Disentangling the outflow and protostars in HH 900 in the Carina Nebula

Abstract

HH 900 is a peculiar protostellar outflow emerging from a small, tadpole-shaped globule in the Carina nebula. Previous Hα imaging with HST/ACS showed an ionized outflow with a wide opening angle that is distinct from the highly collimated structures typically seen in protostellar jets. We present new narrowband near-IR [Fe II] images taken with the Wide Field Camera 3 on the Hubble Space Telescope that reveal a remarkably different structure than Hα. In contrast to the unusual broad Hα outflow, the [Fe II] emission traces a symmetric, collimated bipolar jet with the morphology and kinematics that are more typical of protostellar jets. In addition, new Gemini adaptive optics images reveal near-IR H${}_2$ emission coincident with the Hα emission, but not the [Fe II]. Spectra of these three components trace three separate and distinct velocity components: (1) H${}_2$ from the slow, entrained molecular gas, (2) Hα from the ionized skin of the accelerating outflow sheath, and (3) [Fe II] from the fast, dense, and collimated protostellar jet itself. Together, these data require a driving source inside the dark globule that remains undetected behind a large column density of material. In contrast, Hα and H${}_2$ emission trace the broad outflow of material entrained by the jet, which is irradiated outside the globule. As it get dissociated and ionized, it remains visible for only a short time after it is dragged into the H II region.

accepted to MNRAS

References in corpus (16)

• Which jet launching mechanism(s) in TTauri stars?
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• The Evolution of Outflow-Envelope Interactions in Low-Mass Protostars
• Comparing Star Formation on Large Scales in the c2d Legacy Clouds: Bolocam 1.1 mm Dust Continuum Surveys of Serpens, Perseus, and Ophiuchus
• A hot compact dust disk around a massive young stellar object
• Ionisation-induced star formation I: The collect and collapse model
• Recipes for stellar jets: results of combined optical/infrared diagnostics
• The M31 Velocity Vector. I. Hubble Space Telescope Proper Motion Measurements
• Ionisation-induced star formation II: External irradiation of a turbulent molecular cloud
• ALMA observations of a high-density core in Taurus: dynamical gas interaction at the possible site of a multiple star formation
• On the nature of outflows in intermediate-mass protostars: a case study of IRAS 20050+2720
• ATCA 3mm observations of NGC6334I and I(N): dense cores, outflows and an UCHII region
• A Survey of Irradiated Pillars, Globules, and Jets in the Carina Nebul
• The tiny globulettes in the Carina Nebula
• Anatomy of HH 111 from CO observations : a bow shock driven molecular outflow
• Kinematics of powerful jets from intermediate-mass protostars in the Carina nebula

Cited by in corpus (9)

• Ancient eruptions of Eta Carinae: A tale written in proper motions
• Proper motions of collimated jets from intermediate-mass protostars in the Carina Nebula
• [Fe II] jets from intermediate-mass protostars in Carina
• HH 666: Different kinematics from Hα and [Fe II] emission provide a missing link between jets and outflows
• Illuminating the Tadpole's metamorphosis I: MUSE observations of a small globule in a sea of ionizing photons
• Near-IR imaging towards a puzzling YSO precessing jet
• Illuminating a tadpole's metamorphosis III: quantifying past and present environmental impact
• Illuminating a tadpole's metamorphosis II: observing the on-going transformation with ALMA
• The Dusty Silhouette Jet HH 1019 in the Carina Nebula