellar mass outside the break radius is ~15% for
truncated galaxies and ~9% for antitruncated galaxies.
Related projects
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro