Improved distances and ages for stars common to TGAS and RAVE

McMillan, Paul J.; Kordopatis, Georges; Kunder, Andrea; Binney, James; Wojno, Jennifer; Zwitter, Tomaž; Steinmetz, Matthias; Bland-Hawthorn, Joss; Gibson, Brad K.; Gilmore, Gerard; Grebel, Eva K.; Helmi, Amina; Munari, Ulisse; Navarro, Julio F.; Parker, Quentin A.; Seabroke, George; Watson, Fred; Wyse, Rosemary F.G.

Abstract

We combine parallaxes from the first Gaia data release with the spectrophotometric distance estimation framework for stars in the fifth RAVE survey data release. The combined distance estimates are more accurate than either determination in isolation – uncertainties are on average two times smaller than for RAVE-only distances (three times smaller for dwarfs), and 1.4 times smaller than TGAS parallax uncertainties (two times smaller for giants). We are also able to compare the estimates from spectrophotometry to those from Gaia, and use this to assess the reliability of both catalogues and improve our distance estimates. We find that the distances to the lowest log g stars are, on average, overestimated and caution that they may not be reliable. We also find that it is likely that the Gaia random uncertainties are smaller than the reported values. As a by-product we derive ages for the RAVE stars, many with relative uncertainties less than 20 per cent. These results for 219 566 RAVE sources have been made publicly available, and we encourage their use for studies that combine the radial velocities provided by RAVE with the proper motions provided by Gaia. A sample that we believe to be reliable can be found by taking only the stars with the flag notification ‘flag_any=0’.

Citation

McMillan, P. J., Kordopatis, G., Kunder, A., Binney, J., Wojno, J., Zwitter, T., Steinmetz, M., Bland-Hawthorn, J., Gibson, B. K., Gilmore, G., Grebel, E. K., Helmi, A., Munari, U., Navarro, J. F., Parker, Q. A., Seabroke, G., Watson, F., & Wyse, R. F. (2018). Improved distances and ages for stars common to TGAS and RAVE. Monthly notices of the Royal Astronomical Society, 477(4), 5279-5300. https://doi.org/10.1093/MNRAS/STY990

• Journal Article Type: Article
• Acceptance Date: Apr 18, 2018
• Online Publication Date: Apr 21, 2018
• Publication Date: Jul 11, 2018
• Deposit Date: Jun 22, 2018
• Publicly Available Date: Jun 25, 2018
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 477
• Issue: 4
• Pages: 5279-5300
• DOI: https://doi.org/10.1093/MNRAS/STY990
• Keywords: Methods: statistical; Galaxy: fundamental parameters; Galaxy: kinematics and dynamics; Galaxy: structure
• Public URL: https://hull-repository.worktribe.com/output/889268
• Publisher URL: https://academic.oup.com/mnras/article-abstract/477/4/5279/4980952?redirectedFrom=fulltext
• Contract Date: Jun 22, 2018