Halo structure, masses of dark objects and parallax microlensing

dc.creatorMarkovic, D.
dc.date1997-08-11
dc.date.accessioned2026-07-25T20:28:50Z
dc.descriptionWe study the use of parallax microlensing to separate the effects of the mass function of dark massive halo objects (MHOs or `machos') on the one hand and their spatial distribution and kinematics on the other. This disentanglement is supposed to allow a much better determination of the two than could be achieved entirely on the basis of the durations of events. We restrict our treatment to the same class of power-law spherical models for the halo of MHOs studied in a previous paper (astro-ph/9609187). Whereas the duration-based error in the average MHO mass, μexceeds (at N=100 events) μby a factor of 2 or more, parallax microlensing remarkably brings it down to 15-20% of μ, regardless of the shape of the mass function. In addition, the slope αof the mass function, dn/dμ\proptoμ^α, can be inferred relatively accurately (σ_α < 0.4) for a broader range, -3 <α< 0. The improvement in the inference of the halo structure is also significant: the index γof the density profile (ρ\sim R^{-γ}) can be obtained with the error σ_γ <0.4. While in a typical situation the errors for the parameters specifying the velocity dispersion profile are of about the same magnitude as the parameters themselves, virtually all the uncertainty is `concentrated' in linear combinations of the parameters that may have little influence on the profile and thus allow its reasonably accurate inference.
dc.descriptionMNRAS LaTeX style, 14 pages, 13 multi-part figures embeded. Also available from http://www.tac.dk/~draza/papers/macho1.ps.Z
dc.identifierhttps://arxiv.org/abs/astro-ph/9708100
dc.identifierhttp://arxiv.org/abs/astro-ph/9708100
dc.identifier.urihttps://dspace.dare.co.zw/handle/123456789/71196
dc.subjectAstrophysics
dc.titleHalo structure, masses of dark objects and parallax microlensing
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