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Gaps in the GD-1 Star Stream

Carlberg, R. G. and Grillmair, C. J. (2013) Gaps in the GD-1 Star Stream. Astrophysical Journal, 768 (2). Art. No. 171. ISSN 0004-637X. doi:10.1088/0004-637X/768/2/171.

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GD-1 is a long, thin, Milky Way star stream that has readily visible density variations along its length. We quantify the locations, sizes, and statistical significance of the density structure, i.e., gaps, using a set of scaled filters. The shapes of the filters are based on the gaps that develop in simulations of dark matter sub-halos crossing a star stream. The high Galactic latitude 8.4 kpc long segment of GD-1 that we examine has 8 ± 3 gaps of 99% significance or greater, with the error estimated on the basis of tests of the gap-filtering technique. The cumulative distribution of gaps more than three times the width of the stream is in good agreement with predictions for dark matter sub-halo encounters with cold star streams. The number of gaps narrower than three times the width of the GD-1 stream falls well below the cold stream prediction which is taken into account for the gap creation rate integrated over all sizes. Simple warm stream simulations scaled to GD-1 show that the falloff in gaps is expected for sub-halos below a mass of 10^6 M_☉. The GD-1 gaps requires 100 sub-halos >10^6 M_☉ within 30 kpc, the apocenter of GD-1 orbit. These results are consistent with LCDM sub-halo predictions but further improvements in stream signal-to-noise and gap modeling will be welcome.

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Grillmair, C. J.0000-0003-4072-169X
Additional Information:© 2013 American Astronomical Society. Received 2012 December 31; accepted 2013 April 2; published 2013 April 25. This research was supported by CIFAR and NSERC Canada. Thoughtful comments from an anonymous referee lead to improvements in content and presentation. The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. The Participating Institutions are the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, University of Cambridge, Case Western Reserve University, University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max-Planck-Institute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington. Facility: Sloan
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Canadian Institute for Advanced Research (CIFAR)UNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Subject Keywords:dark matter; galaxies: dwarf; Local Group
Issue or Number:2
Record Number:CaltechAUTHORS:20130605-083146754
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Official Citation:Gaps in the GD-1 Star Stream R. G. Carlberg and C. J. Grillmair doi:10.1088/0004-637X/768/2/171
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:38800
Deposited By: Ruth Sustaita
Deposited On:05 Jun 2013 15:47
Last Modified:09 Nov 2021 23:40

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