Very High Energy $\gamma$-ray and Near Infrared observations of 1ES2344+514 during 2004-05

Abstract

We have observed the BL Lac object 1ES2344+514 (z = 0.044) in Very High Energy (VHE) gamma-ray and near-infrared wavelength bands with TACTIC and MIRO telescopes respectively. The observations were made from 18th October to 9th December 2004 and 27th October 2005 to 1st January 2006. Detailed analysis of the TACTIC data indicates absence of a statistically significant gamma-ray signal both in overall data and on a nightly basis from the source direction. We estimate an upper limit of I($\ge$1.5 TeV)$\le 3.84\times 10^{-12}$ photons cm${}^{-2}$ s${}^{-1}$ at a 3$\sigma$ confidence level on the integrated $\gamma$-ray flux. In addition, we have also compared TACTIC TeV light curves with those of the RXTE ASM (2-12keV) for the contemporary period and find that there are no statistically significant increases in the signal strengths from the source in both these energy regions. During 2004 IR observations, 1ES2344+514 shows low level (~0.06 magnitude) day-to-day variation in both, J & H bands. However, during 2005 observation epoch, the source brightens up by about 0.41 magnitude from its October 2005 level J magnitude= 12.64 to J = 12.23 on December 6, 2005. It then fades by about 0.2 magnitude during 6 to 10 December, 2005. The variation is seen in both, J & H, bands simultaneously. The light travel time arguments suggest that the emission region size is of the order of $10^{17}$ cms.

arXiv comment15 pages, 6 figures, 4 tables, accepted for publication in Journal of Physics G

References in corpus (8)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• A Multi-wavelength View of the TeV Blazar Markarian 421: Correlated Variability, Flaring, and Spectral Evolution
• Discovery of >350 GeV Gamma Rays from the BL Lacertae Object 1ES 2344+514
• Hadronic Production of TeV Gamma Ray Flares from Blazars
• Observations of 54 Active Galactic Nuclei with the HEGRA System of Cherenkov Telescopes
• Detection of Exceptional X-Ray Spectral Variability in the TeV BL Lac 1ES 2344+514
• Extremely violent optical microvariability in blazars: fact or fiction?
• Upper Limits on the Extragalactic Background Light from the Gamma-Ray Spectra of Blazars

Cited by in corpus (8)

• The TACTIC atmospheric Cherenkov Imaging telescope
• Multiwavelength Observations of the VHE Blazar 1ES 2344+514
• An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state
• Very-High-Energy $\gamma$-Ray Observations of the Blazar 1ES 2344+514 with VERITAS
• Artificial Neural Network based gamma-hadron segregation methodology for TACTIC telescope
• Simulation studies for optimizing the trigger generation criteria for the TACTIC telescope
• Photohadronic interpretation of the different incarnation of 1ES 2344+514
• Broadband Spectral Analysis of 1ES2344+514: A Multi-epoch study