Nitya Kallivayalil
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Nitya Kallivayalil has a total of 12 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
2 shared publications - Charles Alcock
Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
2 shared publications - M. Geha
Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101
2 shared publications - Roeland P. van der Marel
Space Telescope Science Institute
2 shared publications - Tim Axelrod
Steward Observatory, The University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721
2 shared publications Brian M. Patten
1 shared publication
Latest Publications
- Open Access
Identification of the Microlens in Event MACHO-LMC-20
We report on the identification of the lens responsible for microlensing event MACHO-LMC-20. As part of a \textit{Spitzer}/IRAC program conducting mid-infrared follow-up of the MACHO Large Magellanic Cloud microlensing fields, we discovered a significant flux excess at the position of the source star for this event. These data, in combination with high resolution near-infrared \textit{Magellan}/PANIC data has allowed us to classify the lens as an early M dwarf in the thick disk of the Milky Way, at a distance of $\sim 2$ kpc. This is only the second microlens to have been identified, the first also being a M dwarf star in the disk. Together, these two events are still consistent with the expected frequency of nearby stars in the Milky Way thin and thick disks acting as lenses.Open AccessIdentification of the Microlens in Event MACHO-LMC-20
We report on the identification of the lens responsible for microlensing event MACHO-LMC-20. As part of a \textit{Spitzer}/IRAC program conducting mid-infrared follow-up of the MACHO Large Magellanic Cloud microlensing fields, we discovered a significant flux excess at the position of the source star for this event. These data, in combination with high resolution near-infrared \textit{Magellan}/PANIC data has allowed us to classify the lens as an early M dwarf in the thick disk of the Milky Way, at a distance of $\sim 2$ kpc. This is only the second microlens to have been identified, the first also being a M dwarf star in the disk. Together, these two events are still consistent with the expected frequency of nearby stars in the Milky Way thin and thick disks acting as lenses. - 20 February 2006
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 638 (2) , 772-785
The Proper Motion of the Large Magellanic Cloud UsingHST
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.Comment: 40 pages, 15 figures, submitted to Ap
- 20 February 2006
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 638 (2) , 772-785
The Proper Motion of the Large Magellanic Cloud UsingHST
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.Comment: 40 pages, 15 figures, submitted to Ap
- 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.