The Origin of the Magellanic Stream and Its Leading Arm
Open Access
- 20 May 2008
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 679 (1), 432-459
- https://doi.org/10.1086/587042
Abstract
We explore the Magellanic Stream (MS) using a Gaussian decomposition of the HI velocity profiles in the Leiden-Argentine-Bonn (LAB) all-sky HI survey. This decomposition exposes the MS to be composed of two filaments distinct both spatially (as first pointed out by Putman et al.) and in velocity. Using the velocity coherence of the filaments, one can be traced back to its origin in what we identify as the SouthEast HI Overdensity (SEHO) of the Large Magellanic Cloud (LMC), which includes 30 Doradus. Parts of the Leading Arm (LA) can also be traced back to the SEHO in velocity and position. Therefore, at least one-half of the trailing Stream and most of the LA originates in the LMC, contrary to previous assertions that both the MS and the LA originate in the Small Magellanic Cloud (SMC) and/or in the Magellanic Bridge. The two MS filaments show strong periodic, undulating spatial and velocity patterns that we speculate are an imprint of the LMC rotation curve. If true, then the drift rate of the Stream gas away from the Magellanic Clouds is ~49 km/s and the age of the MS is ~1.74 Gyr. The Staveley-Smith et al. high-resolution HI data of the LMC show gas outflows from supergiant shells in the SEHO that seem to be creating the LA and LMC filament of the MS. Blowout of LMC gas is an effect not previously accounted for but one that probably plays an important role in creating the MS and LA.Keywords
Other Versions
This publication has 100 references indexed in Scilit:
- Feedback from multiple supernova explosions inside a wind-blown bubbleNew Astronomy, 2007
- The Magellanic Bridge: The Nearest Purely Tidal Stellar PopulationThe Astrophysical Journal, 2007
- TheSpitzerSurvey of the Small Magellanic Cloud: S3MC Imaging and Photometry in the Mid‐ and Far‐Infrared Wave BandsThe Astrophysical Journal, 2007
- Exploring Halo Substructure with Giant Stars. XI. The Tidal Tails of the Carina Dwarf Spheroidal Galaxy and the Discovery of Magellanic Cloud Stars in the Carina ForegroundThe Astrophysical Journal, 2006
- The Parkes H I Survey of the Magellanic SystemAstronomy & Astrophysics, 2005
- The Star Formation History of the Small Magellanic CloudThe Astronomical Journal, 2004
- Deep H I observations of the compact high-velocity cloud HVC 125+41-207Astronomy & Astrophysics, 2001
- Structure of the Large Magellanic Cloud from 2MASSThe Astrophysical Journal, 2001
- A high sensitivity Hi survey of the sky at δ ≤ -25°Astronomy and Astrophysics Supplement Series, 2000
- The UM/CTIO Magellanic Cloud Emission-line SurveyPublications of the Astronomical Society of Australia, 1998