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Potential Direct Single-Star Mass Measurement
- Source :
- The Astrophysical Journal, The Astrophysical Journal, American Astronomical Society, 2004, 615, pp.450
- Publication Year :
- 2004
- Publisher :
- HAL CCSD, 2004.
-
Abstract
- We analyze the lightcurve of the microlensing event OGLE-2003-BLG-175/MOA-2003-BLG-45 and show that it has two properties that, when combined with future high resolution astrometry, could lead to a direct, accurate measurement of the lens mass. First, the lightcurve shows clear signs of distortion due to the Earth's accelerated motion, which yields a measurement of the projected Einstein radius \tilde r_E. Second, from precise astrometric measurements, we show that the blended light in the event is coincident with the microlensed source to within about 15 mas. This argues strongly that this blended light is the lens and hence opens the possibility of directly measuring the lens-source relative proper motion \vec\mu_\rel and so the mass M=(c^2/4G)\mu_\rel t_E \tilde r_E, where t_E is the measured Einstein timescale. While the lightcurve-based measurement of \tilde r_E is, by itself, severely degenerate, we show that this degeneracy can be completely resolved by measuring the direction of proper motion \vec\mu_\rel.<br />Comment: 28 pages including 7 figures. Submitted to ApJ
- Subjects :
- Physics
Proper motion
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]
Degenerate energy levels
Astrophysics (astro-ph)
FOS: Physical sciences
Astronomy and Astrophysics
Astrophysics
Astrometry
Gravitational microlensing
[SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph]
01 natural sciences
Einstein radius
Distortion (mathematics)
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
Space and Planetary Science
Coincident
[PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
0103 physical sciences
Astrophysics::Earth and Planetary Astrophysics
010306 general physics
Degeneracy (mathematics)
010303 astronomy & astrophysics
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X and 15384357
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal, The Astrophysical Journal, American Astronomical Society, 2004, 615, pp.450
- Accession number :
- edsair.doi.dedup.....a37e9845ca840d7a9b2ca9cb1bd5e954