New Dwarf Satellite Galaxy of Messier 83 Discovered

Astronomers have found a new dwarf satellite of Messier 83 (M83, also known as the Southern Pinwheel Galaxy) located some 85,000 light years from its host. This satellite galaxy was designated dw1335-29 and could be an irregular or a transition dwarf. The findings were presented in a paper published Nov. 30 on arXiv.org.

Messier 83 is one of the closest and brightest barred spiral galaxies. It is located about 15 million light years away in the constellation Hydra. Finding new satellites of galaxies beyond the Local Group such as Messier 83 could provide essential insights on galaxy formation in a cosmological context.

In 2015, the detection of 16 dwarf galaxy candidates near Messier 83 was announced. However, it remained unclear which of them were satellites of this galaxy. To confirm this, follow-up observations were needed to estimate reliable distances.

Now, a team of astronomers led by Andreia Carrillo of the University of Michigan used images from the Galaxy Halos, Outer disks, Substructure, Thick disks and Star clusters (GHOSTS) survey provided by the Hubble Space Telescope (HST) and data from the Very Large Telescope's (VLT) Visible MultiObject Spectrograph (VIMOS) to confirm that one of the 16 candidates is indeed a satellite of Messier 83.

Phys.Org Read more at: http://phys.org/news/2016-12-dwarf-satellite-galaxy-messier.html

Southern Pinwheel Galaxy (GIF)

Clip credit: ESO