相关论文: Refractive Index of Humid Air in the Infrared: Mod…

We obtained laboratory spectra of absorption by water vapor at the wavelengths 6500-10500 {\AA} with the multipass cell. The water vapor content along the line of view varied from 0.1 to 3.0 cm of precipitated water, the pressure from 0.1…

Numerous observational evidence has suggested the presence of active meteorology in the atmospheres of brown dwarfs. A near-infrared brightness variability has been observed. Clouds have a major role in shaping the thermal structure and…

We explore the effect of varying the spectral energy distribution of the incident continuum, by simultaneously and self-consistently computing the structure of an H II region and a photodissociation region that are in pressure equilibrium.…

The 21 cm hyperfine transition of the atomic hydrogen (HI) in ground state is a powerful probe of the neutral gas content of the universe. This radio frequency transition has been used routinely for decades to observe, both in emission and…

We use high quality echelle spectra of 24 QSOs to provide a calibrated measurement of the total amount of Lyman-alpha forest absorption (DA) over the redshift range 2.2 < z < 3.2. Our measurement of DA excludes absorption from metal lines…

We write a nonlinear model that predicts the climate (temperature and humidity) on the surface of a small region on Earth, perform numerical investigations using the model, and compare the results to real climate on a variety of regions on…

We study methods for calculating the thermal diffusivity of solids from laser flash experiments. This experiment involves subjecting the front surface of a small sample of the material to a heat pulse and recording the resulting temperature…

Context. Semi-grey atmospheric models (with one opacity for the visible and one opacity for the infrared) are useful to understand the global structure of irradiated atmospheres, their dynamics and the interior structure and evolution of…

We demonstrate a new technique for determining the physical conditions of the broad line emitting gas in quasars, using near-infrared hydrogen emission lines. Unlike higher ionisation species, hydrogen is an efficient line emitter for a…

The set of realizable refractive indices as a function of frequency is considered. For passive media we give bounds for the refractive index variation in a finite bandwidth. Special attention is given to the loss and index variation in the…

Numerical simulations indicate that the smooth, photoionized intergalactic medium (IGM) responsible for the low column density Lyman-alpha forest follows a well defined temperature-density relation. We show that such an equation of state…

We developed a phase correction method for broadband terahertz time-domain spectroscopy in reflection geometry, which allows us to obtain quantitative and accurate values for the complex refractive index of materials. The process is…

Measurements of surface temperature fields are used to determine the heat transfer by conduction and convection from an inhomogeneously heated metallic tube into environment. For most of the here reported measurements we use a low-cost…

The multiple passages of light through an absorption inhomogeneity of finite size deep within a turbid medium is analyzed for optical imaging using the ``self-energy'' diagram. The nonlinear correction becomes more important for an…

Two types of active region feature prominent at transition region temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007 January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in emission lines formed at…

The specification of the upper atmosphere strongly relies on solar proxies that can properly reproduce the solar energetic input in the UV. Whilst the microwave flux at 10.7 cm (also called F10.7 index) has been routinely used as a solar…

An iterative method is presented for reconstructing the height-temperature profile of the solar atmosphere above a sunspot using multi-frequency spectro-polarimetric microwave observations. It is assumed that the emission is formed…

We present a theoretical model fit to the HST/STIS optical transit transmission spectrum of HD209458b. In our fit, we use the sodium absorption line profile along with the Rayleigh scattering by H_2 to help determine the average…

In this paper thermal conductivity and thermal diffusivity of a two layer system is examined from the theoretical point of view. We use the one dimensional heat diffusion equation with the appropriate solution in each layer and boundary…

This work focuses on the characterization of various bulk silicon (Si) samples using Fourier Transform InfraRed (FTIR) and grating spectrometers in order to get them suitable for applications in astronomy. Different samples at different…