Skip navigation
  • INAF logo
  • Home
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects
  • Explore by
    • Research outputs
    • Researchers
    • Organization units
    • Projects
  • Login:
    • My DSpace
    • Receive email
      updates
    • Edit Account details
  • Italian
  • English

  1. OA@INAF
  2. PRODOTTI RICERCA INAF
  3. 1 CONTRIBUTI IN RIVISTE (Journal articles)
  4. 1.01 Articoli in rivista
Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12386/28414
Title: Strong X-Ray and Multiwavelength Flaring Activity for 1ES 1959+650, 2016 August-2017 November
Authors: Kapanadze, B.
Dorner, D.
VERCELLONE, STEFANO 
ROMANO, Patrizia 
Hughes, P.
Aller, M.
Aller, H.
Reynolds, M.
Tabagari, L.
Issue Date: 2018
Journal: THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 
Number: 238
Issue: 1
First Page: 13
Abstract: We present the detailed timing and spectral results obtained during the Swift observations of the TeV-detected blazar 1ES 1959+650 in 2016 August-2017 November. The source continued its trend of gradually enhancing X-ray flaring activity in the 0.3-10 keV energy range, starting in 2015 August, and a new highest historical brightness state was recorded twice. A long-term high state was superimposed by both weak and strong flares, and we detected 32 instances of intraday X-ray flux variability, including several occasions of extremely fast fluctuations with fractional amplitudes of 5.4%-7.5% within 1 ks exposures. The 0.3-10 keV spectra generally showed a best fit with the log-parabolic model, yielding a very wide range of the curvature parameter b and the photon index at 1 keV. The position of the synchrotron SED peak E <SUB>p</SUB> showed an extreme variability on various timescales between energies less than 0.1 keV and 7.7 ± 0.7 keV, with 25% of the spectra peaking at hard X-rays. In 2017 May-November, the source mostly showed lower spectral curvature and an anticorrelation b-E <SUB>p</SUB>, expected in the case of efficient stochastic acceleration of X-ray-emitting electrons. The 0.3-100 GeV and optical-UV fluxes also attained their highest historical values in this period, although the latter showed an anticorrelation with the 0.3-10 keV emission, which is explained by the stochastic acceleration of electrons with a narrow initial energy distribution, having an average energy significantly higher than the equilibrium energy.
URI: http://hdl.handle.net/20.500.12386/28414
URL: https://iopscience.iop.org/article/10.3847/1538-4365/aad8b5
ISSN: 0067-0049
DOI: 10.3847/1538-4365/aad8b5
Bibcode ADS: 2018ApJS..238...13K
Fulltext: open
Appears in Collections:1.01 Articoli in rivista

Files in This Item:
File Description SizeFormat 
Kapanadze_2018_ApJS_238_13.pdfPdf editoriale3.14 MBAdobe PDFView/Open
Show full item record

Page view(s)

4
checked on Jan 17, 2021

Download(s)

2
checked on Jan 17, 2021

Google ScholarTM

Check

Altmetric


Items in DSpace are published in Open Access, unless otherwise indicated.


Explore by
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects

Informazioni e guide per autori

https://openaccess-info.inaf.it: tutte le informazioni sull'accesso aperto in INAF

Come si inserisce un prodotto: le guide a OA@INAF

La Policy INAF sull'accesso aperto

Documenti e modelli scaricabili

Feedback
Built with DSpace-CRIS - Extension maintained and optimized by Logo 4SCIENCE