The PMA Catalogue: 420 million positions and absolute proper motions

Abstract

We present a catalogue that contains about 420 million absolute proper motions of stars. It was derived from the combination of positions from Gaia DR1 and 2MASS, with a mean difference of epochs of about 15 yr. Most of the systematic zonal errors inherent in the 2MASS Catalogue were eliminated before deriving the absolute proper motions. The absolute calibration procedure (zero-pointing of the proper motions) was carried out using about 1.6 million positions of extragalactic sources. The mean formal error of the absolute calibration is less than 0.35 mas yr−1. The derived proper motions cover the whole celestial sphere without gaps for a range of stellar magnitudes from 8 to 21 mag. In the sky areas where the extragalactic sources are invisible (the avoidance zone), a dedicated procedure was used that transforms the relative proper motions into absolute ones. The rms error of proper motions depends on stellar magnitude and ranges from 2–5 mas yr−1 for stars with 10 mag < G < 17 mag to 5–10 mas yr−1 for faint ones. The present catalogue contains the Gaia DR1 positions of stars for the J2015 epoch. The system of the PMA proper motions does not depend on the systematic errors of the 2MASS positions, and in the range from 14 to 21 mag represents an independent realization of a quasi-inertial reference frame in the optical and near-infrared wavelength range. The Catalogue also contains stellar magnitudes taken from the Gaia DR1 and 2MASS catalogues. A comparison of the PMA proper motions of stars with similar data from certain recent catalogues has been undertaken.

KiDS-SQuaD

“…Here, instead, we discuss three of the many possible validation procedures, for one or more classes of objects, performed using external data (from the Gaia astrometric survey, from the AllWISE infrared catalogue, and from the GAMA survey). Using an external dataset to validate catalogues obtained with ML techniques is a rather standard procedure, as already shown in for example , where the PMA (Akhmetov et al 2017) catalogue of proper motions was used to validate the purity of a sample of galaxies.…”

Development and Improvements of Computational Methods Implemented to the Colitec Software

“…After the estimation of the object's position the software starts the frames identification with the stellar catalogs (Akhmetov et al, 2017). This is a very difficult procedure because these catalogs contain more than billions objects with appropriate information about them including astrometric and photometric measurements.…”

Kinematics of the Milky Way From Velocities of Young Red Clump Giants Using the Pma and Gaia Dr2 Data

“…Àñòðîìåòðè÷íi êàòàëîãè, êiíåìàòèêà Ãàëàêòèêè, âëàñíi ðóõè çiðîê, ïðîìåíåâi øâèäêîñòi çiðîê, äiàãðàìà Ãåðöøïðóíãà-Ðàññåëà. DOI: http://dx.doi.org/10.18524/1810DOI: http://dx.doi.org/10.18524/ -4215.2018 On April 25, 2018 the second release of the Gaia mission (Gaia DR2) has came out (Gaia collaboration et al, 2016;Gaia collaboration et al, 2018b). Based on 22 month observational time baseline, it provides coordinates, proper motions and parallaxes for more than 1.3 bln stars distributed uniformly through the celestial sphere.…”

“…Stellar ages of the Gaia DR2 RV subsample used are not known but we have took advantage of the known property of the secondary clump of red giants in the colourmagnitude diagram (CMD). Since the works by Girardi et al(1998) and Girardi (1999), the clump of stars located in the slightly bluer and fainter part of the CMD than the ordinary (main) clump of red giants is recognized as being formed by stars with initial masses M ≥ M Hef ∼ 2 − 2.5 M ⊙ in the stage of central helium burning (CHeB). The main dierence between giants belonging to the main and secondary clumps is that in the latter case stars reach the CHeB stage skipping the electron-degenerate core phase after the central hydrogen exhaustion, i.e.…”

“…The main dierence between giants belonging to the main and secondary clumps is that in the latter case stars reach the CHeB stage skipping the electron-degenerate core phase after the central hydrogen exhaustion, i.e. helium ignition begins under non-degenerate conditions (Girardi, 1999). Lifetimes of stars with masses M > 2 − 2.5M ⊙ do not exceed 2 Gyr.…”