Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/218388

Title

LEDA 074886: a remarkable rectangular-looking galaxy

Author(s)

Graham, Alister W.;  Spitler, Lee R.;  Forbes, Duncan A.;  Lisker, Thorsten;  Moore, Ben;  Janz, Joachim

Abstract

We report the discovery of an interesting and rare, rectangular-shaped galaxy. At a distance of 21 Mpc, the dwarf galaxy LEDA 074886 has an absolute R-band magnitude of -17.3 mag. Adding to this galaxy's intrigue is the presence of an embedded, edge-on stellar disk (of extent 2Re,disk = 12 arcseconds = 1.2 kpc) for which Forbes et al. reported Vrot/σ ∝ 1.4. We speculate that this galaxy may be the remnant of two (nearly edge-one) merged disk galaxies in which the initial gas was driven inward and subsequently formed the inner disk, while the stars at larger radii effectively experienced a dissipationless merger event resulting in this 'emerald cut galaxy' having very boxy isophotes with a4/a = -0.05 to -0.08 from 3 to 5 kpc. This galaxy suggests that knowledge from simulations of both 'wet' and 'dry' galaxy mergers may need to be combined to properly understand the various paths that galaxy evolution can take, with a particular relevance to blue elliptical galaxies.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Astrophysical Journal, Vol. 750, no. 2 (May 2012), article no. 121

Publication year

2012

FOR Code(s)

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

Keyword(s)

Dynamics;  Galaxy formation;  Galaxy structure;  Kinematics;  LEDA 074886

Publisher

Institute of Physics Publishing

ISSN

0004-637X

Publisher URL

http://dx.doi.org/10.1088/0004-637x/750/2/121

Publisher URL

http://www.swinburne.edu.au/chancellery/mediacentre/media-centre/news/2012/03/astronomers-discover-emerald-cut-galaxy

Publisher URL

http://blogs.discovery.com/inscider/2012/12/top-space-discoveries-of-2012.html

Copyright

Copyright © 2012 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 read an earlier version of the full text here: http://arxiv.org/abs/1203.3608.

Research Projects

Massive black holes in dense star clusters, Australian Research Council grant number DP110103509
The hearts of galaxies, Australian Research Council grant number FT110100263

Additional information

The research described in this article has been listed as one of the Top 5 Space Discoveries of 2012 by the Discovery Channel's science channel. See http://blogs.discovery.com/inscider/2012/12/top-space-discoveries-of-2012.html

Peer reviewed