Intracluster light in the Virgo cluster: large scale distribution

Abstract

Aims. The intracluster light (ICL) is a faint diffuse stellar component of clusters made of stars that are not bound to individual galaxies. We have carried out a large scale study of this component in the nearby Virgo cluster. Methods. The diffuse light is traced using planetary nebulae (PNe). The surveyed areas were observed with a narrow-band filter centered on the [OIII]λ5007 Å emission line redshifted to the Virgo cluster distance (the on-band image), and a broad-band filter (the off-band image). For some fields, additional narrow band imaging data corresponding to the Hα emission were also obtained. The PNe are detected in the on-band image due to their strong emission in the [OIII]λ5007 Å line, but disappear in the off-band image. The contribution of Ly-α emitters at z = 3.14 are corrected statistically using blank field surveys, when the Hα image at the field position is not available. Results. We have surveyed a total area of 3.3 square degrees in the Virgo cluster with eleven fields located at different radial distances. Those fields located at smaller radii than 80 arcmin from the cluster center contain most of the detected diffuse light. In this central region of the cluster, the ICL has a surface brightness in the range μ B = 28.8−30 mag arsec −2 , it is not uniformly distributed, and represents about 7% of the total galaxy light in this area. At distances larger than 80 arcmin the ICL is confined to single fields and individual sub-structures, e.g. in the sub-clump B, the M 60/M 59 group. For several fields at 2 and 3 degrees from the Virgo cluster center we set only upper limits. Conclusions. These results indicate that the ICL is not homogeneously distributed in the Virgo core, and it is concentrated in the high density regions of the Virgo cluster, e.g. the cluster core and other sub-structures. Outside these regions, the ICL is confined within areas of ∼100 kpc in size, where tidal effects may be at work. These observational results link the formation of the ICL with the formation history of the most luminous cluster galaxies.

EVOLUTION OF BRIGHTEST CLUSTER GALAXY STRUCTURAL PARAMETERS IN THE LAST ∼6 Gyr: FEEDBACK PROCESSES VERSUS MERGER EVENTS

“…Although the origin of such extended envelopes is still not completely clear, Patel et al (2006) claimed that the extended stellar halos of the BCGs are likely from the BCGs themselves (see also the works on M87; Arnaboldi et al 2004;Doherty et al 2009). These extended stellar halos are not part of the so-called intracluster light (ICL) formed by non-bounded stars and observed in some nearby clusters (Arnaboldi et al 2002;Aguerri et al 2005;Gerhard et al 2007;Castro-Rodríguez et al 2009). They are formed by stars gravitationally bounded to the BCG.…”

Detection of the Stellar Intracluster Medium in Perseus (Abell 426)

“…For nearby cluster environments (Virgo, Fornax, Coma) the ICL has been probed through resolution into individual stars including red-giant stars (Ferguson et al 1998;Williams et al 2007), planetary nebula (Feldmeier et al 2003;Arnaboldi et al 2007;Castro-Rodriguéz et al 2009;Ventimiglia et al 2011;Longobardi et al 2013), and even novae and supernovae (Neill et al 2005;Gal-Yam et al 2003;McGee & Balogh 2010;Sand et al 2011;Graham et al 2015). But another prominent tracer of the ICL that has so far been underutilized is the globular cluster (GC) population, which accompanies all types of old stellar populations in galaxies.…”

VEGAS: A VST Early-type GAlaxy Survey

“…It has been detected either through direct deep imaging (Mihos et al 2005) or using planetary nebulae as stellar light tracers (ICPNe, e.g., Arnaboldi et al 2002;Aguerri et al 2005). In the area around NGC 4472, evidence of ICL has been obtained with PNe by Feldmeier et al (2004) (see also Castro-Rodriguéz et al 2009 for a summary of ICPNe observations over a range of Virgo cluster-centric distances). However, none of these studies has addressed a detailed 2D distribution of the ICL around NGC 4472 and its connection with the giant galaxy.…”