Browsing by Author "Filippenko, A. V."

Now showing 1 - 6 of 6
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    First Cosmology Results using Supernovae Ia from the Dark Energy Survey : Survey Overview, Performance, and Supernova Spectroscopy
    (2020) Smith, M.; D'Andrea, C. B.; Sullivan, M.; Moller, A.; Nichol, R. C.; Thomas, R. C.; Kim, A. G.; Sako, M.; Castander, F. J.; Clocchiatti, Alejandro; Filippenko, A. V.; Foley, R. J.; Galbany, L.; González Gaitan, S.; Kasai, E.; Kirshner, R. P.; Lidman, C.; Scolnic, D.; Brout, D.; Davis, T. M.; Gupta, R. R.; Hinton, S. R.; Kessler, R.; Lasker, J.; Macaulay, E.; Wolf, R. C.; Zhang, B.; Asorey, J.; Avelino, A.; Bassett, B. A.; Calcino, J.; Carollo, D.; Casas, R.; Challis, P.; Childress, M.; Crawford, S.; Frohmaier, C.; Glazebrook, K.; Goldstein, D. A.; Graham, M. L.; Hoormann, J. K.; Kuehn, K.; Lewis, G. F.; Mandel, K. S.; Morganson, E.; Muthukrishna, D.; Nugent, P.; Pan, Y. C.; Pursiainen, M.; Sharp, R.
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    Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548
    (IOP PUBLISHING LTD, 2017) Pei, L.; Fausnaugh, M. M.; Barth, A. J.; Peterson, B. M.; Bentz, M. C.; De Rosa, G.; Denney, K. D.; Goad, M. R.; Kochanek, C. S.; Korista, K. T.; Kriss, G. A.; Pogge, R. W.; Bennert, V. N.; Brotherton, M.; Clubb, K. I.; Dalla Bonta, E.; Filippenko, A. V.; Greene, J. E.; Grier, C. J.; Vestergaard, M.; Zheng, W.; Adams, Scott M.; Beatty, Thomas G.; Bigley, A.; Brown, Jacob E.; Brown, Jonathan S.; Canalizo, G.; Comerford, J. M.; Coker, Carl T.; Corsini, E. M.; Croft, S.; Croxall, K. V.; Deason, A. J.; Eracleous, Michael; Fox, O. D.; Gates, E. L.; Henderson, C. B.; Holmbeck, E.; Holoien, T. W. S.; Jensen, J. J.; Johnson, C. A.; Kelly, P. L.; Kim, S.; King, A.; Lau, M. W.; Li, Miao; Lochhaas, Cassandra; Ma, Zhiyuan; Manne Nicholas, E. R.; Mauerhan, J. C.; Malkan, M. A.; McGurk, R.; Morelli, L.; Mosquera, Ana; Mudd, Dale; Sanchez, F. Muller; Nguyen, M. L.; Ochner, P.; Ou Yang, B.; Pancoast, A.; Penny, Matthew T.; Pizzella, A.; Poleski, Radoslaw; Runnoe, Jessie; Scott, B.; Schimoia, Jaderson S.; Shappee, B. J.; Shivvers, I.; Simonian, Gregory V.; Siviero, A.; Somers, Garrett; Stevens, Daniel J.; Strauss, M. A.; Tayar, Jamie; Tejos, N.; Treu, T.; Van Saders, J.; Vican, L.; Villanueva, S., Jr.; Yuk, H.; Zakamska, N. L.; Zhu, W.; Anderson, M. D.; Arevalo, P.; Bazhaw, C.; Bisogni, S.; Borman, G. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Cackett, E. M.; Carini, M. T.; Crenshaw, D. M.; De Lorenzo Caceres, A.; Dietrich, M.; Edelson, R.; Efimova, N. V.; Ely, J.; Evans, P. A.; Ferland, G. J.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; Grupe, D.; Gupta, A.; Hall, P. B.; Hicks, S.; Horenstein, D.; Horne, Keith; Hutchison, T.; Im, M.; Joner, M. D.; Jones, J.; Kaastra, J.; Kaspi, S.; Kelly, B. C.; Kennea, J. A.; Kim, M.; Kim, S. C.; Klimanov, S. A.; Lee, J. C.; Leonard, D. C.; Lira, P.; MacInnis, F.; Mathur, S.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Netzer, H.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Papadakis, I.; Parks, J. R.; Pott, J. U.; Rafter, S. E.; Rix, H. W.; Saylor, D. A.; Schnuelle, K.; Sergeev, S. G.; Siegel, M.; Skielboe, A.; Spencer, M.; Starkey, D.; Sung, H. I.; Teems, K. G.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J. H.; Yan, H.; Young, S.; Zu, Y.
    We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The H beta and He II lambda 4686 broad emission-line light curves lag that of the 5100 angstrom optical continuum by 4.17(-0.36)(+0.36) days and 0.79(-0.34)(+0.35) days, respectively. The H beta lag relative to the 1158 angstrom ultraviolet continuum light curve measured by the Hubble Space Telescope is similar to 50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-line region is similar to 50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for H beta and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broadline region dominated by Keplerian motion. The responses of both the H beta and He II emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C IV, Lya, He II (+ O III]), and Si IV(+ O IV]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured H beta lag is a factor of five shorter than the expected value implied by the R-BLR-L-AGN relation based on the past behavior of NGC 5548.
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    Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy
    (IOP PUBLISHING LTD, 2017) Mathur, S.; Gupta, A.; Page, K.; Pogge, R. W.; Krongold, Y.; Goad, M. R.; Adams, S. M.; Anderson, M. D.; Arevalo, P.; Barth, A. J.; Bazhaw, C.; Beatty, T. G.; Bentz, M. C.; Bigley, A.; Bisogni, S.; Borman, G. A.; Boroson, T. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Brown, J. E.; Brown, J. S.; Cackett, E. M.; Canalizo, G.; Carini, M. T.; Clubb, K. I.; Comerford, J. M.; Coker, C. T.; Corsini, E. M.; Crenshaw, D. M.; Croft, S.; Croxall, K. V.; Dalla Bonta, E.; Deason, A. J.; Denney, K. D.; De Lorenzo Caceres, A.; De Rosa, G.; Dietrich, M.; Edelson, R.; Ely, J.; Eracleous, M.; Evans, P. A.; Fausnaugh, M. M.; Ferland, G. J.; Filippenko, A. V.; Flatland, K.; Fox, O. D.; Gates, E. L.; Gehrels, N.; Geier, S.; Gelbord, J. M.; Gorjian, V.; Greene, J. E.; Grier, C. J.; Grupe, D.; Hall, P. B.; Henderson, C. B.; Hicks, S.; Holmbeck, E.; Holoien, T. W. S.; Horenstein, D.; Horne, Keith; Hutchison, T.; Im, M.; Jensen, J. J.; Johnson, C. A.; Joner, M. D.; Jones, J.; Kaastra, J.; Kaspi, S.; Kelly, B. C.; Kelly, P. L.; Kennea, J. A.; Kim, M.; Kim, S.; Kim, S. C.; King, A.; Klimanov, S. A.; Kochanek, C. S.; Korista, K. T.; Kriss, G. A.; Lau, M. W.; Lee, J. C.; Leonard, D. C.; Li, M.; Lira, P.; Ma, Z.; MacInnis, F.; Manne Nicholas, E. R.; Malkan, M. A.; Mauerhan, J. C.; McGurk, R.; McHardy, I. M.; Montouri, C.; Morelli, L.; Mosquera, A.; Mudd, D.; Muller Sanchez, F.; Musso, R.; Nazarov, S. V.; Netzer, H.; Nguyen, M. L.; Norris, R. P.; Nousek, J. A.; Ochner, P.; Okhmat, D. N.; Ou Yang, B.; Pancoast, A.; Papadakis, I.; Parks, J. R.; Pei, L.; Peterson, B. M.; Pizzella, A.; Poleski, R.; Pott, J. U.; Rafter, S. E.; Rix, H. W.; Runnoe, J.; Saylor, D. A.; Schimoia, J. S.; Schnuelle, K.; Sergeev, S. G.; Shappee, B. J.; Shivvers, I.; Siegel, M.; Simonian, G. V.; Siviero, A.; Skielboe, A.; Somers, G.; Spencer, M.; Starkey, D.; Stevens, D. J.; Sung, H. I.; Tayar, J.; Tejos, N.; Turner, C. S.; Uttley, P.; Van Saders, J.; Vestergaard, M.; Vican, L.; Villanueva, S., Jr.; Villforth, C.; Weiss, Y.; Woo, J. H.; Yan, H.; Young, S.; Yuk, H.; Zheng, W.; Zhu, W.; Zu, Y.
    During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on-and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly.
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    Supernova 2011D in UGC 2498
    (2011) Narla, A.; Cenko, S. B.; Li, W.; Filippenko, A. V.; Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Marion, G. H.; Challis, P.; Berlind, P.
    Via public images from the Catalina Sky Survey (CSS). 2011 UT R.A. (2000.0) Decl. Mag. Offset Observers Jan. 5.09 3 02 14.58 +17 20 58.9 18.2 33".8 E, 14".7 N CSS Jan. 6.30 3 02 14.53 +17 20 58.3 18.2 34".4 E, 14".8 N KAIT Additional magnitudes for 2011D: 2010 Dec. 8.32 UT, [19.3 (KAIT); 10.19, [19.4 (CSS); 2011 Jan. 7.21, 18.2 (KAIT); 8.13, 17.8 (S. Howerton, remotely with the LB-1 0.6-m telescope near Rodeo, NM, U.S.A.). Drake notes that the presumed host galaxy, UGC 2498, has redshift z = 0.0231. G. H. Marion and P. Challis, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm) was obtained of 2011D on Jan. 8 UT by P. Berlind with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011D is a type-IIb supernova a few days before maximum light....
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    Supernova 2011ho in NGC 3847 = Psn J11441295+3330581
    (2011) Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; McNaught, R. H.; Garradd, G.; Beshore, E. C.; Larson, S. M.; Christensen, E.; Foley, R. J.; Kasen, D.; Filippenko, A. V.; Marion, G. H.; Berlind, P.
    Report the discovery of an apparent supernova in public images from the Catalina Sky Survey (CSS). SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011ho Oct. 28.49 11 44 12.95 +33 30 58.1 18.7 12".8 W, 5".8 N This variable was designated PSN J11441295+3330581 when it was posted on the Central Bureau's TOCP webpage and is here designated SN 2011ho based on the spectroscopic confirmation reported below. Further unfiltered CCD magnitudes for 2011ho: June 11.21 UT, [19.0 (CSS); Oct. 30.495, 18.3 (Joseph Brimacombe, Cairns, Australia; position end figures 13s.10, 59".2; image posted at website URL http://www.flickr.com/photos/43846774@N02/6297040020/). R. J. Foley, Harvard-Smithsonian Center for Astrophysics; and D. Kasen and A. V. Filippenko, University of California, Berkeley, report that a CCD spectrum (range 310-1020 nm), obtained on Oct. 31 UT with the Keck I 10-m telescope (+ LRIS), shows that PSN J11441295+3330581 = SN 2011ho is a type-Ia supernova near maximum brightness. The spectrum exhibits a large Si II 597.2-nm/635.5-nm ratio, indicating a cooler photosphere and a lower luminosity. The spectrum is similar to that of SN 1986G at -3 days (Phillips et al. 1987, PASP 99, 592), but it also resembles spectra of the more typical type-Ia supernovae 1992A and 2004eo at a similar epoch. After removing the recession velocity of 9520 km/s (obtained from the Sloan Digital Sky Survey), the minimum of the Si II 635.5-nm feature is blueshifted by 11700 km/s. G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, reports that a spectrum (range 340-740 nm) of PSN J11441295+3330581 = 2011ho was obtained on Nov. 3 UT by P. Berlind with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011ho is a 1991bg-like type-Ia supernova near maximum light. Good fits can be found to several templates of normal and 1991bg-like type-Ia supernovae within three days of maximum. The presence of a strong feature from Si II 597.2-nm and the reported brightness of 2011ho are consistent with a subluminous, or 1991bg-like, type-Ia supernova. Using an estimated redshift of z = 0.031829 for NGC 3847 as reported in NED (de Vaucouleurs et al. 1991, RC3.9C), the velocity of the Si II 635.5-nm and 597.2-nm features are estimated to be 10700 km/s and 10500 km/s, respectively....
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    Supernova 2011jt in Pgc 53208 = Psn J14532301+0257431
    (2012) Drake, A. J.; Djorgovski, S. G.; Graham, M. J.; Mahabal, A.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Silverman, J. M.; Filippenko, A. V.; Chen, J. -C.; Wang, X. -F.; Zhan, X.; Zhang, T. -M.
    Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011jt Dec. 31.54 14 53 23.01 + 2 57 43.1 17.0 5".8 W, 16".4 S The variable was designated PSN J14532301+0257431 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011jt based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2011jt: 2011 June 23.25 UT, [20.3 (CSS); 2012 Jan. 1.526, 16.5 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera + luminance filter at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 23s.02, 42".9; image posted at website URL http://www.flickr.com/photos/43846774@N02/6618245617/). J. M. Silverman and A. V. Filippenko, University of California, Berkeley, report that inspection of a CCD spectrum (range 340-1000 nm), obtained on Jan. 3 UT with the Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory, shows that PSN J14532301+0257431 = SN 2011jt is a type-Ia supernova. After removal of the host-galaxy recession velocity of 8334 km/s (from the Sloan Digital Sky Survey Data Release 1), they find the absorption minimum of the Si II 635.5-nm line to be blueshifted by about 14700 km/s. Cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that the object is a normal type-Ia supernova about six days before maximum brightness. J.-C. Chen and X.-F. Wang, Tsinghua Center for Astrophysics, Tsinghua University; X. Zhan, Beijing Planetarium; T.-M. Zhang, National Astronomical Observatory of China (NAOC), report on an optical spectrogram (range 400-8800 nm) of PSN J14532301+0257431 = SN 2011jt that was obtained on 2012 Jan. 3.9 UT with the 2.16-m telescope (+ OMR) at Xinglong Station of NAOC. The spectrum is consistent with a type-Ia supernova at about one week before maximum. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that it matches with SN 2002bo at -9 days. Adopting a recession velocity of 8334 km/s for the host galaxy from the NED, they measure a velocity of the Si II 635.5-nm absorption feature to be about 15000 km/s....