Globular clusters: absolute proper motions and Galactic orbits A.A. Chemel, E.V. Glushkova, A.K. Dambis, A.S. Rastorguev, L.N. Yalyalieva, and A.D. Klinichev Astrophysical Bulletin, Vol. 73, P. 9999 (2018) Abstract: We cross-match objects from several different astronomical catalogs to determine the absolute proper motions of stars within the 30-arcmin radius fields of 115 Milky-Way globular clusters with the accuracy of 1--2 mas/yr. The proper motions are based on positional data recovered from the USNO-B1, 2MASS, URAT1, ALLWISE, UCAC5, and GAIA DR1 surveys with up to 10 positions spanning an epoch difference of up to 65 years, and reduced to GAIA DR1 TGAS frame using UCAC5 as the reference catalog. Cluster members are photometrically identified by selecting horizontal- and red-giant branch stars on color-magnitude diagrams, and the mean absolute proper motions of the clusters with a typical formal error of 0.4 mas/yr are computed by averaging the proper motions of selected members. The inferred absolute proper motions of clusters are combined with available radial-velocity data and heliocentric distance estimates to compute the cluster orbits in terms of the Galactic potential models based on Miyamoto and Nagai disk, Hernquist spheroid, and modified isothermal dark-matter halo (axisymmetric model without a bar) and the same model + rotating Ferre's bar (non-axisymmetric). Five distant clusters have higher-than-escape velocities, most likely due to large errors of computed transversal velocities, whereas the computed orbits of all other clusters remain bound to the Galaxy. Unlike previously published results, we find the bar to affect substantially the orbits of most of the clusters, even those at large Galactocentric distances, bringing appreciable chaotization, especially in the portions of the orbits close to the Galactic center, and stretching out the orbits of some of the thick-disk clusters. Description: Parameters of 110 Milky-Way globular clusters calculated with using of two models of Galactic gravitational potential: the first model contains only axisymmetric part of gravitational potential (Miyamoto and Nagai disk, Hernquist spheroid and modified isothermal dark matter halo), the second model contains Galactic bar also (Ferrer's potential model with n=2). File Summary: -------------------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------------------- ReadMe 80 . This file catnobar.txt 72 110 Catalog of GC's parameters in model without bar catbar.txt 104 110 Catalog of GC's parameters in model with bar -------------------------------------------------------------------------------------------- Byte-by-byte Description of file: catnobar.txt -------------------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------------------- 1- 8 A8 --- Name Cluster name 10- 15 F6.3 kpc Rmin_min Mininum pericentric distance 17- 22 F6.3 kpc Rmin_avg Average pericentric distance 24- 29 F6.3 kpc Rmax_max Maximum apocentric distance 31- 36 F6.3 kpc Rmax_avg Average apocentric distance 38- 43 F6.3 kpc Zmax_max Maximum distance from the symmetry plane of the Galaxy 45- 50 F6.3 kpc Zmax_avg Average distance from the symmetry plane of the Galaxy 52- 56 F5.3 --- e_avg Average eccentricity of the cluster orbit 58- 64 F7.3 (100 km/s)^2 E Total mechanical energy per unit mass of the cluster 66- 72 F7.3 100 kpc*km/s h Angular momentum per unit mass of the cluster --------------------------------------------------------------------------------------------- Byte-by-byte Description of file: catbar.txt --------------------------------------------------------------------------------------------- Bytes Format Units Label Explanations --------------------------------------------------------------------------------------------- 1- 8 A8 --- Name Cluster name 10- 15 F6.3 kpc Rmin_min Mininum pericentric distance 17- 22 F6.3 kpc Rmin_avg Average pericentric distance 24- 29 F6.3 kpc Rmax_max Maximum apocentric distance 31- 36 F6.3 kpc Rmax_avg Average apocentric distance 38- 43 F6.3 kpc Zmax_max Maximum distance from the symmetry plane of the Galaxy 45- 50 F6.3 kpc Zmax_avg Average distance from the symmetry plane of the Galaxy 52- 56 F5.3 --- e_avg Average eccentricity 58- 64 F7.3 (100 km/s)^2 Emin Minimum energy per unit mass of the cluster 66- 72 F7.3 (100 km/s)^2 Emax Miaximum energy per unit mass of the cluster 74- 80 F7.3 (100 km/s)^2 Eavg Average energy per unit mass of the cluster 82- 88 F7.3 100 kpc*km/s hmin Minimum angular momentum per unit mass of the cluster 90- 96 F7.3 100 kpc*km/s hmax Maximum angular momentum per unit mass of the cluster 98-104 F7.3 100 kpc*km/s havg Average angular momentum per unit mass of the cluster ---------------------------------------------------------------------------------------------