|
iDEA: Drexel E-repository and Archives >
Drexel Academic Community >
College of Arts and Sciences >
Department of Physics >
Faculty Research and Publications (Physics) >
Using astrometry to deblend microlensing events
Please use this identifier to cite or link to this item:
http://hdl.handle.net/1860/1918
|
| Title: | Using astrometry to deblend microlensing events |
| Authors: | Goldberg, David |
| Keywords: | Methods: Data Analysis
Gravitational Lensing |
| Issue Date: | 19-Aug-1997 |
| Publisher: | American Astronomical Society |
| Citation: | The Astrophysical Journal. 498, pp. 156. |
| Abstract: | We discuss the prospect of deblending microlensing events by observing
astrometric shifts of the lensed stars. Since microlensing searches are generally
performed in very crowded fields, it is expected that stars will be confusion
limited rather than limited by photon statistics. By performing simulations of
events in crowded fields, we find that if we assume a dark lens and that the
lensed star obeys a power law luminosity function, n(L) ∝ L− , over half the
simulated events show a measurable astrometric shift. Our simulations included
20000 stars in a 256 × 256 Nyquist sampled CCD frame. For = 2, we found
that 58% of the events were significantly blended (F∗/Ftot ≤ 0.9), and of those,
73% had a large astrometric shift (≥ 0.5 pixels). Likewise, for = 3, we found
that 85% of the events were significantly blended, and that 85% of those had
large shifts. Moreover, the shift is weakly correlated to the degree of blending,
suggesting that it may be possible not only to detect the existence of a blend,
but also to deblend events statistically using shift information. |
| URI: | http://arxiv.org/abs/astro-ph/9708172v1
http://hdl.handle.net/1860/1918 |
| Appears in Collections: | Faculty Research and Publications (Physics)
|
Items in iDEA are protected by copyright, with all rights reserved, unless otherwise indicated.
|
www.drexel.edu
