Large-Scale Filamentary Structures Around the Virgo Cluster Revisited

Abstract

We revisit the filamentary structures of galaxies around the Virgo cluster, exploiting a larger dataset based on the HyperLeda database than previous studies. In particular, this includes a large number of low-luminosity galaxies, resulting in better sampled individual structures. We confirm seven known structures in the distance range 4 h −1 Mpc < SGY < 16 h −1 Mpc, now identified as filaments, where SGY is the axis of the supergalactic coordinate system roughly along the line of sight. The Hubble diagram of the filament galaxies suggests they are infalling toward the main-body of the Virgo cluster. We propose that the collinear distribution of giant elliptical galaxies along the fundamental axis of the Virgo cluster is smoothly connected to two of these filaments (Leo II A and B). Behind the Virgo cluster (16 h −1 Mpc < SGY < 27 h −1 Mpc), we also identify a new filament elongated toward the NGC 5353/4 group ("NGC 5353/4 filament") and confirm a sheet that includes galaxies from the W and M clouds of the Virgo cluster ("W-M sheet"). In the Hubble diagram, the NGC 5353/4 filament galaxies show infall toward the NGC 5353/4 group, whereas the W-M sheet galaxies do not show hints of gravitational influence from the Virgo cluster. The filamentary structures identified can now be used to better understand the generic role of filaments in the build-up of galaxy clusters at z ≈ 0.

The Active Assembly of the Virgo Cluster: Indications for Recent Group Infall From Early-type Dwarf Galaxies

“…Zhang et al 2015) and M87 deviating from the mean of the velocity distribution of galaxies, Binggeli et al (1987) concluded that even the Virgo cluster core is a dynamically young structure. Moreover, using the large number of low-mass galaxies has led to confirming several previously known structures around Virgo (Tully 1982) as filaments that likely feed the cluster with newly infalling galaxies (Kim et al 2016), similar to the findings of Adami et al (2009) for the Coma cluster.…”

“…Galaxies that are likely members of the so-called M and W clouds, located at a distance of 32 Mpc (Gavazzi et al 1999) in the western part of Virgo, are excluded from our working sample. This is also justified because the W-M-Sheet that encompasses those clouds is unlikely to be dynamically connected to Virgo (Kim et al 2016). Following Gavazzi et al (1999), our exclusion criterion is that a galaxy lies in the projected region of one of the clouds and has a velocity v LG relative to the Local Group larger than 1900 km s −1 (with v LG = v heliocen.…”

Ultraviolet and optical view of galaxies in the Coma Supercluster

“…Studies at high redshift (Fadda et al 2008;Geach et al 2011;Coppin et al 2012;Darvish et al 2014) as well as z ∼ 0 (e.g. Porter et al 2008;Mahajan, Haines, & Raychaudhury 2010;Haines et al 2011;Alpaslan et al 2016;Kim et al 2016;Kleiner et al 2017;Kuutma, Tamm, & Tempel 2017;Kraljic et al 2018) have now shown that the intermediate density environment prevalent in filaments not just bridge the gap between the dense interior of clusters and 'voids' devoid of galaxies, but play a rather important role in modulating galaxy observables. Owing to the highly coherent flow of galaxies along the filaments (González & Padilla 2009), they have not just been observed at all wavelengths ⋆ E-mail: smritimahajan@iisermohali.ac.in from ultraviolet (UV) (Gallazzi et al 2009;Geach et al 2011;Coppin et al 2012) to infrared (Fadda et al 2008;Haines, Gargiulo, & Merluzzi 2008) by direct methods such as quantifying the distribution of galaxies, thermal Sunyaev-Ze'ldovich (tSZ) effect (Bonjean et al 2018) and weak gravitational lensing (Dietrich et al 2012;Jauzac et al 2012), but also indirectly using a bent double lobe radio source (Edwards, Fadda, & Frayer 2010b).…”

Galaxy Groups Within 3500 km s−1

“…See also the discussion by Kim et al (2016). For the moment, we draw attention to the concentration of galaxies to the left of the Virgo Cluster, a structure de Vaucouleurs (1961) has called the Virgo Southern Extension.…”