Browsing by Author "Altavilla, G."

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    Supernova 2011iw
    (2011) Mahabal, A.; Drake, A. J.; Djorgovski, S. G.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Tomasella, L.; Benetti, S.; Pastorello, A.; Valenti, S.; Bufano, F.; Altavilla, G.
    Report the discovery of a supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. 2011iw Nov. 29.09 23 34 48.20 +24 45 01.6 16.9 Nothing was visible at this position on a CSS image from Sept. 19.35 UT (limiting mag 19.5). Spectroscopic follow-up observations (range 400-800 nm) were taken with the Palomar 5-m telescope on Nov. 29.25. The spectrum exhibits strong, narrow Balmer emission lines corresponding to a redshift z = 0.023, which are superimposed on a blue continuum. A broad feature is observed near 610 nm that is likely due to He I. The object is thus identified as a likely type-IIn supernova. L. Tomasella, S. Benetti, A. Pastorello, S. Valenti, and F. Bufano, Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Padova; and G. Altavilla, INAF, Osservatorio Astronomico di Bologna, on behalf of a larger collaboration and the Gaia Science Alerts Follow-up Programme, report that spectrograms of 2011iw, obtained on Nov. 30.80 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 350-820 nm, resolution 2.4 nm) by the Service Telescope Operating Team and with the Cassini 1.52-m telescope (+ BFOSC; range 490-800 nm; resolution 1.4 nm) on Nov. 30.81, show it to be a type-IIn supernova soon after explosion. The spectrum is dominated by a blue continuum and intense Balmer emissions with a composite profile. They consist of an unresolved component overimposed on a broader line (FWHM about 4000 km/s). A broad bump (FWHM about 4600 km/s) is also present close to the He I 587.6-nm transition. The redshift of the supernova (z about 0.0230) has been derived from the narrow emissions of the Balmer lines....
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    The early spectral evolution of SN2004dt
    (2007) Altavilla, G.; Pignata, Giuliano
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    The Gaia-ESO Survey: Calibration strategy
    (2017) Pancino, E.; Lardo, C.; Altavilla, G.; Marinoni, S.; Ragaini, S.; Cocozza, G.; Bellazzini, M.; Sabbi, E.; Zoccali, Manuela; Sbordone, L.
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    unVEil the darknesS of The gAlactic buLgE (VESTALE)
    (2018) Bono, G.; Dall'Ora, M.; Fabrizio, M.; Crestani, J.; Braga, V. F.; Fiorentino, G.; Altavilla, G.; Botticella, M. T.; Calamida, A.; Castellani, M.; Catelan, Marcio; Chaboyer, B.; Chiappini, C.; Clarkson, W.; Contreras Ramos, R.; Creevey, O.; da Silva, R.; Debattista, V.; Degl'Innocenti, S.; Ferraro, I.; Gilligan, C. K.; Gonzalez, O.; Hambleton, K.; Iannicola, G.; Inno, L.; Kunder, A.; Lemasle, B.; Magrini, L.; Magurno, D.; Marconi, M.; Marengo, M.; Marinoni, S.; Marrese, P. M.; Martinez-Vazquez, C. E.; Matsunaga, N.; Monelli, M.; Prada Moroni, P. G.; Musella, I.; Navarro, M. G.; Neeley, J.; Nonino, M.; Pietrinferni, A.; Pulone, L.; Rich, M. R.; Ripepi, V.; Sacco, G.; Saha, A.; Salaris, M.; Sneden, C.; Stetson, P. B.; Street, R. A; Szabo, R.; Tantalo, M.; Tognelli, E.; Torelli, M.; Valenti, E.; Walker, A. R.; Zoccali, M.
    The main aim of this experiment is to provide a complete census of old (t > 10 Gyr, RR Lyrae, type II Cepheids, red horizontal branch), intermediate age (red clump, Miras) and young (classical Cepheids) stellar tracers across the Galactic Bulge. To fully exploit the unique photometric quality of LSST images, we plan to perform a Shallow minisurvey (ugrizy, -20 < l < 20 deg, -15 < b < 10 deg) and a Deep minisurvey (izy, -20 < l < 20 deg, -3 < b < 3 deg). The former one is aimed at constraining the 3D structure of the galactic Bulge across the four quadrants, and in particular, the transition between inner and outer Bulge. The u,g,r,i,z,y LSST bands provide fundamental diagnostics to constrain the evolutionary properties of low and intermediate-mass stars when moving from a metal-poor to a metal-rich regime. The deep minisurvey is aimed at tracing RR Lyrae, Red Clump stars, Miras and classical Cepheids in highly reddened regions of the Galactic center. These images will allow us to investigate the role that baryonic mass and dark matter played in the early formation and evolution of the MW....