Tidal Destruction in a Low-mass Galaxy Environment: The Discovery of Tidal Tails around DDO 44
Abstract
We report the discovery of a ≳1° (∼50 kpc) long stellar tidal stream emanating from the dwarf galaxy DDO 44, a likely satellite of Local Volume galaxy NGC 2403 located ∼70 kpc in projection from its companion. NGC 2403 is a roughly Large Magellanic Cloud (LMC) stellar-mass galaxy 3 Mpc away, residing at the outer limits of the M81 group. We are mapping a large region around NGC 2403 as part of our Magellanic Analogs’ Dwarf Companions and Stellar Halos survey, reaching point-source depths (90% completeness) of (g, i) = (26.5, 26.2). Density maps of old, metal-poor RGB stars reveal tidal streams extending on two sides of DDO 44, with the streams directed toward NGC 2403. We estimate total luminosities of the original DDO 44 system (dwarf and streams combined) to be M i,tot = -13.4 and M g,tot = -12.6, with ∼25%-30% of the luminosity in the streams. Analogs of ∼LMC-mass hosts with massive tidally disrupting satellites are rare in the Illustris simulations, especially at large separations such as that of DDO 44. The few analogs that are present in the models suggest that even low-mass hosts can efficiently quench their massive satellites.
Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2019
- DOI:
- 10.3847/1538-4357/ab4c32
- arXiv:
- arXiv:1906.08260
- Bibcode:
- 2019ApJ...886..109C
- Keywords:
-
- Dwarf spheroidal galaxies;
- Galaxy photometry;
- Galaxy interactions;
- Dwarf galaxies;
- Galaxy stellar halos;
- Tidal tails;
- 420;
- 611;
- 600;
- 416;
- 598;
- 1701;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in ApJ. Updated with minor changes in response to referee