Skip navigation
  • INAF logo
  • Home
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects
  • Explore by
    • Research outputs
    • Researchers
    • Organization units
    • Projects
  • Login:
    • My DSpace
    • Receive email
      updates
    • Edit Account details
  • Italian
  • English

  1. OA@INAF
  2. PRODOTTI RICERCA INAF
  3. 1 CONTRIBUTI IN RIVISTE (Journal articles)
  4. 1.01 Articoli in rivista
Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12386/29540
Title: Fossil group origins. X. Velocity segregation in fossil systems
Authors: Zarattini, S.
Aguerri, J. A. L.
BIVIANO, ANDREA 
Girardi, M.
Corsini, E. M.
D'Onghia, E.
Issue Date: 2019
Journal: ASTRONOMY & ASTROPHYSICS 
Number: 631
First Page: A16
Abstract: Aims: We aim to study how the velocity segregation and the radial profile of the velocity dispersion depend on the prominence of the brightest cluster galaxies (BCGs). Methods: We divided a sample of 102 clusters and groups of galaxies into four bins of magnitude gap between the two brightest cluster members. We then computed the velocity segregation in bins of absolute and relative magnitude. Moreover, for each bin of magnitude gap we computed the radial profile of the velocity dispersion. Results: When using absolute magnitudes, the segregation in velocity is limited to the two brightest bins and no significant difference is found for different magnitude gaps. However, when we use relative magnitudes, a trend appears in the brightest bin: the larger the magnitude gap, the larger the velocity segregation. We also show that this trend is mainly due to the presence, in the brightest bin, of satellite galaxies in systems with small magnitude gaps: in fact, if we study central galaxies and satellites separately, this trend is mitigated and central galaxies are more segregated than satellites for any magnitude gap. A similar result is found in the radial velocity dispersion profiles: a trend is visible in central regions (where the BCGs dominate) but, if we analyse the profile using satellites alone, the trend disappears. In the latter case, the shape of the velocity dispersion profile in the centre of the systems with different magnitude gaps shows three types of behaviour: systems with the smallest magnitude gaps have an almost flat profile from the centre to the external regions; systems with the largest magnitude gaps show a monothonical growth from the low values of the central part to the flat ones in the external regions; and finally, systems with 1.0 < ∆m<SUB>12</SUB> ≤ 1.5 show a profile that peaks in the centre and then decreases towards the external regions. Conclusions: We suggest that two mechanisms could be responsible for the observed differences in the velocity segregation of the BCGs: an earlier formation of systems with a larger magnitude gap or a more centrally concentrated halo. However, the radial profiles of the velocity dispersion confirm that central galaxies are more relaxed, but that the satellite galaxies do not seem to be affected by the magnitude gap.
URI: http://hdl.handle.net/20.500.12386/29540
URL: https://www.aanda.org/articles/aa/full_html/2019/11/aa34689-18/aa34689-18.html
ISSN: 0004-6361
DOI: 10.1051/0004-6361/201834689
Bibcode ADS: 2019A&A...631A..16Z
Fulltext: open
Appears in Collections:1.01 Articoli in rivista

Files in This Item:
File Description SizeFormat
fogo_segreg.pdfPDF editoriale500.36 kBAdobe PDFView/Open
Show full item record

Page view(s)

41
checked on Feb 4, 2023

Download(s)

10
checked on Feb 4, 2023

Google ScholarTM

Check

Altmetric

Altmetric


Items in DSpace are published in Open Access, unless otherwise indicated.


Explore by
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects

Informazioni e guide per autori

https://openaccess-info.inaf.it: tutte le informazioni sull'accesso aperto in INAF

Come si inserisce un prodotto: le guide a OA@INAF

La Policy INAF sull'accesso aperto

Documenti e modelli scaricabili

Feedback
Built with DSpace-CRIS - Extension maintained and optimized by Logo 4SCIENCE