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Title: GALACTO-FORENSIC OF LARGE MAGELLANIC CLOUD'S ORBITAL HISTORY AS A PROBE FOR THE DARK MATTER POTENTIAL IN THE OUTSKIRTS OF THE GALAXY

Abstract

The three-dimensional observed velocities of the Large and Small Magellanic Clouds (LMC and SMC) provide an opportunity to probe the Galactic potential in the outskirt of the Galactic halo. Based on a canonical NFW model of the Galactic potential, Besla et al. reconstructed LMC and SMC's orbits and suggested that they are currently on their first perigalacticon passage about the Galaxy. Motivated by several recent revisions of the Sun's motion around the Galactic center, we re-examine the LMC's orbital history and show that it depends sensitively on the dark matter's mass distribution beyond its present Galactic distance. We utilize results of numerical simulations to consider a range of possible structural and evolutionary models for the Galactic potentials. We find that within the theoretical and observational uncertainties, it is possible for the LMC to have had multiple perigalacticon passages on the Hubble timescale, especially if the Galactic circular velocity at the location of the Sun is greater than {approx}228 km s{sup -1}. Based on these models, a more accurate determination of the LMC's motion may be used to determine the dark matter distribution in the outskirt of the Galactic halo.

Authors:
 [1];  [2];  [3];  [4]
  1. Department of Astronomy, Peking University, Beijing 100871 (China)
  2. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)
  3. University Observatory Munich, Scheinerstrasse 1, D-81679 Munich (Germany)
  4. Max-Planck-Institute for Astrophysics, Karl-Schwarzschild-Strasse 1, D-85741 Garching (Germany)
Publication Date:
OSTI Identifier:
22086412
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 759; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; COMPUTERIZED SIMULATION; COSMOLOGY; DISTANCE; GALACTIC EVOLUTION; MAGELLANIC CLOUDS; MASS DISTRIBUTION; NONLUMINOUS MATTER; ORBITS; POTENTIALS; PROBES; SUN; THREE-DIMENSIONAL CALCULATIONS; VELOCITY

Citation Formats

Zhang Xiaojia, Lin, Douglas N. C., Burkert, Andreas, and Oser, Ludwig, E-mail: xiaojia.f.zhang@gmail.com. GALACTO-FORENSIC OF LARGE MAGELLANIC CLOUD'S ORBITAL HISTORY AS A PROBE FOR THE DARK MATTER POTENTIAL IN THE OUTSKIRTS OF THE GALAXY. United States: N. p., 2012. Web. doi:10.1088/0004-637X/759/2/99.
Zhang Xiaojia, Lin, Douglas N. C., Burkert, Andreas, & Oser, Ludwig, E-mail: xiaojia.f.zhang@gmail.com. GALACTO-FORENSIC OF LARGE MAGELLANIC CLOUD'S ORBITAL HISTORY AS A PROBE FOR THE DARK MATTER POTENTIAL IN THE OUTSKIRTS OF THE GALAXY. United States. doi:10.1088/0004-637X/759/2/99.
Zhang Xiaojia, Lin, Douglas N. C., Burkert, Andreas, and Oser, Ludwig, E-mail: xiaojia.f.zhang@gmail.com. Sat . "GALACTO-FORENSIC OF LARGE MAGELLANIC CLOUD'S ORBITAL HISTORY AS A PROBE FOR THE DARK MATTER POTENTIAL IN THE OUTSKIRTS OF THE GALAXY". United States. doi:10.1088/0004-637X/759/2/99.
@article{osti_22086412,
title = {GALACTO-FORENSIC OF LARGE MAGELLANIC CLOUD'S ORBITAL HISTORY AS A PROBE FOR THE DARK MATTER POTENTIAL IN THE OUTSKIRTS OF THE GALAXY},
author = {Zhang Xiaojia and Lin, Douglas N. C. and Burkert, Andreas and Oser, Ludwig, E-mail: xiaojia.f.zhang@gmail.com},
abstractNote = {The three-dimensional observed velocities of the Large and Small Magellanic Clouds (LMC and SMC) provide an opportunity to probe the Galactic potential in the outskirt of the Galactic halo. Based on a canonical NFW model of the Galactic potential, Besla et al. reconstructed LMC and SMC's orbits and suggested that they are currently on their first perigalacticon passage about the Galaxy. Motivated by several recent revisions of the Sun's motion around the Galactic center, we re-examine the LMC's orbital history and show that it depends sensitively on the dark matter's mass distribution beyond its present Galactic distance. We utilize results of numerical simulations to consider a range of possible structural and evolutionary models for the Galactic potentials. We find that within the theoretical and observational uncertainties, it is possible for the LMC to have had multiple perigalacticon passages on the Hubble timescale, especially if the Galactic circular velocity at the location of the Sun is greater than {approx}228 km s{sup -1}. Based on these models, a more accurate determination of the LMC's motion may be used to determine the dark matter distribution in the outskirt of the Galactic halo.},
doi = {10.1088/0004-637X/759/2/99},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}