Environmental Effects on Galaxy Evolution. II. Quantifying the Tidal Features in NIR Images of the Cluster Abell 85

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Venkatapathy, Y (Author) Other; Bravo Alfaro, H (Author) Other; Mayya, YD (Author) Other; Lobo, C (Author) FCUP; Durret, F (Author) Other; Gamez, V (Author) Other; Valerdi, M (Author) Other; Granados Contreras, AP (Author) Other; Navarro Poupard, F (Author) Other

Journal

Title: Astronomical Journal

Vol. 154

Final page: 227

ISSN: 0004-6256

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Other information

Authenticus ID: P-00N-D8Z

DOI: 10.3847/1538-3881/aa8df8

Abstract (EN): This work is part of a series of papers devoted to investigating the evolution of cluster galaxies during their infall. In the present article, we image in NIR a selected sample of galaxies throughout the massive cluster Abell 85 (z = 0.055). We obtain (JHK') photometry for 68 objects, reaching similar to 1 mag arcsec(-2) deeper than 2MASS. We use these images to unveil asymmetries in the outskirts of a sample of bright galaxies and develop a new asymmetry index, alpha An, which allows us to quantify the degree of disruption by the relative area occupied by the tidal features on the plane of the sky. We measure the asymmetries for a subsample of 41 large-area objects, finding clear asymmetries in 10 galaxies; most of these are in groups and pairs projected at different clustercentric distances, and some of them are located beyond R-500. Combining information on the H I gas content of blue galaxies and the distribution of substructures across Abell 85 with the present NIR asymmetry analysis, we obtain a very powerful tool to confirm that tidal mechanisms are indeed present and are currently affecting a fraction of galaxies in Abell 85. However, when comparing our deep NIR images with UV blue images of two very disrupted (jellyfish) galaxies in this cluster, we discard the presence of tidal interactions down to our detection limit. Our results suggest that ram-pressure stripping is at the origin of such spectacular disruptions. We conclude that across a complex cluster like Abell 85, environmental mechanisms, both gravitational and hydrodynamical, are playing an active role in driving galaxy evolution.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 18