Gaia Spectroscopic Orbits Validated with LAMOST and GALAH Radial Velocities

Kavli Affiliate: Subo Dong

| First 5 Authors: Dolev Bashi, Sahar Shahaf, Tsevi Mazeh, Simchon Faigler, Subo Dong

| Summary:

The recently published Gaia DR3 catalog of 181 327 spectroscopic binaries
(SB) includes the Keplerian elements of each orbit, but not the measured radial
velocities (RVs) and their epochs themselves. Instead, the catalog lists a few
parameters that characterize the robustness of each solution. In this work, we
use two external sources to validate the orbits – 17 563 LAMOST DR6 and 6 018
GALAH DR3 stars with measured RVs that have Gaia-SB orbits. We compare the
expected RVs, based on the Gaia orbits, with the LAMOST and GALAH measurements.
Finding some orbits that are not consistent with these measurements, we
constructed a function that estimates the probability of each of the Gaia
orbits to be correct, using the published robust parameters. On this basis, we
devise a clean but still very large Gaia SB1 sample of 91 740 orbits. The
sample differs from the parent sample by the absence of – physically unlikely
and hence presumably spurious – short-period binaries with high eccentricity.
The clean SB1 sample offers the prospect of thorough statistical studies of the
binary population, after careful modeling of the remaining selection effects.
As a first step, we point to two possible emerging features – a circularized
main-sequence sub-sample, and a paucity of short-period low-mass primary
binaries

| Search Query: ArXiv Query: search_query=au:”Subo Dong”&id_list=&start=0&max_results=10

Read More