Ignacio Trujillo, Eleazar R. Carrasco, Anna Ferre-Mateu
Using Gemini North telescope ultra deep and high resolution (sub-kpc) K-band
adaptive optics imaging of a sample of 4 nearby (z~0.15) massive
(~10^{11}M_{sun}) compact (R<1.5 kpc) galaxies, we have explored the structural
properties of these rare objects with an unprecedented detail. Our surface
brightness profiles expand over 12 magnitudes in range, allowing us to explore
the presence of any faint extended envelope on these objects down to stellar
mass densities ~10^{6} M_{sun}/kpc^{2} at radial distances of ~15 kpc. We find
no evidence for any extended faint tail altering the compactness of these
galaxies. Our objects are elongated, resembling visually S0 galaxies and have a
central stellar mass density well above the stellar mass densities of objects
with similar stellar mass but normal size in the present universe. If these
massive compact objects will eventually transform into normal size galaxies,
the processes driving this size growth will have to migrate around
2-3x10^{10}M_{sun} stellar mass from their inner (R<1.7 kpc) region towards
their outskirts. Nearby massive compact galaxies share with high-z compact
massive galaxies not only their stellar mass, size and velocity dispersion but
also the shape of their profiles and age of their stellar populations. This
makes these singular galaxies unique laboratories to explore the early stages
of the formation of massive galaxies.
View original:
http://arxiv.org/abs/1202.4328
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