134 citations · 1.7k across the 64 of their papers we have counts for
16 papers · 1 filter
How Interstellar Chemistry (and Astrochemistry More Generally) Became Useful
T. W. Hartquist, S. Van Loo, S. A. E. G. Falle
In 1986 Alex Dalgarno published a paper entitled "Is Interstellar Chemistry Useful?" By the middle 1970s, and perhaps even earlier, Alex had hoped that astronomical molecules would…
A cosmic-ray precursor model for a Balmer-dominated shock in Tycho's supernova remnant
A. Y. Wagner, J. -J. Lee, J. C. Raymond +2
We present a time-dependent cosmic-ray modified shock model for which the calculated H-alpha emissivity profile agrees well with the H-alpha flux increase ahead of the Balmer-domin…
The turbulent destruction of clouds - I. A k-epsilon treatment of turbulence in 2D models of adiabatic shock-cloud interactions
J. M. Pittard, S. A. E. G. Falle, T. W. Hartquist +1
The interaction of a shock with a cloud has been extensively studied in the literature, where the effects of magnetic fields, radiative cooling and thermal conduction have been con…
Dust in Interstellar Clouds, Evolved Stars and Supernovae
T. W. Hartquist, S. Van Loo, S. A. E. G. Falle +2
Outflows of pre-main-sequence stars drive shocks into molecular material within 0.01 - 1 pc of the young stars. The shock-heated gas emits infrared, millimeter and submillimeter li…
The effect of ambipolar resistivity on the formation of dense cores
S. Van Loo, S. A. E. G. Falle, T. W. Hartquist +1
We aim to understand the formation of dense cores by magnetosonic waves in regions where the thermal to magnetic pressure ratio is small. Because of the low-ionisation fraction in…
Shock-triggered formation of magnetically-dominated clouds
S. Van Loo, S. A. E. G. Falle, T. W. Hartquist +1
To understand the formation of a magnetically dominated molecular cloud out of an atomic cloud, we follow the dynamical evolution of the cloud with a time-dependent axisymmetric ma…
Dense core compression and fragmentation induced by the scattering of hydromagnetic waves
S. Van Loo, S. A. E. G. Falle, T. W. Hartquist
We have performed 2D hydromagnetic simulations with an adaptive mesh refinement code to examine the response of a pre-existing initially spherical dense core to a non-linear fast-m…
The tails in the Helix Nebula NGC 7293
J. E. Dyson, J. M. Pittard, J. Meaburn +1
We have examined a stream-source model for the production of the cometary tails observed in the Helix Nebula NGC 7293 in which a transonic or moderately supersonic stream of ionize…
The Production of Magnetically Dominated Star Forming Regions
A. J. Lim, S. A. E. G. Falle, T. W. Hartquist
We consider the dynamical evolution of an interstellar cloud that is initially in thermal equilibrium in the warm phase and is then subjected to a sudden increase in the pressure o…
Dynamical and Pressure Structures in Winds with Multiple Embedded Evaporating Clumps I. 2D Numerical Simulations
J. M. Pittard, J. E. Dyson, S. A. E. G. Falle +1
Because of its key role in feedback in star formation and galaxy formation, we examine the nature of the interaction of a flow with discrete sources of mass injection. We show the…
The Formation of Broad Emission Line Regions in Supernova-QSO Wind Interactions II. 2D Calculations
J. M. Pittard, J. E. Dyson, S. A. E. G. Falle +1
One aspect of supernova remnant evolution that is relatively unstudied is the influence of an AGN environment. A high density ambient medium and a nearby powerful continuum source…
A numerical scheme for multifluid magnetohydrodynamics
S. A. E. G. Falle
This paper describes a numerical scheme for multi-fluid hydrodynamics in the limit of small mass densities of the charged particles. The inertia of the charged particles can then b…
The Evolution of Mass Loaded Supernova Remnants. II. Temperature Dependent Mass Injection Rates
J. M. Pittard, S. J. Arthur, J. E. Dyson +4
We investigate the evolution of spherically symmetric supernova remnants in which mass loading takes place due to conductively driven evaporation of embedded clouds. Numerical simu…
Rarefaction Shocks, Shock Errors and Low Order of Accuracy in ZEUS
S. A. E. G. Falle
We show that there are simple one dimensional problems for which the MHD code, ZEUS, generates significant errors, whereas upwind conservative schemes perform very well on these pr…
Instabilities in two-fluid magnetized media with inter-component drift
P. V. Tytarenko, R. J. R. Williams, S. A. E. G. Falle
We analyse the stability of a magnetized medium consisting of a neutral fluid and a fluid of charged particles, coupled to each other through a drag force and exposed to differenti…
The Formation of Broad Emission Line Regions in Supernova-QSO Wind Interactions
J. M. Pittard, J. E. Dyson, S. A. E. G. Falle +1
We show that a cooled region of shocked supernova ejecta forms in a type II supernova-QSO wind interaction, and has a density, an ionization parameter, and a column density compati…