TRACING SAGITTARIUS STRUCTURE WITH SDSS AND SEGUE IMAGING AND SPECTROSCOPY

Journal Article · Sat Aug 01 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/700/2/1282; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21313789

Yanny, Brian ^[1]; Newberg, Heidi Jo ^[2]; Johnson, Jennifer A ^[3]; Lee, Young Sun; Beers, Timothy C ^[4]; Bizyaev, Dmitry; Brewington, Howard; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Dan; Pan, Kaike; Simmons, Audrey; Snedden, Stephanie ^[5]; Fiorentin, Paola Re ^[6]; Harding, Paul ^[7]

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1. Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
2. Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute Troy, NY 12180 (United States)
3. Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
4. Department of Physics and Astronomy, CSCE: Center for the Study of Cosmic Evolution, and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)
5. Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States)
6. Department of Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia)
7. Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States)

We show that the Sagittarius dwarf tidal stream can be traced with very red K/M-giant stars, selected from Sloan Digital Sky Survey (SDSS) photometry. A subset of these stars are spectroscopically confirmed with SEGUE and SDSS spectra, and the distance scale of 2MASS and SDSS M giants is calibrated to the RR Lyrae distance scale. The absolute magnitude of the K/M-giant stars at the tip of the giant branch is M{sub g{sub 0}}=-1.0. The line-of-sight velocities of the M giant and blue horizontal-branch (BHB) stars that are spatially coincident with the Sgr dwarf tidal stream are consistent with those of previous authors, reinforcing the need for new models that can explain all of the Sgr tidal debris stream observations. We estimate stellar densities along the tidal tails that can be used to help constrain future models. The K/M giant, BHB, and F-turnoff stars in the lower surface brightness tidal stream that is adjacent to the main leading Sgr dwarf tidal tail have velocities and metallicities that are similar to those of the stars in the leading tidal tail. The ratio of K/M giants to BHBs and BHBs to F-turnoff stars are also similar for both branches of the leading tidal tail. We show that there is an additional low-metallicity tidal stream near the Sgr trailing tidal tail.

• OSTI ID: 21313789
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 700; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ABUNDANCE
BRIGHTNESS
GALAXIES
GIANT STARS
PHOTOMETRY
SPECTRA
SPECTROSCOPY