Proper Motions and Shock Wave Dynamics in the HH 7-11 Stellar Jet

Abstract

We have used the Hubble Space Telescope to acquire new broad-band and narrow-band images of the optical line emission and red continuum associated with the HH 7-11 stellar jet in the NGC 1333 star formation region. Combining the new narrow-band images of H$\alpha$, [O~I] $\lambda$6300 and [S II] $\lambda$6716 allows us to measure electron densities and excitations at each point in the outflow with the spatial resolution of HST, while the I-band image traces out the boundary of the cavity evacuated by the outflow. Comparing these images with those taken $\sim$ 20 years ago yields high precision proper motions for all the HH objects in the outflow. HH 11 is a bullet-like clump, and emerges from the exciting source SVS 13A towards the Earth at 24 degrees to line of sight. In contrast, HH 8 and HH 10 consist of two rings of shocked gas that show no bulk proper motions even though the emitting gas is blueshifted. The HH 8 rings are expanding with time. These shocks mark places where ambient material located along the path of the jet redirects the outflow. HH 7 consists of multiple shells, and emits strongly in H${}_2$ in what appears to be a terminal bow shock for the outflow, implying that the jet has yet to fully break out of its nascent cloud core. The jet largely fragments into clumps by the time it reaches HH 7. As in the case of HH 110, deflection from ambient material plays a key role in producing observable shock waves in the HH 7-11 outflow.

12 figures, plus two animations; Accepted for publication in the Astrophysical Journal

References in corpus (11)

• The Gaia mission
• The UKIDSS Galactic Plane Survey
• Relativistic Jets in Active Galactic Nuclei und Microquasars
• IN-SYNC II: Virial Stars from Sub-Virial Cores -- The Velocity Dispersion of Embedded Pre-Main-Sequence Stars in NGC 1333
• CALYPSO view of SVS 13A with PdBI: Multiple jet sources
• The Launch Region of the SVS 13 Outflow and Jet
• HST/NICMOS Observations of NGC 1333: The Ratio of Stars to Sub-Stellar Objects
• The feedback of atomic jets from embedded protostars in NGC 1333
• Centrifugally driven winds from protostellar accretion discs. I - Formulation and initial results
• Very High Excitation Lines of H${}_2$ in the Orion Molecular Cloud Outflow
• The time evolution of HH~2 from four epochs of HST images

Cited by in corpus (4)

• Deep diving off the `Cosmic Cliffs': previously hidden outflows in NGC 3324 revealed by JWST
• Evolution of the atomic component in protostellar outflows
• A spectacular jet from the bright 244-440 Orion proplyd: the MUSE NFM view
• Bowshocks driven by the pole-on molecular jet of outbursting protostar SVS 13