The current best estimate of the Galactocentric distance of the Sun based on comparison of different statistical techniques

Abstract

In this paper, the current best estimate of a fundamental Galactic parameter Galactocentric distance of the Sun R 0 has been evaluated using all the available estimates published during the last 20 years. Unlike some other studies, our analysis of these results showed no statistically significant trend in R 0 during this period. However we revealed a statistically valuable improvement in the R 0 uncertainties with time of about 0.2 kpc for 20 years. Several statistical techniques have been used and compared to obtain the most reliable common mean of 52 determinations made in 1992-2011 and its realistic uncertainty. The statistical methods used include unweighted mean, seven variants of the weighted mean, and two variants of median technique. The R 0 estimates obtained with these methods range from 7.91 to 8.06 kpc with uncertainties varying from 0.05 to 0.08 kpc. The final value derived in this analysis is R 0 = 7.98±0.15 | stat ±0.20 | syst kpc, which can be recommended as the current best estimate of the Galactocentric distance of the Sun. For most of the practical applications the value of R 0 = 8.0 ± 0.25 kpc can be used.

A New Estimate of the Best Value for the Solar Galactocentric Distance

“…Authors of these papers call their approach "median statistics". Moreover, it is completely different from the median method used, for example, in papers [2,50].…”

Mapping dark matter in the Milky Way

“…The stellar disc and the gas have a marked spiral structure with four main arms (see Ref. [15] and references therein), where the Sun lies in between the Perseus and Sagittarius arms, in a local armlet, at a distance to the Galactic centre R 0 = 7.5 − 8.5 kpc [13,16,17,18 local circular velocity v 0 = 210 − 250 km/s [19,20,21,22,23,18], while the Sun motion with respect to the LSR reads (U,V,W ) = (10 − 11, 5 − 26, 7 − 9) km/s [24,25,23,18]. The three baryonic components described above are supposed to be embedded in a dark matter halo, likely extending hundreds of kpc but whose properties are not well constrained at present.…”

Comptonization of Cosmic Microwave Background by Cold Ultrarelativistic Electron-Positron Pulsar Wind and Origin of ~130 GeV Lines

“…If conversion efficiency is large enough, the mechanism of [1] can produce narrow ∼100 GeV lines with flux F line ∼ 10 −10 erg cm −2 s −1 , consistent with Fermi/LAT observations. Given the distance to Galactic centre ∼ 8 kpc [14], such flux corresponds to luminosity ∼ 10 36 erg/s.…”