Dresden 2013 – scientific programme

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T: Fachverband Teilchenphysik

T 85: Gammaastronomie 5

T 85.3: Talk

Thursday, March 7, 2013, 17:15–17:30, HSZ-E05

A model for the highly variable orphan flare of Markarian 501 — •Stephan Richter and Felix Spanier — ITPA, Universität Würzburg

The spectral energy densities (SEDs) of high peaked BL Lac objects (HBLs) is well known to be explained via the Synchrotron Self Compton model (SSC). Especially a number of extensive multi wavelength observation campaigns invigorated the confidence in this model, explaining the steady state SEDs. However, the observed time variability put the time dependent implementations of the SSC paradigm under pressure. Quite extreme parameters are often needed to explain light curves, that sometimes contradict the steady state fit.

In this talk we argue, that the flare of Markarian 501 on MJD 54952 in the gamma range can't be explained with a one component SSC model, starting from the steady state fit. This is mainly because of the marginal variability in the X-rays and the extreme short time variability. An alternative explanation is presented. In this model, the short variability time scale emerges from a second boost between the main blob and a second component within the jet. Using the limits of non direct detection of this second component, an estimate for its properties is computed.

The derived parameters are well within the expected range. Although the connection between observed, individual VLBI components and modeled blobs is not yet possible, the existence of multiple components is supported by such observations.