Browsing by Author "Aldering, G"

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    Multiepoch multiwavelength spectra and models for blazar 3C 279
    (2001) Hartman, RC; Böttcher, M; Aldering, G; Aller, H; Aller, M; Backman, DE; Balonek, TJ; Bertsch, DL; Bloom, SD; Bock, H; Boltwood, P; Carini, MT; Collmar, W; De Francesco, G; Ferrara, EC; Freudling, W; Gear, WK; Hall, PB; Heidt, J; Hughes, P; Hunter, SD; Jogee, S; Johnson, WN; Kanbach, G; Katajainen, S; Kidger, M; Kii, T; Koskimies, M; Kraus, A; Kubo, H; Kurtanidze, O; Lanteri, L; Lawson, A; Lin, YC; Lisenfeld, U; Madejski, G; Makino, F; Maraschi, L; Marscher, AP; McFarland, JP; McHardy, I; Miller, HR; Nikolashvili, M; Nilsson, K; Noble, JC; Nucciarelli, G; Ostorero, L; Pian, E; Pursimo, T; Raiteri, CM; Reich, W; Rekola, R; Richter, GM; Robson, EI; Sadun, A; Savolainen, T; Sillanpää, A; Smale, A; Sobrito, G; Sreekumar, P; Stevens, JA; Takalo, LO; Tavecchio, F; Teräsranta, H; Thompson, DJ; Tornikoski, M; Tosti, G; Ungerechts, H; Urry, CM; Valtaoja, E; Villata, M; Wagner, SJ; Wehrle, AE; Wilson, JW
    Of the blazars detected by EGRET in GeV gamma -rays, 3C 279 is not only the best observed by EGRET but also one of the best monitored at lower frequencies. We have assembled 11 spectra, from GHz radio through GeV gamma -rays, from the time intervals of EGRET observations. Although some of the data have appeared in previous publications, most are new, including data taken during the high states in early 1999 and early 2000. All of the spectra show substantial gamma -ray contribution to the total luminosity of the object; in a high state, the gamma -ray luminosity dominates over that at all other frequencies by a factor of more than 10. There is no clear pattern of time correlation; different bands do not always rise and fall together, even in the optical, X-ray, and gamma -ray bands. The spectra are modeled using a leptonic jet, with combined synchrotron self-Compton plus external Compton gamma -ray production. Spectral variability of 3C 279 is consistent with variations of the bulk Lorentz factor of the jet, accompanied by changes in the spectral shape of the electron distribution. Our modeling results are consistent with the UV spectrum of 3C 279 being dominated by accretion disk radiation during times of low gamma -ray intensity.
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    The Type Ia supernova 1999aw
    (2002) Strolger, LG; Smith, RC; Suntzeff, NB; Phillips, MM; Aldering, G; Nugent, P; Knop, R; Perlmutter, S; Schommer, RA; Ho, LC; Hamuy, M; Krisciunas, K; Germany, LM; Covarrubias, R; Candia, P; Athey, A; Blanc, G; Bonacic, A; Bowers, T; Conley, A; Dahlén, T; Freedman, W; Galaz, G; Gates, E; Goldhaber, G; Goobar, A; Groom, D; Hook, IM; Marzke, R; Mateo, M; McCarthy, P; Méndez, J; Muena, C; Persson, SE; Quimby, R; Roth, M; Ruiz-Lapuente, P; Seguel, J; Szentgyorgyi, A; von Braun, K; Wood-Vasey, WM; York, T
    SN 1999aw was discovered during the first campaign of the Nearby Galaxies Supernova Search project. This luminous, slow-declining [Deltam(15)(B) = 0.81 +/- 0.03] Type Ia supernova was noteworthy in at least two respects. First, it occurred in an extremely low luminosity host galaxy that was not visible in the template images nor in initial subsequent deep imaging. Second, the photometric and spectral properties of this supernova indicate that it very likely was similar to the subclass of Type Ia supernovae whose prototype is SN 1999aa. This paper presents the BVRI and J(s)HK(s) light curves of SN 1999aw ( through similar to100 days past maximum light), as well as several epochs of optical spectra. From these data, we calculate the bolometric light curve and give estimates of the luminosity at maximum light and the initial Ni-56 mass. In addition, we present deep BVI images obtained recently with the Baade 6.5 m telescope at Las Campanas Observatory that reveal the remarkably low-luminosity host galaxy.