Related papers: Investigation on the solar spectrum using Blackbod…
The spectral energy distribution (SED) of a non-spherical star could differ significantly from the SED of a spherical star with the same average temperature and luminosity. Calculation of the SED of a deformed star is often approximated as…
Blackbody radiation (BBR) sources are calculable radiation sources that are frequently used in radiometry, temperature dissemination, and remote sensing. Despite their ubiquity, blackbody sources and radiometers have a plethora of…
We discuss the bremsstrahlung of photons into a heat bath, and calculate from first principles the energy radiated. Even to lowest order the spectrum of the radiation at low frequency is no more singular than at zero temperature. In…
Radio occultations are commonly used to assess remotely the thermodynamic properties of planets or satellites' atmospheres within the solar system. The data processing usually involves the so-called Abel inversion method or the numerical…
Stefan-Boltzmann's law indicates that far-field blackbody radiation scales at the fourth power of temperature. The temperature dependence of radiative heat transfer in the near field is expected to be very different due to the contribution…
Radio interferometric data are used to estimate the sky brightness distributions in radio frequencies. Here we focus on estimators of the large-scale structure and the power spectrum of the sky brightness distribution inferred from radio…
We present bounds on mirror dark matter scenario derived by using the effect of mirror matter on the luminosity of the Sun. In the perturbative regime where the mirror matter concentration is small relative to the ordinary matter we…
Spectral energy distributions for models of arbitrarily rotating stars are computed using two dimensional rotating stellar models, NLTE plane parallel model atmospheres, and a code to integrate the appropriately weighted intensities over…
The early spectra of the kilonova AT2017gfo have a remarkably smooth blackbody continuum, which reveals information on the thermal properties and radioactive heating within the ejecta. However, the widespread use of a single-temperature…
Due to the exponential high gravitational red shift near the event horizon of a black hole, it might appear that the Hawking radiation would be highly sensitive to some unknown high energy physics. To study effects of any unknown physics at…
This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic…
Temperature inversions occur in nature, e.g., in the solar corona and in interstellar molecular clouds: somewhat counterintuitively, denser parts of the system are colder than dilute ones. We propose a simple and appealing way to…
All spectrometers rely on some mechanism to achieve spectral selectivity; common examples include gratings, prisms, and interferometers with moving mirrors. We experimentally demonstrated and validated a spectroscopic technique -- here…
The total and spectral irradiance varies over short time scales, i.e. from days to months, and longer time scales from years to decades, centuries, and beyond. In this talk we review the current understanding of irradiance changes from days…
The brightness temperature is an effective parameter that describes the physical properties of emitting material in astrophysical objects. It is commonly determined by imaging and modeling the structure of the emitting region and estimating…
We extend the analysis of Gabor transforms on a Cosmic Microwave Background (CMB) temperature map (Hansen, Gorski and Hivon 2002) to polarisation. We study the temperature and polarisation power spectra on the cut sky, the so-called pseudo…
Thermal states of light are widely used in quantum optics due to their correlation properties. As is well known, their correlation properties and the photon number distribution as a whole are strongly dependent on the mode number selected…
We derive Planck's radiation law in a uniformly accelerated frame expressed in Rindler coordinates. The black-body spectrum is time-dependent by its temperature and Planckian at each instantaneous time, but it is scaled by an emissivity…
The Sun is the most constrained and well-studied of all stars. As a consequence, the physical ingredients entering solar models are used as a reference to study all other stars observed in the Universe. However, our understanding of the…
We investigate the radiative heat transfer and spatial distributions of stationary temperatures in periodic many-body systems composed of alternating slabs of two different materials. We show that temperature distributions exhibit an…