Search Publications
The Absolute Magnitude of the Sun in Several Filters
Willmer, Christopher N. A.
This paper presents a table with estimates of the absolute magnitude of the Sun and the conversions from vegamag to the AB and ST systems for several wide-band filters used in ground-based and space-based observatories. These estimates use the dustless spectral energy distribution (SED) of Vega, calibrated absolutely using the SED of Sirius, to se…
The Habitability of Proxima Centauri b: Environmental States and Observational Discriminants
Lustig-Yaeger, Jacob; Meadows, Victoria S.; Arney, Giada N. +11 more
Proxima Centauri b provides an unprecedented opportunity to understand the evolution and nature of terrestrial planets orbiting M dwarfs. Although Proxima Cen b orbits within its star's habitable zone, multiple plausible evolutionary paths could have generated different environments that may or may not be habitable. Here, we use 1-D coupled climat…
Detection of Additional Be+sdO Systems from IUE Spectroscopy
Gies, Douglas R.; Wang, Luqian; Peters, Geraldine J.
There is growing evidence that some Be stars were spun up through mass transfer in a close binary system, leaving the former mass donor star as a hot, stripped-down object. There are five known cases of Be stars with hot subdwarf (sdO) companions that were discovered through International Ultraviolet Explorer (IUE) spectroscopy. Here we expand the…
Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. I. Spatially Resolved Mass Outflow Rates for the Seyfert 2 Galaxy Markarian 573
Kraemer, S. B.; Crenshaw, D. M.; Schmitt, H. R. +3 more
We present the first spatially resolved mass outflow rate measurements ({\dot{M}}out}) of the optical emission line gas in the narrow line region (NLR) of a Seyfert 2 galaxy, Markarian 573. Using long slit spectra and [O III] imaging from the Hubble Space Telescope and Apache Point Observatory in conjunction with emission line diagnosti…
The GJ 504 system revisited. Combining interferometric, radial velocity, and high contrast imaging data
Kuzuhara, M.; Tamura, M.; Rouan, D. +79 more
Context. The G-type star GJ504A is known to host a 3-35 MJup companion whose temperature, mass, and projected separation all contribute to making it a test case for planet formation theories and atmospheric models of giant planets and light brown dwarfs.
Aims: We aim at revisiting the system age, architecture, and companion physica…
Stellar population of the superbubble N 206 in the LMC. II. Parameters of the OB and WR stars, and the total massive star feedback
Hamann, W. -R.; Gallagher, J. S.; Oskinova, L. M. +5 more
Context. Clusters or associations of early-type stars are often associated with a "superbubble" of hot gas. The formation of such superbubbles is caused by the feedback from massive stars. The complex N 206 in the Large Magellanic Cloud (LMC) exhibits a superbubble and a rich massive star population.
Aims: Our goal is to perform quantitative …
Coupling hydrodynamics with comoving frame radiative transfer. II. Stellar wind stratification in the high-mass X-ray binary Vela X-1
Hamann, W. -R.; Oskinova, L. M.; Sander, A. A. C. +5 more
Context. Vela X-1, a prototypical high-mass X-ray binary (HMXB), hosts a neutron star (NS) in a close orbit around an early-B supergiant donor star. Accretion of the donor star's wind onto the NS powers its strong X-ray luminosity. To understand the physics of HMXBs, detailed knowledge about the donor star winds is required.
Aims: To gain a r…
On the production of He, C, and N by low- and intermediate-mass stars: a comparison of observed and model-predicted planetary nebula abundances
Balick, B.; Henry, R. B. C.; Stephenson, B. G. +2 more
The primary goal of this paper is to make a direct comparison between the measured and model-predicted abundances of He, C, and N in a sample of 35 well-observed Galactic planetary nebulae (PNe). All observations, data reductions, and abundance determinations were performed in house to ensure maximum homogeneity. Progenitor star masses (M ≤ 4 M
Stellar population of the superbubble N 206 in the LMC. I. Analysis of the Of-type stars
Hamann, W. -R.; Gallagher, J. S.; Oskinova, L. M. +5 more
Context. Massive stars severely influence their environment by their strong ionizing radiation and by the momentum and kinetic energy input provided by their stellar winds and supernovae. Quantitative analyses of massive stars are required to understand how their feedback creates and shapes large scale structures of the interstellar medium. The gi…
Global hot-star wind models for stars from Magellanic Clouds
Krtička, J.; Kubát, J.
We provide mass-loss rate predictions for O stars from Large and Small Magellanic Clouds. We calculate global (unified, hydrodynamic) model atmospheres of main sequence, giant, and supergiant stars for chemical composition corresponding to Magellanic Clouds. The models solve radiative transfer equation in comoving frame, kinetic equilibrium equati…