Universität zu Köln

Rohde, P. F., Walch, S., Seifried, D., Whitworth, A. P., Clarke, S. D. and Hubber, D. A. (2019). Evolution of Hubble wedges in episodic protostellar outflows. Mon. Not. Roy. Astron. Soc., 483 (2). S. 2563 - 2581. OXFORD: OXFORD UNIV PRESS. ISSN 1365-2966

Full text not available from this repository.

Abstract

Young low-mass protostars undergo short phases of high accretion and outburst activity leading to lumpy outflows. Recent observations have shown that the position-velocity and mass-velocity diagrams of such outflows exhibit individual bullet-like features; some of these bullets subscribe to a 'Hubble Law' velocity relation, and others are manifest as 'Hubble wedges'. In order to explore the origin of these features, we have developed a new episodic outflow model for the SPH code GANDALF, which mimics the accretion and ejection behaviour of FU-Ori-type stars. We apply this model to simulations of star formation, invoking two types of initial conditions: spherically symmetric cores in solid-body rotation with rho proportional to r(-2), and spherically symmetric turbulent cores with density proportional to the density of an Bonnor-Ebert sphere. For a wide range of model parameters, we find that episodic outflows lead to self-regulation of the ejected mass and momentum, and we achieve acceptable results, even with relatively low resolution. Using this model, we find that recently ejected outflow bullets produce a 'Hubble wedge' in the position-velocity relation. However, once such a bullet hits the leading shock front, it decelerates and aligns with older bullets to form a 'Hubble-law'. Bullets can be identified as bumps in the mass-velocity relation, which can be fit with a power-law, dM/dv(RAD) proportional to v(RAD)(-1.5).

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Rohde, P. F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Walch, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Seifried, D. UNSPECIFIED UNSPECIFIED UNSPECIFIED Whitworth, A. P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Clarke, S. D. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hubber, D. A. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-157204
DOI:	10.1093/mnras/sty3302
Journal or Publication Title:	Mon. Not. Roy. Astron. Soc.
Volume:	483
Number:	2
Page Range:	S. 2563 - 2581
Date:	2019
Publisher:	OXFORD UNIV PRESS
Place of Publication:	OXFORD
ISSN:	1365-2966
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language VELOCITY MOLECULAR BULLETS; LONG-TERM EVOLUTION; STAR-FORMATION; MASS-LOSS; HYDRODYNAMIC SIMULATIONS; RADIATIVE-TRANSFER; ACCRETION DISKS; BIPOLAR OUTFLOW; JET; COLLAPSE Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/15720