The QUEST (QUasar Equatorial Survey Team) Phase 1 camera has collected multibandpass photometry on a large strip of high Galactic latitude sky over a period of 26 months. This robust data set has been reduced and nightly catalogs compared to determine the photometric variability of the ensemble objects. Subsequent spectroscopic observations have

We report the result of a new Chandra observation of the black hole X-ray transient H 1705-250 in quiescence. H 1705-250 was barely detected in the new ˜50 ks Chandra observation. With five detected counts, we estimate the source quiescent luminosity to be LX ˜ 9.1 × 1030 erg s-1 in the 0.5-10 keV band (adopting a distance of 8.6 kpc). This value

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We studied the quiet-Sun magnetic fields interpreting spectro-polarimetric observations of infrared and visible spectral lines. Magnetic field strengths and filling factors were inferred by the simultaneous inversion of Stokes profiles of the Fe I lines at 6301.5, 6302.5, 15648, and 15653 Å under the MISMA hypothesis. They cover a solar intra

Aims: We present a detailed study of the radial distribution of the multiple populations identified in the Galactic globular cluster ω Cen. Methods: We used both space-based images (ACS/WFC and WFPC2) and ground-based images (FORS1@VLT and WFI@2.2m ESO telescopes) to map the cluster from the inner core to the outskirts ( 20 arcmin). These data sets

We study radiative transfer through a weakly polarizing medium, i.e., a medium in which the degree of polarization of the absorbed, retarded, and emitted light is always weak. In this case, the general radiative transfer equation for the Stokes parameters yields very simple formal solutions. The intensity does not depend on the polarization, and