دورية أكاديمية
SPACE TELESCOPE AND OPTICAL REVERBERATION MAPPING PROJECT. IV. ANOMALOUS BEHAVIOR OF THE BROAD ULTRAVIOLET EMISSION LINES IN NGC 5548
| العنوان: | SPACE TELESCOPE AND OPTICAL REVERBERATION MAPPING PROJECT. IV. ANOMALOUS BEHAVIOR OF THE BROAD ULTRAVIOLET EMISSION LINES IN NGC 5548 |
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| المؤلفون: | Goad, M. R., Korista, K. T., Rosa, G. De, Kriss, G. A., Edelson, R., Barth, A. J., Ferland, G. J., Kochanek, C. S., Netzer, H., Peterson, B. M., Bentz, M. C., Bisogni, S., Crenshaw, D. M., Denney, K. D., Ely, J., Fausnaugh, M. M., Grier, C. J., Gupta, A., Horne, K. D., Kaastra, J., Pancoast, A., Pei, L., Pogge, R. W., Skielboe, A., Starkey, D., Vestergaard, M., Zu, Y., Anderson, M. D., Arévalo, P., Bazhaw, C., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brewer, B. J., Cackett, E. M., Carini, M. T., Croxall, K. V., Bontà, E. Dalla, Lorenzo-Cáceres, A. De, Dietrich, M., Efimova, N. V., Evans, P. A., Filippenko, A. V., Flatland, K., Gehrels, N., Geier, S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Grupe, D., Hall, P. B., Hicks, S., Horenstein, D., Hutchison, T., Im, M., Jensen, J. J., Joner, M. D., Jones, 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., Manne-Nicholas, E. R., Mathur, S., McHardy, I. M., Montouri, C., Musso, R., Nazarov, S. V., 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., Schimoia, J. S., Schnülle, K., Sergeev, S. G., Siegel, M., Spencer, M., Sung, H.-I., Teems, K. G., Treu, T., Turner, C. S., Uttley, P., Villforth, C., Weiss, Y., Woo, J.-H., Yan, H., Young, S., Zheng, W.-K. |
| مرشدي الرسالة: | Univ Arizona, Steward Observ |
| بيانات النشر: | IOP PUBLISHING LTD, 2016. |
| سنة النشر: | 2016 |
| المجموعة: | University of Arizona |
| Original Material: | SPACE TELESCOPE AND OPTICAL REVERBERATION MAPPING PROJECT. IV. ANOMALOUS BEHAVIOR OF THE BROAD ULTRAVIOLET EMISSION LINES IN NGC 5548 2016, 824 (1):11 The Astrophysical Journal The Astrophysical Journal |
| مصطلحات موضوعية: | galaxies: active, galaxies: individual (NGC-5548), galaxies: nuclei, galaxies: Seyfert |
| الوصف: | During an intensive Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) UV monitoring campaign of the Seyfert 1 galaxy NGC 5548 performed from 2014 February to July, the normally highly correlated far UV continuum and broad emission line variations decorrelated for similar to 60-70 days, starting similar to 75 days after the first HST/COS observation. Following this anomalous state, the flux and variability of the broad emission lines returned to a more normal state. This transient behavior, characterized by significant deficits in flux and equivalent width of the strong broad UV emission lines, is the first of its kind to be unambiguously identified in an active galactic nucleus reverberation mapping campaign. The largest corresponding emission line flux deficits occurred for the high ionization, collisionally excited lines C IV and Si IV(+O IV]), and also He II(+O III]), while the anomaly in Ly alpha was substantially smaller. This pattern of behavior indicates a depletion in the flux of photons with E-ph > 54 eV relative to those near 13.6 eV. We suggest two plausible mechanisms for the observed behavior: (i) temporary obscuration of the ionizing continuum incident upon broad line region (BLR) clouds by a moving veil of material lying between the inner accretion disk and inner (BLR), perhaps resulting from an episodic ejection of material from the disk, or (ii) a temporary change in the intrinsic ionizing continuum spectral energy distribution resulting in a deficit of ionizing photons with energies > 54 eV, possibly due to a transient restructuring of the Comptonizing atmosphere above the disk. Current evidence appears to favor the latter explanation. |
| Original Identifier: | oai:arizona.openrepository.com:10150/621259 |
| نوع الوثيقة: | Article |
| اللغة: | English |
| تدمد: | 1538-4357 |
| العلاقة: | http://stacks.iop.org/0004-637X/824/i=1/a=11?key=crossref.42b4a2e314fb318f6397064159e618e8Test |
| DOI: | 10.3847/0004-637X/824/1/11 |
| الإتاحة: | http://hdl.handle.net/10150/621259Test http://arizona.openrepository.com/arizona/handle/10150/621259Test |
| حقوق: | © 2016. The American Astronomical Society. All rights reserved. |
| رقم الانضمام: | edsndl.arizona.edu.oai.arizona.openrepository.com.10150.621259 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
Full Text Finder | تدمد: | 15384357 |
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| DOI: | 10.3847/0004-637X/824/1/11 |