Bibcode
Martín-Navarro, I.; Trujillo, I.; Bakos, J.; Knapen, J. H.
Bibliographical reference
Memorie della Societa Astronomica Italiana Supplement, v.25, p.25 (2013)
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2013
Citations
0
Refereed citations
0
Description
Departures from a simple exponential decay (usually called breaks or
truncations) in the surface brightness distribution of galaxy disks are
found in the vast majority of spirals. Understanding the origin of these
breaks and how they evolve with time are key to address the mechanisms
of galaxy growth. However, the community has encountered a significant
discrepancy among the results obtained when the galaxies are observed
face-on versus those cases where the projection is edge-on. In fact,
truncations in edge-on disks are found at much larger radial distances
than the breaks observed in face-on projections. In order to solve this
puzzle, we have explored a large collection of edge-on late-type spiral
galaxies using the SDSS and the S4G (Spitzer)
surveys. We observe that breaks and truncations are not the same
phenomena: we find both features coexisting in our spiral galaxies. We
propose a unified picture where breaks are likely caused by a threshold
in the star formation activity whereas truncations are associated to a
drop in the distribution of stars caused by the maximum angular momentum
of the disk. Our scheme is capable of unifying all the previous
observations into a simple picture.