Study of blazar spectrum of TEV blazar MARKARIAN 501

Abstract

The blazar spectrum of TeV blazar markarian 501 (mrk 501), we studied the gamma-ray flux variability of BL Lac object Markarian 501 (Redshift Z = 0.034), an active galactic nuclei (AGN) using Fermi-LAT and Swift-XRT, KVA and MAGIC telescope data between the period MJD56858.97 to MJD56859.98, we found the source to be extremely variable during this period, and a few bright flares were detected. We believe, active galactic nuclei (AGN) are powered by the creation of mass onto supermassive black holes (SMBHs), mass like 10^8 – 10^10 M⊙ at the center of the host galaxies and the rotational energy of SMBHs, So blazar has very bright nuclei, So bright means that the central region can be more luminous than the remaining galaxy light. Blazar emits broadband emission has been studied at multi-wavelengths from radio to gamma rays. In particular, the spectral energy distributions (SEDs) of blazars have been measured and modeled for many years. There are two main blazar sub-classes, namely BL Lacertae (BL Lac) and flat spectrum radio quasars (FSRQs). So markarian 501 is Bl lacertae Object. They differ primarily in their optical spectra. The whipple observatory discovered Mrk 501 (z=0.034) as the second extragalactic TeV source exceeding 500 GeV in 1996 (J.Quinn et al., Astrophys. J. Lett). Markarian 501 belongs to the high-energy peaked blazars, a subclass of AGN (HBL). In these sources, the broadband emission (radio to gamma rays) is produced in a jet that is pointed very near the line of sight. These jets composition is unknown. It is unclear if they are made of electron-positron plasma or electron-proton plasma. A double-peaked profile characterises markarian 501 spectral energy distribution (SED). When the SED is displayed ν Fν (frequency × flux ) on the y-axis and ν (frequency) on the x-axis, these peaks appear at energies of keV and GeV/TeV. The first hump of the SED is assumed to be created by synchrotron radiation from the relativistic electron population gyrating in the jet’s magnetic fields, but the origin of the GeV/TeV hump remains unknown. we can use two type emission model i.e., leptonic or hadronic models. In leptonic models, this hump may be caused by interactions between electrons and photons. In hadronic models, the hump may be caused by interaction between protons and photon or magnetic field, Flux variability and the source’s spectral modeling are used to constrain the particle acceleration processes in the Tev blazar jet.