GRB221218A

Alert Information

• Name/type of the alert:
• GCN notice: [1]
• Triggered by: INTEGRAL
• Alert coordinates:
  • RA: +23 22 36 (hh mm ss), Dec: -04 15 38 (dd mm ss)
  • RA, Dec in deg (ICRS): 350.65deg, -4.26deg
• Alert arrival time: 2022-12-18T08:14:36UTC
• Other relevant information:
  • Redshift (z):

LST Observations

• Dates of data-taking: 2022-12-18
  • 2022-12-18
    • Zenith range (deg): 35 --> 53
    • Transmission9km: N.A. (lidar not working)
    • Observation condition: dark
    • Observation mode: std wobbles
    • Runs: 11448 - 11454
    • Joint observations with MAGIC? : yes
    • ELOG link:[2]
    • Important comments:

Analysis by Irene Burelli (University of Udine - irene.burelli@gmail.com)

Data-taking information

• Overall selected observation time: 127.2 min
• Selected runs: 10884 -> 10889
• Position analyzed: RA 350.65deg, Dec -4.26deg

DL1 data

Used DL1b files produced by LSTOSA

/fefs/aswg/data/real/DL1/20221218/v0.9/tailcut84/

DL2 data

• Random forest:

/fefs/aswg/data/models/20200629_prod5_trans_80/zenith_40deg/south_pointing/20220304_v0.9.3_prod5_trans_80_zen40az180_local_tailcut_8_4

• lstchain v0.9.6 with config file

/fefs/aswg/data/real/DL1/20210809/v0.9/tailcut84/log/lstchain_config_tailcut84_v092.json

Theta2 plot from DL2

• Cuts and parameters used:
  • intensity > 50
  • gammaness > 0.7
  • Theta2_global_cut=0.04
  • leakage < 0.2
  • norm_range_theta2_min=0.3
  • norm_range_theta2_max=0.5

Theta2 plot for GRB221218A.