HST FUV C iv observations of the hot DG Tauri jet

Author(s)

P. C. Schneider, J. Eislöffel, M. Güdel, H. M. Günther, G. Herczeg, J. Robrade, J. H. M. M. Schmitt

Abstract

Protostellar jets are tightly connected to the accretion process and

regulate the angular momentum balance of accreting star-disk systems.

The DG Tau jet is one of the best-studied protostellar jets and contains

plasma with temperatures ranging over three orders of magnitude within

the innermost 50 AU of the jet. We present new Hubble Space Telescope

(HST) far-ultraviolet (FUV) long-slit spectra spatially resolving the C

iv emission (T ~ 105 K) from the jet for the first time, in

addition to quasi-simultaneous HST observations of optical forbidden

emission lines ([O i], [N ii], [S ii], and [O iii]) and fluorescent

H2 lines. The C iv emission peaks at ≈ 42 AU from the

stellar position and has a FWHM of ≈ 52 AU along the jet. Its

deprojected velocity of around 200 km s-1 decreases

monotonically away from the driving source. In addition, we compare our

HST data with the X-ray emission from the DG Tau jet. We investigate the

requirements to explain the data by an initially hot jet compared to

local heating. Both scenarios indicate a mass loss by the T ~

105 K jet of ~10-9 M⊙

yr-1, i.e., between the values for the lower temperature jet

(T ≈ 104 K) and the hotter X-ray emitting part (T ≳

106 K). However, a simple initially hot wind requires a large

launching region (~1 AU), and we therefore favor local heating.

Organisation(s)

Department of Astrophysics

External organisation(s)

Universität Hamburg, Peking University, Harvard-Smithsonian Center for Astrophysics, Thüringer Landessternwarte Tautenburg

Journal

Astronomy & Astrophysics

Volume

550

No. of pages

4

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/201118592

Publication date

02-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics, 103003 Astronomy

Keywords

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