Models of Neptune-Mass Exoplanets: Emergent Fluxes and Albedos (2009)
Spiegel, David S., Burrows, Adam, Ibgui, Laurent, Hubeny, Ivan, Milsom, John A.
There are now many known exoplanets with Msin(i) within a factor of two of Neptune's, including the transiting planets GJ436b and HAT-P-11b. Planets in this mass-range are different from their more...
V3885 Sagittarius: a Comparison with a Range of Standard Model Accretion Disks (2009)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula, Barrett, Paul E.
A $\widetilde{\chi}^2$ analysis of standard model accretion disk synthetic spectrum fits to combined $FUSE$ and STIS spectra of V3885 Sagittarius, on an absolute flux basis, selects a model that...
Modeling UX Ursae Majoris: An abundance of challenges (2008)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula
We present a system model for optical and far UV spectra of the nova-like variable UX UMa involving a white dwarf, secondary star, gas stream, hot spot and accretion disk using our code BINSYN and...
Spectrum and atmosphere models of irradiated transiting extrasolar giant planets (2008)
We show that a consistent fit to observed secondary eclipse data for several strongly irradiated transiting planets demands a temperature inversion (stratosphere) at altitude. Such a thermal...
Synthetic Spectrum Constraints on a Model of the Cataclysmic Variable QU Carinae (2008)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula, Barrett, Paul E.
Neither standard model SEDs nor truncated standard model SEDs fit observed spectra of QU Carinae with acceptable accuracy over the range 900\AA to 3000\AA. Non-standard model SEDs fit the observation...
Martin A. Barstow, Ivan Hubeny, Thierry Lanz, Edward M. Sion, Jay B. Holberg
V opacity and places limits on the abundance of He which may be present. 1. Introduction - the view from EUV surveys Among the most significant problems in the study of hot white dwarf evolution has...
Preprint typeset using L A T E X style emulateapj v. 04/03/99 (2007)
Carlos Allende Prieto, Ivan Hubeny, David L. Lambert
We test our knowledge of the atomic opacity in the solar UV spectrum. Using the atomic data compiled in Paper I from modern, publicly available, databases, we perform calculations that are confronted...
Preprint typeset using L A T E X style emulateapj v. 04/03/99 (2007)
Carlos Allende Prieto, David L. Lambert, Ivan Hubeny, Thierry Lanz
With the goal of producing a reliable set of model atoms and singly-ionized ions for use in building NLTE model atmospheres, we have combined measured energy levels, critically-compiled line...
Burrows, Adam, Hubeny, Ivan, Budaj, Jano, Knutson, Heather, Charbonneau, David
We find that a theoretical fit to all the HD 209458b data at secondary eclipse requires that the dayside atmosphere of HD 209458b have a thermal inversion and a stratosphere. This inversion is caused...
Lanz, Thierry, Cunha, Katia, Holtzman, Jon, Hubeny, Ivan
Argon abundances have been derived for a sample of B main-sequence stars in the Orion association. The abundance calculations are based on NLTE metal line-blanketed model atmospheres calculated with...
We present a systematic study of the spectral consequences of departures from chemical equilibrium in the atmospheres of L and T dwarfs, and for even cooler dwarfs. The temperature/pressure profiles...
Linnell, Albert P., Hoard, D. W., Szkody, Paula, Long, Knox S., Hubeny, Ivan, Gansicke, Boris, ...
We use FUSE, HST, and SDSS spectra of the cataclysmic variable SDSSJ0809 to illustrate procedures for calculating and testing system models. Our final model has an accretion disk temperature profile...
MV Lyrae in Low, Intermediate, and High States (2006)
Linnell, Albert P., Szkody, Paula, Gansicke, Boris, Long, Knox S., Sion, Edward M., Hoard, D. W., ...
We use analysis results from a low state of the VY Sculptoris system MV Lyrae, considered in an earlier paper (Hoard et al., 2004, ApJ, 604, 346), to study archival IUE spectra taken during an...
A Synthetic Spectrum and Light Curve Analysis of the Cataclysmic Variable IX Velorum (2006)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula
Spectrum synthesis analysis of FUSE and STIS spectra of the cataclysmic variable IX Velorum successfully produces a system model. Light synthesis analysis of K band photometry shows that the...
A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars (2006)
We have constructed a comprehensive grid of 1540 metal line-blanketed, NLTE, plane-parallel, hydrostatic model atmospheres for the basic parameters appropriate to early B-type stars. The BSTAR2006...
We derive new equations using the mixed-frame approach for one- and two-dimensional (axisymmetric) time-dependent radiation transport and the associated couplings with matter. Our formulation is...
Neon Abundances in B-Stars of the Orion Association: Solving the Solar Model Problem? (2006)
Cunha, Katia, Hubeny, Ivan, Lanz, Thierry
We report on non-LTE Ne abundances for a sample of B-type stellar members of the Orion Association. The abundances were derived by means of non-LTE fully metal-blanketed model atmospheres and...
Self-consistent vertical structure models together with non-LTE radiative transfer should produce spectra from accretion disks around black holes which differ from multitemperature blackbodies at...
The hot white dwarf in the cataclysmic variable MV Lyrae (2005)
Hoard, D. W., Linnell, A. P., Szkody, Paula, Fried, Robert E., Sion, Edward M., Hubeny, Ivan, ...
We have obtained the first far-ultraviolet spectrum of the novalike cataclysmic variable MV Lyrae using the Far Ultraviolet Spectroscopic Explorer. We also obtained contemporaneous optical light...
L and T Dwarf Models and the L to T Transition (2005)
Burrows, Adam, Sudarsky, David, Hubeny, Ivan
Using a model for refractory clouds, a novel algorithm for handling them, and the latest gas-phase molecular opacities, we have produced a new series of L and T dwarf spectral and atmosphere models...
Photospheric phosphorus in the FUSE spectra of GD71 and two similar DA white dwarfs (2005)
Dobbie, Paul, Barstow, Martin, Hubeny, Ivan, Holberg, Jay, Burleigh, Matt, Forbes, Anne
We report the detection, from FUSE data, of phosphorus in the atmospheres of GD71 and two similar DA white dwarfs. This is the first detection of a trace metal in the photosphere of the...
A near-IR spectrum of the DO white dwarf RE J0503-285 (2005)
Dobbie, Paul, Burleigh, Matt, Levan, Andrew, Barstow, Martin, Napiwotzki, Ralf, Hubeny, Ivan, ...
We present a near-IR spectroscopic analysis of the intriguing DO white dwarf RE J0503-285. The IR spectrum fails to reveal evidence of the presence of a spatially unresolved, cool, late-type...
A Study of the Near-Ultraviolet Spectrum of Vega (2005)
García-Gil, Alejandro, López, Ramón J. García, Prieto, Carlos Allende, Hubeny, Ivan
UV, optical, and near-IR spectra of Vega have been combined to test our understanding of stellar atmospheric opacities, and to examine the possibility of constraining chemical abundances from...
Phase Functions and Light Curves of Wide Separation Extrasolar Giant Planets (2005)
Sudarsky, David, Burrows, Adam, Hubeny, Ivan, Li, Aigen
We calculate self-consistent extrasolar giant planet (EGP) phase functions and light curves for orbital distances ranging from 0.2 AU to 15 AU. We explore the dependence on wavelength, cloud...
Fundamental Properties of O-Type Stars (2004)
Heap, Sara R., Lanz, Thierry, Hubeny, Ivan
We present a comprehensive analysis of high-resolution, far-UV HST/STIS, FUSE, and optical spectra of 17 O stars in the SMC. Our analysis is based on NLTE metal line-blanketed model atmospheres...
NLTE Model Atmosphere Analysis of the LMC Supersoft X-ray Source CAL 83 (2004)
Lanz, Thierry, Telis, Gisela A., Audard, Marc, Paerels, Frits, Rasmussen, Andrew P., Hubeny, Ivan
We present a non-LTE model atmosphere analysis of Chandra HRC-S/LETG and XMM-Newton RGS spectroscopy of the prototypical supersoft source CAL 83 in the Large Magellanic Cloud. Taken with a 16-month...
Quasars and the Big Blue Bump (2004)
Shang, Zhaohui, Brotherton, Michael S., Green, Richard F., Kriss, Gerard A., Scott, Jennifer, Quijano, Jessica Kim, ...
We investigate the ultraviolet-to-optical spectral energy distributions (SEDs) of 17 active galactic nuclei (AGNs) using quasi-simultaneous spectrophotometry spanning 900-9000 Angstrom (rest frame)....
Relativistic Accretion Disk Models of High State Black Hole X-ray Binary Spectra (2004)
Davis, Shane W., Blaes, Omer M., Hubeny, Ivan, Turner, Neal J.
We present calculations of non-LTE, relativistic accretion disk models applicable to the high/soft state of black hole X-ray binaries. We include the effects of thermal Comptonization and bound-free...
Spectra and Diagnostics for the Direct Detection of Wide-Separation Extrasolar Giant Planets (2004)
Burrows, Adam, Sudarsky, David, Hubeny, Ivan
We calculate as a function of orbital distance, mass, and age the theoretical spectra and orbit-averaged planet/star flux ratios for representative wide-separation extrasolar giant planets (EGPs) in...
Evidence for Flash Mixing in He-rich sdB Stars (2003)
Sweigart, Allen V., Lanz, Thierry, Brown, Thomas M., Hubeny, Ivan, Landsman, Wayne B.
We present FUSE spectra of three He-rich sdB stars. Two of these stars, PG1544+488 and JL87, reveal extremely strong C III lines, suggesting that they have mixed triple-alpha carbon from the deep...
Flash Mixing on the White Dwarf Cooling Curve: FUSE Observations of three He-rich sdB Stars (2003)
Lanz, Thierry, Brown, Thomas M., Sweigart, Allen V., Hubeny, Ivan, Landsman, Wayne B.
We present FUSE spectra of 3 He-rich sdB stars. Two of these stars, PG1544+488 and JL87, reveal extremely strong C III lines at 977 and 1176A, while the carbon lines are quite weak in the third star,...
Gänsicke, Boris T., Szkody, Paula, De Martino, Domitilla, Beuermann, Klaus, Long, Knox S., Sion, Edward M., ...
Brief HST/STIS spectroscopic snapshot exposures of the cataclysmic variables 1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg reveal very large NV/CIV line flux ratios, similar to those observed in AE...
Theoretical Spectra and Atmospheres of Extrasolar Giant Planets (2002)
Sudarsky, David, Burrows, Adam, Hubeny, Ivan
We present a comprehensive theory of the spectra and atmospheres of irradiated extrasolar giant planets. We explore the dependences on stellar type, orbital distance, cloud characteristics, planet...
A Grid of NLTE Line-Blanketed Model Atmospheres of O-type Stars (2002)
We have constructed a comprehensive grid of 690 metal line-blanketed, NLTE, plane-parallel, hydrostatic model atmospheres for the basic parameters appropriate to O-type stars. The OSTAR2002 grid...
Isolating Clusters with Wolf-Rayet Stars in I Zw 18 (2002)
Brown, Thomas M., Heap, Sara R., Hubeny, Ivan, Lanz, Thierry, Lindler, Don
We present UV images and spectra of the starburst galaxy I Zw 18, taken with the Space Telescope Imaging Spectrograph. The high spatial resolution of these data allows us to isolate clusters...
A New Formation Mechanism for the Hottest Horizontal-Branch Stars (2002)
Sweigart, Allen V., Brown, Thomas M., Lanz, Thierry, Landsman, Wayne B., Hubeny, Ivan
Stars with very large mass loss on the red-giant branch can undergo the helium flash while descending the white-dwarf cooling curve. Under these conditions the flash convection zone will mix the...
The Origin of Hot Subluminous Horizontal-Branch Stars in Omega Centauri and NGC 2808 (2002)
Sweigart, Allen V., Brown, Thomas M., Lanz, Thierry, Landsman, Wayne B., Hubeny, Ivan
Hot subluminous stars lying up to 0.7 mag below the extreme horizontal branch (EHB) are found in the UV color-magnitude diagrams of omega Cen and NGC 2808. Such stars are unexplained by canonical HB...
Theoretical Spectral Models of T Dwarfs at Short Wavelengths and Their Comparison with Data (2001)
Burrows, Adam, Burgasser, Adam J., Kirkpatrick, J. Davy, Liebert, James, Milsom, J. A., Sudarsky, David, ...
We have generated new, self-consistent spectral and atmosphere models for the effective temperature range 600 K to 1300 K thought to encompass the known T dwarfs. For the first time, theoretical...
Blaes, Omer, Hubeny, Ivan, Agol, Eric, Krolik, Julian H.
We fit general relativistic, geometrically thin accretion disk models with non-LTE atmospheres to near simultaneous multiwavelength data of 3C~273, extending from the optical to the far ultraviolet....
Brown, Thomas M., Sweigart, Allen V., Lanz, Thierry, Landsman, Wayne B., Hubeny, Ivan
We present a UV CMD spanning the hot horizontal branch (HB), blue straggler, and white dwarf populations of the globular cluster NGC 2808. These data were obtained with the Space Telescope Imaging...
Hubeny, Ivan, Blaes, Omer, Krolik, Julian H., Agol, E.
We extend our models of the vertical structure and emergent radiation field of accretion disks around supermassive black holes described in previous papers of this series. Our models now include both...
STIS Coronagraphic Observations of Beta Pictoris (1999)
Heap, Sara R., Lindler, Don J., Lanz, Thierry M., Cornett, Robert H., Hubeny, Ivan, Maran, Stephen P., ...
We present new coronagraphic images of Beta Pictoris obtained with the Space Telescope Imaging Spectrograph (STIS) in September 1997. The high-resolution images (0.1") clearly detect the...
Hubeny, Ivan, Agol, Eric, Blaes, Omer, Krolik, Julian
We have constructed a grid of non-LTE disk models for a wide range of black hole mass and mass accretion rate, for several values of viscosity parameter alpha, and for two extreme values of the black...
Hot stellar population synthesis from the UV spectrum: the globular cluster M79 (NGC 1904) (1999)
Vink, Jorick S., Heap, Sara R., Sweigart, Allen V., Lanz, Thierry, Hubeny, Ivan
We have analyzed the far UV-spectrum of the globular cluster M79. We show that the nearly Gaussian mass distribution of zero-age horizontal-branch stars, as derived by Dixon et al.(1996), is able to...
Detailed Mid- and Far-Ultraviolet Model Spectra for Accretion Disks in Cataclysmic Binaries (1998)
Wade, Richard A., Hubeny, Ivan
We present a large grid of computed far- and mid-ultraviolet spectra (850 Angstroms to 2000 Angstroms) of the integrated light from steady-state accretion disks in luminous cataclysmic variables. The...
Continuum Spectra of Quasar Accretion Disk Models (1997)
Agol, Eric, Hubeny, Ivan, Blaes, Omer
We have calculated the spectrum and polarization of a standard thin accretion disk with parameters appropriate for a bright quasar. This model improves upon previous work by including ultraviolet...