A Search for Herbig-Haro Objects in NGC 7023 and Barnard 175

TL;DR

This study used wide-field optical imaging to discover four new Herbig-Haro objects in NGC 7023, revealing new insights into star formation and outflows, while clarifying the nature of a previously misclassified knot in B175.

Contribution

First detection of Herbig-Haro objects in NGC 7023, expanding knowledge of star-forming regions and outflow structures in this nebula.

Findings

Four new HH objects discovered in NGC 7023.

HH objects are part of at least two distinct outflows.

Reclassification of HH450X as a background galaxy.

Abstract

Wide-field optical imaging was obtained of the cluster and reflection nebula NGC 7023 and the Bok globule B175. We report the discovery of four new Herbig-Haro (HH) objects in NGC 7023, the first HH objects to be found in this region. They were first detected by their H-alpha and [S II] emission but are also visible at 3.6 and 4.5micron in archival Spitzer observations of this field. These HH objects are part of at least two distinct outflows. Both outflows are aligned with embedded "Class I" YSOs in a tight group on the western edge of the nebula. One of the outflows may have a projected distance of 0.75pc, which is a notable length for an embedded source. No new HH objects were discovered in B175. However, we reclassify the knot HH450X, in B175, as a background galaxy. The discovery that HH 450X is not a shock front weakens the argument that HH 450 and SNR G110.3+11.3 are co-located and interacting.