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The orbital structure of the massive elliptical galaxy NGC 5846
Author(s) -
Das P.,
Gerhard O.,
Coccato L.,
Churazov E.,
Forman W.,
Finoguenov A.,
Böhringer H.,
Arnaboldi M.,
Capaccioli M.,
Cortesi A.,
Lorenzi F. de,
Douglas N. G.,
Freeman K. C.,
Kuijken K.,
Merrifield M. R.,
Napolitano N. R.,
Noordermeer E.,
Romanowsky A. J.
Publication year - 2008
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200811052
Subject(s) - physics , halo , galaxy , extrapolation , velocity dispersion , astrophysics , planetary nebula , mass distribution , elliptical galaxy , anisotropy , astronomy , stars , optics , mathematical analysis , mathematics
We use density and temperature profiles obtained from XMM‐Newton observations to derive a potential of NGC 5846 out to 11 R e , thus probing the mass distribution deep into the halo. The inferred circular velocity is significantly higher than the extrapolation of dynamical models implying a halo, more massive than previously thought. Using an I ‐band surfacebrightness profile and a projected velocity dispersion profile consisting of long‐slit kinematic measurements and planetary nebulae (PNe) velocity dispersions, we solve the Jeans equations, assuming a non‐rotating spherical system. The solutions suggest a highly radially anisotropic galaxy outside 0.7 R e with β ∼ 0.75. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)