University of Oulu

Raj, M., Iodice, E., Napolitano, N., Spavone, M., Su, H., Peletier, R., Davis, T., Zabel, N., Hilker, M., Mieske, S., Falcon Barroso, J., Cantiello, M., van de Ven, G., Watkins, A., Salo, H., Schipani, P., Capaccioli, M., Venhola, A. (2019) The Fornax Deep Survey with the VST. Astronomy & Astrophysics, 628, A4. doi:10.1051/0004-6361/201935433

The Fornax Deep Survey with the VST : VII. Evolution and structure of late type galaxies inside the virial radius of the Fornax cluster

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Author: Raj, M. A.1,2; Iodice, E.1; Napolitano, N. R.1,3;
Organizations: 1INAF-Astronomical observatory of Capodimonte, via Moiariello 16, Naples 80131, Italy
2University of Naples “Federico II”, C.U, Monte Santangelo, Via Cinthia, 80126 Naples, Italy
3School of Physics and Astronomy, Sun Yat-sen University Zhuhai Campus, 2 Daxue Road, Tangjia, Zhuhai, Guangdong 519082, PR China
4Division of Astronomy, Department of Physics, University of Oulu, Oulu, Finland
5Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands
6School of Physics and Astronomy, Cardiff University, Queen’s Building, The Parade, Cardiff, CF24 3AA Wales, UK
7European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei Munchen, Germany
8European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile
9Instituto de Astrofìsica de Canarias, C Via Lactea s/n, 38200 La Laguna, Canary Islands, Spain
10Departamento de Astrofìsica, Universidad de La Laguna, 38200 La Laguna, Tenerife, Spain
11INAF-Astronomical Abruzzo Observatory, Via Maggini, 64100 Teramo, Italy
12Department of Astrophysics, University of Vienna, Türkenschanzstrasse, 17, 1180 Vienna, Austria
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 80.7 MB)
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Language: English
Published: EDP Sciences, 2019
Publish Date: 2019-08-16


Context: We present the study of a magnitude limited sample (mB ≤ 16.6 mag) of 13 late type galaxies (LTGs), observed inside the virial radius, Rvir ∼ 0.7 Mpc, of the Fornax cluster within the Fornax Deep Survey (FDS).

Aims: The main objective is to use surface brightness profiles and g − i colour maps to obtain information on the internal structure of these galaxies and find signatures of the mechanisms that drive their evolution in high-density environments inside the virial radius of the cluster.

Methods: By modelling galaxy isophotes, we extract the azimuthally averaged surface brightness profiles in four optical bands. We also derive g − i colour profiles, and relevant structural parameters like total magnitude and effective radius. For ten of the galaxies in this sample, we observe a clear discontinuity in their typical exponential surface brightness profiles, derive their “break radius”, and classify their disc-breaks into Type II (down-bending) or Type III (up-bending).

Results: We find that Type II galaxies have bluer average (g − i) colour in their outer discs while Type III galaxies are redder. The break radius increases with stellar mass and molecular gas mass while it decreases with molecular gas-fractions. The inner and outer scale-lengths increase monotonically with absolute magnitude, as found in other works. For galaxies with CO(1-0) measurements, there is no detected cold gas beyond the break radius (within the uncertainties). In the context of morphological segregation of LTGs in clusters, we also find that, in Fornax, galaxies with morphological type 5 <  T ≤ 9 (∼60% of the sample) are located beyond the high-density, ETG-dominated regions, however there is no correlation between T and the disc-break type. We do not find any correlation between the average (g − i) colours and cluster-centric distance, but the colour-magnitude relation holds true.

Conclusions: The main results of this work suggest that the disc-breaks of LTGs inside the virial radius of the Fornax cluster seem to have arisen through a variety of mechanisms (e.g. ram-pressure stripping, tidal disruption), which is evident in their outer-disc colours and the absence of molecular gas beyond their break radius in some cases. This can result in a variety of stellar populations inside and outside the break radii.

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Series: Astronomy and astrophysics
ISSN: 0004-6361
ISSN-E: 1432-0746
ISSN-L: 0004-6361
Volume: 628
Article number: A4
DOI: 10.1051/0004-6361/201935433
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: This publication has received funding from the European Union Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement n. 721463 to the SUNDIAL ITN network. This work is based on visitor mode observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under the following VST GTO programs: 094.B-0512(B), 094.B-0496(A), 096.B-0501(B), 096.B-0582(A). This research has made use of the NASA/IPAC Extragalactic Database(NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. E.I and M. S. acknowledge financial support from the VST project (P.I. P. Schipani). NRN acknowledges financial support from the “One hundred top talent program of Sun Yat-sen University”-grant N. 71000-18841229. GvdV acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 724857 (Consolidator Grant ArcheoDyn).
EU Grant Number: (721463) SUNDIAL - SUrvey Network for Deep Imaging Analysis and Learning
Copyright information: © ESO, 2019.