ar X iv : a st ro - p h / 99 07 19 1 v 1 1 4 Ju l 1 99 9 Extinction bias of microlensed stars towards the LMC and the fraction of machos in the halo
نویسنده
چکیده
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 ordinary stars in the immediate neighbouring lines of sight. Clearly such bias would not occur if the lenses are machos in the Galactic halo. 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. Subject headings: dust, extinction – Magellanic Clouds — Galaxy: structure
منابع مشابه
ar X iv : a st ro - p h / 99 06 21 4 v 2 2 5 O ct 1 99 9 Reddening of microlensed LMC stars vs . the location of the lenses HongSheng
We propose an observational test that can break the degeneracy of two main classes of microlensing models to the Magellanic Clouds: (a) the lenses are located in the Galactic halo, and (b) the lenses are located in the LMC disk. The source stars in the latter (self-lensing) models tend to be at the far side or behind the LMC disk, thus experience more reddening and extinction by dust in the LMC...
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