GRB221009A

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Alert Information

• Name/type of the alert:
• GCN notice: []
• Triggered by: Fermi GBM/Swift BAT
• Alert coordinates:
  • RA: h m s, Dec: deg m s
  • RA, Dec in deg (ICRS): 288.26452 deg, +19.77350 deg
• Alert arrival time:
• Other relevant information:
  • Redshift (z): 0.151

Multi-wavelength Observations

Some references useful to understand the multi-wavelength context:

• Swift: https://www.swift.ac.uk/burst_analyser/01126853/

• Fermi-GBM: https://arxiv.org/pdf/2303.14172.pdf

• Fermi-LAT: https://agenda.infn.it/event/33457/contributions/204976/attachments/109809/156172/BISSALDI_TeVPa_BoatGRB_230913.pdf

• H.E.S.S. paper. (53 hours after) : https://arxiv.org/pdf/2303.10558.pdf

• LHAASO paper (last stage at 10^3s): https://arxiv.org/pdf/2306.06372.pdf

• AGILE paper: https://arxiv.org/pdf/2309.10515

• Discussion on how to retrieve points in the non-detection case:
  • MAGIC sGRB https://arxiv.org/abs/2012.07193

• Discussion on modelling/jet structure:

• • Clearest evidence of structure of a jet so far.Indirect evidence for structured jets in long GRBs has been around for a while: https://arxiv.org/abs/2206.11088
  • HESS upper limits combined with radio measurements indeed already constrain parameters such as the circumburst density for the outer jet. https://arxiv.org/abs/2310.12856
  • numerical simulations to study the structured jets e.g. Gottlieb et al. https://ui.adsabs.harvard.edu/abs/2022MNRAS.510.4962G/abstract
  • structure evolution of the afterglow using VLBI observations. Giarratana, Salafia, Ghirlanda et al. https://arxiv.org/pdf/2311.05527.pdf
  • Model with late-time TeV emission in excess of the LHAASO light curve extrapolation: Zheng et al. https://arxiv.org/abs/2310.12856. They argue that the HESS upper limits provide strong constraints on the circumburst medium density at large radii (Fig. 1).
  • Model with late-time TeV emission consistent with LHAASO light curve extrapolation: Ren et al. https://arxiv.org/abs/2310.15886 See Fig. 3.
  • Two component jet model: https://arxiv.org/pdf/2212.09266

Publication status

Targeted journal:

Section	Preliminary deadline	Status	Responsible (and main responsible)
Introduction		Ongoing	All (Monica)
Observations		Ongoing	All (Alice?)
Data Analysis (Moon)		Ongoing	Arnau, Kenta
Data Analysis (Dark)		Ongoing	Arnau, Kenta
Results		Ongoing	Arnau, Kenta
Modelling		Not started	Susumu
Discussion		Not started	All (Alessandro)
Conclusion		Not started	All

LST Observations

• Observation conditions
  • camera summary plot [1]
  • first night (Oct 10) of the GRB observation and moon Crab observation (Nov 3-5) superplots
• Dates of data-taking: 2022-10-10,12,15-18,21,23-26,28,31. 2022-11-13,16,17,20

• • 2022-10-10
    • Zenith range (deg): 38.8 -> 57.9
    • Transmission9km: n/a
    • Observation condition: moon
    • Observation mode: std wobble, reduced HV
    • Runs: 9604 - 9607
    • Joint observations with MAGIC? : No
    • ELOG link: [2]
    • Important comments: Data were affected by timestamp issue. (Reprocessing is already done and results below are from reprocessed data)

• • 2022-10-12
    • Zenith range (deg): 34.6 -> 50.5
    • Transmission9km: n/a
    • Observation condition: moon
    • Observation mode: std wobble, reduced HV
    • Runs: 9613 - 9617
    • Joint observations with MAGIC? : Yes
    • ELOG link: [3]
    • Important comments: Data were affected by timestamp issue. (Reprocessing is already done and results below are from reprocessed data). Run 9613 taken with HV setting "set_hv_reduced_0.5", the others with "set_hv_reduced_0.3"

• • 2022-10-15
    • Zenith range (deg): 23.8 -> 57.9
    • Transmission9km: n/a
    • Observation condition: dark and moon (9629,9630)
    • Observation mode: std wobble
    • Runs: 9625 - 9630
    • Joint observations with MAGIC? : Yes, except the first 2 runs
    • ELOG link: [4]
    • Important comments: Data were affected by timestamp issue. (Reprocessing is already done and results below are from reprocessed data)

• • 2022-10-16
    • Zenith range (deg): 32.1 -> 64.1
    • Transmission9km: n/a
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9640 - 9647
    • Joint observations with MAGIC? : No
    • ELOG link: [5]
    • Important comments: Data were affected by timestamp issue. (Reprocessing is already done and results below are from reprocessed data)

• • 2022-10-17
    • Zenith range (deg): 25.9 -> 58.6
    • Transmission9km: n/a
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9670 - 9677
    • Joint observations with MAGIC? : Yes
    • ELOG link: [6]
    • Important comments: Data were affected by timestamp issue. (Reprocessing is already done and results below are from reprocessed data)

• • 2022-10-18
    • Zenith range (deg): 23.1 -> 43.5
    • Transmission9km: n/a
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9691 - 9696
    • Joint observations with MAGIC? : No
    • ELOG link: [7]
    • Important comments: unstable rate in run 9691

• • 2022-10-21
    • Zenith range (deg): 34.6 -> 55.6
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9802 - 9807
    • Joint observations with MAGIC? : Yes
    • ELOG link: [8]
    • Important comments:

• • 2022-10-23
    • Zenith range (deg): 32.07 -> 59.21
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9829 - 9835
    • Joint observations with MAGIC? : Yes
    • ELOG link: [9]
    • Important comments:

• • 2022-10-24
    • Zenith range (deg): 49.6 -> 58.8
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9861 - 9863
    • Joint observations with MAGIC? : No
    • ELOG link: [10]
    • Important comments: some clouds

• • 2022-10-25
    • Zenith range (deg): 43.6 -> 56
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9888 - 9891
    • Joint observations with MAGIC? : Yes
    • ELOG link: [11]
    • Important comments:

• • 2022-10-26
    • Zenith range (deg): 40 -> 56
    • Observation condition: dark
    • Observation mode: std wobble
    • Runs: 9917 - 9920
    • Joint observations with MAGIC? : Only run 9919
    • ELOG link: [12]
    • Important comments: run 9918,9919 are both in W2

• • 2022-10-28
    • Zenith range (deg): 36.04 -> 50.09
    • Observation condition: moon (first 3 runs) and dark
    • Observation mode: std wobble
    • Runs: 9956 - 9960
    • Joint observations with MAGIC? : yes
    • ELOG link: [13]
    • Important comments:

• • 2022-10-31
    • Zenith range (deg): 58
    • Observation condition: moon
    • Observation mode: std wobble
    • Runs: 10021
    • Joint observations with MAGIC? : yes
    • ELOG link: [14]
    • Important comments: calibration rate is zero, but Calibox is connected and firing

• • 2022-11-13
    • Zenith range (deg): 41->58
    • Observation condition: dark conditions
    • Observation mode: std wobble
    • Runs: 10501 - 10505
    • Joint observations with MAGIC? : no
    • ELOG link: [15]
    • Important comments: Structure in FAULT, BUSY spikes.

• • 2022-11-16
    • Zenith range (deg): 48->64
    • Observation condition: dark conditions
    • Observation mode: std wobble
    • Runs: 10611 - 10614
    • Joint observations with MAGIC? : yes
    • ELOG link: [16]
    • Important comments: Several spikes in rates. At 20:19, MAGIC stopped util 21:15.

• • 2022-11-17
    • Zenith range (deg): 43->65
    • Observation condition: dark conditions
    • Observation mode: std wobble
    • Runs: 10643 - 10650
    • Joint observations with MAGIC? : no for 10643, yes for the rest
    • ELOG link: [17]
    • Important comments: Several spikes in rates.

• • 2022-11-20
    • Zenith range (deg): 45->67
    • Observation condition: dark conditions
    • Observation mode: std wobble
    • Runs: 10892 - 10899
    • Joint observations with MAGIC? : yes
    • ELOG link: [18]
    • Important comments: Several car flashes (19:47, 19:58 and 20:58)

Fast check: Src-indep analysis by Kenta (Kyoto)

• Email address of analyser: terauchi.kenta.74s@st.kyoto-u.ac.jp

Data info

• Overall selected observation time: min ( h)
• Selected runs: 9604 - 9607
• Position analyzed: RA 288.26452 deg, Dec +19.77350 deg

DL1 data

Used DL1b files produced by LSTOSA (lstchain v0.9.6)

/fefs/aswg/data/real/DL1/20221010/v0.9/tailcut84/

DL2 data

• Random forest:

/fefs/aswg/data/models/AllSky/20220511_allsky_std/dec_2276

• lstchain v0.9.6 with config file taken from the All Sky model

/fefs/aswg/data/models/AllSky/20220511_allsky_std/dec_2276/lstchain_84.json

Theta2 plot

• Cuts and parameters used:
  • intensity > 100
  • gammaness > 0.6, 0.3
  • leakage < 0.2
  • Eest range: 0.3 - 10 TeV
  • th2 cut = 0.04
  • background normalization range: 0.2 < th2 < 0.4

1 OFF position; gammaness > 0.6; no background normalization

1 OFF position; gammaness > 0.6; background normalization applied

1 OFF position; gammaness > 0.3; no background normalization

1 OFF position; gammaness > 0.3; background normalization applied

Significance evolution

1 OFF position; gammaness > 0.6; with background normalization

1 OFF position; gammaness > 0.3; with background normalization

Detailed analysis

Related analysis pages

• Low-level reprocessing: strong moon condition

Source-dependent analysis

• Source-dependent analysis in strong moon condition

Source-independent analysis

• Source-independent analysis strong moon conditions
• Source-independent strong moon analysis results for discussion (not updated)
• Source-independent analysis dark conditions

Conferences

• HEPRO VIII GRB221009A analysis