A 'head/tail' plasmon model with a Hubble law velocity profile. (24th September 2020)

• Record Type: Journal Article
• Authors: Raga, A C; Rodríguez-González, A; Hernández-Martínez, L; Cantó, J; Castellanos-Ramírez, A
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 499:Number 1(2020)
• Page Start: L91
• Page End: L95
• Publication Date: 2020-09-24
• Subjects: hydrodynamics -- shock waves -- stars: winds, outflows -- ISM: Herbig–Haro objects -- ISM: jets and outflows -- ISM: planetary nebulae: general; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/slaa165
• Languages: English
• ISSNs: 1745-3933

Abstract

ABSTRACT: We present a model of a hypersonic, collimated, 'single pulse' outflow, produced by an event with an ejection velocity that first grows, reaches a peak, and then decreases again to zero velocity in a finite time (simultaneously, the ejection density can have an arbitrary time-variability). We obtain a flow with a leading 'head' and a trailing 'tail' that for times greater than the width of the pulse develops a linear, 'Hubble law' velocity versus position. We present an analytical model for a simple pulse with a parabolic ejection velocity versus time and time-independent mass-loss rate, and compare it to an axisymmetric gasdynamic simulation with parameters appropriate for fast knots in planetary nebulae. This 'head/tail plasmon' flow might be applicable to other high-velocity clumps with 'Hubble law' tails.