LEDA 074886: A remarkable rectangular-looking galaxy

Дата и время публикации : 2012-03-16T03:10:25Z

Авторы публикации и институты :
Alister W. Graham
Lee R. Spitler
Duncan A. Forbes
Thorsten Lisker
Ben Moore
Joachim Janz

Ссылка на журнал-издание: (2012) ApJ, 750, 121
Коментарии к cтатье: To appear in ApJ. Six pages including references and figures
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO

Краткий обзор статьи: 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 2R_{e,disk} = 12 arcsec = 1.2 kpc) for which Forbes et al. reported V_rot/sigma ~ 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 a_4/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.

Category: Physics