Examinando por Autor "Gutierrez, C.P."

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    Luminous Type II supernovae for their low expansion velocities
    (Oxford University Press, 2020-05) Rodríguez, O.; Pignata, G.; Anderson, J.P.; Moriya, T.J.; Clocchiatti, A.; Forster, F.; Prieto, J.L.; Phillips, M.M.; Burns, C.R.; Contreras, C.; Folatelli, G.; Gutierrez, C.P.; Hamuy, M.; Morrell, N.I.; Stritzinger, M.D.; Suntzeff, N.B.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Pastorello, A.; Turatto, M.; Maza, J.; Antezana, R.; Cartier, R.; Gonzalez, L.; Haislip, J.B.; Kouprianov, V.; Lopez, P.; Marchi-Lasch, S.; Reichart, D.
    We present optical and near-infrared data of three Type II supernovae (SNe II), SN 2008bm, SN 2009aj, and SN 2009au. These SNe display the following common characteristics: signs of early interaction of the ejecta with circumstellar material (CSM), blue B - V colours, weakness of metal lines, low expansion velocities, and V-band absolute magnitudes 2-3 mag brighter than those expected for normal SNe II based on their expansion velocities. Two more SNe reported in the literature (SN 1983K and LSQ13fn) share properties similar to our sample. Analysing this set of five SNe II, which are luminous for their low expansion velocities (LLEV), we find that their properties can be reproduced assuming ejecta-CSM interaction that lasts between 4 and 11 weeks post-explosion. The contribution of this interaction to the radiation field seems to be the dominant component determining the observed weakness of metal lines in the spectra rather than the progenitor metallicity. Based on hydrodynamic simulations, we find that the interaction of the ejecta with a CSM of ∼3.6 M⊙ can reproduce the light curves and expansion velocities of SN 2009aj. Using data collected by the Chilean Automatic Supernova Search, we estimate an upper limit for the LLEV SNe II fraction to be 2-4 per cent of all normal SNe II. With the current data set, it is not clear whether the LLEV events are a separated class of SNe II with a different progenitor system, or whether they are the extreme of a continuum mediated by CSM interaction with the rest of the normal SN II population. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
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    Photometric and spectroscopic evolution of the interacting transient at 2016jbu(Gaia16cfr)
    (Oxford University Press, 2022-07-01) Brennan, S.J.; Fraser, M.; Johansson, J.; Pastorello, A.; Kotak, R.; Stevance, H.F.; Chen, T.-W.; Eldridge, J.J.; Bose, S.; Brown, P.J.; Callis, E.; Cartier, R.; Dennefeld, M.; Dong, Subo; Duffy, P.; Elias Rosa, N.; Hosseinzadeh, G.; Hsiao, E.; Kuncarayakti, H.; Martin Carrillo, A.; Monard, B.; Nyholm, A.; Pignata, G.; Sand, D.; Shappee, B.J.; Smartt, S.J.; Tucker, B.E.; Wyrzykowski, L.; Abbot, H.; Benetti, S.; Bento, J.; Blondin, S.; Chen, Ping; Delgado, A.; Galbany, L.; Gromadzki, M.; Gutierrez, C.P.; Hanlon, L.; Harrison, D.L.; Hiramatsu, D.; Hodgkin, S.T.; Holoien, T.W.-S.; Howell, D.A.; Inserra, C.; Kankare, E.; Kozłowski, S.; Müller Bravo, T.E.; Maguire, K.; McCully, C.; Meintjes, P.; Morrell, N.; Nicholl, M.; O'Neill, D.; Pietrukowicz, P.; Poleski, R.; Prieto, J.L.; Rau, A.; Reichart, D.E.; Schweyer, T.; Shahbandeh, M.; Skowron, J.; Sollerman, J.; Soszyński, I.; Stritzinger, M.D.; Szymański, M.; Tartaglia, L.; Udalski, A.; Ulaczyk, K.; Young, D.R.; Van Leeuwen, M.; Van Soelen, B.
    We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of MV ∼-18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s-1 seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s-1 seen in broad absorption from some high-velocity material. Late-time spectra (∼+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He i, and Ca ii. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H α among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
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    Progenitor, environment, and modelling of the interacting transient AT 2016jbu (Gaia16cfr)
    (Oxford University Press, 2022-07-01) Brennan, S.J.; Fraser, M.; Johansson, J.; Pastorello, A.; Kotak, R.; Stevance, H.F.; Chen, T.-W.; Eldridge, J.J.; Bose, S.; Brown, P.J.; Callis, E.; Cartier, R.; Dennefeld, M.; Dong, Subo; Duffy, P.; Elias Rosa, N.; Hosseinzadeh, G.; Hsiao, E.; Kuncarayakti, H.; Martin Carrillo, A.; Monard, B.; Pignata, G.; Sand, D.; Shappee, B.J.; Smartt, S.J.; Tucker, B.E.; Wyrzykowski, L.; Abbot, H.; Benetti, S.; Bento, J.; Blondin, S.; Chen, Ping; Delgado, A.; Galbany, L.; Gromadzki, M.; Gutierrez, C.P.; Hanlon, L.; Harrison, D.L.; Hiramatsu, D.; Hodgkin, S.T.; Holoien, T.W.-S.; Howell, D.A.; Inserra, C.; Kankare, E.; Kozłowski, S.; Müller Bravo, T.E.; Maguire, K.; Mccully, C.; Meintjes, P.; Morrell, N.; Nicholl, M.; O'neill, D.; Pietrukowicz, P.; Poleski, R.; Prieto, J.L.; Rau, A.; Reichart, D.E.; Schweyer, T.; Shahbandeh, M.; Skowron, J.; Sollerman, J.; Soszyński, I.; Stritzinger, M.D.; Szymański, M.; Tartaglia, L.; Udalski, A.; Ulaczyk, K.; Young, D.R.; Van Leeuwen, M.; Van Soelen, B.
    We present the bolometric light curve, identification and analysis of the progenitor candidate, and preliminary modelling of AT 2016jbu (Gaia16cfr). We find a progenitor consistent with a ∼22-25 M⊙ yellow hypergiant surrounded by a dusty circumstellar shell, in agreement with what has been previously reported. We see evidence for significant photometric variability in the progenitor, as well as strong Hα emission consistent with pre-existing circumstellar material. The age of the environment, as well as the resolved stellar population surrounding AT 2016jbu, supports a progenitor age of >10 Myr, consistent with a progenitor mass of ∼22 M⊙. A joint analysis of the velocity evolution of AT 2016jbu and the photospheric radius inferred from the bolometric light curve shows the transient is consistent with two successive outbursts/explosions. The first outburst ejected material with velocity ∼650 km s-1, while the second, more energetic event ejected material at ∼4500 km s-1. Whether the latter is the core collapse of the progenitor remains uncertain. We place a limit on the ejected 56Ni mass of [removed]
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    SN 2016gsd: An unusually luminous and linear Type II supernova with high velocities
    (Oxford University Press, 2020-04) Reynolds, T.M.; Fraser, M.; Mattila, S.; Ergon, M.; Dessart, L.; Lundqvist, P.; Dong, S.; Elias-Rosa, N.; Galbany, L.; Gutierrez, C.P.; Kangas, T.; Kankare, E.; Kotak, R.; Kuncarayakti, H.; Pastorello, A.; Rodriguez, O.; Smartt, S.J.; Stritzinger, M.; Tomasella, L.; Chen, P.; Harmanen, J.; Hosseinzadeh, G.; Howell, D.A.; Inserra, C.; Nicholl, M.; Nielsen, M.; Smith, K.; Somero, A.; Tronsgaard, R.; Young, D.R.
    We present observations of the unusually luminous Type II supernova (SN) 2016gsd. With a peak absolute magnitude of V = -19.95 ± 0.08, this object is one of the brightest Type II SNe, and lies in the gap of magnitudes between the majority of Type II SNe and the superluminous SNe. Its light curve shows little evidence of the expected drop from the optically thick phase to the radioactively powered tail. The velocities derived from the absorption in H α are also unusually high with the blue edge tracing the fastest moving gas initially at 20 000 km s-1, and then declining approximately linearly to 15 000 km s-1 over ∼100 d. The dwarf host galaxy of the SN indicates a low-metallicity progenitor which may also contribute to the weakness of the metal lines in its spectra. We examine SN 2016gsd with reference to similarly luminous, linear Type II SNe such as SNe 1979C and 1998S, and discuss the interpretation of its observational characteristics. We compare the observations with a model produced by the jekyll code and find that a massive star with a depleted and inflated hydrogen envelope struggles to reproduce the high luminosity and extreme linearity of SN 2016gsd. Instead, we suggest that the influence of interaction between the SN ejecta and circumstellar material can explain the majority of the observed properties of the SN. The high velocities and strong H α absorption present throughout the evolution of the SN may imply a circumstellar medium configured in an asymmetric geometry. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
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    SN 2021foa, a transitional event between a Type IIn (SN 2009ip-like) and a Type Ibn supernova
    (EDP Sciences, 2022-06-01) Reguitti, A.; Pastorello, A.; Pignata, G.; Fraser, M.; Stritzinger, M.D.; Brennan, S.J.; Cai, Y.-Z.; Elias-Rosa, N.; Fugazza, D.; Gutierrez, C.P.; Kankare, E.; Kotak, R.; Lundqvist, P.; Mazzali, P.A.; Moran, S.; Salmaso, I.; Tomasella, L.; Valerin, G.; Kuncarayakti, H.
    We present photometric and spectroscopic data of the unusual interacting supernova (SN) 2021foa. It rose to an absolute magnitude peak of Mr= 18 mag in 20 days. The initial light curve decline shows some luminosity fluctuations before a long-lasting flattening. A faint source (Mr∼ 14 mag) was detected in the weeks preceding the main event, showing a slowly rising luminosity trend. The r-band absolute light curve is very similar to those of SN 2009ip-like events, with a faint and shorter duration brightening ('Event A') followed by a much brighter peak ('Event B'). The early spectra of SN 2021foa show a blue continuum with narrow (∼400 km s1) H emission lines that, two weeks later, reveal a complex profile, with a narrow P Cygni on top of an intermediate-width (∼2700 km s1) component. At +12 days, metal lines in emission appear and Hea lines become very strong, with Hea λ5876 reaching half of the Hα luminosity, much higher than in previous SN 2009ip-like objects. We propose that SN 2021foa is a transitional event between the H-rich SN 2009ip-like SNe and the He-rich Type Ibn SNe. © A. Reguitti et al. 2022.