The continuous star formation history of a giant HII region in M101

We present results about the star formation process in the giant HII region NGC 5471 in the outskirts of M101. From resolved HST/WPFC2 photometry we find that star formation has been going for the last 70 Myr. We further compare previous results from integrated infrared-optical photometry with the stellar resolved CMD and we discuss the star formation properties of this region and its individual knots, as well as characterizing the different stellar content. This result has very important consequences in our understanding of the burst versus continuous star formation activity in spiral galaxies.Comment: 2 pages, 2 figures. Proceeding of the conference From Stars to Galaxies: Building the pieces to build up the Universe (Venice, Italy

Stellar indices and kinematics in Seyfert 1 nuclei

We present spectra of 6 type 1 Seyfert galaxies, 2 Seyfert 2, a starburst galaxy and a compact narrow line radiogalaxy, taken in two spectral ranges centered around the near--IR CaII triplet (CaT) (at ~8600 Angstroms), and the Mgb stellar feature at 5180 Angstroms. We measured the equivalent width (EWs) of these features and the Fe52 and Fe53 spectral indices. We found that the strength of the CaT in type 1 Seyfert galaxies with prominent central point sources, is larger than what would be expected from the observed strength of the blue indices. This could be explained by the presence of red supergiants in the nuclei of Seyfert 1 galaxies. On the other hand, the blue indices of these galaxies could also be diluted by the strong FeII multiplets that can be seen in their spectra. We have also measured the stellar and gas velocity dispersions of the galaxies in the sample. The stellar velocity dispersions were measured using both, the Mgb and CaT stellar features. The velocity dispersion of the gas in the narrow line region (NLR) was measured using the strong emission lines [OIII] 5007, 4959 and [SIII] 9069. We compare the gas and star velocity dispersions and find that both magnitudes are correlated in Seyfert galaxies. Most of the Seyfert 1 we observe have stellar velocity dispersion somehow greater than that of the gas in the NLR.Comment: To appear in MNRAS, 18 pages, 9 figure

Els "clamores" de Sant Cugat contra el fill del gran senescal: i altres episodis de terrorisme nobiliari (1161-1162)

Entre la fin de l'année 1161 et les premiers mois de 1162, les moines de labbaye bénédictine de Sant Cugat del Vallès, près de Barcelone, rédigèrent un mémoire de plaintes, adressé au comte Ramon Berenguer IV, dans lequel ils dénonçaient les actes de violence perpétrés contre les hommes et les propriétés du monastère par divers nobles, parmi lesquels se détache tout particulièrement Guillem de Monteada, fils du sénéchal Guillem Ramon. Le résultat fut une des querimoniae (chartes de doléances) les plus longues et les plus originales qui nous soient parvenues. Rédigée dans un latin correct et un style soigné, cette production élaborée du scriptorium monastique constitue un témoignage littéraire unique de la manière par laquelle, dans la Catalogne de la seconde moitié du Xlle siècle, la seigneurie arbitraire des barons se fit sentir sur la paysannerie. Cet article comprend la présentation, létude et l'édition de cette source, jusqu'à aujourd'hui pratiquement inconnue de l'historiographie, du fait que, comme d'autres anciens documents non datés, elle avait été déclassée. On identifie les personnages du texte, on reconstruit la suite des événements, on essaie de dater le document, de cerner les mobiles qui portèrent les moines à le rédiger et les objectifs ultimes que ceux-ci poursuivaient