20.500.12556/RUL-141911 The GALAH+ survey a new library of observed stellar spectra improves radial velocities and hints at motions within M67 GALAH+ is a magnitude-limited survey of high-resolution stellar spectra obtained by the HERMES spectrograph at the Australian Astronomical Observatory. Its third data release provides reduced spectra with new derivations of stellar parameters and abundances of 30 chemical elements for 584 015 dwarfs and giants, 88 per cent of them in the Gaia magnitude range 11 < G < 14. Here, we use these improved values of stellar parameters to build a library of observed spectra which is useful to study variations of individual spectral lines with stellar parameters. This and other improvements are used to derive radial velocities with uncertainties which are generally within 0.1 km s$^{−1}$ or ∼25 per cent smaller than in the previous release. Median differences in radial velocities measured here and by the Gaia DR2 or APOGEE DR16 surveys are smaller than 30 m s$^{−1}$, a larger offset is present only for Gaia measurements of giant stars. We identify 4483 stars with intrinsically variable velocities and 225 stars for which the velocity stays constant over ≥3 visits spanning more than a year. The combination of radial velocities from GALAH+ with distances and sky plane motions from Gaia enables studies of dynamics within streams and clusters. For example, we estimate that the open cluster M67 has a total mass of ∼3300 M$_⊙$ and its outer parts seem to be expanding, though astrometry with a larger time-span than currently available from Gaia eDR3 is needed to judge if the latter result is real. Galaxy spectroscopy kinematics dynamics methods data analysis surveys stars fundamental parameters open clusters and associations individual stars M67 true false true Angleški jezik Ni določen Članek v reviji 2022-10-11 12:15:34 2022-10-11 12:15:34 2022-11-09 03:54:41 0000-00-00 00:00:00 2021 0 0 Str. 4202-4215 iss. 3 Vol. 508 Dec. 2021 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 524.3 1365-2966 10.1093/mnras/stab2673 83933187 stab2673.pdf stab2673.pdf 1 791FDCB231030B38148EC35A9DA78ABD 19d4f024ef46cee67324f58549d4f0f09a42cb502053be30bfc06469716ef4ec 7e5472d6-5f37-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=163806 https://academic.oup.com/mnras/article/508/3/4202/6372926 0 dae9e887-494d-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=163090 Fakulteta za matematiko in fiziko 0 0 0