Direct imaging of haloes and truncations in face-on nearby galaxies

Knapen, J. H.; Peters, Stephan; van der Kruit, Piet; Trujillo, I.; Fliri, J.; Cisternas, M.
Bibliographical reference

IAU General Assembly, Meeting #29, #2256853

Advertised on:
8
2015
Number of authors
6
IAC number of authors
4
Citations
0
Refereed citations
0
Description
We use ultra-deep imaging from the IAC Stripe82 Legacy Project to study the surface photometry of 22 nearby, face-on to moderately inclined spiral galaxies. The reprocessed and co-added SDSS/Stripe82 imaging allows us to probe the galaxy down to 29-30 r‧-magnitudes/arcsec2 and thus reach into the very faint outskirts of the galaxies. We find extended stellar haloes in over half of our sample galaxies, and truncations in three of them. The presence of stellar haloes and truncations is mutually exclusive, and we argue that the presence of a stellar halo can hide a truncation. We find that the onset of the halo and the truncation scales tightly with galaxy size. Interestingly, the fraction of light does not correlate with dynamic mass. We highlight the importance of a proper analysis of the extended wings of the point spread function (PSF), finding that around half the light at the faintest levels is from the inner regions, though not the nucleus, of a galaxy, re-distributed to the outskirts by the PSF. We discuss implications of this effect for future deep imaging surveys, such as with the LSST.