Examinando por Autor "Silverman, J. M."
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Ítem EXTENSIVE SPECTROSCOPY AND PHOTOMETRY OF THE TYPE IIP SUPERNOVA 2013ej(IOP PUBLISHING, 2016) Dhungana, G.; Kehoe, R.; Vinko, J.; Silverman, J. M.; Wheeler, J. C.; Zheng, W.; Marion, G. H.; Fox, O. D.; Akerlof, C.; Biro, B. I.; Borkovits, T.; Cenko, S. B.; Clubb, K. I.; Filippenko, A. V.; Ferrante, F. V.; Gibson, C. A.; Graham, M. L.; Hegedus, T.; Kelly, P.; Kelemen, J.; Lee, W. H.; Marschalko, G.; Molnár, L.; Nagy, A. P.; Ordasi, A.; Pal, A.; Sarneczky, K.; Shivvers, I.; Szakats, R.; Szalai, T.; Szegedi-Elek, E.; Székely, P.; Szing, A.; Takáts, K.; Vida, K.We present extensive optical (UBV RI, g' r' i' z', and open CCD) and near-infrared (ZY JH) photometry for the very nearby Type IIP SN. 2013ej extending from + 1 to + 461 days after shock breakout, estimated to be MJD 56496.9 +/- 0.3. Substantial time series ultraviolet and optical spectroscopy obtained from + 8 to + 135 days are also presented. Considering well-observed SNe IIP from the literature, we derive UBV RIJHK bolometric calibrations from UBV RI and unfiltered measurements that potentially reach 2% precision with a B - V color-dependent correction. We observe moderately strong Si II lambda 6355 as early as + 8 days. The photospheric velocity (vph) is determined by modeling the spectra in the vicinity of Fe II lambda 5169 whenever observed, and interpolating at photometric epochs based on a semianalytic method. This gives vph= 4500. 500 km s(-1) at + 50 days. We also observe spectral homogeneity of ultraviolet spectra at + 10-12 days for SNe IIP, while variations are evident a week after explosion. Using the expanding photosphere method, from combined analysis of SN 2013ej and SN 2002ap, we estimate the distance to the host galaxy to be 9.0(-0.6)(+0.4) Mpc, consistent with distance estimates from other methods. Photometric and spectroscopic analysis during the plateau phase, which we estimated to be 94 +/- 7 days long, yields an explosion energy of 0.9 +/- 0.3 x 10(51) erg, a final pre-explosion progenitor mass of 15.2 +/- 4.2 M-circle dot and a radius of 250 +/- 70 R-circle dot. We observe a broken exponential profile beyond + 120 days, with a break point at + 183 +/- 16 days. Measurements beyond this break time yield a Ni-56 mass of 0.013 +/- 0.001. M-circle dot.Ítem LIGHT CURVES OF 213 TYPE Ia SUPERNOVAE FROM THE ESSENCE SURVEY(IOP PUBLISHING, 2016) Narayan, G.; Rest, A.; Tucker, B. E.; Foley, R. J.; Wood-Vasey, W. M.; Challis, P.; Stubbs, C.; Kirshner, R. P.; Aguilera, C.; Becker, A. C.; Blondin, S.; Clocchiatti, A.; Covarrubias, R.; Damke, G.; Davis, T. M.; Filippenko, A. V.; Ganeshalingam, M.; Garg, A.; Garnavich, P. M.; Hicken, M.; Jha, S. W.; Krisciunas, K.; Leibundgut, B.; Li, W.; Matheson, T.; Miknaitis, G.; Pignata, G.; Prieto, J. L.; Riess, A. G.; Schmidt, B. P.; Silverman, J. M.; Smith, R. C.; Sollerman, J.; Spyromilio, J.; Suntzeff, N. B.; Tonry, J. L.; Zenteno, A.The ESSENCE survey discovered 213 Type Ia supernovae at redshifts 0.1 < z < 0.81 between 2002 and 2008. We present their R- and I-band photometry, measured from images obtained using the MOSAIC II camera at the CTIO Blanco, along with rapid-response spectroscopy for each object. We use our spectroscopic follow-up observations to determine an accurate, quantitative classification, and precise redshift. Through an extensive calibration program we have improved the precision of the CTIO Blanco natural photometric system. We use several empirical metrics to measure our internal photometric consistency and our absolute calibration of the survey. We assess the effect of various potential sources of systematic bias on our measured fluxes, and estimate the dominant term in the systematic error budget from the photometric calibration on our absolute fluxes is similar to 1%.Ítem Supernova 2013fc in a circumnuclear ring of a luminous infrared galaxy: The big brother of SN 1998S(OXFORD UNIV PRESS, 2016-02) Kangas, T.; Mattila, S.; Kankare, E.; Lundqvist, P.; Väisänen, P.; Childress, M.; Pignata, G.; McCully, C.; Valenti, S.; Vinkó, J.; Pastorello, A.; Elias-Rosa, N.; Fraser, M.; Gal-Yam, A.; Kotak, R.; Kotilainen, J. K.; Smartt, S. J.; Galbany, L.; Harmanen, J.; Howell, D. A.; Inserra, C.; Marion, G. H.; Quimby, R. M.; Silverman, J. M.; Szalai, T.; Wheeler, J. C.; Ashall, C.; Benetti, S.; Romero-Cañizales, C.; Smith, K. W.; Sullivan, M.; Takáts, K.; Young, D. R.We present photometric and spectroscopic observations of SN 2013fc, a bright type II supernova (SN) in a circumnuclear star-forming ring in the luminous infrared galaxy ESO 154-G010, observed as part of the Public ESO Spectroscopic Survey of Transient Objects. SN 2013fc is both photometrically and spectroscopically similar to the well-studied type IIn SN 1998S and to the bright type II-L SN 1979C. It exhibits an initial linear decline, followed by a short plateau phase and a tail phase with a decline too fast for Co-56 decay with full. gamma-ray trapping. Initially, the spectrum was blue and featureless. Later on, a strong broad (similar to 8000 km s(-1)) H alpha emission profile became prominent. We apply a STARLIGHT stellar population model fit to the SN location (observed when the SN had faded) to estimate a high extinction of A(V) = 2.9 +/- 0.2 mag and an age of 10(+ 3) (- 2) Myr for the underlying cluster. We compare the SN to SNe 1998S and 1979C and discuss its possible progenitor star considering the similarities to these events. With a peak brightness of B = - 20.46 +/- 0.21 mag, SN 2013fc is 0.9 mag brighter than SN 1998S and of comparable brightness to SN 1979C. We suggest that SN 2013fc was consistent with a massive red supergiant (RSG) progenitor. Recent mass loss probably due to a strong RSG wind created the circumstellar matter illuminated through its interaction with the SN ejecta. We also observe a near- infrared excess, possibly due to newly condensed dust.