Fast offline analysis GRB240811A August 2024 P067

General information

• Name of the source: GRB240811A
• Brief description of the source:
  • Object type : GRB
  • Redshift (z) : ?
  • Other relevant information
  • RA, Dec in deg (ICRS): 226.3622, 28.8957
• Analysis by:
  • Ryuji Takeishi (ICRR - take@icrr.u-tokyo.ac.jp)

Data-taking information

• Dates of data-taking: 2024-08-11
  • • ZD range (deg): --> 30-50 deg
    • AZ range (deg): -->
    • Transmission9km:
    • Observation condition: moon
    • Observation mode: std wobbles
    • Observations:

'2024-08-11': [18574, 18575, 18576, 18577, 18578] 1.84 h

• Data quality selection: Almost runs did not survive the default dR/dI@442pe limit of 1.5. Likely due to high dust concentration. Since almost runs exceed dark NSB limit, we did both analyses with dark NSB MC and high NSB image cleaning MC.
• Joint observations with MAGIC? : yes
• Information on data-taking (observations summaries): https://www.lst1.iac.es/datacheck/observation_overview/2024/08/run_summary_2024_08_11.pdf

General analysis information

• source-independent analysis
• lstchain version: v0.10.11
• DL1b standard production (v0.10/tailcut84), run-wise merged files in:

/fefs/aswg/data/real/DL1/20240811/v0.10/tailcut84/dl1_LST-1.Run18574.h5
/fefs/aswg/data/real/DL1/20240811/v0.10/tailcut84/dl1_LST-1.Run18575.h5
/fefs/aswg/data/real/DL1/20240811/v0.10/tailcut84/dl1_LST-1.Run18576.h5
/fefs/aswg/data/real/DL1/20240811/v0.10/tailcut84/dl1_LST-1.Run18577.h5
/fefs/aswg/data/real/DL1/20240811/v0.10/tailcut84/dl1_LST-1.Run18578.h5

Monte Carlo information

Write below the MC production id among the existing MC

• All-sky MC production used: 20240131_allsky_v0.10.5_all_dec_base
  • Declination line (training): dec_3476

High-NSB analysis:

• All-sky MC production used: 20240229_dec34_nsb14
  • Declination line (training): dec_3476

Random forest

Path to the models used:

/fefs/aswg/data/models/AllSky/20240131_allsky_v0.10.5_all_dec_base/dec_3476

High-NSB analysis:

/fefs/aswg/data/models/AllSky/20240229_dec34_nsb14/dec_3476

DL2 data

Config file (standard):

/fefs/aswg/data/models/AllSky/20240131_allsky_v0.10.5_all_dec_base/dec_3476/lstchain_config_2024-01-31.json

Config file (high-nsb):

/fefs/aswg/data/models/AllSky/20240229_dec34_nsb14/dec_3476/llstchain_config_2024-02-29.json

Files in:

/fefs/aswg/workspace/ryuji.takeishi/FOA/GRB240811A/DL2
/fefs/aswg/workspace/ryuji.takeishi/FOA/GRB240811A/NSB14/DL2

DL3 data & IRF

 "EventSelector": {
   "filters": {
     "intensity": [50, Infinity],
     "width": [0, Infinity],
     "length": [0, Infinity],
     "r": [0, 1],
     "wl": [0.01, 1],
     "leakage_intensity_width_2": [0, 1],
     "event_type": [32, 32]
   }
 },
 "DL3Cuts": {
   "min_event_p_en_bin": 100,
   "min_gh_cut": 0.1,
   "max_gh_cut": 0.98,
   "min_theta_cut": 0.1,
   "max_theta_cut": 0.32,
   "fill_theta_cut": 0.32,
   "allowed_tels": [1]
 },

• 70 % efficiency for both gammaness and theta gamma-ray selection cuts
• Point-like IRF

Files in:

/fefs/aswg/workspace/ryuji.takeishi/FOA/GRB240811A/DL3
/fefs/aswg/workspace/ryuji.takeishi/FOA/GRB240811A/NSB14/DL3

High-level analysis

• Gammapy 1.1
• 1D analysis (point-like IRF)

Analysis Results

Theta2 plot

Settings:

• Theta2 cut for signal extraction: 0.04 deg2
• Normalization range: 0.1 - 0.4 deg2
• Number of off positions: 3
• Energy range: 100 GeV - 10 TeV

Daily results

Dark NSB image cleaning: No detection

High NSB image cleaning: No detection 500 px