Related papers: Measuring Diffuse Interstellar Bands with cool sta…
The aureoles around stars caused by thin cirrus limit nighttime measurement opportunities for ground-based astronomy but can provide information on high-altitude ice crystals for climate research. In this paper we attempt to demonstrate…
We use a sample of 149 spectroscopically confirmed UV-selected galaxies at $z\sim 2$ to investigate the relative dust attenuation of the stellar continuum and the nebular emission lines. For each galaxy in the sample, at least one…
Potential vibrational modes associated with diffuse interstellar bands (DIBs) could be discerned by examining energy differences between correlated DIBs. Consequently, $\approx 10^3$ higher correlated DIB pairs ($r-\sigma_r \ge 0.8$, $\ge…
Spectral synthesis is basically the decomposition of an observed spectrum in terms of the superposition of a base of simple stellar populations of various ages and metallicities, producing as output the star formation and chemical histories…
We investigate the star formation and dust extinction properties of very luminous infrared galaxies whose spectra display a strong Hdelta line in absorption and a moderate [OII] emission (e[a] spectrum). This spectral combination has been…
We have extended the evolutionary synthesis models by Leitherer et al. (1999b) by including a new library of B stars generated from the IUE high-dispersion spectra archive. We present the library and show how the stellar spectral properties…
The use of high resolution, high signal-to-noise stellar spectra is essential in order to determine the most accurate and precise stellar atmospheric parameters via spectroscopy. This is particularly important for determining the…
We present brutus, an open source Python package for quickly deriving stellar properties, distances, and reddenings to stars based on grids of stellar models constrained by photometric and astrometric data. We outline the statistical…
We have detected a broad interstellar absorption band centred close to 7700 \r{A} and with a FWHM of 176.6$\pm$3.9 \r{A}. This is the first such absorption band detected in the optical range and is significantly wider than the numerous…
We present synthetic ultraviolet spectra of metal-poor star-forming galaxies which were calculated with the Starburst99 package. A new spectral library was generated from HST observations of O stars in the Large and Small Magellanic Clouds.…
We obtained the near-infrared (NIR) high-resolution ($R\equiv\lambda/\Delta\lambda\sim20,000$) spectra of the seven brightest early-type stars in the Cygnus OB2 association for investigating the environmental dependence of diffuse…
Sun-like stars are a new probe of variations in the fine-structure constant, $\alpha$, via the solar twins approach: velocity separations of close pairs of absorption lines are compared between stars with very similar stellar parameters,…
Circumbinary planets - planets that orbit both stars in a binary system - offer the opportunity to study planet formation and orbital migration in a different environment compare to single stars. However, despite the fact that > 90% of…
Context: Nearly one century after their discovery, the carrier(s) of Diffuse Interstellar Bands is/are still unknown and there are few sightlines studied in detail for a large number of DIBs. Aims: We want to study the ISM sightlines…
New views on the diffuse interstellar bands are discussed. In particular results from DIB surveys and the study of near-infrared DIBs.
The presence of Galactic cirrus is an obstacle for studying both faint objects in our Galaxy and low surface brightness extragalactic structures. With the aim of studying individual cirrus filaments in SDSS Stripe 82 data, we develop…
We have observed 152 nearby solar-type stars with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope. Including stars that met our criteria but were observed in other surveys, we get an overall success rate for finding excesses…
Ultracool stellar atmospheres show absorption by alkali resonance lines severely broadened by collisions with neutral perturbers. In the coolest and densest atmospheres, such as those of T dwarfs, Na I and K I broadened by molecular…
Ultraviolet spectroscopy is a powerful method to study planetary surface composition through reflectance measurements and atmospheric composition through stellar/solar occultations, transits of other planetary bodies, and direct imaging of…
We are carrying out a search for planets around a sample of solar twin stars using the HARPS spectrograph. The goal of this project is to exploit the advantage offered by solar twins to obtain chemical abundances of unmatched precision.…