Related papers: Structure and clumping in the fast wind of NGC6543
Most of the observed emission lines and continuum excess from young accreting low mass stars (Classical T Tauri stars -- CTTSs) take place in the star-disk or inner disk region. These regions have a complex emission topology still largely…
We pesent models for the velocity structure in the supersonic part of hot star winds in order to estimate the effects of clumping in density and velocity. XSTAR (Kallman,2018) was used to calculate radiation pressure in spectral lines…
We present the first non-LTE atmosphere models for WR stars that incorporate a self-consistent solution of the hydrodynamic equations. The models account for iron-group line-blanketing and clumping, and compute the hydrodynamic structure of…
The INTEGRAL satellite has revealed a previously hidden population of absorbed high-mass X-ray binaries (HMXBs) hosting supergiant (SG) stars. Among them, IGR J16320-4751 is a classical system intrinsically obscured by its environment, with…
High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass accretion. Chandra-HETGS observations…
We report on the discovery of a rapidly co-rotating stellar and gas component in the nucleus of the shell elliptical NGC2865. The stellar component extends ~ 0.51/h100 kpc along the major axis, and shows depressed velocity dispersion and…
X-rays give direct evidence of instabilities, time-variable structure, and shock heating in the winds of O stars. The observed broad X-ray emission lines provide information about the kinematics of shock-heated wind plasma, enabling us to…
We present high-resolution Keck Cosmic Web Imager (KCWI) and MUSE IFU spectroscopy of VV 114, a local infrared-luminous merger undergoing a vigorous starburst and showing evidence of galactic-scale feedback. The high-resolution data allow…
We present a detailed spectroscopic investigation of the young eruptive star PV Cep, to improve our understanding of its nature and characterise its circumstellar environment after its last outburst in 2004. The analysis of our…
[Abridged] We present Gemini-North GMOS/IFU observations of a young star cluster (cluster 10) and its environment near the centre of the dwarf irregular starburst galaxy NGC 1569. This forms part of a larger and on-going study of the…
A deep, continuum-subtracted, image of NGC 7293 has been obtained in the light of the Halpha+[N II] emission lines. New images of two filamentary halo stuctures have been obtained and the possible detection of a collimated outflow made.…
We have undertaken quantitative analysis of four LMC and SMC O4--9.7 extreme supergiants using far-ultraviolet FUSE, ultraviolet IUE/HSTand optical VLT UVES spectroscopy. Extended, non-LTE model atmospheres that allow for the consistent…
We compare the predictions of hydrodynamic models of the LMC X-4 X-ray binary system with observations of UV P Cygni lines with the GHRS and STIS spectrographs on the Hubble Space Telescope. The hydrodynamic model determines density and…
Mass loss through a stellar wind is an important physical process that steers the evolution of massive stars and controls the properties of their end-of-life products, such as the supernova type and the mass of compact remnants. For an…
The central stars of planetary nebulae (PNe) are natural targets for FUSE due to their UV brightness. The FUSE spectra of many PNe show absorption features due to circumstellar material in species ranging from H_2 and neutrals in the…
New radio continuum (8 GHz and 1.4 GHz) and HI 21 cm line observations of the Seyfert 2 galaxy IC 5063 (PKS 2048-572) were obtained with the Australia Telescope Compact Array (ATCA). The 8 GHz image reveals a linear triple structure (~4'',…
Blueshifted absorption lines in the X-ray spectra of AGN show that ultra-fast outflows with typical velocities $v \sim 0.1c$ are a common feature of these luminous objects. Such powerful AGN winds offer an explanation of the observed…
The nearby quasar, PG 1211+143, has one of the prototype examples of an ultra fast outflow (UFO), as seen in several past XMM-Newton and Chandra observations. In December 2024, PG 1211+143 was observed simultaneously with XRISM Resolve and…
Cygnus X-1 is a high mass X-ray binary where accretion onto the black hole is mediated by the stellar wind from the blue supergiant companion star HDE 226868. Depending on the position of the black hole along the orbit, X-ray observations…
We report on the results of an extended optical spectroscopic monitoring campaign on the early-type B supergiant HD64760 (B0.5Ib) designed to probe the deep-seated origin of spatial wind structure. This new study is based on high-resolution…