Open Access0422−476: a shell galaxy with azimuthally distributed shells
Author(s) -
Wilkinson A.,
Prieur J.L.,
Lemoine R.,
Carter D.,
Malin D.,
Sparks W. B.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03418.x
Subject(s) - physics , galaxy , astrophysics , photometry (optics) , astronomy , lenticular galaxy , shell (structure) , stars , galaxy cluster , materials science , composite material
A morphological and two‐colour charge‐coupled device photometry study of the shell galaxy 0422−476, one of the richest known azimuthally distributed shell galaxies, is presented. Taking this galaxy as a prototype, a general method for reducing observational data of these objects is defined and quantitative parameters for use in further theoretical studies are derived. According to some recent models (e.g. that of Thomson and Wright in 1990), the shells in such a galaxy could be density waves induced in a thick disc population of dynamically cold stars by a weak interaction with another galaxy. In 0422−476 there is no evidence of either a conventional exponential disc or a thick disc. Although it is not possible to rule out the weak interaction model, the observations continue to favour the merger model (e.g. that of Quinn from 1984).