Examinando por Autor "Malesani, D."
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Ítem Diversity of gamma-ray burst energetics vs. supernova homogeneity: SN 2013cq associated with GRB 130427A(EDP Sciences, 2014-07) Melandri, A.; Pian, E.; D'Elia, V.; D'Avanzo, P.; Della Valle, M.; Mazzali, P.A.; Tagliaferri, G.; Cano, Z.; Levan, A.J.; Moller, P.; Amati, L.; Bernardini, M.G.; Bersier, D.; Bufano, F.; Campana, S.; Castro-Tirado, A.J.; Covino, S.; Ghirlanda, G.; Hurley, K.; Malesani, D.; Masetti, N.; Palazzi, E.; Piranomonte, S.; Rossi, A.; Salvaterra, R.; Starling, R.L.C.; Tanaka, M.; Tanvir, N.R.; Vergani, S.D.Aims. Long-duration gamma-ray bursts (GRBs) have been found to be associated with broad-lined type-Ic supernovae (SNe), but only a handful of cases have been studied in detail. Prompted by the discovery of the exceptionally bright, nearby GRB 130427A (redshift z = 0.3399), we aim at characterising the properties of its associated SN 2013cq. This is the first opportunity to test the progenitors of high-luminosity GRBs directly. Methods. We monitored the field of the Swift long-duration GRB 130427A using the 3.6 m TNG and the 8.2 m VLT during the time interval between 3.6 and 51.6 days after the burst. Photometric and spectroscopic observations revealed the presence of the type Ic SN 2013cq. Results. Spectroscopic analysis suggests that SN 2013cq resembles two previous GRB-SNe, SN 1998bw and SN 2010bh, associated with GRB 980425 and X-ray flash (XRF) 100316D, respectively. The bolometric light curve of SN 2013cq, which is significantly af fected by the host galaxy contribution, is systematically more luminous than that of SN 2010bh (∼2 mag at peak), but is consistent with SN 1998bw. The comparison with the light curve model of another GRB-connected SN 2003dh indicates that SN 2013cq is consistent with the model when brightened by 20%. This suggests a synthesised radioactive 56Ni mass of ∼0.4M . GRB 130427A/SN 2013cq is the first case of low-z GRB-SN connection where the GRB energetics are extreme (Eγ,iso ∼ 1054 erg). We show that the maximum luminosities attained by SNe associated with GRBs span a very narrow range, but those associated with XRFs are significantly less luminous. On the other hand the isotropic energies of the accompanying GRBs span 6 orders of magnitude (1048 erg < Eγ,iso < 1054 erg), although this range is reduced when corrected for jet collimation. The GRB total radiated energy is in fact a small fraction of the SN energy budget.Ítem Identifying the host galaxy of the short GRB 100628A(EDP Sciences, 2015-11) Nicuesa Guelbenzu, A.; Klose, S.; Palazzi, E.; Greiner, J.; Michałowski, M.J.; Kann, D.A.; Hunt, L.K.; Malesani, D.; Rossi, A.; Savaglio, S.; Schulze, S.; Xu, D.; Afonso, P.M.J.; Elliott, J.; Ferrero, P.; Filgas, R.; Hartmann, D.H.; Krühler, T.; Knust, F.; Masetti, N.; Olivares, E. F.; Rau, A.; Schady, P.; Schmidl, S.; Tanga, M.; Updike, A.C.; Varela, K.We report on the results of a comprehensive observing campaign to reveal the host galaxy of the short GRB 100628A. This burst was followed by a faint X-ray afterglow but no optical counterpart was discovered. However, inside the X-ray error circle a potential host galaxy at a redshift of z = 0.102 was soon reported in the literature. If this system is the host, then GRB 100628A was the cosmologically most nearby unambiguous short burst with a measured redshift so far. We used the multi-colour imager GROND at the ESO/La Silla MPG 2.2 m telescope, ESO/VLT spectroscopy, and deep Australia Telescope Compact Array (ATCA) radio-continuum observations together with publicly available Gemini imaging data to study the putative host and the galaxies in the field of GRB 100628A. We confirm that inside the X-ray error circle the most probable host-galaxy candidate is the morphologically disturbed, interacting galaxy system at z = 0.102. The interacting galaxies are connected by a several kpc long tidal stream, which our VLT/FORS2 spectroscopy reveals strong emission lines of [O ii], [O iii], Hα and Hβ, characteristic for the class of extreme emission-line galaxies and indicative of ongoing star formation. The latter leaves open the possibility that the GRB progenitor was a member of a young stellar population. However, we indentify a second host-galaxy candidate slightly outside the X-ray error circle. It is a radio-bright, luminous elliptical galaxy at a redshift z = 0.311. With a K-band luminosity of 2 × 1011L this galaxy resembles the probable giant elliptical host of the first well-localized short burst, GRB 050509B. If this is the host, then the progenitor of GRB 100628A was a member of an old stellar population. © ESO, 2015.Ítem Quasar lenses and pairs in the VST-ATLAS and Gaia(Oxford University Press, 2018-04) Agnello, A.; Schechter, P.L.; Morgan, N.D.; Treu, T.; Grillo, C.; Malesani, D.; Anguita, T.; Apostolovski, Y.; Rusu, C.E.; Motta, V.; Rojas, K.; Chehade, B.; Shanks, T.We report on discovery results from a quasar lens search in the ATLAS-DR3 public footprint. Spectroscopic follow-up campaigns, conducted at the 2.6 m Nordic Optical Telescope (La Palma) and 3.6mNew Technology Telescope (La Silla) in 2016, yielded seven pairs of quasars exhibiting the same lines at the same redshift and monotonic flux ratios with wavelength (hereafter NIQs, nearly identical quasar pairs). Magellan spectra of A0140-1152 (01h40m03.s0-11d52m19.s0, zs = 1.807) confirm it as a lens with deflector at zl = 0.277 and Einstein radius θE = (0.73 ± 0.02) arcsec. Follow-up imaging of the NIQ A2213-2652 (22h13m38.s4-26d52m27.s1) reveals the deflector galaxy and confirms it as a lens. We show the use of spatial resolution from the Gaia mission to select lenses and list additional systems from a WISEGaia- ATLAS search, yielding three additional lenses (02h35m27.s4-24d33m13.s2, 02h59m33s- 23d38m01.s8, 01h46m32.s9-11d33m39.s0). The overall sample consists of 11 lenses/NIQs, plus three lenses known before 2016, over the ATLAS-DR3 footprint (≈3500 deg2). Finally, we discuss future prospects for objective classification of pair/NIQ/contaminant spectra. © 2017 The Authors.Ítem SN 2013dx associated with GRB 130702A: A detailed photometric and spectroscopic monitoring and a study of the environment(EDP Sciences, 2015-05) D'Elia, V.; Pian, E.; Melandri, A.; D'Avanzo, P.; Della Valle, M.; Mazzali, P.A.; Piranomonte, S.; Tagliaferri, G.; Antonelli, L.A.; Bufano, F.; Covino, S.; Fugazza, D.; Malesani, D.; Møller, P.; Palazzi, E.Aims. Long-duration gamma-ray bursts (GRBs) and broad-line, type Ic supernovae (SNe) are strongly connected. We aim at characterizing SN 2013dx, which is associated with GRB? 130702A, through a sensitive and extensive ground-based observational campaign in the optical-IR band. Methods. We monitored the field of the Swift GRB 130702A (redshift z = 0.145) using the 8.2 m VLT, the 3.6 m TNG and the 0.6 m REM telescopes during the time interval between 4 and 40 days after the burst. Photometric and spectroscopic observations revealed the associated type Ic SN 2013dx. Our multiband photometry allowed constructing a bolometric light curve. Results. The bolometric light curve of SN 2013dx resembles that of 2003dh (associated with GRB? 030329), but is ~10% faster and ~25% dimmer. From this we infer a synthesized 56Ni mass of ∼0.2 Mo. The multi-epoch optical spectroscopy shows that the SN 2013dx behavior is best matched by SN 1998bw, among the other well-known low-redshift SNe associated with GRBs and XRFs, and by SN 2010ah, an energetic type Ic SN not associated with any GRB. The photospheric velocity of the ejected material declines from ∼2.7 × 104 km? s-1 at 8 rest frame days from the explosion, to ∼3.5 × 103 km? s-1 at 40 days. These values are extremely close to those of SN1998bw and 2010ah. We deduce for SN 2013dx a kinetic energy of ∼35 × 1051 erg and an ejected mass of ∼7 M. This suggests that the progenitor of SN2013dx had a mass of ∼25-30 M, which is 15-20% less massive than that of SN 1998bw. Finally, we studied the SN 2013dx environment through spectroscopy of the closeby galaxies: 9 out of the 14 inspected galaxies lie within 0.03 in redshift from z = 0.145, indicating that the host of GRB? 130702A/SN 2013dx belongs to a group of galaxies, an unprecedented finding for a GRB-associated SN and, to our knowledge, for long GRBs in general. © ESO, 2015.Ítem Spectroscopic identification of r-process nucleosynthesis in a double neutron-star merger(Nature Publishing Group, 2017-11) Pian, E.; D'Avanzo, P.; Benetti, S.; Branchesi, M.; Brocato, Campana S.; Cappellaro, E.; Covino, S.; D'Elia, V.; Fynbo, J.P.U.; Getman, F.; Ghirlanda, G.; Ghisellini, G.; Grado, A.; Greco, G.; Hjorth, J.; Kouveliotou, C.; Levan, A.; Limatola, L.; Malesani, D.; Mazzali, P.A.; Melandri, A.; Møller, P.; Nicastro, L.; Palazzi, E.; Piranomonte, S.; Rossi, A.; Salafia, O.S.; Selsing, J.; Stratta, G.; Tanaka, M.; Tanvir, N.R.; Tomasella, L.; Watson, D.; Yang, S.; Amati, L.; Antonelli, L.A.; Ascenzi, S.; Bernardini, M.G.; Boër, M.; Bufano, F.; Bulgarelli, A.; Capaccioli, M.; Casella, P.; Castro-Tirado, A.J.; Chassande-Mottin, E.; Ciolfi, R.; Copperwheat, C.M.; Dadina, M.; De Cesare, G.; Di Paola, A.; Fan, Y.Z.; Gendre, B.; Giuffrida, G.; Giunta, A.; Hunt, L.K.; Israel, G.L.; Jin, Z.-P.; Kasliwal, M.M.; Klose, S.; Lisi, M.; Longo, F.; Maiorano, E.; Mapelli, M.; Masetti, N.; Nava, L.; Patricelli, B.; Perley, D.; Pescalli, A.; Piran, T.; Possenti, A.; Pulone, L.; Razzano, M.; Salvaterra, R.; Schipani, P.; Spera, M.; Stamerra, A.; Stella, L.; Tagliaferri, G.; Testa, V.; Troja, E.; Turatto, M.; Vergani, S.D.; Vergani, D.The merger of two neutron stars is predicted to give rise to three major detectable phenomena: a short burst of γ-rays, a gravitational-wave signal, and a transient optical-near-infrared source powered by the synthesis of large amounts of very heavy elements via rapid neutron capture (the r-process)1-3. Such transients, named 'macronovae' or 'kilonovae'4-7, are believed to be centres of production of rare elements such as gold and platinum8. The most compelling evidence so far for a kilonova was a very faint near-infrared rebrightening in the afterglow of a short γ-ray burst9,10 at redshift z = 0.356, although findings indicating bluer events have been reported11. Here we report the spectral identification and describe the physical properties of a bright kilonova associated with the gravitational-wave source12 GW170817 and γ-ray burst13,14 GRB 170817A associated with a galaxy at a distance of 40 megaparsecs from Earth. Using a series of spectra from ground-based observatories covering the wavelength range from the ultraviolet to the near-infrared, we find that the kilonova is characterized by rapidly expanding ejecta with spectral features similar to those predicted by current models15,16. The ejecta is optically thick early on, with a velocity of about 0.2 times light speed, and reaches a radius of about 50 astronomical units in only 1.5 days. As the ejecta expands, broad absorption-like lines appear on the spectral continuum, indicating atomic species produced by nucleosynthesis that occurs in the post-merger fast-moving dynamical ejecta and in two slower (0.05 times light speed) wind regions. Comparison with spectral models suggests that the merger ejected 0.03 to 0.05 solar masses of material, including high-opacity lanthanides. © 2017 Macmillan Publishers Limited, part of Springer Nature.Ítem The supernova of the MAGIC gamma-ray burst GRB 190114C(EDP Sciences, 2022-03) Melandri, A.; Izzo, L.; Pian, E.; Malesani, D.; Della Valle, M.; Rossi, A.; DAvanzo, P.; Guetta, D.; Mazzali, P.; Benetti, S.; Masetti, N.; Palazzi, E.; Savaglio, S.; Amati, L.; Antonelli, L.; Ashall, C.; Bernardini, M.; Campana, S.; Carini, R.; Covino, S.; DElia, V.; De Ugarte Postigo, A.; De Pasquale, M.; Filippenko, A.; Fruchter, A.; Fynbo, J.; Giunta, A.; Hartmann, D.; Jakobsson, P.; Japelj, J.; Jonker, P.; Kann, D.; Lamb, G.; Levan, A.; Martin-Carrillo, A.; Møller, P.; Piranomonte, S.; Pugliese, G.; Salvaterra, R.; Schulze, S.; Starling, R.; Stella, L.; Tagliaferri, G.; Tanvir, N.; Watson, D.We observed GRB 190114C (redshift z = 0.4245), the first gamma-ray burst (GRB) ever detected at TeV energies, at optical and near-infrared wavelengths with several ground-based telescopes and the Hubble Space Telescope, with the primary goal of studying its underlying supernova, SN 2019jrj. The monitoring spanned the time interval between 1.3 and 370 days after the burst, in the observer frame. We find that the afterglow emission can be modelled with a forward shock propagating in a uniform medium modified by time-variable extinction along the line of sight. A jet break could be present after 7 rest-frame days, and accordingly the maximum luminosity of the underlying supernova (SN) ranges between that of stripped-envelope core-collapse SNe of intermediate luminosity and that of the luminous GRB-associated SN 2013dx. The observed spectral absorption lines of SN 2019jrj are not as broad as in classical GRB SNe and are instead more similar to those of less-luminous core-collapse SNe. Taking the broad-lined stripped-envelope core-collapse SN 2004aw as an analogue, we tentatively derive the basic physical properties of SN 2019jrj. We discuss the possibility that a fraction of the TeV emission of this source might have had a hadronic origin and estimate the expected high-energy neutrino detection level with IceCube.