Not Available

Not Available

We present the results of a new spectroscopic survey for dusty intervening absorption systems, particularly damped Lyα absorbers (DLAs), toward reddened quasars. The candidate quasars are selected from mid-infrared photometry from the Wide-field Infrared Survey Explorer combined with optical and near-infrared photometry. Out of 1073 candidates, we

We present high quality long-slit spectra of the extended narrow line region (ENLR) near the nucleus of NGC 4151. We have used these data to map the spatial variations of the emission line intensities along three slit positions: one passing radially through the nucleus along the main NE-SW axis of the ENLR and two across this axis at offsets center

We have obtained low-resolution optical spectra of three faint brown dwarf candidates in the Pleiades open cluster. The objects observed are Roque 12 (I_C=18.5), Roque 5 (I_C=19.7), and Roque 25 (I_C=21.2). The spectrum of Roque 25 does not show the strong TiO band heads that characterize the optical spectra of M-type stars, but molecular bands of

High resolution H alpha and white light observation of the birth of 73 active regions (AR) were used to check models of sunspots. It is concluded that large AR result from the emergence of a compact and twisted flux rope, while the small ones are produced by the clustering of flux tubes by supergranular motions.