Related papers: Near-Limb Zeeman and Hanle Diagnostics
I very briefly describe the latest generation near infrared (1-2.5 micron) instruments which are available on, or under development for `large' (D>=3.5 m) telescopes. Most of the imagers under construction are limited to relatively small…
We obtain high-precision limb-darkening measurements in five bands (V, V_E, I_E, I, and H) for the K3 III (Teff=4200 K, [Fe/H]=+0.3, log(g)=2.3) source of the Galactic bulge microlensing event EROS BLG-2000-5. These measurements are…
With the availability of thousands of type Ia supernovae in the near future the magnitude scatter induced by lensing will become a major issue as it affects parameter estimation. Current N-body simulations are too time consuming to be…
Despite the influence of magnetic fields on the structure and evolution of stars is largely demonstrated from the theoretical point of view, their observational evidence in non-degenerated stars is still rather scanty and mainly…
The sky observed by space telescopes in Low Earth Orbit (LEO) can be dominated by stray light from multiple sources including the Earth, Sun and Moon. This stray light presents a significant challenge to missions that aim to make a secure…
We introduce a method to measure with high resolution the solar diameter from the ground, through the eclipse observations by reconsidering the definition of the solar edge. The outer part of the Limb Darkening Function (LDF) is recovered…
The 10-100 keV region of the electromagnetic spectrum contains the potential for a dramatic improvement in our understanding of a number of key problems in high energy astrophysics. A deep inspection of the universe in this band is on the…
To detect Earth-like planets in the visible with a coronagraphic telescope, two major noise sources have to be overcome: the photon noise of the diffracted star light, and the speckle noise due to the star light scattered by instrumental…
The LAMP (Lightweight Asymmetry and Magnetism Probe) X-ray telescope is a mission concept to measure the polarization of X-ray astronomical sources at 250 eV via imaging mirrors that reflect at incidence angles near the polarization angle,…
We determine the evolution of the faint, high-redshift, optical luminosity function (LF) of AGN implied by several observationally-motivated models of the ionizing background. Our results depend crucially on whether we use the total…
Direct solar coronal magnetic field measurements have become possible since recent development of high-sensitivity infrared detection technology. The SOLARC instrument installed on Mt. Haleakala is such a polarimetric coronagraph that was…
The Laser Interferometer Space Antenna is a foreseen gravitational wave detector, which aims to detect $10^{-20}$ strains in the frequency range from 0.1 mHz to 1 Hz. It is a triangular constellation, with equal sides of $2,5 \times 10^9$…
We study how the addition of on-board optical photometric bands to future space-based weak lensing instruments could affect the photometric redshift estimation of galaxies, and hence improve estimations of the dark energy parameters through…
The measurement of solar magnetic fields using the Zeeman effect diagnostics has a fundamental 180 degree ambiguity in the determination of the azimuth angle of the transverse field component. There are several methods that are used in the…
The contrasts of features in the quiet Sun are studied using filtergrams recorded by the Broad-band Filter Imager on the Hinode/Solar Optical Telescope. In a first step, the scattered light originating in the instrument is modeled using…
Weak gravitational lensing surveys measure the distortion of the image of distant sources due to the deflections of light rays by the fluctuations of the gravitational potential along the line of sight. Since they probe the non-linear…
Paradoxically, imaging with resolution much below the wavelength $\lambda$ - now common place in the visible spectrum - remains challenging at lower frequencies, where arguably it is needed most due to the large wavelengths used. Techniques…
The weak field approximation (WFA) is a conceptually simple and computationally light method for inferring the magnetic field strength and its orientation in the Sun's atmosphere. In this work we study the validity and limitations of this…
We present a new technique to quantify the light contribution coming from the faint high redshift ($z\sim6$) galaxies below the detection threshold of imaging data, set conventionally at S/N=4.5. We illustrate the technique with an…
We have proposed a method for measuring weak lensing using the Lyman-alpha forest. Here we estimate the noise expected in weak lensing maps and power spectra for different sets of observational parameters. We find that surveys of the size…