Bibcode
Bakos, Judit; Trujillo, Ignacio; Pohlen, Michael
Referencia bibliográfica
Journal of Physics: Conference Series, Volume 218, Issue 1, pp. 012015 (2010).
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3
2010
Número de citas
0
Número de citas referidas
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Descripción
We present our results on the stellar population properties of the
outskirts of disk galaxies. In particular, we focus on spiral galaxies
with stellar disk truncations in their radial surface brightness
profiles. Using SDSS data we show color gradients. We find that the
color radial profile exhibits a "U'-shape", showing a minimum at the
position of the break of the surface brightness profile. We obtain
stellar surface mass density profiles of truncated galaxies as well,
these show a peculiar behaviour: they follow very closely an exponential
decrement. This suggests the idea that the observed properties of
truncated galaxies are not caused by a drop in the mass distribution but
by a different stellar population in the outer regions of the disks.
Confronting this with current theoretical scenarios we find that this is
likely to be a result of secular evolution, in which scenario stars are
being formed inside the break and then being motioned outwards which
would result in an inverted age gradient corresponding to the observed
color profiles. Having maintained this idea, using multiwave-length data
from GALEX, SDSS, UKIDSS and SPITZER we showed a dependence of the
inner-outer scale-length ratio of truncated disks. Our results suggest
that there is an existing general trend of the scale-length ratio: from
bluer to redder bands the scale-length ratio decreases, which is in
accordance with the stellar disk being dominated by an older stellar
population in the outer disk.