Back to Search
Start Over
The stellar mass distribution in early-type disc galaxies: surface photometry and bulge–disc decompositions
- Source :
- Monthly Notices of the Royal Astronomical Society, 376(4), 1480-1512. Oxford University Press
- Publication Year :
- 2007
- Publisher :
- Oxford University Press (OUP), 2007.
-
Abstract
- We present deep B- and R-band surface photometry for a sample of 21 galaxies with morphological types between S0 and Sab. We present radial profiles of surface brightness, colour, ellipticity, position angle and deviations of axisymmetry for all galaxies, as well as isophotal and effective radii and total magnitudes. We have decomposed the images into contributions from a spheroidal bulge and a flat disk, using an interactive, 2D decomposition technique. We study in detail the relations between various bulge and disk parameters. In particular, we find that the bulges of our galaxies have surface brightness profiles ranging from exponential to De Vaucouleurs, with the average value of the Sersic shape parameter n being 2.5. In agreement with previous studies, we find that the shape of the bulge intensity distribution depends on luminosity, with the more luminous bulges having more centrally peaked light profiles. By comparing the ellipticity of the isophotes in the bulges to those in the outer, disk dominated regions, we are able to derive the intrinsic axis ratio q_b of the bulges. The average axis ratio is 0.55, with an rms spread of 0.12. None of the bulges in our sample is spherical, whereas in some cases, the bulges can be as flat as q_b = 0.3 - 0.4. The bulge flattening seems to be weakly coupled to luminosity, more luminous bulges being on average slightly more flattened than their lower-luminosity counterparts. Our finding that most bulges are significantly flattened and have an intensity profile shallower than R^{1/4} suggests that `pseudobulges', formed from disk material by secular processes, do not only occur in late-type spiral galaxies, but are a common feature in early-type disk galaxies as well. (abridged)<br />Comment: 26 pages, 11 figures. Accepted for publication in MNRAS. A pdf-version with full resolution figures and the full atlas can be found at http://www.nottingham.ac.uk/~ppzen/surfphot.accepted.pdf
- Subjects :
- Stellar mass
FOS: Physical sciences
DWARF ELLIPTIC GALAXIES
galaxies : kinematics and dynamics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
galaxies : stellar content
STAR-FORMATION
Luminosity
SEYFERT-GALAXIES
Photometry (optics)
BRIGHTNESS PROFILES
IRREGULAR GALAXIES
galaxies : fundamental parameters
Bulge
galaxies : structure
Surface brightness
DOMINATED GALAXIES
Astrophysics::Galaxy Astrophysics
LENTICULAR GALAXIES
Physics
Spiral galaxy
galaxies : photometry
Astrophysics (astro-ph)
Astronomy and Astrophysics
WESTERBORK HI SURVEY
Position angle
Galaxy
Space and Planetary Science
SECULAR EVOLUTION
galaxies : spiral
SPIRAL GALAXIES
Subjects
Details
- ISSN :
- 13652966 and 00358711
- Volume :
- 376
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Accession number :
- edsair.doi.dedup.....c458d4b518f1b507bb77b13353b12f9f