A Caltech Library Service

Characterizing galaxy groups: spectroscopic observations of the Shakhbazyan sample

Capozzi, Diego and Spavone, Marilena and Barbati, Silvio and Paolillo, Maurizio and De Filippis, Elisabetta and Longo, Giuseppe (2012) Characterizing galaxy groups: spectroscopic observations of the Shakhbazyan sample. Monthly Notices of the Royal Astronomical Society, 426 (3). pp. 2019-2045. ISSN 0035-8711. doi:10.1111/j.1365-2966.2012.21825.x.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Groups of galaxies are the most common cosmic structures. However, due to the poor statistics, projection effects and the lack of accurate distances, our understanding of their dynamical and evolutionary status is still limited. This is particularly true for the so-called Shakhbazyan groups (SHK) which are still largely unexplored due to the lack of systematic spectroscopic studies of both their member galaxies and the surrounding environment. In our previous paper, we investigated the statistical properties of a large sample of SHK groups using Sloan Digital Sky Survey data and photometric redshifts. Here we present the follow-up of five SHK groups (SHK 10, 71, 75, 80, 259) observed within our spectroscopic campaign with the Telescopio Nazionale Galileo, aimed at confirming their physical reality and strengthening our photometric results. For each of the selected groups, we were able to identify between 6 and 13 spectroscopic members, thus confirming the robustness of the photometric redshift approach in identifying real galaxy over-densities. Consistently with the finding of our previous paper, the structures studied here have properties spanning from those of compact and isolated groups to those of loose groups. For what the global physical properties are concerned (total mass, mass-to-light ratios, etc.), we find systematic differences with those reported in the literature by previous studies. Our analysis suggests that previous results should be revisited; we show in fact that if the literature data are re-analysed in a consistent and homogeneous way, the properties obtained are in agreement with those estimated for our sample.

Item Type:Article
Related URLs:
URLURL TypeDescription
Spavone, Marilena0000-0002-6427-7039
Paolillo, Maurizio0000-0003-4210-7693
Longo, Giuseppe0000-0002-9182-8414
Additional Information:© 2012 The Authors. Monthly Notices of the Royal Astronomical Society © 2012 RAS. Accepted 2012 July 29. Received 2012 July 29; in original form 2012 January 11. Article first published online: 9 Oct. 2012. This study is based on observations made under the programme ID AOT18-TAC38 with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The authors thank the anonymous referee for his valuable comments. They also thank Ilaria Formicola for the help provided with the photometric pre-selection. DC acknowledges financial support from the University of Portsmouth and thanks Claudia Maraston and Lado Samushia for valuable discussions. MS acknowledges financial contribution from the ‘Fondi di Ateneo 2011’ (e.g. 60 per cent) of Padua University. MP acknowledges support from Miur grant PRIN 2009 and grant FARO 2011 from the Federico II University. GL wishes to thank the Department of Astronomy at the California Institute of Technology for support and hospitality.
Funding AgencyGrant Number
University of PortsmouthUNSPECIFIED
Padua UniversityUNSPECIFIED
Federico II UniversityPRIN 2009
Federico II UniversityFARO 2011
Subject Keywords:galaxies: evolution; galaxies: groups: individual: Shakhbazyan groups; galaxies: kinematics and dynamics; galaxies: photometry
Issue or Number:3
Record Number:CaltechAUTHORS:20121129-084307779
Persistent URL:
Official Citation:Capozzi, D., Spavone, M., Barbati, S., Paolillo, M., De Filippis, E. and Longo, G. (2012), Characterizing galaxy groups: spectroscopic observations of the Shakhbazyan sample. Monthly Notices of the Royal Astronomical Society, 426: 2019–2045. doi: 10.1111/j.1365-2966.2012.21825.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35719
Deposited By: Jason Perez
Deposited On:29 Nov 2012 20:54
Last Modified:09 Nov 2021 23:17

Repository Staff Only: item control page