13,835 research outputs found
N-body simulations of the Magellanic Stream
A suite of high-resolution N-body simulations of the Magellanic Clouds --
Milky Way system are presented and compared directly with newly available data
from the HI Parkes All-Sky Survey (HIPASS). We show that the interaction
between Small and Large Magellanic Clouds results in both a spatial and
kinematical bifurcation of both the Stream and the Leading Arm. The spatial
bifurcation of the Stream is readily apparent in the HIPASS data, and the
kinematical bifurcation is also tentatively identified. This bifurcation
provides strong support for the tidal disruption origin for the Magellanic
Stream. A fiducial model for the Magellanic Clouds is presented upon completion
of an extensive parameter survey of the potential orbital configurations of the
Magellanic Clouds and the viable initial boundary conditions for the disc of
the Small Magellanic Cloud. The impact of the choice of these critical
parameters upon the final configurations of the Stream and Leading Arm is
detailed.Comment: Accepted by MNRAS, 07 Jun 2006. 14 pages, 14 figures, 3 tables. LaTeX
(mn2e.sty). File with decent resolution images (strongly recommended)
available at http://astronomy.swin.edu.au/~tconnors/publications/ .
References added; distance and HI-LOres difference figures added; clearer
figures; discussion added to, but conclusions unchange
The high-velocity clouds and the Magellanic Clouds
From an analysis of the sky and velocity distributions of the high-velocity
clouds (HVCs) we show that the majority of the HVCs has a common origin. We
conclude that the HVCs surround the Galaxy, forming a metacloud of 300 kpc in
size and with a mass of 3 10^9 M_sun, and that they are the product of a
powerful ``superwind'' (about 10^58 ergs), which occurred in the Magellanic
Clouds about 570 Myr ago as a consequence of the interaction of the Large and
Small Magellanic Clouds. The HVCs might be magnetic bubbles of semi-ionized
gas, blown from the Magellanic Clouds around 570 Myr ago, that circulate
largely through the halo of the Galaxy as a stream or flow of gas.Comment: 28 pages with 23 figure
Sub-millimeter to centimeter excess emission from the Magellanic Clouds. I. Global spectral energy distribution
In order to reconstruct the global SEDs of the Magellanic Clouds over eight
decades in spectral range, we combined literature flux densities representing
the entire LMC and SMC respectively, and complemented these with maps extracted
from the WMAP and COBE databases covering the missing the 23--90 GHz (13--3.2
mm) and the poorly sampled 1.25--250 THz (240--1.25 micron). We have discovered
a pronounced excess of emission from both Magellanic Clouds, but especially the
SMC, at millimeter and sub-millimeter wavelengths. We also determined accurate
thermal radio fluxes and very low global extinctions for both LMC and SMC.
Possible explanations are briefly considered but as long as the nature of the
excess emission is unknown, the total dust masses and gas-to-dust ratios of the
Magellanic Clouds cannot reliably be determined.Comment: Accepted for publication by A&
Stellar dust production and composition in the Magellanic Clouds
The dust reservoir in the interstellar medium of a galaxy is constantly being
replenished by dust formed in the stellar winds of evolved stars. Due to their
vicinity, nearby irregular dwarf galaxies the Magellanic Clouds provide an
opportunity to obtain a global picture of the dust production in galaxies. The
Small and Large Magellanic Clouds have been mapped with the Spitzer Space
Telescope from 3.6 to 160 {\mu}m, and these wavelengths are especially suitable
to study thermal dust emission. In addition, a large number of individual
evolved stars have been targeted for 5-40 {\mu}m spectroscopy, revealing the
mineralogy of these sources. Here I present an overview on the work done on
determining the total dust production rate in the Large and Small Magellanic
Clouds, as well as a first attempt at revealing the global composition of the
freshly produced stardust.Comment: accepted for publication by Earth, Planets & Spac
Spatial distribution of stellar populations in the Magellanic Clouds: Implementation to Gaia
The main goal of our project is to investigate the spatial distribution of
different stellar populations in the Magellanic Clouds. The results from
modelling the Magellanic Clouds can be useful, among others, for simulations
during the Gaia mission preparation. Isodensity contour maps have been used in
order to trace the morphology of the different stellar populations and estimate
the size of these structures. Moreover, star density maps are constructed
through star counts and projected radial density profiles are obtained. Fitting
exponential disk and King law curves to the spatial distribution allows us to
derive the structural parameters that describe these profiles. The
morphological structure and spatial distributions of various stellar components
in the Magellanic Clouds (young and intermediate age stars, carbon stars) along
with the overall spatial distribution in both Clouds are provided.Comment: 12 pages, 9 figures, to be published in Astronomy & Astrophysics;
typos and language correcte
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