Bibcode
Comerón, Sébastien; Elmegreen, Bruce G.; Salo, Heikki; Laurikainen, Eija; Athanassoula, E.; Bosma, Albert; Knapen, J. H.; Gadotti, Dimitri A.; Sheth, Kartik; Hinz, Joannah L.; Regan, Michael W.; Gil de Paz, Armando; Muñoz-Mateos, Juan Carlos; Menéndez-Delmestre, Karín; Seibert, Mark; Kim, Taehyun; Mizusawa, Trisha; Laine, Jarkko; Ho, Luis C.; Holwerda, Benne
Bibliographical reference
The Astrophysical Journal, Volume 759, Issue 2, article id. 98, 29pp, (2012).
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11
2012
Journal
Citations
81
Refereed citations
77
Description
Breaks in the radial luminosity profiles of galaxies have until now been
mostly studied averaged over disks. Here, we study separately breaks in
thin and thick disks in 70 edge-on galaxies using imaging from the
Spitzer Survey of Stellar Structure in Galaxies. We built luminosity
profiles of the thin and thick disks parallel to midplanes and we found
that thin disks often truncate (77%). Thick disks truncate less often
(31%), but when they do, their break radius is comparable with that in
the thin disk. This suggests either two different truncation
mechanisms—one of dynamical origin affecting both disks
simultaneously and another one only affecting the thin disk—or a
single mechanism that creates a truncation in one disk or in both
depending on some galaxy property. Thin disks apparently antitruncate in
around 40% of galaxies. However, in many cases, these antitruncations
are an artifact caused by the superposition of a thin disk and a thick
disk, with the latter having a longer scale length. We estimate the real
thin disk antitruncation fraction to be less than 15%. We found that the
ratio of the thick and thin stellar disk mass is roughly constant (0.2
< MT /Mt < 0.7) for circular velocities
vc > 120 km s–1, but becomes much larger
at smaller velocities. We hypothesize that this is due to a combination
of a high efficiency of supernova feedback and a slower dynamical
evolution in lower-mass galaxies causing stellar thin disks to be
younger and less massive than in higher-mass galaxies.
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Our small group is well known and respected internationally for our innovative and important work on various aspects of the structure and evolution of nearby spiral galaxies. We primarily use observations at various wavelengths, exploiting synergies that allow us to answer the most pertinent questions relating to what the main properties of
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