Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/225028

Title

Measuring the spin of spiral galaxies

Author(s)

Tonini, C.;  Lapi, A.;  Shankar, F.;  Salucci, P.

Abstract

We compute the angular momentum, the spin parameter, and the related distribution function for dark matter halos hosting a spiral galaxy. We rely on scaling laws, inferred from observations, that link the properties of the galaxy to those of the host halo; we further assume that the dark matter has the same total specific angular momentum of the baryons. Our main results are as follows: (1) We find that the gas component of the disk significantly contributes to the total angular momentum of the system. (2) By adopting for the dark matter the observationally supported Burkert profile, we compute the total angular momentum of the disk and its correlation with the rotation velocity. (3) We find that the distribution function of the spin parameter X peaks at a value of about 0.03, consistent with a no-major-merger scenario for the late evolution of spiral galaxies.

Publication type

Journal article

Source

Astrophysical Journal Letters, Vol. 638, no. 1 (Feb 2006), pp. L13-L16

Publication year

2006

FOR Code(s)

0201 Astronomical and Space Sciences;  0305 Organic Chemistry;  0306 Physical Chemistry (Incl. Structural)

Keyword(s)

Galaxies;  Galaxy formation;  Galaxy kinematics and dynamics;  Halos;  Spiral galaxies

Publisher

Institute of Physics Publishing

ISSN

2041-8205

Publisher URL

http://dx.doi.org/10.1086/500556

Copyright

Copyright © 2006 The American Astronomical Society. All rights reserved. The American Astronomical Society does not allow Swinburne Research Bank to archive either the accepted manuscript or the published version of the article. However you can find an earlier version of the full text here: http://arxiv.org/abs/astro-ph/0510577

Peer reviewed