Geometrodynamical Distances to the Galaxy's Hydrogen Streams

Abstract

We present a geometrodynamical method for determining distances to orbital streams of HI gas in the Galaxy. The method makes use of our offset from the Galactic centre and assumes that the gas comprising the stream nearly follows a planar orbit about the Galactic centre. We apply this technique to the Magellanic Stream and determine the distances to all points along it; a consistency check shows that the angular momentum is approximately constant. Applying this technique to the Large Magellanic Cloud itself gives an independent distance which agrees within its accuracy of around 10%. Relaxing the demand for exact conservation of energy and angular momentum at all points along the stream allows for an increase in orbital period between the lagging end and the front end led by the Magellanic Clouds. Similar methods are applicable to other long streams of high-velocity clouds, provided they also nearly follow planar orbits; these would allow otherwise unknown distances to be determined.

9 pages, 7 figures; typos corrected after being accepted by MNRAS

References in corpus (12)

• Distances and Metallicities of High- and Intermediate-Velocity Clouds
• N-body Simulations of the Small Magellanic Cloud and the Magellanic Stream
• An Orphan in the "Field of Streams"
• Galactic Halo substructure in the Sloan Digital Sky Survey: the ancient tidal stream from the Sagittarius dwarf galaxy
• The gravitational and hydrodynamical interaction between the LMC and the Galaxy
• N-body simulations of the Magellanic Stream
• A Review of the Distance and Structure of the Large Magellanic Cloud
• Exploring Halo Substructure with Giant Stars IV: The Extended Structure of the Ursa Minor Dwarf Spheroidal
• The Galactic Nature of High Velocity Cloud Complex WB
• A Limit on the Metallicity of Compact High Velocity Clouds
• The Gaseous Trail of the Sagittarius Dwarf Galaxy
• Are Complex A and the Orphan Stream related?

Cited by in corpus (17)

• The Role of Dwarf Galaxy Interactions in Shaping the Magellanic System and Implications for Magellanic Irregulars
• The Tidal Origin of the Magellanic Stream and the Possibility of a Stellar Counterpart
• The COS/UVES Absorption Survey of the Magellanic Stream. III: Ionization, Total Mass, and Inflow Rate onto the Milky Way
• An HST/COS legacy survey of high-velocity ultraviolet absorption in the Milky Way's circumgalactic medium and the Local Group
• Stellar distances from spectroscopic observations: a new technique
• Fossil imprint of a powerful flare at the Galactic Centre along the Magellanic Stream
• Kinematics and simulations of the stellar stream in the halo of the Umbrella Galaxy
• The large-scale ionization cones in the Galaxy
• Constraining the Milky Way Halo Shape Using Thin Streams
• A Genetic Approach to the History of the Magellanic Clouds
• Gas Accretion onto the Milky Way
• Revealing the Ionization Properties of the Magellanic Stream using Optical Emission
• Probing the Structure and Kinematics of the transition Layer between the Magellanic Stream and the Halo in HI
• GCN: a gaseous Galactic halo stream?
• Inferring the dynamics of stellar streams via distance gradients
• Hydrodynamics of Clustered Clouds: Drafting, Survival, Condensation, and Ablation
• The Discovery and Origin of A Very-High Velocity Cloud Toward M33