Milky Way mass models for orbit calculations

By A. Irrgang, Benjamin Wilcox, E. Tucker, Lucas Schiefelbein. 2012

162 citations recorded by the source corpus.

Studying the trajectories of objects like stars, globular clusters or satellite galaxies in the Milky Way allows to trace the dark matter halo but requires reliable models of its gravitational potential. Realistic, yet simple and fully analytical models have already been presented in the past. However, improved as well as new observational constraints have become available in the meantime calling for a recalibration of the respective model parameters. Three widely used model potentials are revisited. By a simultaneous least-squared fit to the observed rotation curve, in-plane proper motion of Sgr A*, local mass/surface density and the velocity dispersion in Baade's window, parameters of the potentials are brought up-to-date. The mass at large radii - and thus in particular that of the dark matter halo - is hereby constrained by imposing that the most extreme halo blue horizontal-branch star known has to be bound to the Milky Way. The Galactic mass models are tuned to yield a very good match to recent observations. The mass of the dark matter halo is - within the limitations of the applied models - estimated in a fully consistent way. As a first application, the trajectory of the hypervelocity star HE 0437-5439 is re-investigated to check its suggested origin in the Large Magellanic Cloud (LMC). Despite their simplicity, the presented Milky Way mass models are well able to reproduce all observational constraints. Their analytical and simple form makes them ideally suited for fast and accurate orbit calculations. The LMC cannot be ruled out as HE 0437-5439's birthplace.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/6dd14e2e949045e2e83ab8ca53efe0d5fd91eb52

How researchers see this paper

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In Astronomy and Astrophysics

1. A. Helmi
2. Joss Bland-Hawthorn
3. Simon D. M. White
4. I. Minchev
5. Volker Springel
6. J. Navarro
7. James S. Bullock
8. G. Gilmore

In Electrical and Electronic Engineering

1. A. Helmi
2. C. Scannapieco
3. J. Binney
4. Matthias Steinmetz
5. E. Grebel

In Instrumentation

1. Joss Bland-Hawthorn
2. A. Helmi
3. J. Navarro
4. Simon D. M. White
5. G. Gilmore
6. O. Gerhard
7. Kenneth C. Freeman
8. B. Gibson

Citations in the corpus

• ON THE SHOULDERS OF GIANTS: PROPERTIES OF THE STELLAR HALO AND THE MILKY WAY MASS DISTRIBUTION (2014, methodology): “This is largely similar to earlier works by e.g. Dehnen & Binney (1998); McMillan (2011); Irrgang et al. (2013) but includes detailed modeling of distant halo stars.”
• The RAVE survey : the Galactic escape speed and the mass of the Milky Way (2013, background): “The authors argue that this star should therefore be bound to the Milky Way (see also Irrgang et al. 2013).”
• Mean proper motions, space orbits, and velocity dispersion profiles of Galactic globular clusters derived fromGaiaDR2 data (2018, methodology): “Table 1 lists the values that we obtain for the Milky Way mass model presented in Table 1 of Irrgang et al. (2013).”