Proper Motions of Young Stellar Outflows in the Mid-Infrared with Spitzer (IRAC). I. The NGC 1333 region

TL;DR

This study demonstrates the first successful measurement of proper motions of stellar outflows in the NGC 1333 region using mid-infrared Spitzer data over a 7-year span, revealing that many outflows have intrinsically low velocities.

Contribution

It introduces a novel method for measuring proper motions of stellar outflows in the mid-infrared with Spitzer, providing new insights into outflow velocities.

Findings

Proper motions of 8 outflows measured, ranging from 10 to 100 km/s.

Some outflows have low velocities, indicating intrinsic slow movement.

Results are consistent with optical measurements for HH objects.

Abstract

We use two 4.5micron Spitzer (IRAC) maps of the NGC 1333 region taken over approx. 7 yr interval to determine proper motions of its associated outflows. This is a first, successful attempt at obtaining proper motions of stellars outflow from Spitzer observations. For the outflow formed by the Herbig-Haro objects HH7, 8 and 10, we find proper motions of approx. 9-13 km/s, which are consistent with previously determined optical proper motions of these objects. We determine proper motions for a total of 8 outflows, ranging from approx. 10 to 100 km/s. The derived proper motions show that out of these 8 outflows, 3 have tangential velocities less or equal to 20 km/s. This result shows that a large fraction of the observed outflows have low intrinsic velocities, and that the low proper motions are not merely a projection effect.