Bibcode
Borlaff, A.; Eliche-Moral, M. C.; Beckman, J.; Font, J.
Bibliographical reference
Astronomy and Astrophysics, Volume 591, id.L7, 5 pp.
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6
2016
Journal
Citations
8
Refereed citations
8
Description
Previous numerical studies had apparently ruled out the possibility that
flares in galaxy discs could give rise to the apparent breaks in their
luminosity profiles when observed edge-on. However the studies have not,
until now, analysed this hypothesis systematically using realistic
models for the disc, the flare, and the bulge. We revisit this theme by
analysing a series of models which sample a wide range of
observationally based structural parameters for these three components.
Using observational data, we have considered realistic distributions of
bulge-to-disc ratios, morphological parameters of bulges and discs,
vertical scale heights of discs and their radial gradients defining the
flare for different morphological types and stellar mass bins. The
surface brightness profiles for the face-on and edge-on views of each
model were simulated to find out whether the flared disc produces a
Type-II break in the disc profile when observed edge-on, and if so under
what conditions. Contrary to previous claims, we find that discs with
realistic flares can produce significant breaks in discs when observed
edge-on. Specifically a flare with the parameters of that of the Milky
Way would produce a significant break of the disc at a RbrkII
of ~8.6 kpc if observed edge-on. Central bulges have no significant
effects on the results. These simulations show that flared discs can
explain the existence of many Type-II breaks observed in edge-on
galaxies, in a range of galaxies with intermediate to low break strength
values of -0.25