Bibcode
Aguerri, J. A. L.; Castro-Rodríguez, N.; Napolitano, N.; Arnaboldi, M.; Gerhard, O.
Bibliographical reference
Astronomy and Astrophysics, Volume 457, Issue 3, October III 2006, pp.771-778
Advertised on:
10
2006
Journal
Citations
27
Refereed citations
25
Description
Context: .Compact groups are associations of a few galaxies in which the
environment plays an important role in galaxy evolution. The low group
velocity dispersion favors tidal interactions and mergers, which may
bring stars from galaxies to the diffuse intragroup light. Numerical
simulations of galaxy clusters in hierarchical cosmologies show that the
amount of the diffuse light increases with the dynamical evolution of
the cluster. Aims: .We search for diffuse light in the galaxy
group HCG 44 in order to determine its luminosity and luminosity
fraction. Combining with literature data, we aim to constrain the
dynamical status of Hickson compact groups. Methods: .We use Intra
Group planetary nebulae (IGPNe) as tracers of diffuse light. These are
detected by the so-called on band-off band technique. Results: .We
found 12 emission line objects in HCG 44, none of them associated with
the galaxies of the group. The absence of PNe in the elliptical galaxy,
NGC 3193, implies that this galaxy is located behind the group, leaving
only three spiral galaxy members in HCG 44. 6/12 emission line objects
are consistent with being IGPNe in HCG 44, but are also consistent with
being Lyα background galaxies. Thus we derive an upper limit to
the diffuse light fraction in HCG 44 of 4.7%, corresponding to
1.06× 109 L&sun;,B and mean surface
brightness of μB=30.04 mag arcsec-2. We find a
correlation between the fraction of elliptical galaxies and the amount
of diffuse light in Hickson compact groups. Those with large fraction of
diffuse light are those with large fractions in number and luminosity of
E/S0 galaxies. This indicates that the diffuse light is mainly created
in dynamical processes during the formation of bright elliptical
galaxies in major mergers. Conclusions: .We propose an
evolutionary sequence for Hickson compact groups in which the amount of
diffuse light increases with the dynamical evolution of the group.