Microlensing with Hubble
Abstract
Microlensing can be used to study dark matter, galactic structure, and to search for extra-solar planets. However, a significant problem with microlensing is the mass determination of the lens. Typically, microlensing events provides only a single measured quantity that depends on the lens mass, the Einstein angle crossing time, τ, which also depends on the distances to the lens and source as well as the relative transverse velocity. Thus, it is difficult to derive unique mass estimates for the lens. Non-degenerate solutions are possible, as was shown by Alcock et al. for MACHO LMC-5, when the source and lens can be resolved. It may be possible to distinguish between the lens and source by re-observing a microlensing candidate years after the first observation. As it turns out, a substantial number of fields containing microlensing events have been observed by the Hubble Space Telescope (HST). We currently have identified over 180 possible matches to lensing events. In many of these cases, there was a time difference of years between the HST observation (or observations) and the ground-based detection. We present initial results from our archival program and discuss the implications for future studies.
- Publication:
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American Astronomical Society Meeting Abstracts #224
- Pub Date:
- June 2014
- Bibcode:
- 2014AAS...22441101G