Influence of the Gould Belt on Interstellar Extinction

TL;DR

This paper introduces a physically justified 3D model of interstellar extinction within 500 parsecs, accounting for the Gould Belt and equatorial layer, improving upon previous models by incorporating layered absorption and geometric details.

Contribution

A new analytical 3D interstellar extinction model that explicitly includes the Gould Belt and equatorial layer, with geometric and physical considerations, validated with stellar data.

Findings

The absorbing layers intersect at 17 degrees.

The Sun is near the axial plane of the Gould Belt.

The model fits stellar extinction data from three catalogs.

Abstract

A new analytical 3D model of interstellar extinction within 500 pc of the Sun as a function of the Galactic spherical coordinates is suggested. This model is physically more justified than the widely used Arenou model, since it takes into account the presence of absorbing matter both in the layer along the equatorial Galactic plane and in the Gould Belt. The extinction in the equatorial layer varies as the sine of the Galactic longitude and in the Gould Belt as the sine of twice the longitude in the Belt plane. The extinction across the layers varies according to a barometric law. It has been found that the absorbing layers intersect at an angle of 17 deg and that the Sun is located near the axial plane of the absorbing layer of the Gould Belt and is probably several parsecs below the axial plane of the equatorial absorbing layer but above the Galactic plane. The model has been tested using the extinction of real stars from three catalogs.