Identification and distance measurement of dust clouds at high latitude by a clustering hierarchical algorithm

TL;DR

This paper creates a catalog of high-latitude dust clouds using Planck data and a hierarchical clustering algorithm, providing insights into dust properties and the local bubble structure.

Contribution

It introduces a novel hierarchical clustering method to identify dust clouds and derives their distances and properties using stellar extinction data.

Findings

Identified 315 high-latitude dust clouds.

Derived distances and physical properties for 190 clouds.

Confirmed dust grain size variations with Galactic distance.

Abstract

We present a catalog of dust clouds at high Galactic latitude based on the Planck 857 GHz dust emission data. Using a clustering hierarchical algorithm, 315 dust cloud at high Galactic latitudes are identified. Additionally, using the optical and ultraviolet extinction of 4 million and 1 million stars, respectively, provided by Sun et al., we derive the distances and physical properties for 190 high Galactic latitude dust clouds and the ultraviolet excess ratios for 165 of them. Through the study of color excess ratios, this work confirms that molecular clouds with large Galactic distances and low extinction likely have a higher proportion of small-sized dust grains. In addition, clouds with well-defined distances in the catalog are used to trace the local bubble, showing good consistency with the boundary of the local bubble from the literature.