Fulltext

Unveiling the counter-rotating nature of the kinematically distinct core in NGC5813 with MUSE

Krajnović, Davor ; Weilbacher, Peter M. ; Urrutia, Tanya ; Emsellem, Eric ; Carollo, C. Marcella ; Shirazi, Maryam ; Bacon, Roland ; Contini, Thierry ; Epinat, Benoît ; Kamann, Sebastian ; Martinsson, Thomas ; Steinmetz, Matthias

In: Monthly Notices of the Royal Astronomical Society, 2015, vol. 452, no. 1, p. 2-18

Zum persönliche Liste hinzufügen
    Titel
    • Unveiling the counter-rotating nature of the kinematically distinct core in NGC5813 with MUSE
    Autor
    • Krajnović, Davor. Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany
    • Weilbacher, Peter M.. Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany
    • Urrutia, Tanya. Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany
    • Emsellem, Eric. ESO, European Southern Observatory, Karl-Schwarzschild Str. 2, D-85748 Garching bei Muenchen, Germany
    • Carollo, C. Marcella. ETH Zurich, Institute of Astronomy, Wolfgang-Pauli-Str. 27, CH-8093 Zurich, Switzerland
    • Shirazi, Maryam. ETH Zurich, Institute of Astronomy, Wolfgang-Pauli-Str. 27, CH-8093 Zurich, Switzerland
    • Bacon, Roland. CRAL, Observatoire de Lyon, CNRS, Université Lyon 1, 9 Avenue Ch. André, F-69561 Saint Genis Laval Cedex, France
    • Contini, Thierry. IRAP, Institut de Recherche en Astrophysique et Planétologie, CNRS, 14, avenue Edouard Belin, F-31400 Toulouse, France
    • Epinat, Benoît. IRAP, Institut de Recherche en Astrophysique et Planétologie, CNRS, 14, avenue Edouard Belin, F-31400 Toulouse, France
    • Kamann, Sebastian. IAG, Institut für Astrophysik, Universität Göttingen, Friedrich-Hund-Platz 1, D-37077Göttingen, Germany
    • Martinsson, Thomas. Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
    • Steinmetz, Matthias. Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany
    Dokumententyp
    • Postprint
    Sprache
    • Englisch
    Veröffentlicht in
    • Monthly Notices of the Royal Astronomical Society, 2015, vol. 452, no. 1, p. 2-18. Oxford University Press
    Andere elektronische Ausgabe
    OAI-PMH-ID
    • oai:doc.rero.ch:302661
    Summary
    Multi-Unit Spectroscopic Explorer (MUSE) observations of NGC5813 reveal a complex structure in the velocity dispersion map, previously hinted at by SAURON observations. The structure is reminiscent of velocity dispersion maps of galaxies comprising two counter-rotating discs, and might explain the existence of the kinematically distinct core (KDC). Further evidence for two counter-rotating components comes from the analysis of the higher moments of the stellar line-of-sight velocity distributions and fitting MUSE spectra with two separate Gaussian line-of-sight velocity distributions. The emission-line kinematics show evidence of being linked to the present cooling flows and the buoyant cavities seen in X-rays. We detect ionized gas in a nuclear disc-like structure, oriented like the KDC, which is, however, not directly related to the KDC. We build an axisymmetric Schwarzschild dynamical model, which shows that the MUSE kinematics can be reproduced well with two counter-rotating orbit families, characterized by relatively low angular momentum components, but clearly separated in integral phase space and with radially varying contributions. The model indicates that the counter-rotating components in NGC5813 are not thin discs, but dynamically hot structures. Our findings give further evidence that KDCs in massive galaxies should not necessarily be considered as structurally or dynamically decoupled regions, but as the outcomes of the mixing of different orbital families, where the balance in the distribution of mass of the orbital families is crucial. We discuss the formation of the KDC in NGC5813 within the framework of gas accretion, binary mergers and formation of turbulent thick discs from cold streams at high redshift