Astronomers discover square galaxy.
ABSTRACT(pdf)
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′′ = 1.2
kpc) for which Forbes et al. reported vrot/ 1.4. We speculate that this galaxymay 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.
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