Bibcode
Bakos, J.; Trujillo, I.; Pohlen, Michael
Referencia bibliográfica
Highlights of Spanish Astrophysics V, Astrophysics and Space Science Proceedings. ISBN 978-3-642-11249-2. Springer-Verlag Berlin Heidelberg, 2010, p. 257
Advertised on:
2010
Número de citas
0
Número de citas referidas
0
Descripción
We have explored radial color and stellar surface mass density profiles
for a sample of 85 late-type galaxies with available deep (down
to˜27.0mag/arcsec2) 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). Their associated
color profiles show significantly different behavior. For the truncated
galaxies a radial inside-out bluing reaches a minimum of
(g'-r')=0.47±0.02mag at the position of the break radius, this is
followed by a reddening outwards. The antitruncated galaxies reveal a
more complex behavior: at the break position (calculated from the light
profiles) the color profile reaches a plateau region-preceded with a
reddening- with a mean color of about (g'-r')=0.57±0.02mag. 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 Type II galaxies, are almost gone, and the mass profiles resemble
now those of the pure exponential Type I galaxies. This result suggests
that the origin of the break in Type II galaxies are most likely to be a
radial change in stellar population, rather than being caused by an
actual drop in the distribution of mass. The antitruncated galaxies on
the other hand preserve their shape to some extent in the stellar
surface mass density profiles. We find that the stellar surface mass
density at the break for truncated (Type II) galaxies is 13.6± 1.
6 M&sun; pc- 2 and 9. 9 ± 1. 3
M&sun; pc- 2 for the antitruncated (Type III)
ones. We estimate that ˜ 15% of the total stellar mass in case of
Type II galaxies and ˜ 9% in case of Type III galaxies are to be
found beyond the measured break radii.