Astrophysics, abstract
astro-ph/0611590

From: Tommy Grav [view email]

Date: Sat, 18 Nov 2006 02:33:24 GMT (435kb)

A deeper look at the color of Saturnian irregular satellites

Authors: T. Grav (Harvard-Smithsonian Center for Astrophysics and Institute for Astronomy, University of Hawaii), J. Bauer (Jet Propolsion Laboratory, California Institute of Technology)

Comments: 34 pages, with 11 figures and 5 tables

We have performed broadband color photometry of the twelve brightest irregular satellites of Saturn with the goal of understanding their surface composition, as well as their physical relationship. We find that the satellites have a wide variety of different surface colors, from the negative spectral slopes of the two retrograde satellites S IX Phoebe (S'=-2.5+/-0.4 %/100nm) and S XXV Mundilfari (S'=-5.0+/-1.9 %/100nm) to the fairly red slope of S XXII Ijiraq (S'=19.5+/-0.9 %/100nm). We further find that there exist a correlation between dynamical families and spectral slope, with the prograde clusters, the Gallic and Inuit, showing tight clustering in colors among most of their members. The retrograde objects are dynamically and physically more dispersed, but some internal structure is apparent.

http://arxiv.org/abs/astro-ph/0611590