Extinction bias of microlensed stars towards the LMC and the fraction of machos in the halo
arXiv:astro-ph/9907191 · doi:10.1086/308365
Abstract
We study the effect of reddening on microlensed stars towards the LMC. If lenses are in the LMC disk, then the source stars should be at the far side or behind the LMC disk. Thus they should experience more reddening and extinction by dust in the LMC disk than typical stars in the immediate neighbouring lines of sight. We simulate this effect in a variety of models for the LMC stars and dust. We stress that the optical depth is not one number, but a function of the reddening of the survey stars. We discuss how these effects could be used to constrain the fraction of machos in the dark halo. The effect of patchiness of dust can be controled by working with faint stars in the smallest patches of the sky around the microlensed stars. This can be done most effectively with the Hubble Space Telescope in the ultra-violet. The non-detection of the reddening bias would be strongly in favor of machos in the Galactic halo.
A longer Introduction and minor changes with text and figure format. 18 pages with 9 postscript figures. ApJ submitted
References in corpus (3)
Cited by in corpus (7)
- The Origin of the Microlensing Events Observed Towards the LMC and the Stellar Counterpart of the Magellanic Stream
- The MACHO Project Hubble Space Telescope Follow-Up: Preliminary Results on the Location of the Large Magellanic Cloud Microlensing Source Stars
- MACHO 96-LMC-2: Lensing of a Binary Source in the LMC and Constraints on the Lensing Object
- Constraining the Galactic Bar Parameters with Red Clump Giants
- Studying the Galactic Bulge Through Spectroscopy of Microlensed Sources: I. Theoretical Considerations
- Magnitude bias of microlensed sources towards the Large Magellanic Cloud
- Using Optical and Near-IR Photometry to Test MACHO Lens Candidates