Edge-on Low Surface Brightness Galaxies in the SDSS and the Red Halo Phenomenon
Abstract
Extremely red halos have been detected around high surface brightness (HSB) disk galaxies, blue compact galaxies and, most recently, elliptical galaxies. We analyse the halo emission of a sample of 1199 edge-on low surface brightness (LSB) galaxies in the fourth data release of the Sloan Digital Sky Survey (SDSS-DR4). This total sample is divided by g-r colour limits into a blue Sample A (377 galaxies), a yellowish Sample B (436 galaxies) and a red Sample C (386 galaxies). Surface photometry is conducted on stacked images in the g-, r- and i-bands after masking out all unwanted sources, shifting to make the images superposible and homogeneously rescaling them to the same metric size. We are able to measure surface brightnesses as deep as m(r) ∼30 mag arcsec-2. Preliminary results point to the existence of spheroidal envelopes around LSB galaxies. The colour r-i plot indicates a prominent red colour excess in keeping with previous findings. Our data are in reasonable agreement with the explanation of this Red Halo Phenomenon as being due to low mass low metallicity stars. We also discuss other possible explanations for these results.
- Publication:
-
Galaxy Evolution across the Hubble Time
- Pub Date:
- May 2007
- DOI:
- 10.1017/S1743921306005199
- Bibcode:
- 2007IAUS..235...82C