The Phoenix stream: A cold stream in the southern hemisphere
- Univ. of Surrey, Guildford (United Kingdom). et al.
In this study, we report the discovery of a stellar stream in the Dark Energy Survey (DES) Year 1 (Y1A1) data. The discovery was made through simple color-magnitude filters and visual inspection of the Y1A1 data. We refer to this new object as the Phoenix stream, after its resident constellation. After subtraction of the background stellar population we detect a clear signal of a simple stellar population. By fitting the ridge line of the stream in color-magnitude space, we find that a stellar population with age $$\tau=11.5\pm0.5$$ Gyr and $[Fe/H]<-1.6$ located 17.5$$\pm$$0.9 kpc from the Sun gives an adequate description of the stream stellar population. The stream is detected over an extension of 8$$^{\circ}.$$1 (2.5 kpc) and has a width of $$\sim$$54 pc assuming a Gaussian profile, indicating that a globular cluster is a probable progenitor. There is no known globular cluster within 5 kpc compatible with being the progenitor of the stream, assuming that the stream traces its orbit. We examined overdensities along the stream, however no obvious counterpart bound stellar system is visible in the coadded images. We also find overdensities along the stream that appear to be symmetrically distributed - consistent with the epicyclic overdensity scenario for the formation of cold streams - as well as a misalignment between the Northern and Southern part of stream. Despite the close proximity we find no evidence that this stream and the halo cluster NGC 1261 have a common accretion origin linked to the recently found EriPhe overdensity (Li et al. 2016).
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- Contributing Organization:
- DES Collaboration
- Grant/Contract Number:
- AC02-07CH11359; AC02-76SF00515
- OSTI ID:
- 1247527
- Alternate ID(s):
- OSTI ID: 1259213
- Report Number(s):
- arXiv:1509.04283; FERMILAB-PUB-16-041-AE; SLAC-PUB-16590; 1423504
- Journal Information:
- The Astrophysical Journal (Online), Vol. 820, Issue 1; ISSN 1538-4357
- Publisher:
- Institute of Physics (IOP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Discovery of a stellar overdensity in Eridanus–Phoenix in the Dark Energy Survey
The nature and orbit of the Ophiuchus stream