Abstract
We perform a search for stellar streams around the Milky Way using the first 3 yr of multiband optical imaging data from the Dark Energy Survey (DES). We use DES data covering ∼5000 deg2 to a depth of g > 23.5 with a relative photometric calibration uncertainty of <1%. This data set yields unprecedented sensitivity to the stellar density field in the southern celestial hemisphere, enabling the detection of faint stellar streams to a heliocentric distance of ∼50 kpc. We search for stellar streams using a matched filter in color-magnitude space derived from a synthetic isochrone of an old, metal-poor stellar population. Our detection technique recovers four previously known thin stellar streams: Phoenix, ATLAS, Tucana III, and a possible extension of Molonglo. In addition, we report the discovery of 11 new stellar streams. In general, the new streams detected by DES are fainter, more distant, and lower surface brightness than streams detected by similar techniques in previous photometric surveys. As a by-product of our stellar stream search, we find evidence for extratidal stellar structure associated with four globular clusters: NGC 288, NGC 1261, NGC 1851, and NGC 1904. The ever-growing sample of stellar streams will provide insight into the formation of the Galactic stellar halo, the Milky Way gravitational potential, and the large- and small-scale distribution of dark matter around the Milky Way.
| Original language | English |
|---|---|
| Article number | 114 |
| Journal | Astrophysical Journal |
| Volume | 862 |
| Issue number | 2 |
| DOIs | |
| State | Published - Aug 1 2018 |
Bibliographical note
Publisher Copyright:© 2018. The American Astronomical Society. All rights reserved.
Funding
The DES data management system is supported by the National Science Foundation under grant nos. AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015-71825, ESP2015-88861, FPA2015-68048, SEV-2012-0234, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013), including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project no. CE110001020. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungs-gemeinschaft, and the Collaborating Institutions in the Dark Energy Survey. This manuscript has been authored by Fermi Research Alliance, LLC, under contract no. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. Facility: Blanco (DECam). N.S. acknowledges support by NASA ATP grant NNH12ZDA001N and NSF grant AST-1412107 and thanks the LSSTC Data Science Fellowship Program; her time as a Fellow has benefited this work. E.B. acknowledges financial support from the European Research Council (ERC-StG-335936).
| Funders | Funder number |
|---|---|
| Australian Research Council Centre of Excellence for All-sky Astrophysics | CE110001020 |
| Collaborating Institutions in the Dark Energy Survey | |
| Deutsche Forschungs-gemeinschaft | |
| European Union’s Seventh Framework Program | |
| FP7/2007 | |
| Fermi Research Alliance, LLC | DE-AC02-07CH11359 |
| Kavli Institute of Cosmological Physics at the University of Chicago | |
| Ministry of Science and Education of Spain | |
| Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University | |
| National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign | |
| U.S. National Science Foundation | |
| National Science Foundation | AST-1138766, AST-1412107, AST-1536171 |
| U.S. Department of Energy | |
| National Aeronautics and Space Administration | NNH12ZDA001N |
| Office of Science | |
| High Energy Physics | |
| Seventh Framework Programme | 1138766, 240672, 306478, 335936, 291329 |
| Higher Education Funding Council for England | |
| Center for Cosmology and Astroparticle Physics, Ohio State University | |
| Engineering Research Centers | |
| Science and Technology Facilities Council | |
| European Commission | |
| European Research Council | |
| Generalitat de Catalunya | |
| Ministerio de Economía y Competitividad | ESP2015-88861, SEV-2016-0597, MDM-2015-0509, FPA2015-68048, SEV-2012-0234, AYA2015-71825 |
| Ministério da Ciência, Tecnologia e Inovação | |
| Conselho Nacional de Desenvolvimento Científico e Tecnológico | |
| Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro | |
| Financiadora de Estudos e Projetos | |
| European Regional Development Fund |
Keywords
- Galaxy: halo
- Galaxy: structure
- Local Group