Using the standard one-zone synchrotron self-Compton (SSC) model and Markov chain Monte Carlo (MCMC) technique, we systematically analyze quasi-simultaneous multi-wavelength (MWL) spectral energy distributions (SEDs) of Mrk 421 501 during states relatively low activity. With this in place, a semi-analytical method is developed to examine uncertainty jet power estimation caused by degeneracy rad...

* Technical University of Košice, Department of Electronics and Multimedia Communications, Park Komenského 13, 04120 Košice, Slovak Republic, E-mail: [email protected], Tel: ++421-55-6024169 , Fax: ++421-55-6323989 ** Laboratoire Traitement du Signal et Instrumentation, Unité Mixte de Recherche CNRS 5516, Université Jean Monnet, Saint-Etienne, France, E-mail: [email protected] ...

STACEE is a ground based γ-ray observatory that uses a heliostat array, built for solar energy research, to detect atmospheric Cherenkov radiation from γ-ray initiated extensive air showers. During the first half of 2001, a prototype detector, STACEE-48, was used to detect the blazar Markarian 421, which was in an extremely active state. Observations from March to May of 2001 yielded an integra...

Mkn 421 was repeatedly observed with BeppoSAX in 1997–1998. We present highlights of the results of the thorough temporal and spectral analysis discussed by Fossati et al. (1999) and Maraschi et al. (1999), focusing on the flare of April 1998, which was simultaneously observed also at TeV energies. The detailed study of the flare in different energy bands reveals a few very important new result...

Pachmarhi Array of Čerenkov Telescopes (PACT), based on wavefront sampling technique, has been used for detecting TeV gamma rays from galactic and extra-galactic γ-ray sources. The Blazar, Mkn 421 was one such extragalactic source observed during the winter nights of 2000 and 2001. We have carried out a preliminary analysis of the data taken during the nights of January, 2000 and 2001. Results ...

We observed the BL Lac object Markarian 421 with the X-ray satellite RXTE and the Whipple Air Cerenkov Telescope during a two week correlated Xray/gamma-ray campaign in May 1996. Two dramatic outbursts with extremely rapid and strong flux variations were observed at TeV energies during this period. The X-ray emission in the 2-10 keV band was highly variable and reached a peak flux of 5.6×10 erg...

We conducted a daily monitoring campaign on Mrk 421 in 2003 and 2004 with the Whipple 10 m telescope and the large-area instruments aboard RXTE, simultaneously covering TeV and X-ray energies. Supporting observations at optical and radio wavelengths were also frequently carried out. Mrk 421 was observed over a wide range of fluxes (with a dynamic range of ∼30 both at TeV and X-ray energies). Th...

VERITAS, the Very Energetic Radiation Telescope Imaging Array System, is an array of four imaging Atmospheric Cherenkov telescopes in southern Arizona. It is sensitive to gamma rays at energies above 100GeV. Here, we discuss the results of observations of two well known VHE blazars, Markarian 421 and Markarian 501, during Spring 2006 which were made with the first two telescopes during the comi...

Oxygen-regulated protein 150 (ORP150) is an inducible ER chaperone by numerous cellular insults and sustains cellular viability. We have previously reported that ORP150 is differentially induced in a panel thyroid cancer cells and represents as an unwanted molecular consequence during exposure to proteasome inhibition. However, the molecular basis for induction of ORP150 by proteasome inhibitor...