Genetic Aspects of Lipidoses

Fuhrmann, Walter

doi:10.1007/978-3-642-87367-6_18

Cited by 20 publications

(31 citation statements)

References 95 publications

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“…The SF at 2.8 cm differs substantially from the more similar ones seen at 6 and 11 cm. Such different shapes towards higher frequencies were also seen previously in this source (Fuhrmann et al ) and were interpreted as an indication for the presence of physically different variability mechanisms, as for example ISS dominating at the longer wavelength and with a frequency increasing contribution of source intrinsic variability. In this context, variability time‐scales which are seen in the 2.8 cm data, but are not seen in the 11 and 6 cm data, may be related to some source intrinsic variability and may well therefore also appear in the optical, which is not affected by ISS.…”

Section: Analysis and Resultssupporting

confidence: 83%

“…We characterize the variability parameters in the same way as in Fuhrmann et al (), by the variability index, m , the noise‐bias corrected variability amplitude, Y , and a reduced chi‐square value,

χ_{r}^{2}

, for a fit to a constant flux . In Table , we summarize the results.…”

Section: Analysis and Resultsmentioning

confidence: 99%

“…This observing and calibration technique is well established and has been applied before for various IDV observations. The details of the observing strategy, the receiver parameters and the calibration methods have been described before (Gabányi et al ; Fuhrmann et al ; Marchili et al ). As secondary calibrators, the two non‐variable radio sources 0951+699 and 0836+710 were used.…”

Section: Observations and Data Reductionsmentioning

confidence: 99%

“…These requirements have led to several intensive campaigns in the past that have looked at individual blazars with multiple telescopes at widely separated longitudes over a few days through several months where simultaneous observations are obtained at different bands of the electromagnetic spectrum (e.g. Villata et al ; Raiteri et al ; Böttcher et al , ; Agudo et al ; Ostorero et al ; Fuhrmann et al ; Larionov et al , and references therein).…”

Section: Introductionmentioning

confidence: 99%

“…There have been earlier papers in which the variability properties of S5 0716+714 were discussed in both of these bands (e.g. Quirrenbach et al ; Wagner & Witzel ; Wagner et al ; Ostorero et al ; Fuhrmann et al ). Quirrenbach et al () reported correlated optical and radio variability in the source which, however, was not again seen in later observational campaigns.…”

Section: Introductionmentioning

confidence: 99%

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Multiwavelength intraday variability of the BL Lacertae S5 0716+714

Gupta

Krichbaum

Wiita

et al. 2012

Monthly Notices of the Royal Astronomical Society

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We report results from a one‐week multiwavelength campaign to monitor the BL Lacertae object (BL Lac) S5 0716+714 (on 2009 December 9–16). Nine ground‐based telescopes at widely separated longitudes and one space‐based telescope aboard the Swift satellite collected optical data. Radio data were obtained from the Effelsberg and Urumqi observatories and X‐ray data from Swift. In the radio bands, the source shows rapid [∼(0.5–1.5) d] intraday variability with peak amplitudes of up to ∼10 per cent. The variability at 2.8 cm leads by about 1 d the variability at 6 and 11 cm. This time lag and more rapid variations suggest an intrinsic contribution to the source's intraday variability at 2.8 cm, while at 6 and 11 cm, interstellar scintillation (ISS) seems to predominate. Large and quasi‐sinusoidal variations of ∼0.8 mag were detected in the V, R and I bands. The X‐ray data (0.2–10 keV) do not reveal significant variability on a 4 d time‐scale, favouring reprocessed inverse Compton over synchrotron radiation in this band. The characteristic variability time‐scales in radio and optical bands are similar. A quasi‐periodic variation of 0.9–1.1 d in the optical data may be present, but if so it is marginal and limited to 2.2 cycles. Cross‐correlations between radio and optical bands are discussed. The lack of a strong radio–optical correlation indicates different physical causes of variability (ISS at long radio wavelengths, source intrinsic origin in the optical) and is consistent with a high jet opacity and a compact synchrotron component peaking at ≃100 GHz in an ongoing very prominent flux‐density outburst. For the campaign period, we construct a quasi‐simultaneous spectral energy distribution, including γ‐ray data from the Fermi satellite. We obtain lower limits for the relativistic Doppler boosting of δ ≥ 12–26, which for a BL Lac‐type object is remarkably high.

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Section: Analysis and Resultssupporting

confidence: 83%