Kem H. Cook
Research Subjects
Research Interests
Kem H. Cook has a total of 6 co-authors. Here are the top co-authors by number of shared publications:
- A. J. Drake
Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
1 shared publication - Charles Alcock
Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
1 shared publication - M. Geha
Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101
1 shared publication - Nitya Kallivayalil
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138
1 shared publication - Roeland P. van der Marel
Space Telescope Science Institute
1 shared publication - Tim Axelrod
Steward Observatory, The University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721
1 shared publication
Latest Publications
- Open Access
The Proper Motion of the Large Magellanic Cloud using HST
We present a measurement of the systemic proper motion of the Large Magellanic Cloud (LMC) from astrometry with the High Resolution Camera (HRC) of the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). We observed LMC fields centered on 21 background QSOs that were discovered from their optical variability in the MACHO database. The QSOs are distributed homogeneously behind the central few degrees of the LMC. With 2 epochs of HRC data and a ~2 year baseline we determine the proper motion of the LMC to better than 5% accuracy: mu_W = -2.03 +/- 0.08 mas/yr; mu_N = 0.44 +/- 0.05 mas/yr. This is the most accurate proper motion measurement for any Milky Way satellite thus far. When combined with HI data from the Magellanic Stream this should provide new constraints on both the mass distribution of the Galactic Halo and models of the Stream.
Open AccessThe Proper Motion of the Large Magellanic Cloud using HST
We present a measurement of the systemic proper motion of the Large Magellanic Cloud (LMC) from astrometry with the High Resolution Camera (HRC) of the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). We observed LMC fields centered on 21 background QSOs that were discovered from their optical variability in the MACHO database. The QSOs are distributed homogeneously behind the central few degrees of the LMC. With 2 epochs of HRC data and a ~2 year baseline we determine the proper motion of the LMC to better than 5% accuracy: mu_W = -2.03 +/- 0.08 mas/yr; mu_N = 0.44 +/- 0.05 mas/yr. This is the most accurate proper motion measurement for any Milky Way satellite thus far. When combined with HI data from the Magellanic Stream this should provide new constraints on both the mass distribution of the Galactic Halo and models of the Stream.