The local standard of rest from data on young objects with account for the Galactic spiral density wave

TL;DR

This study estimates the Sun's peculiar velocity relative to the Local Standard of Rest by analyzing young objects affected by the Galactic spiral density wave, accounting for differential rotation and spiral wave influence.

Contribution

It provides a new estimation of the Sun's velocity components considering the spiral density wave and demonstrates their insensitivity to the Galactic radius but sensitivity to the spiral phase.

Findings

The Sun's velocity components are (6.0, 10.6, 6.5) km/s with uncertainties.

Velocity components are insensitive to the Galactic radius within 7.5-8.5 kpc.

Components are highly sensitive to the Solar phase in the spiral density wave.

Abstract

To estimate the peculiar velocity of the Sun with respect to the Local Standard of Rest (LSR), we used young objects in the Solar neighborhood with distance measurement errors within 10%-15%. These objects were the nearest Hipparcos stars of spectral classes O-B2.5, masers with trigonometric parallaxes measured by means of VLBI, and two samples of the youngest and middle-aged Cepheids. The most significant component of motion of all these stars is induced by the spiral density wave. As a result of using all these samples and taking into account the differential Galactic rotation, as well as the influence of the spiral density wave, we obtained the following components of the vector of the peculiar velocity of the Sun with respect to the LSR: (Uo,Vo,Wo)_{LSR}=(6.0,10.6,6.5)+\-(0.5,0.8,0.3) km/s. We have found that components of the Solar velocity are quite insensitive to errors of the distance Ro in a broad range of its values, from Ro=7.5 kpc to Ro=8.5 kpc, that affect the Galactic rotation curve parameters. In the same time, the Solar velocity components(Uo)_{LSR} and (Vo)_{LSR}$ are very sensitive to the Solar radial phase in the spiral density wave.