Spitzer observations of the HH 1/2 system. The discovery of the counterjet

Abstract

We present unpublished Spitzer IRAC observations of the HH 1/2 young stellar outflow processed with a high angular resolution deconvolution algorithm that produces sub-arcsecond (approx. 0.6" - 0.8") images. In the resulting mid-infrared images the optically invisible counterjet is detected for the first time. The counterjet is approximately half as bright as the jet at 4.5 micron (the IRAC band that best traces young stellar outflows) and has a length of approx. 10". The NW optical jet itself can be followed back in the mid-IR to the position of the exciting VLA 1 source. An analysis of the IRAC colors indicates that the jet/counterjet emission is dominated by collisionally excited H2 pure rotational lines arising from a medium with a neutral Hydrogen gas density of 1000-2000 per cubic cm and a temperature of 1500 K. The observed jet/counterjet brightness asymmetry is consistent with an intrinsically symmetric outflow with extinction from a dense, circumstellar structure of 6" size (along the outflow axis), and with a mean visual extinction of Av=11 mag.

Accepted for publication in the Astrophysical Journal

References in corpus (5)

• Fluid Dynamics of Stellar Jets in Real Time: Third Epoch HST Images of HH 1, HH 34, and HH 47
• Highly Collimated Jets and Wide-Angle Outflows in HH46/47: New Evidence from Spitzer IR Images
• Spitzer IRAC Detection and Analysis of Shocked Molecular Hydrogen Emission
• Variation of the extinction law in the Trifid nebula
• Jets and Wide Angle Outflows in Cepheus E: New Evidence from Spitzer

Cited by in corpus (10)

• ALMA Observations of the HH 46/47 Molecular Outflow
• HiRes Deconvolved Spitzer Images of 89 Protostellar Jets and Outflows: New Data on Evolution of Outflow Morphology
• ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact
• Proper Motions of Young Stellar Outflows in the Mid-Infrared with Spitzer (IRAC). I. The NGC 1333 region
• Evolution of the atomic component in protostellar outflows
• Collisionally excited filaments in HST H$\alpha$ and H$\beta$ images of HH~1/2
• Warm gas in protostellar outflows. II. EHV jet and outflows from OMC-2/3
• The jet/counter-jet symmetry of the HH 212 outflow
• Proper Motions of Young Stellar Outflows in the Mid-Infrared with Spitzer. II. HH 377/Cep E
• The time evolution of HH~2 from four epochs of HST images