title: The WEBT campaign on the BL Lac object PG 1553+113 in 2013. An analysis of the enigmatic synchrotron emission
metadata.name: dc.contributor.author
metadata.value: Morozova, Daria
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2016-04-07T15:16:31Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2016-04-07T15:16:31Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2015-11
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: MNRAS 454, 353–367 (2015)
metadata.lang: en_GB
metadata.name: dc.identifier.issn
metadata.value: 0035-8711
metadata.lang: -
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/1925
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: A multifrequency campaign on the BL Lac object PG 1553+113 was organized by the Whole
  Earth Blazar Telescope (WEBT) in 2013 April–August, involving 19 optical, two near-IR,
  and three radio telescopes. The aim was to study the source behaviour at low energies during
  and around the high-energy observations by the Major Atmospheric Gamma-ray Imaging
  Cherenkov telescopes in April–July. We also analyse the UV and X-ray data acquired by the
  Swift and XMM–Newton satellites in the same period. The WEBT and satellite observations
  allow us to detail the synchrotron emission bump in the source spectral energy distribution
  (SED). In the optical, we found a general bluer-when-brighter trend. The X-ray spectrum
  remained stable during 2013, but a comparison with previous observations suggests that it be-
  comes harder when the X-ray flux increases. The long XMM–Newton exposure reveals a curved
  X-ray spectrum. In the SED, the XMM–Newton data show a hard near-UV spectrum, while
  Swift data display a softer shape that is confirmed by previous Hubble Space Telescope/Cosmic
  Origins Spectrograph and International Ultraviolet Explorer observations. Polynomial fits to
  the optical–X-ray SED show that the synchrotron peak likely lies in the 4–30 eV energy range,
  with a general shift towards higher frequencies for increasing X-ray brightness. However, the
  UV and X-ray spectra do not connect smoothly. Possible interpretations include: (i) orienta-
  tion effects, (ii) additional absorption, (iii) multiple emission components, and (iv) a peculiar
  energy distribution of relativistic electrons. We discuss the first possibility in terms of an
  inhomogeneous helical jet model.
metadata.lang: en_GB
metadata.name: dc.description.sponsorship
metadata.value: RFBR grant 15-02-00949
  St Petersburg University research grant 6.38.335.2015
metadata.lang: en_GB
metadata.name: dc.language.iso
metadata.value: en
metadata.lang: en_GB
metadata.name: dc.publisher
metadata.value: Oxford University Press
metadata.lang: en_GB
metadata.name: dc.relation.ispartofseries
metadata.value: Monthly Notices of the Royal Astronomical Society;454
metadata.lang: -
metadata.name: dc.subject
metadata.value: galaxies: active – BL Lacertae objects: general – BL Lacertae objects: individual: PG 1553+113.
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: The WEBT campaign on the BL Lac object PG 1553+113 in 2013. An analysis of the enigmatic synchrotron emission
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: MNRAS-2015-Raiteri-353-67.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/1925/1/MNRAS-2015-Raiteri-353-67.pdf
resources.format: Adobe PDF
resources.size: 1,56 MB