Related papers: [NeII] emission line profiles from photoevaporativ…
We model the gas and dust dynamics in a turbulent protoplanetary disc undergoing extreme-UV photoevaporation in order to better characterise the dust properties in thermal winds (e.g. size distribution, flux rate, trajectories). Our…
Computing the flow from externally FUV irradiated protoplanetary discs requires solving complicated and expensive photodissociation physics iteratively in conjunction with hydrodynamics. Previous studies have therefore been limited to 1D…
Echelle spectroscopy of H2, [FeII] and Br-gamma line emission from a very young planetary nebula, IRAS 21282+5050, and from four proto-planetary nebulae, IRAS 19343+2926 (M 1-92), IRAS 17150-3224 (AFGL 6815), IRAS 17423-1755 (Hen 3-1475),…
We present self-consistent models of gas in optically-thick dusty disks and calculate its thermal, density and chemical structure. The models focus on an accurate treatment of the upper layers where line emission originates, and at radii…
Spectro-astrometry is used to investigate the low velocity component (LVC) of the optical forbidden emission from the T Tauri stars RU Lupi and AS 205 N. Both stars also have high velocity forbidden emission (HVC) which is tracing a jet.…
The nature of non-variable high-excitation emission lines detected in the optical spectra of normal late-B type and chemically peculiar HgMn and PGa stars is still poorly understood. To better understand the origin of the weak emission…
Emission-line abundances have been uncertain for more than a decade due to unexplained discrepancies in the relative intensities of the forbidden lines and weak permitted recombination lines in planetary nebulae (PNe) and H II regions. The…
We present theoretical X-ray line profiles from a range of model colliding wind systems. In particular, we investigate the effects of varying the stellar mass-loss rates, the wind speeds, and the viewing orientation. We find that a wide…
We investigate the continuum emission of viscous decretion discs around Be stars in this paper. The results obtained from non-LTE (local thermodynamic equilibrium) radiative transfer models show two regimes in the disc surface brightness…
The sample of 379 extragalactic sources is presented that have mid-infrared, high resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS) and also spectroscopy of the [CII] 158 um line with the Herschel Photodetector Array…
Star formation is one of the most important processes in galaxy formation. The luminosity of Halpha recombination and [OII] forbidden emissions remain to be most used in measuring formation rate of massive stars in galaxies. Here we report…
How protoplanetary discs evolve remains an unanswered question. Competing theories of viscosity and magnetohydrodynamic disc winds have been put forward as the drivers of angular momentum transport in protoplanetary discs. These two models…
Protoplanetary discs are thought to evolve either through angular momentum transport driven by viscous processes or through angular momentum removal induced by magnetohydrodynamic (MHD) winds. One proposed method to distinguish between…
Photoevaporation is an important dispersal mechanism for protoplanetary disks. We conduct hydrodynamic simulations coupled with ray-tracing radiative transfer and consistent thermochemistry to study photoevaporative winds driven by…
Solar convection is visible as a net blueshift of absorption lines, which becomes apparent when observing quiet Sun granulation. This blueshift exhibits variations from the disc centre to the solar limb due to differing projection angles…
Previously unrecognized weak emission lines originating from high excitation states of Si II (12.84 eV) and Al II (13.08 eV) are detected in the red region spectra of slowly rotating early B-type stars. We surveyed high resolution spectra…
This paper presents calculations for forbidden emission line profile shapes arising from colliding wind binaries. The main application is for systems involving a Wolf-Rayet (WR) star and an OB star companion. The WR wind is assumed to…
Deep HST broad-band images taken with ACS and WFPC2 of the giant ($\sim 1000$ AU diameter) dark silhouette proplyd 114-426 in the Orion Nebula show that this system is tilted, asymmetric, warped and photoevaporated. The exquisite angular…
We present 24 micron images of three protoplanetary disks being photoevaporated around high mass O type stars. These objects have ``cometary'' structure where the dust pulled away from the disk by the photoevaporating flow is forced away…
Non-resonant FeII* 2365, 2396, 2612, 2626 emission can potentially trace galactic winds in emission and provide useful constraints to wind models. From the 3'x3' mosaic of the Hubble Ultra Deep Field (UDF) obtained with the VLT/MUSE…