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dc.contributor.authorLang, Mark
dc.date.accessioned2014-11-17T10:46:46Z
dc.date.available2014-11-17T10:46:46Z
dc.date.issued2007en
dc.identifier.urihttp://hdl.handle.net/10379/4725
dc.description.abstract(Abridged) We present a detailed analysis of week-long simultaneous observations of the blazar Mrk421 at 2-60 keV X-rays (RXTE) and TeV gamma-rays (Whipple and HEGRA) in 2001. The unprecedented quality of this dataset enables us to establish firmly the existence of the correlation between the TeV and X-ray luminosities, and to start unveiling some of its more detailed characteristics, in particular its energy dependence, and time variability. The source shows strong, highly correlated variations in X-ray and gamma-ray. No evidence of X-ray/gamma-ray interband lag is found on the full week dataset (<3 ks). However, a detailed analysis of the March 19 flare reveals that data are not consistent with the peak of the outburst in the 2-4 keV X-ray and TeV band being simultaneous. We estimate a 2.1+/-0.7 ks TeV lag. The amplitudes of the X-ray and gamma-ray variations are also highly correlated, and the TeV luminosity increases more than linearly w.r.t. the X-ray one. The strong correlation supports the standard model in which a unique electrons population produces the X-rays by synchrotron radiation and the gamma-ray component by inverse Compton scattering. However, for the individual best observed flares the gamma-ray flux scales approximately quadratically w.r.t. the X-ray flux, posing a serious challenge to emission models for TeV blazars. Rather special conditions and/or fine tuning of the temporal evolution of the physical parameters of the emission region are required in order to reproduce the quadratic correlation.en_US
dc.formatapplication/pdfen_US
dc.language.isoenen_US
dc.subjectAstrophysicsen_US
dc.subjectCentre for Astronomyen_US
dc.titleMultiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variabilityen_US
dc.typeArticleen_US
dc.local.publishedsourcehttp://arxiv.org/pdf/0710.4138en_US
dc.description.peer-reviewedpeer-revieweden_US
dc.local.authorsG. Fossati (1), J. H. Buckley (2), I. H. Bond (3), S. M. Bradbury (3), D. A. Carter-Lewis (4), Y. C. K. Chow (5), W. Cui (6), A. D. Falcone (7), J. P. Finley (6), J. A. Gaidos (6), J. Grube (3), J. Holder (8), D. Horan (9,10), D. Horns (11), M. M. Jordan (12), D. B. Kieda (13), J. Kildea (9), H. Krawczynski (2), F. Krennrich (4), M. J. Lang (14), S. LeBohec (13), K. Lee (2), P. Moriarty (15), R. A. Ong (5), D. Petry (4,16), J. Quinn (17), G. H. Sembroski (6), S. P. Wakely (18), T. C. Weekes (9) ((1) Rice University, (2) Washington University, (3) University of Leeds, (4) Iowa State University, (5) UCLA, (6) Purdue University, (7) PennState, (8) University of Delaware, (9) Fred Lawrence Whipple Observatory, (10) Argonne National Lab, (11) Hamburg University, (12) Raytheon (13) University of Utah, (14) National University of Ireland, (15) Galway-Mayo Institute of Technology, (16) MPE Garching, (17) University College Dublin, (18) University of Chicago)en
dc.local.arxivid0710.4138en
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