Astron. Astrophys. 324, 80-90 (1997)

Tidally-triggered disk thickening

II. Results and interpretations

Vladimir Reshetnikov ^{1, 2} and Françoise Combes <sup>2

1</sup> Astronomical Institute of St. Petersburg State University, 198904 St. Petersburg, Russia
² DEMIRM, Observatoire de Paris, 61 Av. de l'Observatoire, F-75014 Paris, France

Received 15 October 1996 / Accepted 29 January 1997

Abstract

We have reported in a previous paper (Paper I) B,V and I band photometric data for a sample of 24 edge-on interacting spiral galaxies, together with a control sample of 7 edge-on isolated galaxies. We discuss here the main result found in this study: the ratio of the radial exponential scalelength h to the constant scaleheight is about twice smaller for interacting galaxies. This is found to be due both to a thickening of the plane, and to a radial stripping or shrinking of the stellar disk. If we believe that any galaxy experienced a tidal interaction in the past, we must conclude that continuous gas accretion and subsequent star formation can bring back the ratio to higher values, in a time scale of 1 Gyr.

Key words: galaxies: evolution, general, interactions, photometry, peculiar, spiral

Send offprint requests to: F. Combes, bottaro@obspm.fr

© European Southern Observatory (ESO) 1997

Online publication: May 26, 1998

helpdesk.link@springer.de