相关论文: Blue Supergiants as a Tool for Extragalactic Dista…
Gamma-ray bursts (GRBs) are spectacularly energetic events, with the potential to inform on the early universe and its evolution, once their redshifts are known. Unfortunately, determining redshifts is a painstaking procedure requiring…
Microlensing of stars in strongly lensed galaxies can lead to temporary extreme magnification factors ($\mu\!>\!1000$), enabling their detection at high redshifts. Following the discovery of Icarus, several stars at cosmological distances…
We have obtained VLT low-resolution (~5 A) multi-object spectroscopy in the 4,000-5,000 A spectral range of about 70 blue supergiant candidates in the Sculptor Group spiral galaxy NGC 300. We present a detailed spectral catalog containing…
This is a review of high energy neutrino astronomy that might be done with a kilometer-scale detector. The emphasis is on diffuse neutrinos of extragalactic origin and their relation to possible sources of the highest energy cosmic rays,…
Luminous blue variables (LBVs) are suprisingly isolated from the massive O-type stars that are their putative progenitors in single-star evolution, implicating LBVs as binary evolution products. Aadland et al. (A19) found that LBVs are,…
Long Gamma-Ray Bursts (GRBs) are the brightest electromagnetic explosions in the Universe, associated to the death of massive stars. As such, GRBs are potential tracers of the evolution of the cosmic massive star formation, metallicity, and…
In this first paper of the series we describe our project to calibrate the distance determination method based on early-type binary systems. The final objective is to measure accurate, geometrical distances to galaxies beyond the Magellanic…
We describe the results of a search for galaxies with large (> 350 km/s) velocity dispersions. The largest systems we have found appear to be the extremes of the early-type galaxy population: compared to other galaxies with similar…
This review covers the measurements related to the extragalactic background light (EBL) intensity from gamma-rays to radio in the electromagnetic spectrum over 20 decades in the wavelength. The cosmic microwave background (CMB) remains the…
In the last decade, over 7000 eclipsing binaries have been discovered in the Local Group through various variability surveys. Measuring fundamental parameters of these eclipsing binaries has become feasible with 8 meter class telescopes,…
We calculate as a function of orbital distance, mass, and age the theoretical spectra and orbit-averaged planet/star flux ratios for representative wide-separation extrasolar giant planets (EGPs) in the optical, near-infrared, and…
Gamma rays constitute a privileged point of view for the study of the extreme Universe. Unlike charged cosmic rays, which are thought to have a common origin, gamma rays are not deflected by galactic and intergalactic magnetic fields. This…
We have analysed the infrared hydrogen recombination lines of a sample of well studied hot massive stars observed with the Infrared Space Observatory. Our sample contains stars from several classes of objects, whose circumstellar…
Asteroseismology is a powerful tool to measure the fundamental properties of stars and probe their interiors. This is particularly efficient for red giants because their modes are well detectable and give information on their deep layers.…
Context. Distances to evolved massive stars in the Milky Way are not well constrained by Gaia parallaxes due to their brightness and variability. This makes it difficult to determine their fundamental stellar parameters, such as radius or…
A quantitative spectroscopic study of blue supergiant stars in the Hubble constant anchor galaxy NGC 4258 is presented. The non-LTE analysis of Keck I telescope LRIS spectra yields a central logarithmic metallicity (in units of the solar…
We have commenced a detailed analysis of the known sample of Galactic post-asymptotic giant branch (PAGB) objects compiled in the Toru\'n catalogue of Szczerba et al., and present, for the first time, homogeneously derived distance…
Scattering and absorption of light by a homogeneous distribution of intergalactic large dust grains has been proposed as an alternative, non-cosmological explanation for the faintness of Type Ia supernovae at $z\s im 0.5$. We investigate…
We present a precise optical and near-infrared determination of the Tip of the Red Giant Branch (TRGB) brightness in the Large and Small Magellanic Clouds (respectively LMC and SMC). The commonly used calibrations of the absolute magnitude…
I briefly describe some results about luminous distant dusty galaxies obtained in the 5 years since sensitive two-dimensional bolometer array cameras became available. The key requirements for making additional progress in understanding the…