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

LST Observations

Dates of data-taking: 2022-10-10,12,15-18,21,23-28
- 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: [1]
  - 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: [2]
  - 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: [3]
  - 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: [4]
  - 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: [5]
  - 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: [6]
  - 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: [7]
  - 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: [8]
  - 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: [9]
  - 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: [10]
  - Important comments: some clouds

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