A Morphological Type Dependence in the μ0-log h Plane of Spiral Galaxy Disks

Graham, Alister W.; de Blok, W. J. G.
Bibliographical reference

The Astrophysical Journal, Volume 556, Issue 1, pp. 177-180.

Advertised on:
7
2001
Number of authors
2
IAC number of authors
1
Citations
37
Refereed citations
31
Description
We present observational evidence for a galaxy ``type'' dependence to the location of a spiral galaxy's disk parameters in the μ0-logh plane. With a sample of approximately 40 low surface brightness galaxies (both bulge- and disk-dominated) and approximately 80 high surface brightness galaxies, the early-type disk galaxies (<=Sc) tend to define a bright envelope in the μ0-logh plane, while the late-type (>=Scd) spiral galaxies have, in general, smaller and fainter disks. Below the defining surface brightness threshold for a low surface brightness galaxy (i.e., more than 1 mag fainter than the 21.65 B mag arcsec-2 Freeman value), the early-type spiral galaxies have scale lengths greater than 8-9 kpc, while the late-type spiral galaxies have smaller scale lengths. All galaxies have been modeled with a seeing-convolved Sérsic r1/n bulge and exponential disk model. We show that the trend of decreasing bulge shape parameter n with increasing Hubble type and decreasing bulge-to-disk luminosity ratio, which has been observed among the high surface brightness galaxies, extends to the low surface brightness galaxies, revealing a continuous range of structural parameters.