Bibcode
Graham, Alister W.; Prieto, Mercedes
Bibliographical reference
Astrophysics and Space Science, v. 269/270, p. 653-654 (1999).
Advertised on:
12
1999
Journal
Citations
1
Refereed citations
1
Description
Recent studies have claimed that the Hubble sequence of late-type
spirals, and spirals in general, is scale-free. Within the photometric
data used in these works, a trend exists between morphological type and
bulge profile shape such that late-type spiral bulges are described by
an exponential luminosity profile, where-as the early-type spiral bulges
are better described by an r^1/2 or r^1/4 law. The universal application
of an exponential light-profile to the disk and bulge of all spiral
galaxies is not justified. Taking structural parameters from exponential
disk models and the best-fitting r^1/n bulge models (with n = 1, 2 or
4), the mean effective-bulge-radius to disk scale-length ratio (r_e/h)
increases at the 3σ significance level. Additionally, the
early-type spiral galaxies are shown to have a larger r_e/h ratio than
the late-type spirals in all passbands.