The evolution of the emission line ratios of a photoionized cloud described by standard BLR parameters which is exposed to a varying ionizing continuum is studied. The hardness of the ionizing distribution was varied by decoupling the UV increase from that of the X-ray component. After many tests using various ionizing distributions, it became

As the triangular libration points in the Earth-Moon system are of potential interest for optical interferometry, their dynamical property was analyzed adopting realistic models. Quasi-periodic orbits were identified, and their stability investigated. Results show that relative motion leads to baseline variation of 1 to 20 cm/sec, which may be

We report on the installation of a laser frequency comb (LFC) at the HARPS spectrograph, which we characterize relative to a second LFC that we had brought to HARPS for testing. This allowed us for the first time to probe the relative stability of two independent astronomical LFCs over an extended wavelength range. Both LFCs covered the spectral

Abstract Available from http://www.agu.org

In 2010, we organised a workshop in Tenerife with the aim of bringing together scientists concerned with the completeness and accuracy of atomic data for astrophysical applications. Participants included atomic physicists, theoretical astrophysicists and astronomers, and the workshop covered topics such as the evaluation of uncertainties in atomic

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