127 citations · 1.1k across the 46 of their papers we have counts for
48 papers
Distinct Population of Wolf-Rayet Stars in the Low-Metallicity Galaxy NGC 6822. Quantitative analysis of optical and UV spectra of the complete sample
R. Trigg, L. M. Oskinova, W. -R. Hamann +9
Context: Wolf-Rayet (WR) stars are particularly rare in low-metallicity galaxies and remain poorly understood. Detailed studies of the presumably complete population of WR stars in…
Potsdam Wolf-Rayet stellar atmosphere grids of OB-type stars: I. Spectroscopic temperature diagnostics across metallicity
D. Pauli, H. Todt, W. -R. Hamann +5
Massive hot stars are among the major ionizing sources in the Universe. The ionizing flux of a star strongly depends on its temperature, which is best measured spectroscopically us…
Multiplicity of Massive Stars at Low Metallicity: Early Results from the BLOeM Campaign
T. Shenar, J. Bodensteiner, M. Abdul-Masih +73
Massive stars at low metallicity (Z) play a central role in shaping the high-redshift Universe, yet their multiplicity remains poorly constrained. The Binarity at Low Metallicity (…
Can Wolf-Rayet stars be the missing ingredient to explain high-z He II ionizing radiation?
G. González-Torà, A. A. C. Sander, E. Egorova +7
Classical Wolf-Rayet (WR) stars are hot, massive stars with depleted hydrogen. At low metallicities (Z), WN3-type WR stars have relatively thin winds and are major sources of ioniz…
SDSS-V LVM: Detectability of Wolf-Rayet stars and their He II ionizing flux in low-metallicity environments I. The weak-lined, early-type WN3 stars in the SMC
G. González-Torà, A. A. C. Sander, E. Egorova +18
The Small Magellanic Cloud (SMC) is the nearest low-metallicity dwarf galaxy. Its proximity and low reddening has enabled us to detect its Wolf-Rayet (WR) star population with 12 k…
A high fraction of close massive binary stars at low metallicity
H. Sana, T. Shenar, J. Bodensteiner +74
At high metallicity, a majority of massive stars have at least one close stellar companion. The evolution of such binaries is subject to strong interaction processes, heavily impac…
Hidden massive eclipsing binaries in red supergiant systems: The hierarchical triple system KQ Puppis and other candidates
D. Jadlovský, L. Molnár, A. Ercolino +26
The majority of massive stars are part of binary systems that may interact during their evolution. However, not many RSGs are known binaries, and only a few have constrained orbita…
First JWST/NIRSpec Spectroscopy of O Stars in the Small Magellanic Cloud
Armin Mang Román, Peter Zeidler, Wolf-Rainer Hamann +10
Determining how much mass is removed by stellar winds is crucial to understanding massive star evolution and feedback. However, traditional spectroscopic diagnostics in the UV and…
Comprehensive UV and Optical spectral analysis of Cygnus X-1: Stellar and wind parameters, abundances, and evolutionary implications
V. Ramachandran, A. A. C. Sander, L. M. Oskinova +7
We present a comprehensive analysis of Cyg X-1, utilizing archival high-resolution UV and optical spectra in conjunction with sophisticated atmospheric models. Notably, this is the…
Extremely iron-poor O-type stars in the Magellanic Bridge
E. C. Schösser, V. Ramachandran, A. A. C. Sander +7
To study stars analogous to those in the early Universe with redshift z > 3, we need to probe environments with low metallicities. Until recently, massive O-type stars with metalli…
Binarity at LOw Metallicity (BLOeM): Enhanced multiplicity of early B-type dwarfs and giants at
J. I. Villaseñor, H. Sana, L. Mahy +32
Early B-type stars ( M) are frequently in multiple systems, as evidenced by spectroscopic campaigns in the Milky Way (MW) and the Large Magellanic Cloud (LMC). Pr…
Binarity at Low Metallicity (BLOeM) -- Multiplicity properties of Oe and Be stars
J. Bodensteiner, T. Shenar, H. Sana +40
Rapidly rotating classical OBe stars have been proposed as the products of binary interactions, and the fraction of Be stars with compact companions implies that at least some are.…
Binarity at LOw Metallicity (BLOeM): Multiplicity of early B-type supergiants in the Small Magellanic Cloud
N. Britavskiy, L. Mahy, D. J. Lennon +32
The blue supergiant (BSG) domain contains a large variety of stars whose past and future evolutionary paths are still highly uncertain. Since binary interaction plays a crucial rol…
Determining stellar properties of massive stars in NGC346 in the SMC with a Bayesian statistic technique
M. J. Rickard, R. Hainich, D. Pauli +8
NGC 346 is a young cluster with numerous hot OB stars. It is part of the Small Magellanic Cloud (SMC), and has an average metallicity that is one-seventh of the Milky Way's. A deta…
X-Shooting ULLYSES: Massive Stars at Low Metallicity X. Physical Parameters and Feedback of Massive Stars in the LMC N11 B Star-Forming Region
V. M. A. Gómez-González, L. M. Oskinova, W. -R. Hamann +23
Massive stars lead the ionization and mechanical feedback within young star-forming regions. The Large Magellanic Cloud (LMC) is an ideal galaxy for studying individual massive sta…
X-Shooting ULLYSES: Massive stars at low metallicity VI. Atmosphere and mass-loss properties of O-type giants in the Small Magellanic Cloud
Frank Backs, S. A. Brands, A. de Koter +21
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…
Multi-wavelength spectroscopic analysis of the ULX Holmberg II X-1 and its nebula suggests the presence of a heavy black hole accreting from a B-type donor
S. Reyero Serantes, L. Oskinova, W. -R. Hamann +11
Ultra-luminous X-ray sources (ULXs) are high-mass X-ray binaries with an X-ray luminosity above erg s. These ULXs can be powered by black holes that are more massi…
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…
X-Shooting ULLYSES: Massive stars at low metallicity VII. Stellar and wind properties of B supergiants in the Small Magellanic Cloud
M. Bernini-Peron, A. A. C. Sander, V. Ramachandran +22
Context. B supergiants (BSGs) represent an important connection between the main sequence and more extreme evolutionary stages of massive stars. Additionally, lying toward the cool…
Binarity at LOw Metallicity (BLOeM): a spectroscopic VLT monitoring survey of massive stars in the SMC
T. Shenar, J. Bodensteiner, H. Sana +74
Surveys in the Milky Way and Large Magellanic Cloud revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary p…
X-Shooting ULLYSES: Massive Stars at low metallicity VIII. Stellar and wind parameters of newly revealed stripped stars in Be binaries
V. Ramachandran, A. A. C. Sander, D. Pauli +16
On the route towards merging neutron stars and stripped-envelope supernovae, binary population synthesis predicts a large number of post-interaction systems with massive stars that…
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…
Clumping and X-Rays in cooler B supergiant stars
Matheus Bernini-Peron, Wagner L. F. Marcolino, Andreas A. C. Sander +6
B supergiants (BSGs) are evolved stars with effective temperatures between 10 to 30 kK and are important to understand massive star evolution. Located on the edge of the line-drive…