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30 results on '"McGurk, R"'

1. Resolving the explosion of supernova 2023ixf in Messier 101 within its complex circumstellar environment

Author

Zimmerman, E. A., Irani, I., Chen, P., Gal-Yam, A., Schulze, S., Perley, D. A., Sollerman, J., Filippenko, A. V., Shenar, T., Yaron, O., Shahaf, S., Bruch, R. J., Ofek, E. O., De Cia, A., Brink, T. G., Yang, Y., Vasylyev, S. S., Ami, S. Ben, Aubert, M., Badash, A., Bloom, J. S., Brown, P. J., De, K., Dimitriadis, G., Fransson, C., Fremling, C., Hinds, K., Horesh, A., Johansson, J. P., Kasliwal, M. M., Kulkarni, S. R., Kushnir, D., Martin, C., Matuzewski, M., McGurk, R. C., Miller, A. A., Morag, J., Neil, J. D., Nugent, P. E., Post, R. S., Prusinski, N. Z., Qin, Y., Raichoor, A., Riddle, R., Rowe, M., Rusholme, B., Sfaradi, I., Sjoberg, K. M., Soumagnac, M., Stein, R. D., Strotjohann, N. L., Terwel, J. H., Wasserman, T., Wise, J., Wold, A., Yan, L., and Zhang, K.

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

Observing a supernova explosion shortly after it occurs can reveal important information about the physics of stellar explosions and the nature of the progenitor stars of supernovae (SNe). When a star with a well-defined edge explodes in vacuum, the first photons to escape from its surface appear as a brief shock-breakout flare. The duration of this flare can extend to at most a few hours even for nonspherical breakouts from supergiant stars, after which the explosion ejecta should expand and cool. Alternatively, for stars exploding within a distribution of sufficiently dense optically thick circumstellar material, the first photons escape from the material beyond the stellar edge, and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating. The difficulty in detecting SN explosions promptly after the event has so far limited data regarding supergiant stellar explosions mostly to serendipitous observations that, owing to the lack of ultraviolet (UV) data, were unable to determine whether the early emission is heating or cooling, and hence the nature of the early explosion event. Here, we report observations of SN 2023ixf in the nearby galaxy M101, covering the early days of the event. Using UV spectroscopy from the Hubble Space Telescope (HST) as well as a comprehensive set of additional multiwavelength observations, we trace the photometric and spectroscopic evolution of the event and are able to temporally resolve the emergence and evolution of the SN emission.

Published
2023
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2. The complex circumstellar environment of supernova 2023ixf

Author

Zimmerman, E. A., Irani, I., Chen, P., Gal-Yam, A., Schulze, S., Perley, D. A., Sollerman, J., Filippenko, A. V., Shenar, T., Yaron, O., Shahaf, S., Bruch, R. J., Ofek, E. O., De Cia, A., Brink, T. G., Yang, Y., Vasylyev, S. S., Ben Ami, S., Aubert, M., Badash, A., Bloom, J. S., Brown, P. J., De, K., Dimitriadis, G., Fransson, C., Fremling, C., Hinds, K., Horesh, A., Johansson, J. P., Kasliwal, M. M., Kulkarni, S. R., Kushnir, D., Martin, C., Matuzewski, M., McGurk, R. C., Miller, A. A., Morag, J., Neil, J. D., Nugent, P. E., Post, R. S., Prusinski, N. Z., Qin, Y., Raichoor, A., Riddle, R., Rowe, M., Rusholme, B., Sfaradi, I., Sjoberg, K. M., Soumagnac, M., Stein, R. D., Strotjohann, N. L., Terwel, J. H., Wasserman, T., Wise, J., Wold, A., Yan, L., and Zhang, K.

Published
2024
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3. 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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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. 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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6. Alignment and preliminary outcomes of an ELT-size instrument to a very large telescope: LINC-NIRVANA at LBT

Author

Bergomi, M., Marafatto, L., Viotto, V., Arcidiacono, C., Farinato, J., Santhakumari, K. K. R., McGurk, R., Dima, M., Baumeister, H., Bertram, T., Berwein, J., Bizenberger, P., Briegel, F., Kittman, F., Conrad, A., Ragazzoni, R., and Herbst, T. M.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

LINC-NIRVANA (LN) is a high resolution, near infrared imager that uses a multiple field-of-view, layer-oriented, multi-conjugate AO system, consisting of four multi-pyramid wavefront sensors (two for each arm of the Large Binocular Telescope, each conjugated to a different altitude). The system employs up to 40 star probes, looking at up to 20 natural guide stars simultaneously. Its final goal is to perform Fizeau interferometric imaging, thereby achieving ELT-like spatial resolution (22.8 m baseline resolution). For this reason, LN is also equipped with a fringe tracker, a beam combiner and a NIR science camera, for a total of more than 250 optical components and an overall size of approximately 6x4x4.5 meters. This paper describes the tradeoffs evaluated in order to achieve the alignment of the system to the telescope. We note that LN is comparable in size to planned ELT instrumentation. The impact of such alignment strategies will be compared and the selected procedure, where the LBT telescope is, in fact, aligned to the instrument, will be described. Furthermore, results coming from early night-time commissioning of the system will be presented., Comment: 8 pages, 6 pages, AO4ELT5 Proceedings, 2017

Published
2018
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7. 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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8. 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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9. Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

Author

Mathur, S, Gupta, A, Page, K, Pogge, RW, Krongold, Y, Goad, MR, Adams, SM, Anderson, MD, Arévalo, P, Barth, AJ, Bazhaw, C, Beatty, TG, Bentz, MC, Bigley, A, Bisogni, S, Borman, GA, Boroson, TA, Bottorff, MC, Brandt, WN, Breeveld, AA, Brown, JE, Brown, JS, Cackett, EM, Canalizo, G, Carini, MT, Clubb, KI, Comerford, JM, Coker, CT, Corsini, EM, Crenshaw, DM, Croft, S, Croxall, KV, Bontà, E Dalla, Deason, AJ, Denney, KD, De Lorenzo-Cáceres, A, De Rosa, G, Dietrich, M, Edelson, R, Ely, J, Eracleous, M, Evans, PA, Fausnaugh, MM, Ferland, GJ, Filippenko, AV, Flatland, K, Fox, OD, Gates, EL, Gehrels, N, Geier, S, Gelbord, JM, Gorjian, V, Greene, JE, Grier, CJ, Grupe, D, Hall, PB, Henderson, CB, Hicks, S, Holmbeck, E, Holoien, TW-S, Horenstein, D, Horne, Keith, Hutchison, T, Im, M, Jensen, JJ, Johnson, CA, Joner, MD, Jones, J, Kaastra, J, Kaspi, S, Kelly, BC, Kelly, PL, Kennea, JA, Kim, M, Kim, S, Kim, SC, King, A, Klimanov, SA, Kochanek, CS, Korista, KT, Kriss, GA, Lau, MW, Lee, JC, Leonard, DC, Li, M, Lira, P, Ma, Z, MacInnis, F, Manne-Nicholas, ER, Malkan, MA, Mauerhan, JC, McGurk, R, McHardy, IM, Montouri, C, Morelli, L, Mosquera, A, Mudd, D, Muller-Sanchez, F, Musso, R, and Nazarov, SV

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

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.

Published
2017

10. 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

12. Assessing the Sustainability of Initiatives Aimed to Enhance Patient Safety Culture: A > 10-year Experience with Multifaceted Interventions

Author

Mazur, L., primary, Amos, A., additional, Weiner, A.A., additional, Chera, B.S., additional, Dance, M.J., additional, McGurk, R., additional, Person, T., additional, Pineiro, B., additional, Couch, A., additional, Risgaard, S., additional, Herath, J., additional, Das, S.K., additional, and Marks, L.B., additional

Published
2023
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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. 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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20. 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. 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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25. Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum

Author

Andrew J. King, K. G. Teems, Gabriele Ponti, J. S. Schimoia, Calen B. Henderson, Michael S. Brotherton, S. Paltani, Nahum Arav, Alessandro Siviero, Radosław Poleski, P. Lira, Sang Chul Kim, Thomas W.-S. Holoien, Wei Zhu, A. de Lorenzo-Cáceres, M. C. Bottorff, Dirk Grupe, Gabriela Canalizo, M. Eracleous, S. G. Sergeev, F. MacInnis, Massimo Cappi, M. Dietrich, Alis J. Deason, Haojing Yan, Giorgio Matt, Ciro Pinto, Michael T. Carini, Minjin Kim, Brandon C. Kelly, I. M. McHardy, Scott M. Adams, L. Gonzalez, J. J. Jensen, Julia M. Comerford, Yair Krongold, Tim Waters, B. Scott, C. S. Turner, G. A. Borman, R. McGurk, Nicolas Tejos, J. R. Parks, K. Flatland, Michael D. Joner, Kirk T. Korista, L. Di Gesu, Emma Gardner, Jon C. Mauerhan, Jessie C. Runnoe, Douglas C. Leonard, Kelsey I. Clubb, M. H. Siegel, C. A. Johnson, D. A. Starkey, H. Yuk, M. A. Malkan, Justin Ely, Ying Zu, Aaron J. Barth, Cassandra Lochhaas, Patrick L. Kelly, E. Holmbeck, Hyun-Il Sung, Patrick B. Hall, C. Montuori, Christopher S. Kochanek, Bradley M. Peterson, Tommaso Treu, Missagh Mehdipour, Marie Wingyee Lau, A. Skielboe, Catherine J. Grier, J. A. Kennea, Thomas G. Beatty, R. W. Pogge, J. van Saders, A. Bigley, S. Hicks, Catia Silva, H. W. Rix, Vardha N. Bennert, D. M. Crenshaw, E. Dalla Bontà, Miao Li, A. A. Breeveld, Dom Walton, D. N. Okhmat, Elisa Costantini, P. Ochner, Y. Weiss, M. L. Nguyen, Ryan Norris, Susanna Bisogni, Ehud Behar, Jacobo Ebrero, Garrett Somers, Phil Uttley, S. Rafter, Kelly D. Denney, K. Schnülle, Carolin Villforth, Keith Horne, Smita Mathur, G. V. Simonian, R. Boissay-Malaquin, Gary J. Ferland, J. S. Brown, Jelle Kaastra, Ana M. Mosquera, Stefano Bianchi, Misty C. Bentz, A. Pancoast, Alessandro Pizzella, WeiKang Zheng, N. Gehrels, Daniel J. Stevens, M. Dehghanian, Kevin V. Croxall, Isaac Shivvers, A. Gupta, Chris Done, J. E. Brown, B. De Marco, Gerard A. Kriss, Steve Croft, S. V. Nazarov, J. A. Nousek, Jae-Ok Lee, P. Arévalo, G. De Rosa, Michael Fausnaugh, Rick Edelson, Phil Evans, Lorenzo Morelli, S. Geier, Enrico Maria Corsini, M. R. Goad, V. Gorjian, W. N. Brandt, Elinor L. Gates, Shai Kaspi, D. A. Saylor, Jong-Hak Woo, Edward M. Cackett, Liuyi Pei, T. Hutchison, Jamie Tayar, E. R. Manne-Nicholas, Laura Vican, Daniel Proga, Steven Villanueva, D. Mudd, J.-U. Pott, F. Müller-Sánchez, Alexei V. Filippenko, Hagai Netzer, S. A. Klimanov, B. J. Shappee, J. M. Gelbord, Marianne Vestergaard, M. Spencer, Zhiyuan Ma, Carl T. Coker, S. Y. Kim, Myungshin Im, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), 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, 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., Zu, Y., and USA

Subjects
Seyfert [Galaxies], galaxies: active, galaxies: individual (NGC 5548), galaxies: nuclei, galaxies: Seyfert, 010504 meteorology & atmospheric sciences, Absorption spectroscopy, active [Galaxies], individual (NGC 5548) [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, Continuum (design consultancy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Luminosity, 0103 physical sciences, QB Astronomy, Emission spectrum, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Physics, Astronomy and Astrophysics, DAS, Astrophysics - Astrophysics of Galaxies, Galaxy, QC Physics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), nuclei [Galaxies], Reverberation mapping
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

26. Augmenting Quality Assurance Measures in Treatment Review with Machine Learning in Radiation Oncology.

Author

Pillai M, Shumway JW, Adapa K, Dooley J, McGurk R, Mazur LM, Das SK, and Chera BS

Abstract

Purpose: Pretreatment quality assurance (QA) of treatment plans often requires a high cognitive workload and considerable time expenditure. This study explores the use of machine learning to classify pretreatment chart check QA for a given radiation plan as difficult or less difficult, thereby alerting the physicists to increase scrutiny on difficult plans., Methods and Materials: Pretreatment QA data were collected for 973 cases between July 2018 and October 2020. The outcome variable, a degree of difficulty, was collected as a subjective rating by physicists who performed the pretreatment chart checks. Potential features were identified based on clinical relevance, contribution to plan complexity, and QA metrics. Five machine learning models were developed: support vector machine, random forest classifier, adaboost classifier, decision tree classifier, and neural network. These were incorporated into a voting classifier, where at least 2 algorithms needed to predict a case as difficult for it to be classified as such. Sensitivity analyses were conducted to evaluate feature importance., Results: The voting classifier achieved an overall accuracy of 77.4% on the test set, with 76.5% accuracy on difficult cases and 78.4% accuracy on less difficult cases. Sensitivity analysis showed features associated with plan complexity (number of fractions, dose per monitor unit, number of planning structures, and number of image sets) and clinical relevance (patient age) were sensitive across at least 3 algorithms., Conclusions: This approach can be used to equitably allocate plans to physicists rather than randomly allocate them, potentially improving pretreatment chart check effectiveness by reducing errors propagating downstream., (© 2023 The Authors.)

Published
2023
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27. Multi-Institutional Stereotactic Body Radiation Therapy Incident Learning: Evaluation of Safety Barriers Using a Human Factors Analysis and Classification System.

Author

McGurk R, Woch Naheedy K, Kosak T, Hobbs A, Mullins BT, Paradis KC, Kearney M, Roback D, Durney J, Adapa K, Chera BS, Marks LB, Moran JM, Mak RH, and Mazur LM

Subjects
Humans, Health Facilities, Learning, Radiosurgery, Radiation Oncology
Abstract

Objectives: Stereotactic body radiation therapy (SBRT) can improve therapeutic ratios and patient convenience, but delivering higher doses per fraction increases the potential for patient harm. Incident learning systems (ILSs) are being increasingly adopted in radiation oncology to analyze reported events. This study used an ILS coupled with a Human Factor Analysis and Classification System (HFACS) and barriers management to investigate the origin and detection of SBRT events and to elucidate how safeguards can fail allowing errors to propagate through the treatment process., Methods: Reported SBRT events were reviewed using an in-house ILS at 4 institutions over 2014-2019. Each institution used a customized care path describing their SBRT processes, including designated safeguards to prevent error propagation. Incidents were assigned a severity score based on the American Association of Physicists in Medicine Task Group Report 275. An HFACS system analyzed failing safeguards., Results: One hundred sixty events were analyzed with 106 near misses (66.2%) and 54 incidents (33.8%). Fifty incidents were designated as low severity, with 4 considered medium severity. Incidents most often originated in the treatment planning stage (38.1%) and were caught during the pretreatment review and verification stage (37.5%) and treatment delivery stage (31.2%). An HFACS revealed that safeguard failures were attributed to human error (95.2%), routine violation (4.2%), and exceptional violation (0.5%) and driven by personnel factors 32.1% of the time, and operator condition also 32.1% of the time., Conclusions: Improving communication and documentation, reducing time pressures, distractions, and high workload should guide proposed improvements to safeguards in radiation oncology., Competing Interests: B.S.C. and L.M.M. have a financial relationship (e.g., royalties and equity) with Communify Health, which provides software for incident reporting and analysis. The other authors disclose no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Published
2023
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28. Common Error Pathways in CyberKnife™ Radiation Therapy.

Author

Mullins BT, Mazur L, Dance M, McGurk R, Schreiber E, Marks LB, Shen CJ, Lawrence MV, and Chera BS

Abstract

Purpose/Objectives: Stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) may be considered "high risk" due to the high doses per fraction. We analyzed CyberKnife™ (CK) SRS and SBRT-related incidents that were prospectively reported to our in-house incident learning system (ILS) in order to identify severity, contributing factors, and common error pathways. Material and Methods: From 2012 to 2019, 221 reported incidents related to the 4,569 CK fractions delivered (5.8%) were prospectively analyzed by our multi-professional Quality and Safety Committee with regard to severity, contributing factors, as well as the location where the incident occurred ( tripped ), where it was discovered ( caught ), and the safety barriers that were traversed (crossed) on the CK process map. Based on the particular step in the process map that incidents tripped , we categorized incidents into general error pathways. Results: There were 205 severity grade 1-2 (did not reach patient or no clinical impact), 11 grade 3 (clinical impact unlikely), 5 grade 4 (altered the intended treatment), and 0 grade 5-6 (life-threatening or death) incidents, with human performance being the most common contributing factor (79% of incidents). Incidents most commonly tripped near the time when the practitioner requested CK simulation (e.g., pre-CK simulation fiducial marker placement) and most commonly caught during the physics pre-treatment checklist. The four general error pathways included pre-authorization, billing, and scheduling issues ( n = 119); plan quality ( n = 30); administration of IV contrast during simulation or pre-medications during treatment ( n = 22); and image guidance ( n = 12). Conclusion: Most CK incidents led to little or no patient harm and most were related to billing and scheduling issues. Suboptimal human performance appeared to be the most common contributing factor to CK incidents. Additional study is warranted to develop and share best practices to reduce incidents to further improve patient safety., (Copyright © 2020 Mullins, Mazur, Dance, McGurk, Schreiber, Marks, Shen, Lawrence and Chera.)

Published
2020
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29. Human Error Bowtie Analysis to Enhance Patient Safety in Radiation Oncology.

Author

Mullins BT, McGurk R, McLeod RW, Lindsay D, Amos A, Gu D, Chera BS, Marks L, Das S, and Mazur L

Subjects
Humans, Patient Safety standards, Radiation Oncology standards
Abstract

Purpose: Ensuring safety within RT is of paramount importance. To further support and augment patient safety efforts, the purpose of this research was to test and refine a robust methodology for analyzing human errors that defeat individual controls within RT quality assurance (QA) programs., Methods: The method proposed for performing Bowtie Analysis (BTA) was based on training and recommendations from practitioners in the field of Human Factors and Ergonomics practice. Multidisciplinary meetings to iteratively develop BTA focused on incorrect site setup instructions was conducted., Results: From November 2015 to February 2017, we had 12 reported incidents related to site setup notes that could have led to site setup errors. Based on this data, we conducted five BTA analyses related to incorrect site setup instructions. None of the individual controls within our QA program designed to check for potential errors with site setup instructions met the level of robustness to be classified as key safeguards or barriers., Conclusions: The relatively low number of incidents causing patient harm has led us to typically assume that we have sufficient and effective controls in place to prevent serious human errors from leading to severe patient consequences. Based on our BTA, we question how well we truly understand the details of our individual controls. To meet the level of safety achieved by high reliability organizations (HROs), we need to better ensure that our controls are as reliable and robust as we assume., (Published by Elsevier Inc.)

Published
2019
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30. Task Group 174 Report: Utilization of [ 18 F]Fluorodeoxyglucose Positron Emission Tomography ([ 18 F]FDG-PET) in Radiation Therapy.

Author

Das SK, McGurk R, Miften M, Mutic S, Bowsher J, Bayouth J, Erdi Y, Mawlawi O, Boellaard R, Bowen SR, Xing L, Bradley J, Schoder H, Yin FF, Sullivan DC, and Kinahan P

Subjects
Biological Transport, Humans, Image Processing, Computer-Assisted, Neoplasm Staging, Quality Control, Radioactive Tracers, Radiotherapy Planning, Computer-Assisted, Respiratory-Gated Imaging Techniques, Treatment Outcome, Fluorodeoxyglucose F18, Positron-Emission Tomography, Radiotherapy, Research Report
Abstract

The use of positron emission tomography (PET) in radiation therapy (RT) is rapidly increasing in the areas of staging, segmentation, treatment planning, and response assessment. The most common radiotracer is 18 F-fluorodeoxyglucose ([ 18 F]FDG), a glucose analog with demonstrated efficacy in cancer diagnosis and staging. However, diagnosis and RT planning are different endeavors with unique requirements, and very little literature is available for guiding physicists and clinicians in the utilization of [ 18 F]FDG-PET in RT. The two goals of this report are to educate and provide recommendations. The report provides background and education on current PET imaging systems, PET tracers, intensity quantification, and current utilization in RT (staging, segmentation, image registration, treatment planning, and therapy response assessment). Recommendations are provided on acceptance testing, annual and monthly quality assurance, scanning protocols to ensure consistency between interpatient scans and intrapatient longitudinal scans, reporting of patient and scan parameters in literature, requirements for incorporation of [ 18 F]FDG-PET in treatment planning systems, and image registration. The recommendations provided here are minimum requirements and are not meant to cover all aspects of the use of [ 18 F]FDG-PET for RT., (© 2019 American Association of Physicists in Medicine.)

Published
2019
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