MAGIC very large zenith angle observations of the Crab Nebula up to 100 TeV

Abstract

Aims. We measure the Crab Nebula γ-ray spectral energy distribution in the ~100 TeV energy domain and test the validity of existing leptonic emission models at these high energies. Methods. We used the novel very large zenith angle observations with the MAGIC telescope system to increase the collection area above 10 TeV. We also developed an auxiliary procedure of monitoring atmospheric transmission in order to assure proper calibration of the accumulated data. This employs recording optical images of the stellar field next to the source position, which provides a better than 10% accuracy for the transmission measurements. Results. We demonstrate that MAGIC very large zenith angle observations yield a collection area larger than a square kilometer. In only ~ 56 h of observations, we detect the γ-ray emission from the Crab Nebula up to 100 TeV, thus providing the highest energy measurement of this source to date with Imaging Atmospheric Cherenkov Telescopes. Comparing accumulated and archival MAGIC and Fermi/LAT data with some of the existing emission models, we find that none of them provides an accurate description of the 1 GeV to 100 TeV γ-ray signal.

Peta–electron volt gamma-ray emission from the Crab Nebula

“…3B). Figure 3A also shows previous measurements using atmospheric Cherenkov telescopes (5,6,17,18) and air shower arrays (7,8,19). These are consistent with the WCDA and KM2A data from sub-TeV to multi-TeV energies, including the flux at the highest energy previously reported, γ 300 TeV E ≈ (8).…”

“…At the transition from GeV to TeV energies, the spectral energy distribution (SED; E 2 dN / dE, where dN / dE is the differential flux of radiation at the photon energy E) reaches a maximum around 100 GeV (3,4). Previous observations reported a detection at ≈80 TeV (5), and measured the spectrum up to 300 TeV (6)(7)(8). The angular size of the γ-ray source at TeV energies has been reported ≈50 arcsec (9).…”

Probing Quantum Gravity with Imaging Atmospheric Cherenkov Telescopes

“…In addition, similar studies could be performed with IACTs. With the prospect of the CTA to be commissioned in the next few years, and a recent result from the MAGIC Collaboration measuring the Crab nebula spectrum up to 100 TeV [139], feasibility of a similar study with IACTs does not seem so far-fetched.…”

The Crab Pulsar and Nebula as seen in gamma-rays

“…In addition, even before the detection of pulsed TeV radiation, Mochol and Petri [45] predicted multi-TeV gamma-rays as a distinctive signature of gamma-ray production via synchrotron-self-Compton at tens of R L . [50], blue squares for HESS data [51], pink circles for Fermi-LAT ones [52], red diamonds for MAGIC data [53,54], orange stars for HAWC [55], brown triangles for Tibet AS-γ [56] and violet ones for LHAASO data [8,57]. Figure courtesy of Michele Fiori.…”