Search for Very-High-Energy Gamma Rays from the z = 0.896 Quasar 4C +55.17 with the MAGIC telescopes

Abstract

The bright gamma-ray quasar 4C +55.17 is a distant source ($z=0.896$) with a hard spectrum at GeV energies as observed by the Large Area Telescope (LAT) on board the {\it Fermi} satellite. This source is identified as a good source candidate for very-high-energy (VHE; $>30$ GeV) gamma rays. In general VHE gamma rays from distant sources provide an unique opportunity to study the extragalactic background light (EBL) and underlying astrophysics. The flux intensity of this source in the VHE range is investigated. Then, constraints on the EBL are derived from the attenuation of gamma-ray photons coming from the distant blazar. We searched for a gamma-ray signal from this object using the 35-hour observations taken by the MAGIC telescopes between November 2010 and January 2011. No significant VHE gamma-ray signal was detected. We computed the upper limits of the integrated gamma-ray flux at $95\%$ confidence level of $9.4\times 10^{-12}$ cm${}^{-2}$ s${}^{-1}$ and $2.5\times 10^{-12}$ cm${}^{-2}$ s${}^{-1}$ above $100$ GeV and $200$ GeV, respectively. The differential upper limits in four energy bins in the range from $80$ GeV to $500$ GeV are also derived. The upper limits are consistent with the attenuation predicted by low-flux EBL models on the assumption of a simple power-law spectrum extrapolated from LAT data.

7 pages, 3 figures, accepted for publication in MNRAS

References in corpus (14)

• Observations of the Crab Nebula with H.E.S.S
• Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe?
• The Imprint of The Extragalactic Background Light in the Gamma-Ray Spectra of Blazars
• New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200
• The First Fermi-LAT Catalog of Sources Above 10 GeV
• On the Evolution of and High-Energy Emission from GHz-Peaked-Spectrum Sources
• Detection of the cosmic γ-ray horizon from multiwavelength observations of blazars
• The Firm Redshift Lower Limit of the Most Distant TeV-Detected Blazar PKS 1424+240
• The Resolved Near-Infrared Extragalactic Background
• The Resolved NIR Extragalactic Background
• Characteristics of EGRET Blazars in the VLBA Imaging and Polarimetry Survey (VIPS)
• The Production of Ultra High Energy Cosmic Rays during the Early Epochs of Radio-loud AGN
• Physics performance of the upgraded MAGIC telescopes obtained with Crab Nebula data
• VERITAS Results from Deep Exposure on the Distant FSRQ 4C +55.17

Cited by in corpus (2)

• Leptonic and Hadronic Modeling of Fermi-LAT Hard Spectrum Quasars and Predictions for High-Energy Polarization
• Constraints on VHE gamma-ray emission of Flat Spectrum Radio Quasars with the MAGIC telescopes