126 citations · 698 across the 20 of their papers we have counts for
21 papers
Stellar winds of O-type stars traced by high ionization fine-structure emission lines with JWST/MIRI
Calum Hawcroft, David R. Law, Linda J. Smith +8
We investigate the presence of high ionization fine-structure emission lines across a range of 22 OB-type stars observed with JWST-MIRI as part of calibration programmes and the WI…
Probing Thin Winds in Massive OB Stars of the SMC with JWST/NIRSPEC Br-alpha Spectroscopy
Miriam Garcia, Alexander W. Fullerton, Francisco Najarro +12
Mass loss is a key physical process in the evolution of massive stars, the impact of which propagates into galactic evolution, population synthesis models, the interpretation of hi…
X-Shooting ULLYSES: massive stars at low metallicity: XII. The clumped winds of O-type (super)giants in the Large Magellanic Cloud
Sarah A. Brands, Frank Backs, Alex de Koter +23
Mass loss governs the evolution of massive stars and shapes the stellar surroundings. To quantify the impact of the stellar winds we need to know the exact mass-loss rates; however…
The Nature of a Recently Discovered Wolf-Rayet Binary: Archetype of Stripping?
Philip Massey, Kathryn F. Neugent, Nidia I. Morrell +2
LMCe055-1 was recently discovered in a survey for WRs in the Large Magellanic Cloud, and classified as a WN4/O4, a lower excitation version of the WN3/O3 class discovered as part o…
X-Shooting ULLYSES: Massive stars at low metallicity. IV. Spectral analysis methods and exemplary results for O stars
A. A. C. Sander, J. -C. Bouret, M. Bernini-Peron +26
CONTEXT: The spectral analysis of hot, massive stars is a fundamental astrophysical method to obtain their intrinsic properties and their feedback. Quantitative spectroscopy for ho…
CMFGEN grids of atmosphere models for massive stars: OB-type stars at the Magellanic Clouds
W. Marcolino, J. -C. Bouret, F. Martins +1
Large spectroscopic surveys of individual massive stars, such as ULLYSES and XSHOOTU, provide observational data for hundreds of massive stars. Their analysis requires large number…
X-Shooting ULLYSES: Massive stars at low metallicity -- V. Effect of metallicity on surface abundances of O stars
F. Martins, J. -C. Bouret, D. J. Hillier +10
Massive stars rotate faster, on average, than lower mass stars. Stellar rotation triggers hydrodynamical instabilities which transport angular momentum and chemical species from th…
X-Shooting ULLYSES: Massive Stars at low metallicity II. DR1: Advanced optical data products for the Magellanic Clouds
H. Sana, F. Tramper, M. Abdul-Masih +34
Using the medium resolution spectrograph X-shooter, spectra of 235 OB and Wolf-Rayet (WR) stars in sub-solar metallicity environments have been secured. [...]This second paper focu…
WO-Type Wolf-Rayet Stars: the Last Hurrah of Massive Star Evolution
Erin Aadland, Philip Massey, D. John Hillier +3
Are WO-type Wolf Rayet (WR) stars in the final stage of massive star evolution before core-collapse? Although WC- and WO-type WRs have very similar spectra, WOs show a much stronge…
A changing wind collision
Yael Naze, Gloria Koenigsberger, Julian M. Pittard +4
We report on the first detection of a global change in the X-ray emitting properties of a wind-wind collision, thanks to XMM-Newton observations of the massive SMC system HD5980. W…
The Evolutionary Status of WN3/O3 Wolf-Rayet Stars
Kathryn F. Neugent, Phil Massey, D. John Hillier +1
As part of a multi-year survey for Wolf-Rayet stars in the Magellanic Clouds, we have discovered a new type of Wolf-Rayet star with both strong emission and absorption. While one m…
X-ray, UV and optical analysis of supergiants: Ori
Raul E. Puebla, D. John Hillier, Janos Zsargó +2
We present a multi-wavelength (X-ray to optical) analysis, based on non-local thermodynamic equilibrium photospheric+wind models, of the B0 Ia-supergiant: ~Ori. The aim is to te…
No breakdown of the radiatively-driven wind theory in low-metallicity environments
J. -C. Bouret, T. Lanz, D. J. Hillier +3
We present a spectroscopic analysis of HST/COS observations of three massive stars in the low metallicity dwarf galaxies IC 1613 and WLM. These stars, were previously observed with…
The HD5980 multiple system: Masses and evolutionary status
Gloria Koenigsberger, Nidia Morrell, D. John Hillier +5
New spectroscopic observations of the LBV/WR multiple system HD5980 in the Small Magellanic Cloud are used to address the question of the masses and evolutionary status of the two…
A New Class of Wolf-Rayet Stars: WN3/O3s
Philip Massey, Kathryn F. Neugent, Nidia Morrell +1
Our new survey for Wolf-Rayet stars in the Magellanic Clouds is only 15% complete but has already found 9 new WRs in the LMC. This suggests that the total WR population in the LMC…
A Bake-Off Between CMFGEN and FASTWIND: Modeling the Physical Properties of SMC and LMC O-type Stars
Philip Massey, Kathryn F. Neugent, D. John Hillier +1
The model atmosphere programs FASTWIND and CMFGEN are both elegantly designed to perform non-LTE analyses of the spectra of hot massive stars, and include sphericity and mass-loss.…
On the formation of CIII 4647-50-51 and CIII 5696 in O star atmospheres
F. Martins, D. J. Hillier
We investigate the formation of CIII 4647-51-50 and CIII 5696 in the atmosphere of O stars to see if they can be reliably used for abundance determinations. We use atmosphere model…
A quantitative study of O stars in NGC2244 and the Mon OB2 association
F. Martins, L. Mahy, G. Rauw +1
Our goal is to determine the stellar and wind properties of seven O stars in the cluster NGC2244 and three O stars in the OB association MonOB2. These properties give us insight in…
A Method for the Study of Accretion Disk Emission in Cataclysmic Variables I: The Model
Raul E. Puebla, Marcos P. Diaz, D. John Hillier +1
We have developed a spectrum synthesis method for modeling the UV emission from the accretion disk from cataclysmic variables (CVs). The disk is separated into concentric rings, wi…
Metallicity in the Galactic Center: The Quintuplet cluster
Francisco Najarro, Don F. Figer, D. John Hillier +2
We present a measurement of metallicity in the Galactic center Quintuplet Cluster made using quantitative spectral analysis of two Luminous Blue Variables (LBVs). The analysis empl…
Metallicity in the Galactic Center: The Arches cluster
Francisco Najarro, Donald F. Figer, D. John Hillier +1
We present a quantitative spectral analysis of five very massive stars in the Arches cluster, located near the Galactic center, to determine stellar parameters, stellar wind proper…