A non-parametric method for measuring the local dark matter density
Number of Authors: 5
2016 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 459, no 4, 4191-4208 p.Article in journal (Refereed) Published
We present a new method for determining the local dark matter density using kinematic data for a population of tracer stars. The Jeans equation in the z-direction is integrated to yield an equation that gives the velocity dispersion as a function of the total mass density, tracer density, and the 'tilt' term that describes the coupling of vertical and radial motions. We then fit a dark matter mass profile to tracer density and velocity dispersion data to derive credible regions on the vertical dark matter density profile. Our method avoids numerical differentiation, leading to lower numerical noise, and is able to deal with the tilt term while remaining one dimensional. In this study we present the method and perform initial tests on idealized mock data. We also demonstrate the importance of dealing with the tilt term for tracers that sample a parts per thousand(3)1 kpc above the disc plane. If ignored, this results in a systematic underestimation of the dark matter density.
Place, publisher, year, edition, pages
2016. Vol. 459, no 4, 4191-4208 p.
Galaxy: disc, Galaxy: kinematics and dynamics, dark matter
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:su:diva-134291DOI: 10.1093/mnras/stw917ISI: 000379830700060OAI: oai:DiVA.org:su-134291DiVA: diva2:1029515