Related papers: Empirical line lists and absorption cross sections…
The absorption lines observed in quasar spectra have given us a detailed picture of the intergalactic medium and the metal abundance and kinematics of high redshift galaxies. In this review, we present an introduction to the field, starting…
The equation of state for ultra-dense matter can be tested from observations of the ratio of mass to radius of neutron stars. This could be measured precisely from the redshift of a narrow line produced on the surface. X-rays bursts have…
Typically, the interaction between dark matter and ordinary matter is assumed to be very small. Nevertheless, in this article, I show that the effective resonant absorption of dark photon dark matter in the atmosphere is definitely…
A triplet of subordinate lines of Mg II exists in the region around the h&k lines. In solar spectra these lines are seen mostly in absorption, but in some cases can become emission lines. The aim of this work is to study the formation of…
The modeling of stellar spectra is pervasive in astronomy. Conventionally, the shapes of absorption lines are modeled by convolving thermal profiles (computed given some model stellar atmosphere and line list) with broadening kernels…
This white paper emphasizes the potential of QSO absorption lines in the rest-frame far/extreme UV at rest-frame wavelengths from ~500 to 2000 A. In this wavelength range, species such as Ne VIII, Na IX, and Mg X can be detected, providing…
Transmission spectroscopy is a powerful technique widely used to probe exoplanet terminators. Atmospheric retrievals of transmission spectra are enabling comparative studies of exoplanet atmospheres. However, the atmospheric properties…
We present an analysis of seven primary transit observations of the hot Neptune GJ436b at 3.6, 4.5 and $8~\mu$m obtained with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. After correcting for systematic effects, we…
Stellar heating causes atmospheres of close-in exoplanets to expand and escape. These extended atmospheres are difficult to observe because their main spectral signature - neutral hydrogen at ultraviolet wavelengths - is strongly absorbed…
High-resolution absorption spectra of \NH\ in the region 2100 - 5500 \cm\ at 1027 $^{\circ}$C and atmospheric pressure (1045 $\pm$ 3 mbar) are measured. An \NH\ concentration of 10\% in volume fraction is used in the measurements. Spectra…
We compare high resolution infrared observations of the CO 3-1 bands in the 2.297-2.310 micron region of M dwarfs and one L dwarf with theoretical expectations. We find a good match between the observational and synthetic spectra throughout…
The super-Neptune exoplanet WASP-107b is an exciting target for atmosphere characterization. It has an unusually large atmospheric scale height and a small, bright host star, raising the possibility of precise constraints on its current…
Exoplanets in the ultra-hot Jupiter regime provide an excellent laboratory for testing the impact of stellar irradiation on the dynamics and chemical composition of gas giant atmospheres. In this study, we observed two transits of the…
Determining accurate effective temperatures of stars buried in the dust-obscured Galactic regions is extremely difficult from photometry. Fortunately, high-resolution infrared spectroscopy is a powerful tool for determining the temperatures…
The structures of the outer atmospheres of red giants are very complex. The notion of large optically thick molecular spheres around the stars (MOLspheres) has been invoked in order to explain e.g. spectro-interferometric observations.…
Infrared radiation emitted from a planet contains information about the chemical composition and vertical temperature profile of its atmosphere. If upper layers are cooler than lower layers, molecular gases will produce absorption features…
An analysis of H alpha and H beta spectra in a sample of 30 cool dwarf and subgiant stars is presented using MARCS model atmospheres based on the most recent calculations of the line opacities. A detailed quantitative comparison of the…
A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is presented. High-resolution spectra and synthetic photometry are calculated in the range from 1000{\AA} to 10,000{\AA} using Non-LTE fully…
Aims: We survey the transmission spectrum of WASP-121 b for line-absorption by metals and molecules at high spectral resolution, and elaborate on existing interpretations of the optical transmission spectrum observed with HST/STIS and WFC3.…
Neutral hydrogen traces gravitational potentials. In the nearby universe, 21cm emission-line surveys show that the bulk of the HI resides in well-formed, optically-luminous galaxies. At high redshift, 21cm line absorption against background…