Universität zu Köln

Fitz Axen, Margot ORCID: 0000-0001-7220-5193, Offner, Stella S. S., Gaches, Brandt A. L., Fryer, Chris L., Hungerford, Aimee and Silsbee, Kedron (2021). Transport of Protostellar Cosmic Rays in Turbulent Dense Cores. Astrophys. J., 915 (1). BRISTOL: IOP PUBLISHING LTD. ISSN 1538-4357

Full text not available from this repository.

Abstract

Recent studies have suggested that low-energy cosmic rays (CRs) may be accelerated inside molecular clouds by the shocks associated with star formation. We use a Monte Carlo transport code to model the propagation of CRs accelerated by protostellar accretion shocks through protostellar cores. We calculate the CR attenuation and energy losses and compute the resulting flux and ionization rate as a function of both radial distance from the protostar and angular position. We show that protostellar cores have nonuniform CR fluxes that produce a broad range of CR ionization rates, with the maximum value being up to two orders of magnitude higher than the radial average at a given distance. In particular, the CR flux is focused in the direction of the outflow cavity, creating a flashlight effect and allowing CRs to leak out of the core. The radially averaged ionization rates are less than the measured value for the Milky Way of zeta approximate to 10(-16) s(-1); however, within r approximate to 0.03 pc from the protostar, the maximum ionization rates exceed this value. We show that variation in the protostellar parameters, particularly in the accretion rate, may produce ionization rates that are a couple of orders of magnitude higher or lower than our fiducial values. Finally, we use a statistical method to model unresolved subgrid magnetic turbulence in the core. We show that turbulence modifies the CR spectrum and increases the uniformity of the CR distribution but does not significantly affect the resulting ionization rates.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Fitz Axen, Margot UNSPECIFIED orcid.org/0000-0001-7220-5193 UNSPECIFIED Offner, Stella S. S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Gaches, Brandt A. L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Fryer, Chris L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hungerford, Aimee UNSPECIFIED UNSPECIFIED UNSPECIFIED Silsbee, Kedron UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-590890
DOI:	10.3847/1538-4357/abfc55
Journal or Publication Title:	Astrophys. J.
Volume:	915
Number:	1
Date:	2021
Publisher:	IOP PUBLISHING LTD
Place of Publication:	BRISTOL
ISSN:	1538-4357
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language MAGNETIC-FIELDS; ASTROCHEMICAL IMPACT; STAR-FORMATION; MOLECULAR GAS; CLOUD; IONIZATION; ACCRETION; TRACER; ORION; PENETRATION Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/59089