Pulkovo Compilation of Radial Velocities for 35495 Hipparcos Stars in a Common System

TL;DR

The Pulkovo Compilation of Radial Velocities (PCRV) provides a comprehensive, corrected dataset of radial velocities for nearly 35,500 Hipparcos stars, improving stellar kinematic studies within 500 parsecs of the Sun.

Contribution

This work compiles and calibrates radial velocities from numerous publications into a unified, systematic catalog with improved accuracy and zero-point corrections.

Findings

Median radial velocity accuracy of 0.7 km/s.

Identification of systematic discrepancies in published velocities.

Establishment of a set of secondary standards for calibration.

Abstract

The Pulkovo Compilation of Radial Velocities (PCRV) has been made to study the stellar kinematics in the local spiral arm. The PCRV contains weighted mean absolute radial velocities for 35 495 Hipparcos stars of various spectral types and luminosity classes over the entire celestial sphere mainly within 500 pc of the Sun. The median accuracy of the radial velocities obtained is 0.7 km s$^{-1}$. Results from 203 publications were used in the catalogue. Four of them were used to improve the radial velocities of standard stars from the IAU list. The radial velocities of 155 standard stars turned out to be constant within 0.3 km s$^{-1}$. These stars were used to analyze 47 768 mean radial velocities for 37 200 stars from 12 major publications ($\sim80\%$ of all the data used). Zero-point discrepancies and systematic dependences on radial velocity, $(B-V)$ color index, right ascension, and declination were found in radial velocity differences of the form "publication minus IAU list of standards". These discrepancies and dependences were approximated and taken into account when calculating the weighted mean radial velocities. 1128 stars whose independent radial-velocity determinations were available at least in three of these publications and agreed within 3 km s$^{-1}$ were chosen as the work list of secondary standards. Radial-velocity differences of the form "publication minus list of secondary standards" were used by analogy to correct the zero points and systematic dependences in the radial velocities from 33 more publications (~13\% of the data used). In addition, the radial velocities from 154 minor publications ($\sim7\%$ of the data used) pertaining to well-known instruments were used without any corrections.