H.E.S.S. follow-up observations of GRB221009A

Abstract

GRB221009A is the brightest gamma-ray burst ever detected. To probe the very-high-energy (VHE, $>$\!100 GeV) emission, the High Energy Stereoscopic System (H.E.S.S.) began observations 53 hours after the triggering event, when the brightness of the moonlight no longer precluded observations. We derive differential and integral upper limits using H.E.S.S. data from the third, fourth, and ninth nights after the initial GRB detection, after applying atmospheric corrections. The combined observations yield an integral energy flux upper limit of ${\Phi }_{\mathrm{UL}}^{95\%}=9.7\times 10^{-12}\mathrm{erg}\mathrm{c}{\mathrm{m}}^{-2}{\mathrm{s}}^{-1}$ above $E_{\mathrm{thr}}=650$ GeV. The constraints derived from the H.E.S.S. observations complement the available multiwavelength data. The radio to X-ray data are consistent with synchrotron emission from a single electron population, with the peak in the SED occurring above the X-ray band. Compared to the VHE-bright GRB190829A, the upper limits for GRB221009A imply a smaller gamma-ray to X-ray flux ratio in the afterglow. Even in the absence of a detection, the H.E.S.S. upper limits thus contribute to the multiwavelength picture of GRB221009A, effectively ruling out an IC dominated scenario.

arXiv comment10 pages, 4 figures. Accepted for publication in APJL. Corresponding authors: J. Damascene Mbarubucyeye, H. Ashkar, S. J. Zhu, B. Reville, F. Schüssler

References in corpus (32)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• The Swift X-ray Telescope
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• Fermi Large Area Telescope Fourth Source Catalog
• Observations of the Crab Nebula with H.E.S.S
• Calibration of X-ray absorption in our Galaxy
• Theories of Gamma-Ray Bursts
• Extragalactic Background Light Inferred from AEGIS Galaxy SED-type Fractions
• Limits and Confidence Intervals in the Presence of Nuisance Parameters
• Particle acceleration by ultra-relativistic shocks: theory and simulations
• Background Modelling in Very-High-Energy gamma-ray Astronomy
• A high performance likelihood reconstruction of gamma-rays for Imaging Atmospheric Cherenkov Telescopes
• Teraelectronvolt emission from the $\gamma$-ray burst GRB 190114C
• A very-high-energy component deep in the Gamma-ray Burst afterglow
• Klein-Nishina Effects on Optically Thin Synchrotron and Synchrotron Self-Compton Spectrum
• A Monte Carlo Template based analysis for Air-Cherenkov Arrays
• The Swift Burst Analyser I: BAT and XRT spectral and flux evolution of Gamma Ray Bursts
• Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow
• Gamma-Hadron Separation in Very-High-Energy gamma-ray astronomy using a multivariate analysis method
• Particle Acceleration through Multiple Conversions from Charged into Neutral State and Back
• Impact of aerosols and adverse atmospheric conditions on the data quality for spectral analysis of the H.E.S.S. telescopes
• Multi-wavelength view of the close-by GRB 190829A sheds light on gamma-ray burst physics
• The physical conditions of the afterglow implied by MAGIC's sub-TeV observations of GRB 190114C
• Ultra-high energy Inverse Compton emission from Galactic electron accelerators
• Electromagnetic Catastrophe in Ultrarelativistic Shocks and the Prompt Emission of Gamma-Ray Bursts
• Particle Acceleration in Gamma-Ray Burst Jets
• A Run-Wise Simulation and Analysis Framework for Imaging Atmospheric Cherenkov Telescope Arrays
• Mass-loss predictions for evolved very metal-poor massive stars
• The implications of TeV detected GRB afterglows for acceleration at relativistic shocks
• The variable absorption in the X-ray spectrum of GRB 190114C

Cited by in corpus (10)

• A Narrow Uniform Core with a Wide Structured Wing: Modeling the TeV and Multi-wavelength Afterglows of GRB 221009A
• The origin of very-high-energy gamma-rays from GRB 221009A: implications for reverse shock proton synchrotron emission
• Impact of Cosmology on Lorentz Invariance Violation Constraints from GRB Time-Delays
• GRB 221009A: Spectral signatures based on ALPs candidates
• Impact of Satellite Trails on H.E.S.S. Astronomical Observations
• Probing for Lorentz Invariance Violation in Pantheon Plus Dominated Cosmology
• GRB 221009A: Observations with LST-1 of CTAO and Implications for Structured Jets in Long Gamma-Ray Bursts
• Two-component jet model for the afterglow emission of GRB 201216C and GRB 221009A and implications for jet structure of very-high-energy gamma-ray bursts
• A photohadronic interpretation of the H.E.S.S. afterglow observations from GRB 221009A
• Extreme Transients in Gamma Rays