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1. SN 2015bf: a fast declining type II supernova with flash-ionised signatures

Author

Lin, Han, Wang, Xiaofeng, Zhang, Jujia, Lin, Weili, Mo, Jun, Filippenko, Alexei V., Zheng, WeiKang, Brown, Peter J., Xiang, Danfeng, Huang, Fang, Cai, Yongzhi, Zhang, Tianmeng, Li, Xue, Rui, Liming, Zhang, Xinghan, Sai, Hanna, Zhao, Xulin, Graham, Melissa L., Shivvers, I., Halevi, G., Yuk, H., and Brink, Thomas G.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present optical and ultraviolet photometry, as well as optical spectra, for the type II supernova (SN) 2015bf. Our observations cover the phases from $\sim 2$ to $\sim 200$ d after explosion. The first spectrum is characterised by a blue continuum with a blackbody temperature of $\sim 24,000$K and flash-ionised emission lines. After about one week, the spectra of SN 2015bf evolve like those of a regular SN II. From the luminosity of the narrow emission component of H$\alpha$, we deduce that the mass-loss rate is larger than $\sim 3.7\times10^{-3}\,{\rm M_\odot\,yr^{-1}}$. The disappearance of the flash features in the first week after explosion indicates that the circumstellar material is confined within $\sim 6 \times 10^{14}$ cm. Thus, we suggest that the progenitor of SN 2015bf experienced violent mass loss shortly before the supernova explosion. The multiband light curves show that SN 2015bf has a high peak luminosity with an absolute visual magnitude $M_V = -18.11 \pm 0.08$ mag and a fast post-peak decline with a $V$-band decay of $1.22 \pm 0.09$ mag within $\sim 50$ d after maximum light. Moreover, the $R$-band tail luminosity of SN 2015bf is fainter than that of SNe~II with similar peak by 1--2 mag, suggesting a small amount of ${\rm ^{56}Ni}$ ($\sim 0.009\,{\rm M_\odot}$) synthesised during the explosion. Such a low nickel mass indicates that the progenitor of SN 2015bf could be a super-asymptotic-giant-branch star that collapsed owing to electron capture., Comment: 11 pages, accepted for publication in MNRAS

Published
2021

2. Space Telescope and Optical Reverberation Mapping Project. XII. Broad-Line Region Modeling of NGC 5548

Author

Williams, P. R., Pancoast, A., Treu, T., Brewer, B. J., Peterson, B. M., Barth, A. J., Malkan, M. A., De Rosa, G., Horne, Keith, Kriss, G. A., Arav, N., Bentz, M. C., Cackett, E. M., Bontà, E. Dalla, Dehghanian, M., Done, C., Ferland, G. J., Grier, C. J., Kaastra, J., Kara, E., Kochanek, C. S., Mathur, S., Mehdipour, M., Pogge, R. W., Proga, D., Vestergaard, M., Waters, T., Adams, S. M., Anderson, M. D., Arévalo, P., Beatty, T. G., Bennert, V. N., Bigley, A., Bisogni, S., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brotherton, M., Brown, J. E., Brown, J. S., Canalizo, G., Carini, M. T., Clubb, K. I., Comerford, J. M., Corsini, E. M., Crenshaw, D. M., Croft, S., Croxall, K. V., Deason, A. J., De Lorenzo-Cáceres, A., Denney, K. D., Dietrich, M., Edelson, R., Efimova, N. V., Ely, J., Evans, P. A., Fausnaugh, M. M., Filippenko, A. V., Flatland, K., Fox, O. D., Gardner, E., Gates, E. L., Gehrels, N., Geier, S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Greene, J. E., Grupe, D., Gupta, A., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -S., Hutchison, T., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Jones, J., Kaspi, S., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S., Kim, S. C., King, A., Klimanov, S. A., Knigge, C., Krongold, Y., Lau, M. W., Lee, J. C., Leonard, D. C., Li, Miao, Lira, P., Lochhaas, C., Ma, Zhiyuan, Manne-Nicholas, E. R., MacInnis, F., Mauerhan, J. C., McGurk, R., Hardy, I. M. Mc, Montuori, C., Morelli, L., Mosquera, A., Mudd, D., Müller-Sánchez, F., Nazarov, S. V., Norris, R. P., Nousek, J. A., Nguyen, M. L., Ochner, P., Okhmat, D. N., Papadakis, I., Parks, J. R., Pei, L., Penny, M. T., Pizzella, A., Poleski, R., Pott, J. -U., Rafter, S. E., Rix, H. -W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Scott, B., 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., Vaughan, S. A., Vican, L., Villanueva Jr., S., Villforth, C., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Yuk, H., Zheng, W., Zhu, W., and Zu, Y.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present geometric and dynamical modeling of the broad line region for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The dataset includes photometric and spectroscopic monitoring in the optical and ultraviolet, covering the H$\beta$, C IV, and Ly$\alpha$ broad emission lines. We find an extended disk-like H$\beta$ BLR with a mixture of near-circular and outflowing gas trajectories, while the C IV and Ly$\alpha$ BLRs are much less extended and resemble shell-like structures. There is clear radial structure in the BLR, with C IV and Ly$\alpha$ emission arising at smaller radii than the H$\beta$ emission. Using the three lines, we make three independent black hole mass measurements, all of which are consistent. Combining these results gives a joint inference of $\log_{10}(M_{\rm BH}/M_\odot) = 7.64^{+0.21}_{-0.18}$. We examine the effect of using the $V$ band instead of the UV continuum light curve on the results and find a size difference that is consistent with the measured UV-optical time lag, but the other structural and kinematic parameters remain unchanged, suggesting that the $V$ band is a suitable proxy for the ionizing continuum when exploring the BLR structure and kinematics. Finally, we compare the H$\beta$ results to similar models of data obtained in 2008 when the AGN was at a lower luminosity state. We find that the size of the emitting region increased during this time period, but the geometry and black hole mass remain unchanged, which confirms that the BLR kinematics suitably gauge the gravitational field of the central black hole., Comment: 26 pages, 19 figures, 1 table, accepted for publication in ApJ

Published
2020
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3. The Palomar Transient Factory Core-collapse Supernova Host-galaxy Sample. I. Host-galaxy Distribution Functions and Environment Dependence of Core-collapse Supernovae

Author

Schulze, S, Yaron, O, Sollerman, J, Leloudas, G, Gal, A, Wright, AH, Lunnan, R, Gal-Yam, A, Ofek, EO, Perley, DA, Filippenko, AV, Kasliwal, MM, Kulkarni, SR, Neill, JD, Nugent, PE, Quimby, RM, Sullivan, M, Strotjohann, NL, Arcavi, I, Ben-Ami, S, Bianco, F, Bloom, JS, De, K, Fraser, M, Fremling, CU, Horesh, A, Johansson, J, Kelly, PL, Knežević, N, Knežević, S, Maguire, K, Nyholm, A, Papadogiannakis, S, Petrushevska, T, Rubin, A, Yan, L, Yang, Y, Adams, SM, Bufano, F, Clubb, KI, Foley, RJ, Green, Y, Harmanen, J, Ho, AYQ, Hook, IM, Hosseinzadeh, G, Howell, DA, Kong, AKH, Kotak, R, Matheson, T, McCully, C, Milisavljevic, D, Pan, YC, Poznanski, D, Shivvers, I, Van Velzen, S, and Verbeek, KK

Subjects
Astronomy & Astrophysics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural)
Abstract

Several thousand core-collapse supernovae (CCSNe) of different flavors have been discovered so far. However, identifying their progenitors has remained an outstanding open question in astrophysics. Studies of SN host galaxies have proven to be powerful in providing constraints on the progenitor populations. In this paper, we present all CCSNe detected between 2009 and 2017 by the Palomar Transient Factory. This sample includes 888 SNe of 12 distinct classes out to redshift z ≈ 1. We present the photometric properties of their host galaxies from the far-ultraviolet to the mid-infrared and model the host-galaxy spectral energy distributions to derive physical properties. The galaxy mass function of Type Ic, Ib, IIb, II, and IIn SNe ranges from 105 to 1011.5 M o˙, probing the entire mass range of star-forming galaxies down to the least-massive star-forming galaxies known. Moreover, the galaxy mass distributions are consistent with models of star-formation-weighted mass functions. Regular CCSNe are hence direct tracers of star formation. Small but notable differences exist between some of the SN classes. Type Ib/c SNe prefer galaxies with slightly higher masses (i.e., higher metallicities) and star formation rates than Type IIb and II SNe. These differences are less pronounced than previously thought. H-poor superluminous supernovae (SLSNe) and SNe Ic-BL are scarce in galaxies above 1010 M o˙. Their progenitors require environments with metallicities of < 0.4 and < 1 solar, respectively. In addition, the hosts of H-poor SLSNe are dominated by a younger stellar population than all other classes of CCSNe. Our findings corroborate the notion that low metallicity and young age play an important role in the formation of SLSN progenitors.

Published
2021

4. Space Telescope and Optical Reverberation Mapping Project. IX. Velocity-Delay Maps for Broad Emission Lines in NGC 5548

Author

Horne, Keith, De Rosa, G., Peterson, B. M., Barth, A. J., Ely, J., Fausnaugh, M. M., Kriss, G. A., Pei, L., Adams, S. M., Anderson, M. D., Arevalo, P., Beatty, T G., Bennert, V. N., Bentz, M. C., Bigley, A., Bisogni, S., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brotherton, M., Brown, J. E., Brown, J. S., Cackett, E. M., Canalizo, G., Carini, M. T., Clubb, K. I., Comerford, J. M., Corsini, E. M., Crenshaw, D. M., Croft, S., Croxall, K. V., Bonta, E. Dalla, Deason, A. J., Dehghanian, M., De Lorenzo-Caceres, A., Denney, K. D., Dietrich, M., Done, C., Edelson, R., Efimova, N. V., Eracleous, M., Evans, P. A., Ferland, G. J., Filippenko, A. V., Flatland, K., Fox, O. D., Gardner, E., Gates, E. L., Gehrels, N., Geier, S., Gelbord, J. M., Goad, M. R., Gonzalez, L., Gorjian, V., Greene, J. E., Grier, C. J., Grupe, D., Gupta, A., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -S., Hutchison, T., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Jones, J., Kaastra, J., Kaspi, S., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S., Kim, S. C., King, A., Klimanov, S. A., Kochanek, C. S., Korista, K. T., Krongold, Y., Lau, M. W., Lee, J. C., Leonard, D. C., Li, Miao, Lira, P., Lochhaas, C., Ma, Zhiyuan, MacInnis, F., Malkan, M. A., Manne-Nicholas, E. R., Mathur, S., Mauerhan, J. C., McGurk, R., Hardy, I. M. Mc, Montuori, C., Morelli, L., Mosquera, A., Mudd, D., Mueller-Sanchez, F., Nazarov, S. V., Netzer, H., Norris, R. P., Nousek, J. A., Nguyen, M. L., Ochner, P., Okhmat, D. N., Pancoast, A., Papadakis, I., Parks, J. R., Penny, M. T., Pizzella, A., Pogge, R. W., Poleski, R., Pott, J. -U., Proga, D., Rafter, S. E., Rix, H. -W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Schnuelle, K., Scott, B., 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., Strauss, M. A., Sung, H. -I., Tayar, J., Teems, K. G., Tejos, N., Treu, T., Turner, C. S., Uttley, P., Van Saders, J ., Vestergaard, M., Vican, L., Villanueva Jr, S., Villforth, C., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Yuk, H., Zakamska, N. L., Zheng, W., Zhu, W., and Zu, Y.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We report velocity-delay maps for prominent broad emission lines, Ly_alpha, CIV, HeII and H_beta, in the spectrum of NGC5548. The emission-line responses inhabit the interior of a virial envelope. The velocity-delay maps reveal stratified ionization structure. The HeII response inside 5-10 light-days has a broad single-peaked velocity profile. The Ly_alpha, CIV, and H_beta responses peak inside 10 light-days, extend outside 20 light-days, and exhibit a velocity profile with two peaks separated by 5000 km/s in the 10 to 20 light-day delay range. The velocity-delay maps show that the M-shaped lag vs velocity structure found in previous cross-correlation analysis is the signature of a Keplerian disk with a well-defined outer edge at R=20 light-days. The outer wings of the M arise from the virial envelope, and the U-shaped interior of the M is the lower half of an ellipse in the velocity-delay plane. The far-side response is weaker than that from the near side, so that we see clearly the lower half, but only faintly the upper half, of the velocity--delay ellipse. The delay tau=(R/c)(1-sin(i))=5 light-days at line center is from the near edge of the inclined ring, giving the inclination i=45 deg. A black hole mass of M=7x10^7 Msun is consistent with the velocity-delay structure. A barber-pole pattern with stripes moving from red to blue across the CIV and possibly Ly_alpha line profiles suggests the presence of azimuthal structure rotating around the far side of the broad-line region and may be the signature of precession or orbital motion of structures in the inner disk. Further HST observations of NGC 5548 over a multi-year timespan but with a cadence of perhaps 10 days rather than 1 day could help to clarify the nature of this new AGN phenomenon., Comment: 19 pages, 9 figures, ApJ in press

Published
2020
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5. The Berkeley sample of Type II supernovae: BVRI light curves and spectroscopy of 55 SNe II

Author

de Jaeger, T., Zheng, W., Stahl, B. E., Filippenko, A. V., Brink, T. G., Bigley, A., Blanchard, K., Blanchard, P. K., Bradley, J., Cargill, S. K., Casper, C., Cenko, S. B., Channa, S., Choi, B. Y., Clubb, K. I., Cobb, B. E., Cohen, D., de Kouchkovsky, M., Ellison, M., Falcon, E., Fox, O. D., Fuller, K., Ganeshalingam, M., Gould, C., Graham, M. L., Halevi, G., Hayakawa, K. T., Hestenes, J., Hyland, M. P., Jeffers, B., Joubert, N., Kandrashoff, M. T., Kelly, P. L., Kim, H., Kim, M., Kumar, S., Leonard, E. J., Li, G. Z., Lowe, T. B., Lu, P., Mason, M., McAllister, K. J., Mauerhan, J. C., Modjaz, M., Molloy, J., Perley, D. A., Pina, K., Poznanski, D., Ross, T. W., Shivvers, I., Silverman, J. M., Soler, C., Stegman, S., Taylor, S., Tang, K., Wilkins, A., Wang, Xiaofeng, Wang, Xianggao, Yuk, H., Yunus, S., and Zhang, K. D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

In this work, BV RI light curves of 55 Type II supernovae (SNe II) from the Lick Observatory Supernova Search program obtained with the Katzman Automatic Imaging Telescope and the 1 m Nickel telescope from 2006 to 2018 are presented. Additionally, more than 150 spectra gathered with the 3 m Shane telescope are published. We conduct an analyse of the peak absolute magnitudes, decline rates, and time durations of different phases of the light and colour curves. Typically, our light curves are sampled with a median cadence of 5.5 days for a total of 5093 photometric points. In average V-band plateau declines with a rate of 1.29 mag (100 days)-1, which is consistent with previously published samples. For each band, the plateau slope correlates with the plateau length and the absolute peak magnitude: SNe II with steeper decline have shorter plateau duration and are brighter. A time-evolution analysis of spectral lines in term of velocities and pseudoequivalent widths is also presented in this paper. Our spectroscopic sample ranges between 1 and 200 days post-explosion and has a median ejecta expansion velocity at 50 days post-explosion of 6500 km/s (Halpha line) and a standard dispersion of 2000 km/s. Nebular spectra are in good agreement with theoretical models using a progenitor star having a mass <16 Msol. All the data are available to the community and will help to understand SN II diversity better, and therefore to improve their utility as cosmological distance indicators., Comment: 24 pages, 12 figures, accepted for publication in MNRAS

Published
2019
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6. Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum

Author

Kriss, G. A., De Rosa, G., Ely, J., Peterson, B. M., Kaastra, J., Mehdipour, M., Ferland, G. J., Dehghanian, M., Mathur, S., Edelson, R., Korista, K. T., Arav, N., Barth, A. J., Bentz, M. C., Brandt, W. N., Crenshaw, D. M., Bontà, E. Dalla, Denney, K. D., Done, C., Eracleous, M., Fausnaugh, M. M., Gardner, E., Goad, M. R., Grier, C. J., Horne, Keith, Kochanek, C. S., Mchardy, I. M., Netzer, H., Pancoast, A., Pei, L., Pogge, R. W., Proga, D., Silva, C., Tejos, N., Vestergaard, M., Adams, S. M., Anderson, M. D., Arévalo, P., Beatty, T G., Behar, E., Bennert, V. N., Bianchi, S., Bigley, A., Bisogni, S., Boissay-Malaquin, R., Borman, G. A., Bottorff, M. C., Breeveld, A. A., Brotherton, M., Brown, J. E., Brown, J. S., Cackett, E. M., Canalizo, G., Cappi, M., Carini, M. T., Clubb, K. I., Comerford, J. M., Coker, C. T., Corsini, E. M., Costantini, E., Croft, S., Croxall, K. V., Deason, A. J., De Lorenzo-Cáceres, A., De Marco, B., Dietrich, M., Di Gesu, L., Ebrero, J., Evans, P. A., Filippenko, A. V., Flatland, K., Gates, E. L., Gehrels, N., Geier, Z S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Grupe, D., Gupta, A., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -S., Hutchison, T. A., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Kaspi, S., Kelly, B. C., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S. C., Kim, S. Y., King, A., Klimanov, S. A., Krongold, Y., Lau, M. W., Lee, J. C., Leonard, D. C., Li, Miao, Lira, P., Lochhaas, C., Ma, Zhiyuan, Macinnis, F., Malkan, M. A., Manne-Nicholas, E. R., Matt, G., Mauerhan, J. C., Mcgurk, R., Montuori, C., Morelli, L., Mosquera, A., Mudd, D., Müller-Sánchez, F., Nazarov, S. V., Norris, R. P., Nousek, J. A., Nguyen, M. L., Ochner, P., Okhmat, D. N., Paltani, S., Parks, J. R., Pinto, C., Pizzella, A., Poleski, R., Ponti, G., Pott, J. -U., Rafter, S. E., Rix, H. -W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Schnülle, K., Scott, B., 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., Teems, K. G., Treu, T., Turner, C. S., Uttley, P., Van Saders, J ., Vican, L., Villforth, C., Villanueva Jr., S., Walton, D. J., Waters, T., Weiss, Y., Woo, J. -H., Yan, H., Yuk, H., Zheng, W., Zhu, W., and Zu, Y.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We model the ultraviolet spectra of the Seyfert 1 galaxy NGC~5548 obtained with the Hubble Space Telescope during the 6-month reverberation-mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Ly$\alpha$ and C IV, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. The velocity-binned lag profiles of Ly$\alpha$ and C IV have a double-peaked structure indicative of a truncated Keplerian disk. The narrow absorption lines show delayed response to continuum variations corresponding to recombination in gas with a density of $\sim 10^5~\rm cm^{-3}$. The high-ionization narrow absorption lines decorrelate from continuum variations during the same period as the broad emission lines. Analyzing the response of these absorption lines during this period shows that the ionizing flux is diminished in strength relative to the far-ultraviolet continuum. The broad absorption lines associated with the X-ray obscurer decrease in strength during this same time interval. The appearance of X-ray obscuration in $\sim\,2012$ corresponds with an increase in the luminosity of NGC 5548 following an extended low state. We suggest that the obscurer is a disk wind triggered by the brightening of NGC 5548 following the decrease in size of the broad-line region during the preceding low-luminosity state., Comment: 50 pages, 30 figures, uses aastex62.cls. Accepted for publication in ApJ, 07/06/2019. High-level products page in MAST will go live after 7/15/2019. Replaced Figure 4 on 7/12/2019 to be more red/green color-blind friendly

Published
2019
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7. A surge of light at the birth of a supernova

Author

Bersten, M. C., Folatelli, G., García, F., Van Dyk, S. D., Benvenuto, O. G., Orellana, M., Buso, V., Sánchez, J. L., Tanaka, M., Maeda, K., Filippenko, A. V., Zheng, W., Brink, T. G., Cenko, S. B., de Jaeger, T., Kumar, S., Moriya, T. J., Nomoto, K., Perley, D. A., Shivvers, I., and Smith, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract

It is difficult to establish the properties of massive stars that explode as supernovae. The electromagnetic emission during the first minutes to hours after the emergence of the shock from the stellar surface conveys important information about the final evolution and structure of the exploding star. However, the unpredictable nature of supernova events hinders the detection of this brief initial phase. Here we report the serendipitous discovery of a newly born, normal type IIb supernova (SN 2016gkg), which reveals a rapid brightening at optical wavelengths of about 40 magnitudes per day. The very frequent sampling of the observations allowed us to study in detail the outermost structure of the progenitor of the supernova and the physics of the emergence of the shock. We develop hydrodynamical models of the explosion that naturally account for the complete evolution of the supernova over distinct phases regulated by different physical processes. This result suggests that it is appropriate to decouple the treatment of the shock propagation from the unknown mechanism that triggers the explosion., Comment: Published in Nature on Feb. 22 Three main figures, six extended data Figures, four tables

Published
2018
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8. Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the UV anomaly in NGC 5548 with X-Ray Spectroscopy

Author

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., Bonta, E. Dalla, 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., Schnülle, 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., VillanuevaJr., S., Villforth, C., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Yuk, H., Zheng, W., Zhu, W., and Zu, Y.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

During the Space Telescope and Optical Reverberation Mapping Project (STORM) observations of NGC 5548, the continuum and emission-line variability became de-correlated during the second half of the 6-month long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as a 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 being due to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with 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 the three observations: the UV emission line flux decrease, the soft-excess increase, and the emission line anomaly., Comment: ApJ in press. Replaced with the accepted version

Published
2017
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9. Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-Line Analysis for NGC 5548

Author

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., Bontà, E. Dalla, 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, Radosław, 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 Jr., S., Yuk, H., Zakamska, N. L., Zhu, W., Anderson, M. D., Arévalo, 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-Cáceres, 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., Schnülle, 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., and Zu, Y.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multi-wavelength reverberation mapping campaign. The campaign spanned six 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 $\AA$ optical continuum by $4.17^{+0.36}_{-0.36}$ days and $0.79^{+0.35}_{-0.34}$ days, respectively. The H$\beta$ lag relative to the 1158 $\AA$ ultraviolet continuum light curve measured by the Hubble Space Telescope is roughly $\sim$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 $\sim$50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for H$\beta$ and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broad-line region dominated by Keplerian motion. The responses of both the H$\beta$ and He II $\lambda$4686 emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C IV, Ly $\alpha$, 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 $R_\mathrm{BLR} - L_\mathrm{AGN}$ relation based on the past behavior of NGC 5548., Comment: 22 pages, 13 figures, accepted to ApJ

Published
2017
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10. Discovery and Follow-up Observations of the Young Type Ia Supernova 2016coj

Author

Zheng, W, Filippenko, AV, Mauerhan, J, Graham, ML, Yuk, H, Hosseinzadeh, G, Silverman, JM, Rui, L, Arbour, R, Foley, RJ, Abolfathi, B, Abramson, LE, Arcavi, I, Barth, AJ, Bennert, VN, Brandel, AP, Cooper, MC, Cosens, M, Fillingham, SP, Fulton, BJ, Halevi, G, Howell, DA, Hsyu, T, Kelly, PL, Kumar, S, Li, L, Li, W, Malkan, MA, Manzano-King, C, McCully, C, Nugent, PE, Pan, YC, Pei, L, Scott, B, Sexton, RO, Shivvers, I, Stahl, B, Treu, T, Valenti, S, Vogler, HA, Walsh, JL, and Wang, X

Subjects
supernovae: general, supernovae: individual, astro-ph.SR, astro-ph.GA, astro-ph.HE, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

The Type Ia supernova (SN Ia) 2016coj in NGC 4125 (redshift z = 0.00452 ± 0.00006) was discovered by the Lick Observatory Supernova Search 4.9 days after the fitted first-light time (FFLT; 11.1 days before B-band maximum). Our first detection (prediscovery) is merely 0.6 ± 0.5 days after the FFLT, making SN 2016coj one of the earliest known detections of an SN Ia. A spectrum was taken only 3.7 hr after discovery (5.0 days after the FFLT) and classified as a normal SN Ia. We performed high-quality photometry, low- and high-resolution spectroscopy, and spectropolarimetry, finding that SN 2016coj is a spectroscopically normal SN Ia, but the velocity of Si ii λ6355 around peak brightness (∼12,600 kms-1) is a bit higher than that of typical normal SNe. The Si ii λ6355 velocity evolution can be well fit by a broken-power-law function for up to a month after the FFLT. SN 2016coj has a normal peak luminosity (MB ≈ -18.9 ± 0.2 mag), and it reaches a B-band maximum ∼16.0 days after the FFLT. We estimate there to be low host-galaxy extinction based on the absence of Na i D absorption lines in our low- and high-resolution spectra. The spectropolarimetric data exhibit weak polarization in the continuum, but the Si ii line polarization is quite strong (∼0.9% ± 0.1%) at peak brightness.

Published
2017

11. Extensive Spectroscopy and Photometry of the Type IIP Supernova 2013ej

Author

Dhungana, G., Kehoe, R., Vinko, J., Silverman, J. M., Wheeler, J. C., Marion, G. H., Zheng, W., 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., and Vida, K.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present extensive optical ($UBVRI$, $g'r'i'z'$, and open CCD) and near-infrared ($ZYJH$) photometry for the very nearby Type IIP SN ~2013ej extending from +1 to +461 days after shock breakout, estimated to be MJD $56496.9\pm0.3$. 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 $UBVRIJHK$ bolometric calibrations from $UBVRI$ and unfiltered measurements that potentially reach 2\% precision with a $B-V$ color-dependent correction. We observe moderately strong Si II $\lambda6355$ as early as +8 days. The photospheric velocity ($v_{\rm ph}$) is determined by modeling the spectra in the vicinity of Fe II $\lambda5169$ whenever observed, and interpolating at photometric epochs based on a semianalytic method. This gives $v_{\rm ph} = 4500\pm500$ 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 $94\pm7$ days long, yields an explosion energy of $0.9\pm0.3\times10^{51}$ ergs, a final pre-explosion progenitor mass of $15.2\pm4.2$~M$_\odot$ and a radius of $250\pm70$~R$_\odot$. We observe a broken exponential profile beyond +120 days, with a break point at +$183\pm16$ days. Measurements beyond this break time yield a $^{56}$Ni mass of $0.013\pm0.001$~M$_\odot$., Comment: 29 pages, 23 figures, 15 tables, Published in The Astrophisical Journal

Published
2015
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12. Early-Time Flux Measurements of SN 2014J Obtained with Small Robotic Telescopes: Extending the AAVSO Light Curve

Author

Poppe, B., Plaggenborg, T., Zheng, W., Shivvers, I., Itagaki, K., Filippenko, A. V., and Kunz, J.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

In this work, early-time photometry of supernova (SN) 2014J is presented, extending the AAVSO CCD database to prediscovery dates. The applicability of NASA's small robotic MicroObservatory Network telescopes for photometric measurements is evaluated. Prediscovery and postdiscovery photometry of SN 2014J is measured from images taken by two different telescopes of the network, and is compared to measurements from the Katzman Automatic Imaging Telescope and the Itagaki Observatory. In the early light-curve phase (which exhibits stable spectral behavior with constant color indices), these data agree with reasonably high accuracy (better than 0.05 mag around maximum brightness, and 0.15 mag at earlier times). Owing to the changing spectral energy distribution of the SN and the different spectral characteristics of the systems used, differences increase after maximum light. We augment light curves of SN 2014J downloaded from the American Association of Variable Star Observers (AAVSO) online database with these data, and consider the complete brightness evolution of this important Type Ia SN. Furthermore, the first detection presented here (Jan. 15.427, 2014) appears to be one of the earliest observations of SN 2014J yet published, taken less than a day after the SN exploded.

Published
2015

13. Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548

Author

Pei, L, Fausnaugh, MM, Barth, AJ, Peterson, BM, Bentz, MC, De Rosa, G, Denney, KD, Goad, MR, Kochanek, CS, Korista, KT, Kriss, GA, Pogge, RW, Bennert, VN, Brotherton, M, Clubb, KI, Bontà, E Dalla, Filippenko, AV, Greene, JE, Grier, CJ, Vestergaard, M, Zheng, W, Adams, Scott M, Beatty, Thomas G, Bigley, A, Brown, Jacob E, Brown, Jonathan S, Canalizo, G, Comerford, JM, Coker, Carl T, Corsini, EM, Croft, S, Croxall, KV, Deason, AJ, Eracleous, Michael, Fox, OD, Gates, EL, Henderson, CB, Holmbeck, E, Holoien, TW-S, Jensen, JJ, Johnson, CA, Kelly, PL, Kim, S, King, A, Lau, MW, Li, Miao, Lochhaas, Cassandra, Ma, Zhiyuan, Manne-Nicholas, ER, Mauerhan, JC, Malkan, MA, McGurk, R, Morelli, L, Mosquera, Ana, Mudd, Dale, Sanchez, F Muller, Nguyen, ML, Ochner, P, Ou-Yang, B, Pancoast, A, Penny, Matthew T, Pizzella, A, Poleski, Radosław, Runnoe, Jessie, Scott, B, Schimoia, Jaderson S, Shappee, BJ, Shivvers, I, Simonian, Gregory V, Siviero, A, Somers, Garrett, Stevens, Daniel J, Strauss, MA, Tayar, Jamie, Tejos, N, Treu, T, Van Saders, J, Vican, L, Villanueva, S, Yuk, H, Zakamska, NL, Zhu, W, Anderson, MD, Arévalo, P, Bazhaw, C, Bisogni, S, Borman, GA, Bottorff, MC, Brandt, WN, Breeveld, AA, Cackett, EM, Carini, MT, Crenshaw, DM, De Lorenzo-Cáceres, A, Dietrich, M, Edelson, R, Efimova, NV, Ely, J, Evans, PA, and Ferland, GJ

Subjects
galaxies: active, galaxies: individual, galaxies: nuclei, galaxies: Seyfert, astro-ph.GA, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

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 Hβ and He ii λ4686 broad emission-line light curves lag that of the 5100 +-optical continuum by 4.17+0.36-0.36 and 0.79+0.35-0.34 days, respectively. The Hβ lag relative to the 1158 ultraviolet continuum light curve measured by the Hubble Space Telescope is ∼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 ∼50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for Hβ and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broad-line region dominated by Keplerian motion. The responses of both the Hβ and He ii emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C iv, Lyα, 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 Hβ 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.

Published
2017

14. Optical and ultraviolet spectroscopic analysis of SN 2011fe at late times

Author

Friesen, B, Baron, E, Parrent, JT, Thomas, RC, Branch, D, Nugent, PE, Hauschildt, PH, Foley, RJ, Wright, DE, Pan, YC, Filippenko, AV, Clubb, KI, Silverman, JM, Maeda, K, Shivvers, I, Kelly, PL, Cohen, DP, Rest, A, and Kasen, D

Subjects
supernovae: general, supernovae: individual: SN 2011fe, astro-ph.SR, astro-ph.HE, Astronomy & Astrophysics, Astronomical and Space Sciences
Abstract

We present optical spectra of the nearby Type Ia supernova SN 2011fe at 100, 205, 311, 349 and 578 d post-maximum light, as well as an ultraviolet (UV) spectrum obtained with the Hubble Space Telescope at 360 d post-maximum light. We compare these observations with synthetic spectra produced with the radiative transfer code PHOENIX. The day +100 spectrum can be well fitted with models that neglect collisional and radiative data for forbidden lines. Curiously, including these data and recomputing the fit yields a quite similar spectrum, but with different combinations of lines forming some of the stronger features. At day +205 and later epochs, forbidden lines dominate much of the optical spectrum formation; however, our results indicate that recombination, not collisional excitation, is the most influential physical process driving spectrum formation at these late times. Consequently, our synthetic optical and UV spectra at all epochs presented here are formed almost exclusively through recombinationdriven fluorescence. Furthermore, our models suggest that the UV spectrum even as late as day +360 is optically thick and consists of permitted lines from several iron-peak species. These results indicate that the transition to the 'nebular' phase in Type Ia supernovae is complex and highly wavelength dependent.

Published
2017

15. The Pan-STARRS1 Photometric System

Author

Tonry, J. L., Stubbs, C. W., Lykke, K. R., Doherty, P., Shivvers, I. S., Burgett, W. S., Chambers, K. C., Hodapp, K. W., Kaiser, N., Kudritzki, R. -P., Magnier, E. A., Morgan, J. S., Price, P. A., and Wainscoat, R. J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Pan-STARRS1 survey is collecting multi-epoch, multi-color observations of the sky north of declination -30 deg to unprecedented depths. These data are being photometrically and astrometrically calibrated and will serve as a reference for many other purposes. In this paper we present our determination of the Pan-STARRS photometric system: gp1, rp1, ip1, zp1, yp1, and wp1. The Pan-STARRS photometric system is fundamentally based on the HST Calspec spectrophotometric observations, which in turn are fundamentally based on models of white dwarf atmospheres. We define the Pan-STARRS magnitude system, and describe in detail our measurement of the system passbands, including both the instrumental sensitivity and atmospheric transmission functions. Byproducts, including transformations to other photometric systems, galactic extinction, and stellar locus are also provided. We close with a discussion of remaining systematic errors., Comment: 39 pages, 9 figures, machine readable table of bandpasses, accepted for publication in ApJ

Published
2012
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16. SN 2000cx and SN 2013bh: Extremely rare, nearly twin type ia supernovae

Author

Silverman, JM, Vinko, J, Kasliwal, MM, Fox, OD, Cao, Y, Johansson, J, Perley, DA, Tal, D, Wheeler, JC, Amanullah, R, Arcavi, I, Bloom, JS, Gal-Yam, A, Goobar, A, Kulkarni, SR, Laher, R, Lee, WH, Marion, GH, Nugent, PE, and Shivvers, I

Subjects
supernovae: general, supernovae: individual: SN 2000cx, supernovae: individual: SN 2013bh, astro-ph.SR, astro-ph.CO, Astronomical and Space Sciences, Astronomy & Astrophysics
Abstract

The Type Ia supernova (SN Ia) SN 2000cx was one of the most peculiar transients ever discovered, with a rise to maximum brightness typical of a SN Ia, but a slower decline and a higher photospheric temperature. 13 yr later SN 2013bh (also known as iPTF13abc), a near identical twin, was discovered and we obtained optical and near-infrared photometry and low-resolution optical spectroscopy from discovery until about 1 month past r-band maximum brightness. The spectra of both objects show iron-group elements [Co II, Ni II, FeII, Fe III and high-velocity features (HVFs) of Ti II], intermediate-mass elements (Si II, Si III and S II) and separate normal velocity features (~12 000 km s-1) and HVFs (~24 000 km s-1) of Ca II. Persistent absorption from Fe III and Si III, along with the colour evolution, implies high blackbody temperatures for SNe 2013bh and 2000cx (~12 000 K). Both objects lack narrow Na I D absorption and exploded in the outskirts of their hosts, indicating that the SN environments were relatively free of interstellar or circumstellar material and may imply that the progenitors came from a relatively old and low-metallicity stellar population. Models of SN 2000cx, seemingly applicable to SN 2013bh, imply the production of up to 1 M of 56Ni and (4.3-5.5) × 10-3 M⊙ of fast-moving Ca ejecta. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Published
2013

17. The very young type Ia supernova 2013dy: Discovery, and strong carbon absorption in early-time spectra

Author

Zheng, W, Silverman, JM, Filippenko, AV, Kasen, D, Nugent, PE, Graham, M, Wang, X, Valenti, S, Ciabattari, F, Kelly, PL, Fox, OD, Shivvers, I, Clubb, KI, Cenko, SB, Balam, D, Howell, DA, Hsiao, E, Li, W, Howie Marion, G, Sand, D, Vinko, J, Wheeler, JC, and Zhang, J

Subjects
supernovae: general, supernovae: individual, astro-ph.CO, astro-ph.SR, Astronomy & Astrophysics, Astronomical and Space Sciences
Abstract

The Type Ia supernova (SN Ia) 2013dy in NGC 7250 (d ≈ 13.7 Mpc) was discovered by the Lick Observatory Supernova Search. Combined with a prediscovery detection by the Italian Supernova Search Project, we are able to constrain the first-light time of SN 2013dy to be only 0.10 ± 0.05 days (2.4 ± 1.2 hr) before the first detection. This makes SN 2013dy the earliest known detection of an SN Ia. We infer an upper limit on the radius of the progenitor star of R 0 ≲ 0.25 R ⊙, consistent with that of a white dwarf. The light curve exhibits a broken power law with exponents of 0.88 and then 1.80. A spectrum taken 1.63 days after first light reveals a C II absorption line comparable in strength to Si II. This is the strongest C II feature ever detected in a normal SN Ia, suggesting that the progenitor star had significant unburned material. The C II line in SN 2013dy weakens rapidly and is undetected in a spectrum 7 days later, indicating that C II is detectable for only a very short time in some SNe Ia. SN 2013dy reached a B-band maximum of MB = -18.72 ± 0.03 mag ∼17.7 days after first light. © 2013. The American Astronomical Society. All rights reserved.

Published
2013

18. Space Telescope and Optical Reverberation Mapping Project. IX. Velocity-Delay Maps for Broad Emission Lines in NGC 5548

Author

Horne, Keith, Rosa, G. De, Peterson, B. M., Barth, A. J., Ely, J., Fausnaugh, M. M., Kriss, G. A., Pei, L., Bentz, M. C., Cackett, E. M., Edelson, R., Eracleous, M., Goad, M. R., Grier, C. J., Kaastra, J., Kochanek, C. S., Krongold, Y., Mathur, S., Netzer, H., Proga, D., Tejos, N., Vestergaard, M., Villforth, C., Adams, S. M., Anderson, M. D., Arevalo, P., Beatty, T. G., Bennert, V. N., Bigley, A., Bisogni, S., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brotherton, M., Brown, J. E., Brown, J. S., Canalizo, G., Carini, M. T., Clubb, K. I., Comerford, J. M., Corsini, E. M., Crenshaw, D. M., Croft, S., Croxall, K. V., Bonta, E. Dalla, Deason, A. J., Dehghanian, M., Lorenzo-Caceres, A. De, Denney, K. D., Dietrich, M., Done, C., Efimova, N. V., Evans, P. A., Ferland, G. J., Filippenko, A. V., Flatland, K., Fox, O. D., Gardner, E., Gates, E. L., Gehrels, N., Geier, S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Greene, J. E., Grupe, D., Gupta, A., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -S., Hutchison, T., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Jones, J., Kaspi, S., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S., Kim, S. C., King, A., Klimanov, S. A., Korista, K. T., Lau, M. W., Lee, J. C., Leonard, D. C., Li, Miao, Lira, P., Lochhaas, C., Ma, Zhiyuan, MacInnis, F., Malkan, M. A., Manne-Nicholas, E. R., Mauerhan, J. C., McGurk, R., McHardy, I. M., Montuori, C., Morelli, L., Mosquera, A., Mudd, D., Muller-Sanchez, F., Nazarov, S. V., Norris, R. P., Nousek, J. A., Nguyen, M. L., Ochner, P., Okhmat, D. N., Pancoast, A., Papadakis, I., Parks, J. R., Penny, M. T., Pizzella, A., Pogge, R. W., Poleski, R., Pott, J. -U., Rafter, S. E., Rix, H. -W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Schnuelle, K., Scott, B., 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., Treu, T., Turner, C. S., Uttley, P., Van Saders, J., Vican, L., Villanueva, S., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Yuk, H., Zheng, W., Zhu, W., Zu, Y., Horne, Keith, Rosa, G. De, Peterson, B. M., Barth, A. J., Ely, J., Fausnaugh, M. M., Kriss, G. A., Pei, L., Bentz, M. C., Cackett, E. M., Edelson, R., Eracleous, M., Goad, M. R., Grier, C. J., Kaastra, J., Kochanek, C. S., Krongold, Y., Mathur, S., Netzer, H., Proga, D., Tejos, N., Vestergaard, M., Villforth, C., Adams, S. M., Anderson, M. D., Arevalo, P., Beatty, T. G., Bennert, V. N., Bigley, A., Bisogni, S., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brotherton, M., Brown, J. E., Brown, J. S., Canalizo, G., Carini, M. T., Clubb, K. I., Comerford, J. M., Corsini, E. M., Crenshaw, D. M., Croft, S., Croxall, K. V., Bonta, E. Dalla, Deason, A. J., Dehghanian, M., Lorenzo-Caceres, A. De, Denney, K. D., Dietrich, M., Done, C., Efimova, N. V., Evans, P. A., Ferland, G. J., Filippenko, A. V., Flatland, K., Fox, O. D., Gardner, E., Gates, E. L., Gehrels, N., Geier, S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Greene, J. E., Grupe, D., Gupta, A., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -S., Hutchison, T., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Jones, J., Kaspi, S., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S., Kim, S. C., King, A., Klimanov, S. A., Korista, K. T., Lau, M. W., Lee, J. C., Leonard, D. C., Li, Miao, Lira, P., Lochhaas, C., Ma, Zhiyuan, MacInnis, F., Malkan, M. A., Manne-Nicholas, E. R., Mauerhan, J. C., McGurk, R., McHardy, I. M., Montuori, C., Morelli, L., Mosquera, A., Mudd, D., Muller-Sanchez, F., Nazarov, S. V., Norris, R. P., Nousek, J. A., Nguyen, M. L., Ochner, P., Okhmat, D. N., Pancoast, A., Papadakis, I., Parks, J. R., Penny, M. T., Pizzella, A., Pogge, R. W., Poleski, R., Pott, J. -U., Rafter, S. E., Rix, H. -W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Schnuelle, K., Scott, B., 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., Treu, T., Turner, C. S., Uttley, P., Van Saders, J., Vican, L., Villanueva, S., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Yuk, H., Zheng, W., Zhu, W., and Zu, Y.

Abstract

In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) STORM campaign by recovering velocity-delay maps for the prominent broad emission lines (Ly alpha, C IV, He II, and H beta) in the spectrum of NGC 5548. These are the most detailed velocity-delay maps ever obtained for an AGN, providing unprecedented information on the geometry, ionization structure, and kinematics of the broad-line region. Virial envelopes enclosing the emission-line responses show that the reverberating gas is bound to the black hole. A stratified ionization structure is evident. The He ii response inside 5-10 lt-day has a broad single-peaked velocity profile. The Ly alpha, C IV, and H beta responses extend from inside 2 to outside 20 lt-day, with double peaks at 2500 km s(-1) in the 10-20 lt-day delay range. An incomplete ellipse in the velocity-delay plane is evident in H beta. We interpret the maps in terms of a Keplerian disk with a well-defined outer rim at R = 20 lt-day. The far-side response is weaker than that from the near side. The line-center delay tau = (R/c)(1 - sin i) approximate to 5 days gives the inclination i approximate to 45 degrees. The inferred black hole mass is (BH) 7 x 10(7) M-circle dot. In addition to reverberations, the fit residuals confirm that emission-line fluxes are depressed during the "BLR Holiday" identified in previous work. Moreover, a helical "Barber-Pole" pattern, with stripes moving from red to blue across the C IV and Ly alpha line profiles, suggests azimuthal structure rotating with a 2 yr period that may represent precession or orbital motion of inner-disk structures casting shadows on the emission-line region farther out.

Published
2021

19. SN 2015bf: A fast declining type II supernova with flash-ionized signatures

Author

Lin, Han, primary, Wang, Xiaofeng, additional, Zhang, Jujia, additional, Lin, Weili, additional, Mo, Jun, additional, Filippenko, Alexei V, additional, Zheng, WeiKang, additional, Brown, Peter J, additional, Xiang, Danfeng, additional, Huang, Fang, additional, Cai, Yongzhi, additional, Zhang, Tianmeng, additional, Li, Xue, additional, Rui, Liming, additional, Zhang, Xinghan, additional, Sai, Hanna, additional, Zhao, Xulin, additional, Graham, Melissa L, additional, Shivvers, I, additional, Halevi, G, additional, Yuk, H, additional, and Brink, Thomas G, additional

Published
2021
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20. Space Telescope and Optical Reverberation Mapping Project. IX. Velocity–Delay Maps for Broad Emission Lines in NGC 5548

Author

Horne, Keith, primary, Rosa, G. De, additional, Peterson, B. M., additional, Barth, A. J., additional, Ely, J., additional, Fausnaugh, M. M., additional, Kriss, G. A., additional, Pei, L., additional, Bentz, M. C., additional, Cackett, E. M., additional, Edelson, R., additional, Eracleous, M., additional, Goad, M. R., additional, Grier, C. J., additional, Kaastra, J., additional, Kochanek, C. S., additional, Krongold, Y., additional, Mathur, S., additional, Netzer, H., additional, Proga, D., additional, Tejos, N., additional, Vestergaard, M., additional, Villforth, C., additional, Adams, S. M., additional, Anderson, M. D., additional, Arévalo, P., additional, Beatty, T G., additional, Bennert, V. N., additional, Bigley, A., additional, Bisogni, S., additional, Borman, G. A., additional, Boroson, T. A., additional, Bottorff, M. C., additional, Brandt, W. N., additional, Breeveld, A. A., additional, Brotherton, M., additional, Brown, J. E., additional, Brown, J. S., additional, Canalizo, G., additional, Carini, M. T., additional, Clubb, K. I., additional, Comerford, J. M., additional, Corsini, E. M., additional, Crenshaw, D. M., additional, Croft, S., additional, Croxall, K. V., additional, Bontà, E. Dalla, additional, Deason, A. J., additional, Dehghanian, M., additional, Lorenzo-Cáceres, A. De, additional, Denney, K. D., additional, Dietrich, M., additional, Done, C., additional, Efimova, N. V., additional, Evans, P. A., additional, Ferland, G. J., additional, Filippenko, A. V., additional, Flatland, K., additional, Fox, O. D., additional, Gardner, E., additional, Gates, E. L., additional, Gehrels, N., additional, Geier, S., additional, Gelbord, J. M., additional, Gonzalez, L., additional, Gorjian, V., additional, Greene, J. E., additional, Grupe, D., additional, Gupta, A., additional, Hall, P. B., additional, Henderson, C. B., additional, Hicks, S., additional, Holmbeck, E., additional, Holoien, T. W.-S., additional, Hutchison, T., additional, Im, M., additional, Jensen, J. J., additional, Johnson, C. A., additional, Joner, M. D., additional, Jones, J., additional, Kaspi, S., additional, Kelly, P. L., additional, Kennea, J. A., additional, Kim, M., additional, Kim, S., additional, Kim, S. C., additional, King, A., additional, Klimanov, S. A., additional, Korista, K. T., additional, Lau, M. W., additional, Lee, J. C., additional, Leonard, D. C., additional, Li, Miao, additional, Lira, P., additional, Lochhaas, C., additional, Ma, Zhiyuan, additional, MacInnis, F., additional, Malkan, M. A., additional, Manne-Nicholas, E. R., additional, Mauerhan, J. C., additional, McGurk, R., additional, McHardy, I. M., additional, Montuori, C., additional, Morelli, L., additional, Mosquera, A., additional, Mudd, D., additional, Müller–Sánchez, F., additional, Nazarov, S. V., additional, Norris, R. P., additional, Nousek, J. A., additional, Nguyen, M. L., additional, Ochner, P., additional, Okhmat, D. N., additional, Pancoast, A., additional, Papadakis, I., additional, Parks, J. R., additional, Penny, M. T., additional, Pizzella, A., additional, Pogge, R. W., additional, Poleski, R., additional, Pott, J.-U., additional, Rafter, S. E., additional, Rix, H.-W., additional, Runnoe, J., additional, Saylor, D. A., additional, Schimoia, J. S., additional, Schnülle, K., additional, Scott, B., additional, Sergeev, S. G., additional, Shappee, B. J., additional, Shivvers, I., additional, Siegel, M., additional, Simonian, G. V., additional, Siviero, A., additional, Skielboe, A., additional, Somers, G., additional, Spencer, M., additional, Starkey, D., additional, Stevens, D. J., additional, Sung, H.-I., additional, Tayar, J., additional, Treu, T., additional, Turner, C. S., additional, Uttley, P., additional, Van Saders, J., additional, Vican, L., additional, Villanueva, S., additional, Weiss, Y., additional, Woo, J.-H., additional, Yan, H., additional, Young, S., additional, Yuk, H., additional, Zheng, W., additional, Zhu, W., additional, and Zu, Y., additional

Published
2021
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21. Space Telescope and Optical Reverberation Mapping Project. XII. Broad-line Region Modeling of NGC 5548

Author

Williams, P. R., primary, Pancoast, A., additional, Treu, T., additional, Brewer, B. J., additional, Peterson, B. M., additional, Barth, A. J., additional, Malkan, M. A., additional, Rosa, G. De, additional, Horne, Keith, additional, Kriss, G. A., additional, Arav, N., additional, Bentz, M. C., additional, Cackett, E. M., additional, Bontà, E. Dalla, additional, Dehghanian, M., additional, Done, C., additional, Ferland, G. J., additional, Grier, C. J., additional, Kaastra, J., additional, Kara, E., additional, Kochanek, C. S., additional, Mathur, S., additional, Mehdipour, M., additional, Pogge, R. W., additional, Proga, D., additional, Vestergaard, M., additional, Waters, T., additional, Adams, S. M., additional, Anderson, M. D., additional, Arévalo, P., additional, Beatty, T. G., additional, Bennert, V. N., additional, Bigley, A., additional, Bisogni, S., additional, Borman, G. A., additional, Boroson, T. A., additional, Bottorff, M. C., additional, Brandt, W. N., additional, Breeveld, A. A., additional, Brotherton, M., additional, Brown, J. E., additional, Brown, J. S., additional, Canalizo, G., additional, Carini, M. T., additional, Clubb, K. I., additional, Comerford, J. M., additional, Corsini, E. M., additional, Crenshaw, D. M., additional, Croft, S., additional, Croxall, K. V., additional, Deason, A. J., additional, Lorenzo-Cáceres, A. De, additional, Denney, K. D., additional, Dietrich, M., additional, Edelson, R., additional, Efimova, N. V., additional, Ely, J., additional, Evans, P. A., additional, Fausnaugh, M. M., additional, Filippenko, A. V., additional, Flatland, K., additional, Fox, O. D., additional, Gardner, E., additional, Gates, E. L., additional, Gehrels, N., additional, Geier, S., additional, Gelbord, J. M., additional, Gonzalez, L., additional, Gorjian, V., additional, Greene, J. E., additional, Grupe, D., additional, Gupta, A., additional, Hall, P. B., additional, Henderson, C. B., additional, Hicks, S., additional, Holmbeck, E., additional, Holoien, T. W.-S., additional, Hutchison, T., additional, Im, M., additional, Jensen, J. J., additional, Johnson, C. A., additional, Joner, M. D., additional, Jones, J., additional, Kaspi, S., additional, Kelly, P. L., additional, Kennea, J. A., additional, Kim, M., additional, Kim, S., additional, Kim, S. C., additional, King, A., additional, Klimanov, S. A., additional, Knigge, C., additional, Krongold, Y., additional, Lau, M. W., additional, Lee, J. C., additional, Leonard, D. C., additional, Li, Miao, additional, Lira, P., additional, Lochhaas, C., additional, Ma, Zhiyuan, additional, MacInnis, F., additional, Manne-Nicholas, E. R., additional, Mauerhan, J. C., additional, McGurk, R., additional, McHardy, I. M., additional, Montuori, C., additional, Morelli, L., additional, Mosquera, A., additional, Mudd, D., additional, Müller–Sánchez, F., additional, Nazarov, S. V., additional, Norris, R. P., additional, Nousek, J. A., additional, Nguyen, M. L., additional, Ochner, P., additional, Okhmat, D. N., additional, Papadakis, I., additional, Parks, J. R., additional, Pei, L., additional, Penny, M. T., additional, Pizzella, A., additional, Poleski, R., additional, Pott, J.-U., additional, Rafter, S. E., additional, Rix, H.-W., additional, Runnoe, J., additional, Saylor, D. A., additional, Schimoia, J. S., additional, Scott, B., additional, Sergeev, S. G., additional, Shappee, B. J., additional, Shivvers, I., additional, Siegel, M., additional, Simonian, G. V., additional, Siviero, A., additional, Skielboe, A., additional, Somers, G., additional, Spencer, M., additional, Starkey, D., additional, Stevens, D. J., additional, Sung, H.-I., additional, Tayar, J., additional, Tejos, N., additional, Turner, C. S., additional, Uttley, P., additional, Van Saders, J ., additional, Vaughan, S. A., additional, Vican, L., additional, Villanueva, S., additional, Villforth, C., additional, Weiss, Y., additional, Woo, J.-H., additional, Yan, H., additional, Young, S., additional, Yuk, H., additional, Zheng, W., additional, Zhu, W., additional, and Zu, Y., additional

Published
2020
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22. The Berkeley sample of Type II supernovae: BVRI light curves and spectroscopy of 55 SNe II

Author

de Jaeger, T, primary, Zheng, W, additional, Stahl, B E, additional, Filippenko, A V, additional, Brink, T G, additional, Bigley, A, additional, Blanchard, K, additional, Blanchard, P K, additional, Bradley, J, additional, Cargill, S K, additional, Casper, C, additional, Cenko, S B, additional, Channa, S, additional, Choi, B Y, additional, Clubb, K I, additional, Cobb, B E, additional, Cohen, D, additional, de Kouchkovsky, M, additional, Ellison, M, additional, Falcon, E, additional, Fox, O D, additional, Fuller, K, additional, Ganeshalingam, M, additional, Gould, C, additional, Graham, M L, additional, Halevi, G, additional, Hayakawa, K T, additional, Hestenes, J, additional, Hyland, M P, additional, Jeffers, B, additional, Joubert, N, additional, Kandrashoff, M T, additional, Kelly, P L, additional, Kim, H, additional, Kim, M, additional, Kumar, S, additional, Leonard, E J, additional, Li, G Z, additional, Lowe, T B, additional, Lu, P, additional, Mason, M, additional, McAllister, K J, additional, Mauerhan, J C, additional, Modjaz, M, additional, Molloy, J, additional, Perley, D A, additional, Pina, K, additional, Poznanski, D, additional, Ross, T W, additional, Shivvers, I, additional, Silverman, J M, additional, Soler, C, additional, Stegman, S, additional, Taylor, S, additional, Tang, K, additional, Wilkins, A, additional, Wang, Xiaofeng, additional, Wang, Xianggao, additional, Yuk, H, additional, Yunus, S, additional, and Zhang, K D, additional

Published
2019
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23. Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum

Author

Kriss, G. A., primary, De Rosa, G., additional, Ely, J., additional, Peterson, B. M., additional, Kaastra, J., additional, Mehdipour, M., additional, Ferland, G. J., additional, Dehghanian, M., additional, Mathur, S., additional, Edelson, R., additional, Korista, K. T., additional, Arav, N., additional, Barth, A. J., additional, Bentz, M. C., additional, Brandt, W. N., additional, Crenshaw, D. M., additional, Bontà, E. Dalla, additional, Denney, K. D., additional, Done, C., additional, Eracleous, M., additional, Fausnaugh, M. M., additional, Gardner, E., additional, Goad, M. R., additional, Grier, C. J., additional, Horne, Keith, additional, Kochanek, C. S., additional, McHardy, I. M., additional, Netzer, H., additional, Pancoast, A., additional, Pei, L., additional, Pogge, R. W., additional, Proga, D., additional, Silva, C., additional, Tejos, N., additional, Vestergaard, M., additional, Adams, S. M., additional, Anderson, M. D., additional, Arévalo, P., additional, Beatty, T G., additional, Behar, E., additional, Bennert, V. N., additional, Bianchi, S., additional, Bigley, A., additional, Bisogni, S., additional, Boissay-Malaquin, R., additional, Borman, G. A., additional, Bottorff, M. C., additional, Breeveld, A. A., additional, Brotherton, M., additional, Brown, J. E., additional, Brown, J. S., additional, Cackett, E. M., additional, Canalizo, G., additional, Cappi, M., additional, Carini, M. T., additional, Clubb, K. I., additional, Comerford, J. M., additional, Coker, C. T., additional, Corsini, E. M., additional, Costantini, E., additional, Croft, S., additional, Croxall, K. V., additional, Deason, A. J., additional, De Lorenzo-Cáceres, A., additional, De Marco, B., additional, Dietrich, M., additional, Di Gesu, L., additional, Ebrero, J., additional, Evans, P. A., additional, Filippenko, A. V., additional, Flatland, K., additional, Gates, E. L., additional, Gehrels, N., additional, Geier, S., additional, Gelbord, J. M., additional, Gonzalez, L., additional, Gorjian, V., additional, Grupe, D., additional, Gupta, A., additional, Hall, P. B., additional, Henderson, C. B., additional, Hicks, S., additional, Holmbeck, E., additional, Holoien, T. W.-S., additional, Hutchison, T. A., additional, Im, M., additional, Jensen, J. J., additional, Johnson, C. A., additional, Joner, M. D., additional, Kaspi, S., additional, Kelly, B. C., additional, Kelly, P. L., additional, Kennea, J. A., additional, Kim, M., additional, Kim, S. C., additional, Kim, S. Y., additional, King, A., additional, Klimanov, S. A., additional, Krongold, Y., additional, Lau, M. W., additional, Lee, J. C., additional, Leonard, D. C., additional, Li, Miao, additional, Lira, P., additional, Lochhaas, C., additional, Ma, Zhiyuan, additional, MacInnis, F., additional, Malkan, M. A., additional, Manne-Nicholas, E. R., additional, Matt, G., additional, Mauerhan, J. C., additional, McGurk, R., additional, Montuori, C., additional, Morelli, L., additional, Mosquera, A., additional, Mudd, D., additional, Müller-Sánchez, F., additional, Nazarov, S. V., additional, Norris, R. P., additional, Nousek, J. A., additional, Nguyen, M. L., additional, Ochner, P., additional, Okhmat, D. N., additional, Paltani, S., additional, Parks, J. R., additional, Pinto, C., additional, Pizzella, A., additional, Poleski, R., additional, Ponti, G., additional, Pott, J.-U., additional, Rafter, S. E., additional, Rix, H.-W., additional, Runnoe, J., additional, Saylor, D. A., additional, Schimoia, J. S., additional, Schnülle, K., additional, Scott, B., additional, Sergeev, S. G., additional, Shappee, B. J., additional, Shivvers, I., additional, Siegel, M., additional, Simonian, G. V., additional, Siviero, A., additional, Skielboe, A., additional, Somers, G., additional, Spencer, M., additional, Starkey, D., additional, Stevens, D. J., additional, Sung, H.-I., additional, Tayar, J., additional, Teems, K. G., additional, Treu, T., additional, Turner, C. S., additional, Uttley, P., additional, Van Saders, J ., additional, Vican, L., additional, Villforth, C., additional, Villanueva Jr., S., additional, Walton, D. J., additional, Waters, T., additional, Weiss, Y., additional, Woo, J.-H., additional, Yan, H., additional, Yuk, H., additional, Zheng, W., additional, Zhu, W., additional, and Zu, Y., additional

Published
2019
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24. A surge of light at the birth of a supernova

Author

Bersten, M. C., primary, Folatelli, G., additional, García, F., additional, Van Dyk, S. D., additional, Benvenuto, O. G., additional, Orellana, M., additional, Buso, V., additional, Sánchez, J. L., additional, Tanaka, M., additional, Maeda, K., additional, Filippenko, A. V., additional, Zheng, W., additional, Brink, T. G., additional, Cenko, S. B., additional, de Jaeger, T., additional, Kumar, S., additional, Moriya, T. J., additional, Nomoto, K., additional, Perley, D. A., additional, Shivvers, I., additional, and Smith, N., additional

Published
2018
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25. Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

Author

Mathur, S., primary, Gupta, A., additional, Page, K., additional, Pogge, R. W., additional, Krongold, Y., additional, Goad, M. R., additional, Adams, S. M., additional, Anderson, M. D., additional, Arévalo, P., additional, Barth, A. J., additional, Bazhaw, C., additional, Beatty, T. G., additional, Bentz, M. C., additional, Bigley, A., additional, Bisogni, S., additional, Borman, G. A., additional, Boroson, T. A., additional, Bottorff, M. C., additional, Brandt, W. N., additional, Breeveld, A. A., additional, Brown, J. E., additional, Brown, J. S., additional, Cackett, E. M., additional, Canalizo, G., additional, Carini, M. T., additional, Clubb, K. I., additional, Comerford, J. M., additional, Coker, C. T., additional, Corsini, E. M., additional, Crenshaw, D. M., additional, Croft, S., additional, Croxall, K. V., additional, Dalla Bontà, E., additional, Deason, A. J., additional, Denney, K. D., additional, De Lorenzo-Cáceres, A., additional, De Rosa, G., additional, Dietrich, M., additional, Edelson, R., additional, Ely, J., additional, Eracleous, M., additional, Evans, P. A., additional, Fausnaugh, M. M., additional, Ferland, G. J., additional, Filippenko, A. V., additional, Flatland, K., additional, Fox, O. D., additional, Gates, E. L., additional, Gehrels, N., additional, Geier, S., additional, Gelbord, J. M., additional, Gorjian, V., additional, Greene, J. E., additional, Grier, C. J., additional, Grupe, D., additional, Hall, P. B., additional, Henderson, C. B., additional, Hicks, S., additional, Holmbeck, E., additional, Holoien, T. W.-S., additional, Horenstein, D., additional, Horne, Keith, additional, Hutchison, T., additional, Im, M., additional, Jensen, J. J., additional, Johnson, C. A., additional, Joner, M. D., additional, Jones, J., additional, Kaastra, J., additional, Kaspi, S., additional, Kelly, B. C., additional, Kelly, P. L., additional, Kennea, J. A., additional, Kim, M., additional, Kim, S., additional, Kim, S. C., additional, King, A., additional, Klimanov, S. A., additional, Kochanek, C. S., additional, Korista, K. T., additional, Kriss, G. A., additional, Lau, M. W., additional, Lee, J. C., additional, Leonard, D. C., additional, Li, M., additional, Lira, P., additional, Ma, Z., additional, MacInnis, F., additional, Manne-Nicholas, E. R., additional, Malkan, M. A., additional, Mauerhan, J. C., additional, McGurk, R., additional, McHardy, I. M., additional, Montouri, C., additional, Morelli, L., additional, Mosquera, A., additional, Mudd, D., additional, Muller-Sanchez, F., additional, Musso, R., additional, Nazarov, S. V., additional, Netzer, H., additional, Nguyen, M. L., additional, Norris, R. P., additional, Nousek, J. A., additional, Ochner, P., additional, Okhmat, D. N., additional, Ou-Yang, B., additional, Pancoast, A., additional, Papadakis, I., additional, Parks, J. R., additional, Pei, L., additional, Peterson, B. M., additional, Pizzella, A., additional, Poleski, R., additional, Pott, J.-U., additional, Rafter, S. E., additional, Rix, H.-W., additional, Runnoe, J., additional, Saylor, D. A., additional, Schimoia, J. S., additional, Schnülle, K., additional, Sergeev, S. G., additional, Shappee, B. J., additional, Shivvers, I., additional, Siegel, M., additional, Simonian, G. V., additional, Siviero, A., additional, Skielboe, A., additional, Somers, G., additional, Spencer, M., additional, Starkey, D., additional, Stevens, D. J., additional, Sung, H.-I., additional, Tayar, J., additional, Tejos, N., additional, Turner, C. S., additional, Uttley, P., additional, Van Saders, J., additional, Vestergaard, M., additional, Vican, L., additional, Villanueva Jr., S., additional, Villforth, C., additional, Weiss, Y., additional, Woo, J.-H., additional, Yan, H., additional, Young, S., additional, Yuk, H., additional, Zheng, W., additional, Zhu, W., additional, and Zu, Y., additional

Published
2017
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26. EXTENSIVE SPECTROSCOPY AND PHOTOMETRY OF THE TYPE IIP SUPERNOVA 2013ej

Author

Dhungana, G., primary, Kehoe, R., additional, Vinko, J., additional, Silverman, J. M., additional, Wheeler, J. C., additional, Zheng, W., additional, Marion, G. H., additional, Fox, O. D., additional, Akerlof, C., additional, Biro, B. I., additional, Borkovits, T., additional, Cenko, S. B., additional, Clubb, K. I., additional, Filippenko, A. V., additional, Ferrante, F. V., additional, Gibson, C. A., additional, Graham, M. L., additional, Hegedus, T., additional, Kelly, P., additional, Kelemen, J., additional, Lee, W. H., additional, Marschalko, G., additional, Molnár, L., additional, Nagy, A. P., additional, Ordasi, A., additional, Pal, A., additional, Sarneczky, K., additional, Shivvers, I., additional, Szakats, R., additional, Szalai, T., additional, Szegedi-Elek, E., additional, Székely, P., additional, Szing, A., additional, Takáts, K., additional, and Vida, K., additional

Published
2016
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29. THE Pan-STARRS1 PHOTOMETRIC SYSTEM

Author

Tonry, J. L., primary, Stubbs, C. W., additional, Lykke, K. R., additional, Doherty, P., additional, Shivvers, I. S., additional, Burgett, W. S., additional, Chambers, K. C., additional, Hodapp, K. W., additional, Kaiser, N., additional, Kudritzki, R.-P., additional, Magnier, E. A., additional, Morgan, J. S., additional, Price, P. A., additional, and Wainscoat, R. J., additional

Published
2012
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31. Twins for life? A comparative analysis of the Type Ia supernovae 2011fe and 2011by.

Author

Graham, M. L., Foley, R. J., W. Zheng, Kelly, P. L., Shivvers, I., Silverman, J. M., Filippenko, A. V., Clubb, K. I., and Ganeshalingam, M.

Subjects
GALACTIC X-ray sources, COMPARATIVE studies, TYPE I supernovae, CATACLYSMIC variable stars, GALAXIES, INTEGRAL field spectroscopy, FIBER optical sensors, ASTRONOMICAL observations
Abstract

The nearby Type Ia supernovae (SNe Ia) 2011fe and 2011by had nearly identical photospheric phase optical spectra, light-curve widths, and photometric colours, but at peak brightness SN 2011by reached a fainter absolute magnitude in all optical bands and exhibited lower flux in the near-ultraviolet (NUV). Based on those data, Foley & Kirshner argue that the progenitors of SNe 2011by and 2011fe had supersolar and subsolar metallicity, respectively, and that SN 2011fe generated 1.7 times the amount of 56Ni as SN 2011by. With this work, we extend the comparison of these SNe Ia to 10 d before and 300 d after maximum brightness with newspectra and photometry. We showthat the nebular phase spectra of SNe 2011fe and 2011by are almost identical, and do not support a factor of 1.7 difference in 56Ni mass. Instead, we find it plausible that the Tully-Fisher distance for SN 2011by is an underestimate, in which case these SNe Ia may have reached similar peak luminosity, formed similar amounts of 56Ni, and had lower metallicity progenitors than previously estimated. Regardless of the true distance to SN 2011by, we find that the relative progenitor metallicity difference remains well supported by their disparity in NUV flux, which we show to be even stronger at pre-maximum epochs - although contributions from differences in total ejecta mass, viewing angle, or progenitor density cannot be ruled out. We also demonstrate that, independent of distance modulus, SN 2011by exhibits a late-time luminosity excess that cannot be explained by a light echo, but is more likely to be the result of greater energy trapping by the nucleosynthetic products of SN 2011by. [ABSTRACT FROM AUTHOR]

Published
2015
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32. iPTF Discoveries of Recent Type Ia Supernovae

Author

Papadogiannakis, S., Taddia, F., Ferretti, R., Fremling, C., Karamehmetoglu, E., Petrushevska, T., Nyholm, A., Roy, R., Hangard, L., Vreeswijk, P., Horesh, A., Manulis, I., Rubin, A., Yaron, O., Leloudas, G., Khazov, D., Soumagnac, M., Sladjana Knezevic, Johansson, J., Lunnan, R., Neill, J. D., Barlow, T., Cao, Y., Blagorodnova, N., Walters, R., Kupfer, T., Perley, D., Shivvers, I., Graham, M., and Cenk, S. B.

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