Potential Direct Single-Star Mass Measurement

We analyze the light curve 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 light curve shows clear signs of distortion...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2004-11, Vol.615 (1), p.450-459
Main Authors: Ghosh, H, DePoy, D. L, Gal-Yam, A, Gaudi, B. S, Gould, A, Han, C, Lipkin, Y, Maoz, D, Ofek, E. O, Park, B.-G, Pogge, R. W, Salim, S, Abe, F, Bennett, D. P, Bond, I. A, Eguchi, S, Furuta, Y, Hearnshaw, J. B, Kamiya, K, Kilmartin, P. M, Kurata, Y, Masuda, K, Matsubara, Y, Muraki, Y, Noda, S, Okajima, K, Rattenbury, N. J, Sako, T, Sekiguchi, T, Sullivan, D. J, Sumi, T, Tristram, P. J, Yanagisawa, T, Yock, P. C. M, Udalski, A, Soszyński, I, Wyrzykowski, Ł, Kubiak, M, Szymański, M. K, Pietrzyński, G, Szewczyk, O, Żebruń, K, Albrow, M. D, Beaulieu, J.-P, Caldwell, J. A. R, Cassan, A, Coutures, C, Dominik, M, Donatowicz, J, Fouqué, P, Greenhill, J, Hill, K, Horne, K, Jørgensen, U. G, Kane, S, Kubas, D, Martin, R, Menzies, J, Pollard, K. R, Sahu, K. C, Wambsganss, J, Watson, R, Williams, A
Format: Article
Language:English
Subjects:
Astrophysics
Cosmology and Extra-Galactic Astrophysics
Physics
Sciences of the Universe
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We analyze the light curve 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 light curve shows clear signs of distortion due to the Earth's accelerated motion, which yields a measurement of the projected Einstein radius r sub(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 k sub(rel) and so the mass M = (c super(2)/4G)k sub(rel)t sub(E) r sub(E), where t sub(E) is the measured Einstein timescale. While the light-curve-based measurement of r sub(E) is, by itself, severely degenerate, we show that this degeneracy can be completely resolved by measuring the direction of proper motion k sub(rel).
ISSN:0004-637X
1538-4357
DOI:10.1086/423665