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Title: The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds

Abstract

We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance from the center of the MW, and velocity within the MW halo, are used to evaluate the likelihood that a given halo would have each or all of these properties; the posterior probability distribution function (PDF) for any property of the MW system can thus be constructed. This method provides a constraint on the MW virial mass, 1.2{sup +0.7} - {sub 0.4}(stat.){sup +0.3} - {sub 0.3}(sys.) x 10{sup 12} M {circle_dot} (68% confidence), which is consistent with recent determinations that involve very different assumptions. In addition, we calculate the posterior PDF for the density profile of the MW and its satellite accretion history. Although typical satellites of 10{sup 12} M {circle_dot} halos are accreted over a wide range of epochs over the last 10 Gyr,more » we find a {approx}72% probability that the MCs were accreted within the last Gyr, and a 50% probability that they were accreted together.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1035492
Report Number(s):
SLAC-PUB-14631
Journal ID: ISSN 0004-637X; ASJOAB; arXiv:1011.2203; TRN: US201204%%652
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Astrophys.J.743:40,2011
Additional Journal Information:
Journal Volume: 743; Journal Issue: 1; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DISTRIBUTION FUNCTIONS; GALAXIES; MAGELLANIC CLOUDS; MASS DISTRIBUTION; MILKY WAY; NONLUMINOUS MATTER; PROBABILITY; SATELLITES; SIMULATION; UNIVERSE; VELOCITY; Astrophysics,ASTRO

Citation Formats

Busha, Michael T, /KIPAC, Menlo Park /Zurich U., Marshall, Philip J, /KIPAC, Menlo Park /Oxford U., Wechsler, Risa H, /KIPAC, Menlo Park /SLAC, Klypin, Anatoly, /New Mexico State U., Primack, Joel, and /UC, Santa Cruz, Phys. Dept. The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds. United States: N. p., 2012. Web.
Busha, Michael T, /KIPAC, Menlo Park /Zurich U., Marshall, Philip J, /KIPAC, Menlo Park /Oxford U., Wechsler, Risa H, /KIPAC, Menlo Park /SLAC, Klypin, Anatoly, /New Mexico State U., Primack, Joel, & /UC, Santa Cruz, Phys. Dept. The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds. United States.
Busha, Michael T, /KIPAC, Menlo Park /Zurich U., Marshall, Philip J, /KIPAC, Menlo Park /Oxford U., Wechsler, Risa H, /KIPAC, Menlo Park /SLAC, Klypin, Anatoly, /New Mexico State U., Primack, Joel, and /UC, Santa Cruz, Phys. Dept. 2012. "The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds". United States. https://www.osti.gov/servlets/purl/1035492.
@article{osti_1035492,
title = {The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds},
author = {Busha, Michael T and /KIPAC, Menlo Park /Zurich U. and Marshall, Philip J and /KIPAC, Menlo Park /Oxford U. and Wechsler, Risa H and /KIPAC, Menlo Park /SLAC and Klypin, Anatoly and /New Mexico State U. and Primack, Joel and /UC, Santa Cruz, Phys. Dept.},
abstractNote = {We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance from the center of the MW, and velocity within the MW halo, are used to evaluate the likelihood that a given halo would have each or all of these properties; the posterior probability distribution function (PDF) for any property of the MW system can thus be constructed. This method provides a constraint on the MW virial mass, 1.2{sup +0.7} - {sub 0.4}(stat.){sup +0.3} - {sub 0.3}(sys.) x 10{sup 12} M {circle_dot} (68% confidence), which is consistent with recent determinations that involve very different assumptions. In addition, we calculate the posterior PDF for the density profile of the MW and its satellite accretion history. Although typical satellites of 10{sup 12} M {circle_dot} halos are accreted over a wide range of epochs over the last 10 Gyr, we find a {approx}72% probability that the MCs were accreted within the last Gyr, and a 50% probability that they were accreted together.},
doi = {},
url = {https://www.osti.gov/biblio/1035492}, journal = {Astrophys.J.743:40,2011},
issn = {0004-637X},
number = 1,
volume = 743,
place = {United States},
year = {Wed Feb 29 00:00:00 EST 2012},
month = {Wed Feb 29 00:00:00 EST 2012}
}