相关论文: Gravity and limb-darkening coefficients for compac…
The photospheric radius is one of the fundamental parameters governing the radiative equilibrium of a star. We report new observations of the nearest solar-type stars Alpha Centauri A (G2V) and B (K1V) with the VLTI/PIONIER optical…
We derive analytic, closed-form solutions for the light curve of a planet transiting a star with a limb darkening profile which is a polynomial function of the stellar elevation, up to arbitrary integer order. We provide improved analytic…
We present follow-up spectroscopy of 711 white dwarfs within 100 pc, and present a detailed model atmosphere analysis of the 100 pc white dwarf sample in the SDSS footprint. Our spectroscopic follow-up is complete for 83% of the white…
We present a comprehensive description of the theory and practice of opacity calculations from the infrared to the ultraviolet needed to generate models of the atmospheres of brown dwarfs and extrasolar giant planets. Methods for using…
We present a study of the hypothesis that white dwarfs undergo a spectral change from hydrogen- to helium-dominated atmospheres using a volume-limited photometric sample drawn from the $Gaia$ DR2 catalogue, the Sloan Digital Sky Survey…
In order to interpret H2 (molecular hydrogen) quasar absorption line observations of damped Ly-alpha systems (DLAs) and sub-DLAs, we model their H2 abundance as a function of dust-to-gas ratio, including H2 self-shielding and dust…
We have written a light curve synthesis code that makes direct use of model atmosphere specific intensities, in particular the NEXTGEN model atmosphere grid for cool giants (T_eff <= 6800 K and log(g) <= 3.5, Hauschildt et al. 1999). We…
Energy levels, electric dipole transition probabilities and oscillator strengths in five times ionized silicon have been calculated in intermediate coupling. The present calculations were carried out with the general purpose…
Stellar limb darkening must be properly accounted for to accurately determine the radii of exoplanets at various wavelengths. The standard approach to address limb darkening involves either using laws with coefficients from modelled stellar…
Millisecond pulsars with white dwarf companions have typical eccentricities $e\sim 10^{-6}-10^{-3}$. The eccentricities of helium white dwarfs are explained well by applying the fluctuation-dissipation theorem to convective eddies in their…
In this study we compute the structure and evolution of carbon-oxygen DA white dwarfs by means of a detailed and updated evolutionary code. We treat the energy transport by convection within the formalism of the full spectrum turbulence…
Lyman limit and damped Lyman-alpha absorption systems probe the distribution of collapsed, cold gas at high redshift. Numerical simulations that incorporate gravity and gas dynamics can predict the abundance of such absorbers in…
We present new white dwarf cooling models which incorporate an accurate outer boundary condition based on new opacity and detailed radiative transfer calculations. We find that helium atmosphere dwarfs cool considerably faster than has…
We present equivalent width measurements and limits of six diffuse interstellar bands (DIBs) in seven damped Ly-alpha absorbers (DLAs) over the redshift range 0.091<z<0.524, sampling 20.3<log[N(HI)]<21.7. DIBs were detected in only one of…
We analyze the gas kinematics of damped Lya systems (DLAs) hosting high z gamma-ray bursts (GRBs) and those toward quasars (QSO-DLAs) focusing on threestatistics: (1) dv, the velocity interval encompassing 90% of the totaloptical depth,…
We re-examine the effects of Compton scattering on the emergent spectra of hot DA white dwarfs in the soft X-ray range. Earlier studies have implied that sensitive X-ray observations at wavelengths $\lambda < 50$ \AA might be capable of…
We report on our findings of the bright, pulsating, helium atmosphere white dwarf GD 358, based on time-resolved optical spectrophotometry. We identify 5 real pulsation modes and at least 6 combination modes at frequencies consistent with…
We report results from our mini-survey for molecular hydrogen in eight high redshift damped Lyman-alpha (DLA) systems using the ESO Ultra-violet and Visible Spectrograph on the VLT. In addition, we investigate two systems using ESO public…
We present data analysis methods used in detection and the estimation of parameters of gravitational wave signals from the white dwarf binaries in the mock LISA data challenge. Our main focus is on the analysis of challenge 3.1, where the…
Stars are stretched by tidal interactions in tight binaries, and changes to their projected areas introduce photometric variations twice per orbit. Hermes et al. (2014, ApJ, 792, 39) utilized measurements of these ellipsoidal variations to…