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7 - Tutorial: Modeling tidal streams using N-body simulations

Published online by Cambridge University Press:  05 November 2013

By
J. Peñarrubia
Edited by
David Martínez-Delgado
J. Peñarrubia
Affiliation:
University of Cambridge
David Martínez-Delgado
Affiliation:
Max-Planck-Institut für Astronomie, Heidelberg
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Summary

7.1 Introduction: exercise goals

The main goal of this practical course is to build up a theoretical representation (N-body model) of the observed properties of the stellar stream associated to the globular cluster Palomar 5. Our priors are (i) a static (simplified) representation of the Milky Way potential, (ii) the position on the sky of the cluster remnant core, (iii) its heliocentric radial velocity, and (iv) its heliocentric distance.

We use the position of the stellar stream as detected in the Sloan Digital Sky Survey (SDSS) (see Grillmair and Dionatos, 2006) as observational constraints on the free-parameters of our models, which in this simplistic exercise correspond to the 2D-tangential components of the current velocity vector (i.e., proper motions) of Pal 5. Note that there are available measurements of Pal 5 proper motions. However, measuring those quantities for stellar systems as faint MV = —4.77 ± 0.20 and distant (D ≃ 21 kpc) as Pal 5 is subject to large observational uncertainties that translate into poorly constrained Galactocentric orbital parameters. To illustrate this issue, we adopt the Galactocentric proper motions of Pal 5 (μα,μδ) as free parameters that we derive from fitting the orientation of the stellar stream on the sky, and compare their values with measurements available in the literature. The second main goal of the exercise is thus to inspect the reliability of the existing proper motion measurements for Pal 5.

Type
Chapter
Information
Local Group Cosmology , pp. 226 - 232
Publisher: Cambridge University Press
Print publication year: 2013

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References

Binney, J. and Merrifield, M. 1998. Galactic Astronomy. Princeton, NJ: Princeton University Press.
Dehnen, W., Odenkirchen, M., Grebel, E. K., and Rix, H.-W. 2004. Modeling the disruption of the globular cluster Palomar 5 by Galactic tides. AJ, 127(May), 2753–2770.Google Scholar
Dinescu, D. I., Girard, T. M., and van Altena, W. F. 1999. Space velocities of globular clusters. III. Cluster orbits and halo substructure. AJ, 117(Apr.), 1792–1815.Google Scholar
Eke, V. R., Cole, S., and Frenk, C. S. 1996. Cluster evolution as a diagnostic for Omega. MNRAS, 282(Sept.), 263–280.Google Scholar
Fellhauer, M., Kroupa, P., Baumgardt, H., Bien, R., Boily, C. M., Spurzem, R., and Wassmer, N. 2000. SUPERBOX – an efficient code for collisionless galactic dynamics. New A, 5(Sept.), 305–326.Google Scholar
Grillmair, C. J. and Dionatos, O. 2006. dA 22° tidal tail for Palomar 5. ApJ, 641 (Apr.), L37–L39.Google Scholar
Hernquist, L. 1990. An analytical model for spherical galaxies and bulges. ApJ, 356(June), 359–364.Google Scholar
Kazantzidis, S., Mayer, L., Mastropietro, C., Diemand, J., Stadel, J., and Moore, B. 2004. Density profiles of cold dark matter substructure: implications for the missing satellites problem. ApJ, 608(June), 663–679.Google Scholar
King, I. R. 1966. The structure of star clusters. III. Some simple dynamical models. AJ, 71 (Feb.), 64.Google Scholar
Klypin, A., Zhao, H., and Somerville, R. S. 2002. ACDM-based models for the Milky Way and M31. I. Dynamical models. ApJ, 573(July), 597–613.Google Scholar
Miyamoto, M. and Nagai, R. 1975. Three-dimensional models for the distribution of mass in galaxies. PASJ, 27, 533–543.Google Scholar
Navarro, J. F., Frenk, C. S., and White, S. D. M. 1996. The structure of cold dark matter halos. ApJ, 462(May), 563.Google Scholar
Odenkirchen, M., and 9 colleagues 2003. The extended tails of Palomar 5: A 10° arc of globular cluster tidal debris. AJ, 126(Nov.), 2385–2407.Google Scholar
Peñarrubia, J., Benson, A. J., Martínez-Delgado, D., and Rix, H. W. 2006. Modeling tidal streams in evolving dark matter halos. ApJ, 645(July), 240–255.Google Scholar
Power, C., Navarro, J. F., Jenkins, A., Frenk, C. S., White, S. D. M., Springel, V., Stadel, J., and Quinn, T. 2003. The inner structure of ACDM haloes – I. A numerical convergence study. MNRAS, 338(Jan.), 14–34.Google Scholar
Scholz, R.-D., Irwin, M., Odenkirchen, M., and Meusinger, H. 1998. New space motion of Galactic globular cluster Palomar 5. A&A, 333(May), 531–539.Google Scholar
Schweitzer, A. E., Cudworth, K. M., and Majewski, S. R. 1993. Membership, photometry and kinematics of the globular star cluster PAL 5. The Globular Cluster-Galaxy Connection, 48(Jan.), 113.Google Scholar
Smith, G. H. 1985. Spectroscopy of red giants in the globular cluster Palomar 5. ApJ, 298(Nov.), 249–258.Google Scholar
Spergel, D. N., and 21 colleagues 2007. Three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: implications for cosmology. ApJS, 170(June), 377–408.Google Scholar

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