We identify a spectroscopic sequence of galaxies, analogous to the Hubble sequence of morphological types, based on the Automatic Spectroscopic K-means-based (ASK) classification. Considering galaxy spectra as multidimensional vectors, the majority of the spectral classes are distributed along a well-defined curve going from the earliest to the

At a fixed stellar mass, the size of low-redshift early-type galaxies is found to be a factor of 2 larger than that of their counterparts at z˜ 1, a result with important implications for galaxy formation models. In this paper, we have explored the buildup of the local mass-size relation of elliptical galaxies using two visually classified samples

An assessment on the capabilities of modern spectropolarimeters and magnetographs is in order since most of our astrophysical results rely upon the accuracy of the instrumentation and on the sensitivity of the observables to variations of the sought physical parameters. A contribution to such an assessment will be presented in this talk where

Context. Radial velocity monitoring of very cool dwarfs such as late M- and hot L-dwarfs has become a promising tool in the search for rocky planets as well as follow-up planetary candidates around dwarfs detected by transit surveys. These stars are faint at optical wavelengths, as their spectral flux distribution peaks at near-infrared (NIR)

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Using archival Hubble Space Telescope (HST) imaging data, we report the multiband photometric properties of 13 ultraluminous X-ray sources (ULXs) that have a unique compact optical counterpart. Both magnitude and color variation are detected at timescales of days to years. The optical color, variability, and X-ray to optical flux ratio indicate