Examinando por Autor "Olivares, F.E."

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    Astronomy: ASASSN-15lh: A highly super-luminous supernova
    (American Association for the Advancement of Science, 2016-01) Dong, Subo; Shappee, B.J.; Prieto, J.L.; Jha, S.W.; Stanek, K.Z.; Holoien, T.W.-S.; Kochanek, C.S.; Thompson, T.A.; Morrell, N.; Thompson, I.B.; Basu, U.; Beacom, J.F.; Bersier, D.; Brimacombe, J.; Brown, J.S.; Bufano, F.; Chen, Ping; Conseil, E.; Danilet, A.B.; Falco, E.; Grupe, D.; Kiyota, S.; Masi, G.; Nicholls, B.; Olivares, F.E.; Pignata, G.; Pojmanski, G.; Simonian, G.V.; Szczygiel, D.M.; Woźniak, P.R.
    We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu,AB = –23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 1045 ergs s–1, which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ –25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 1052 ergs, challenging the magnetar model for its engine.
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    GRB 171010A/SN 2017htp: A Grb-Sn at z = 0.33
    (Oxford University Press, 2019-12) Melandri, A.; Malesani, D.B.; Izzo, L.; Japelj, J.; Vergani, S.D.; Schady, P.; Sagués Carracedo, A.; de Ugarte Postigo, A.; Anderson, J.P.; Barbarino, C.; Bolmer, J.; Breeveld, A.; Calissendorff, P.; Campana, S.; Cano, Z.; Carini, R.; Covino, S.; D'Avanzo, P.; D'Elia, V.; della Valle, M.; de Pasquale, M.; Fynbo, J.P.U.; Gromadzki, M.; Hammer, F.; Hartmann, D.H.; Heintz, K.E.; Inserra, C.; Jakobsson, P.; Kann, D.A.; Kotilainen, J.; Maguire, K.; Masetti, N.; Nicholl, M.; Olivares, F.E.; Pugliese, G.; Rossi, A.; Salvaterra, R.; Sollerman, J.; Stone, M.B.; Tagliaferri, G.; Tomasella, L.; Thöne, C.C.; Xu, D.; Young, D.R.
    The number of supernovae known to be connected with long-duration gamma-ray bursts (GRBs) is increasing and the link between these events is no longer exclusively found at low redshift (z ≲ 0.3) but is well established also at larger distances. We present a new case of such a liaison at z = 0.33 between GRB 171010A and SN 2017htp. It is the second closest GRB with an associated supernova of only three events detected by Fermi-LAT. The supernova is one of the few higher redshift cases where spectroscopic observations were possible and shows spectral similarities with the well-studied SN 1998bw, having produced a similar Ni mass (⁠MNi=0.33±0.02 M⊙ ⁠) with slightly lower ejected mass (⁠Mej=4.1±0.7 M⊙ ⁠) and kinetic energy (⁠EK=8.1±2.5×1051 erg ⁠). The host-galaxy is bigger in size than typical GRB host galaxies, but the analysis of the region hosting the GRB revealed spectral properties typically observed in GRB hosts and showed that the progenitor of this event was located in a very bright H II region of its face-on host galaxy, at a projected distance of ∼ 10 kpc from its galactic centre. The star-formation rate (SFRGRB ∼ 0.2 M⊙ yr−1) and metallicity (12 + log(O/H) ∼8.15 ± 0.10) of the GRB star-forming region are consistent with those of the host galaxies of previously studied GRB–SN systems.