Kinematics of powerful jets from intermediate-mass protostars in the Carina nebula

Megan Reiter, Nathan Smith

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We present measurements of proper motions and radial velocities of four powerful Herbig- Haro (HH) jets in the Carina nebula: HH 666, HH 901, HH 902, and HH 1066. Two epochs of Hubble Space Telescope imaging separated by a time baseline of ~4.4 yr provide proper motions that allow us to measure the transverse velocities of the jets, while ground-based spectra sample their Doppler velocities. Together these yield full three-dimensional space velocities. Aside from HH 666, their identification as outflows was previously inferred only from morphology in images. Proper motions now show decisively that these objects are indeed jets, and confirm that the intermediate-mass protostars identified as the candidate driving sources for HH 666 and HH 1066 are indeed the origin of these outflows. The appearance of two new knots in the HH 1066 jet suggests recent (~35 yr) changes in the accretion rate, underscoring the variable nature of accretion and outflowin the formation of intermediate-mass stars. In fact, kinematics and mass-ejection histories for all the jets suggest highly episodic mass loss, and point towards pronounced accretion fluctuations.Overall, we measure velocities similar to those found for low-mass protostars. However, the HH jets in Carina have higher densities and are more massive than their low-mass counterparts. Coarse estimates suggest that the heavy jets of intermediate-mass protostars can compete with or even exceed inject ~10 or more times the cumulative momentum injection of lower mass protostars.

Original languageEnglish (US)
Pages (from-to)3939-3950
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Volume445
Issue number4
DOIs
StatePublished - Sep 29 2014

Fingerprint

protostars
nebulae
kinematics
proper motion
accretion
outflow
Hubble Space Telescope
ejection
radial velocity
momentum
time measurement
histories
injection
stars
estimates
history

Keywords

  • ISM: jets and outflows
  • Stars: formation

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Kinematics of powerful jets from intermediate-mass protostars in the Carina nebula. / Reiter, Megan; Smith, Nathan.

In: Monthly Notices of the Royal Astronomical Society, Vol. 445, No. 4, 29.09.2014, p. 3939-3950.

Research output: Contribution to journalArticle

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