Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-08-07
Astrophys.J.663:960-989,2007
Astronomy and Astrophysics
Astrophysics
Accepted by Astrophysical Journal on March 15, 2007; 49 pages, 26 figures, uses emulateapj.cls
Scientific paper
10.1086/518302
We present a wide-field (4.5 deg^2) photometric and spectroscopic survey of the Leo I dwarf spheroidal (dSph) galaxy to explore its extended morphology and dynamics. As in previous papers in this series, we take advantage of photometry in the M, T_2, and DDO51 filter system to select LeoI red giant branch star candidates, and, so far, this selection technique has proven 100% reliable in selecting actual Leo I members among more than 100 M < 21.5 Leo I giant candidates having previous or new Keck DEIMOS spectroscopy to a radius >1.3 times the limiting radius of the fitted, central King profile. The two-dimensional distribution of all similarly-selected Leo I giant candidates is well fitted by a central single-component King profile of limiting radius 13.3 arcmin, but many giant stars are found outside this newly derived King limiting radius. The density profile thus shows a break at a major axis radial distance of ~10 arcmin produced by an excess of stars at and beyond the King limiting radius (spectroscopically confirmed to be made of true Leo I members), and primarily along the major axis of the main body of the rather elongated satellite. This spatial configuration, a rather flat velocity dispersion profile and an asymmetric radial velocity (RV) distribution among the Leo I members at large radii together support a picture where Leo I has been tidally disrupted on at least one, but at most two, perigalactic passages of a massive Local Group member. (abridged)
Cooper Martin C.
Guhathakurta Puraga
Johnston Kathryn V.
Kunkel William E.
Majewski Steven R.
No associations
LandOfFree
Exploring Halo Substructure with Giant Stars X. Extended Dark Matter or Tidal Disruption?: The Case for the Leo I Dwarf Spheroidal Galaxy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Exploring Halo Substructure with Giant Stars X. Extended Dark Matter or Tidal Disruption?: The Case for the Leo I Dwarf Spheroidal Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exploring Halo Substructure with Giant Stars X. Extended Dark Matter or Tidal Disruption?: The Case for the Leo I Dwarf Spheroidal Galaxy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-601557