• Login
    View Item 
    •   Home
    • UA Faculty Research
    • UA Faculty Publications
    • View Item
    •   Home
    • UA Faculty Research
    • UA Faculty Publications
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Space Telescope and Optical Reverberation Mapping Project. X. Understanding the Absorption-line Holiday in NGC 5548

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Dehghanian_2019_ApJ_877_119.pdf
    Size:
    1.624Mb
    Format:
    PDF
    Description:
    Final Published Version
    Download
    Author
    Dehghanian, M.
    Ferland, G. J. cc
    Kriss, G. A.
    Peterson, B. M.
    Mathur, S.
    Mehdipour, M.
    Guzmán, F.
    Chatzikos, M.
    van Hoof, P. A. M.
    Williams, R. J. R.
    Arav, N.
    Barth, A. J. cc
    Bentz, M. C.
    Bisogni, S.
    Brandt, W. N. cc
    Crenshaw, D. M.
    Bontà, E. Dalla
    De Rosa, G.
    Fausnaugh, M. M.
    Gelbord, J. M.
    Goad, M. R.
    Gupta, A.
    Horne, Keith
    Kaastra, J.
    Knigge, C.
    Korista, K. T.
    McHardy, I. M.
    Pogge, R. W. cc
    Starkey, D. A.
    Vestergaard, M.
    Show allShow less
    Affiliation
    Univ Arizona, Steward Observ
    Issue Date
    2019-06-03
    Keywords
    galaxies: active
    galaxies: individual (NGC 5548)
    galaxies: nuclei
    galaxies: Seyfert
    line: formation
    
    Metadata
    Show full item record
    Publisher
    IOP PUBLISHING LTD
    Citation
    M. Dehghanian et al 2019 ApJ 877 119
    Journal
    ASTROPHYSICAL JOURNAL
    Rights
    Copyright © 2019. The American Astronomical Society. All rights reserved.
    Collection Information
    This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.
    Abstract
    The Space Telescope and Optical Reverberation Mapping Project (AGN STORM) on NGC 5548 in 2014 is one of the most intensive multiwavelength AGN monitoring campaigns ever. For most of the campaign, the emission-line variations followed changes in the continuum with a time lag, as expected. However, the lines varied independently of the observed UV-optical continuum during a 60-70 day "holiday," suggesting that unobserved changes to the ionizing continuum were present. To understand this remarkable phenomenon and to obtain an independent assessment of the ionizing continuum variations, we study the intrinsic absorption lines present in NGC 5548. We identify a novel cycle that reproduces the absorption line variability and thus identify the physics that allows the holiday to occur. In this cycle, variations in this obscurer's line-of-sight covering factor modify the soft X-ray continuum, changing the ionization of helium Ionizing radiation produced by recombining helium then affects the level of ionization of some ions seen by the Hubble Space Telescope. In particular, high-ionization species are affected by changes in the obscurer covering factor, which does not affect the optical or UV continuum, and thus appear as uncorrelated changes, a "holiday." It is likely that any other model that selectively changes the soft X-ray part of the continuum during the holiday can also explain the anomalous emission-line behavior observed.
    ISSN
    0004-637X
    DOI
    10.3847/1538-4357/ab1b48
    Version
    Final published version
    Sponsors
    NASA through a grant from the Space Telescope Science Institute [NNX15AH49G, 80NSSC17K0126, NAS5-26555]; NSF [1816537, AST-1816537, AST-1412693, AST-1009756, AST-1412315]; NASA [NNX15AH49G, 80NSSC17K0126, ATP 17-0141, AR7-18013X, NAS8-03060, PF5-160141]; STScI [HST-AR.13914, HST-AR-15018]; NASA through STScI grant [HST-AR-14556.001A, HST-AR-14286]; Huffaker Scholarship; National Science Foundation [AST-1008882]; NSF CAREER [AST-1253702]; Padua University [DOR1699945/16, DOR1715817/17, DOR1885254/18, BIRD164402/16]; NSF Fellowship award [AST-1302093]; STFC [ST/R000824/1, ST/M001326/1]; NWO; Netherlands Organization for Scientific Research; Packard Foundation; Danish Council [DFF 4002-00275]; Royal Society Leverhulme Trust Senior Research Fellowship [LT160006]; [HST-AR-13240.009]
    ae974a485f413a2113503eed53cd6c53
    10.3847/1538-4357/ab1b48
    Scopus Count
    Collections
    UA Faculty Publications

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.