GRB220521A

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Alert Information

• Name/type of the alert:
• GCN notice: link
• Triggered by: Swift BAT
• Alert coordinates:
  • RA: 18h 20m 47.184s, Dec: +10d 23' 3.480
  • RA, Dec in deg (ICRS): 275.19660 deg, 10.38430 deg
• Alert arrival time: 23:20:36 UTC
• Other relevant information:
  • Redshift (z): 5.6

Multi-wavelength Observations

Timeline

T0+	Instrument	Outcome	Outcome specific value (flux/UL/...)	Comment	Link
-		Initial detection
		UL
		Detection

LST Observations

• Dates of data-taking: 2022-05-21
  • 2022-05-21
    • Zenith range (deg): 65 --> 70
    • Transmission9km:
    • Observation condition: dark & moonlight
    • Observation mode: std wobbles
    • Runs: 8392 - 8403
    • Joint observations with MAGIC? : No
    • ELOG link: link
    • Important comments: run 8393, 8394, 8400 and 8401 are useless. In 8394 telescope was not tracking. Starting from 8399 is moon conditions.

Analysis by Alice (INAF)

Data-taking information

• Overall selected observation time:
• Selected runs:
• Position analyzed: RA, Dec

Monte Carlo information

• Link to MC files used:
  • Particle types:

DL1 data

Please include your settings to produce your DL1a and DL1b files. This includes whether you use LSTOSA, specific versions of lstchain, dllab scripts, cleaning levels, and calibration information.

Example :

Reprocessed using DL1a files produced by LSTOSA (lstchain v0.7.3) and dl1ab script (v0.7.5)

• original DL1a files

/fefs/aswg/data/real/DL1/20210808/v0.7.3/tailcut84/dl1_LST-1.Run0XXXX.XXXX.h5
/fefs/aswg/data/mc/DL1/20200629_prod5_trans_80/XXX/zenith_20deg/south_pointing/20210416_v0.7.3_prod5_trans_80_local_taicut_8_4/

• real data: tailcut8-4 (with cleaning based on pedestal RMS), dynamic cleaning

 /fefs/aswg/workspace/seiya.nozaki/data/BLLac/v0.7.3/tailcut84_dynamic_v075/DL1_raw/lstchain_standard_config.json

• MC: tailcut8-4 (with cleaning based on pedestal RMS), dynamic cleaning, PSF+NSB tuning

 "image_modifier": {
   "increase_nsb": true,
   "extra_noise_in_dim_pixels": 0.74,
   "extra_bias_in_dim_pixels": 0.38,
   "transition_charge": 8,
   "extra_noise_in_bright_pixels": 0.052,
   "increase_psf": true,
   "smeared_light_fraction": 0.125
 },

 /fefs/aswg/workspace/seiya.nozaki/data/MC/v0.7.5/tailcut84_dynamic_bllac/DL1_raw/lstchain_dl1ab_tune_MC_to_BLLac_config.json

• Produced DL1b files

/fefs/aswg/workspace/seiya.nozaki/data/MC/v0.7.5/tailcut84_dynamic_bllac/DL1_raw/data/
/fefs/aswg/workspace/seiya.nozaki/data/BLLac/v0.7.3/tailcut84_dynamic_v075/DL1_raw/Run0XXXX

Random forest

Please include the path to the RF files used or your specific .json files used in producing your RFs and for which source analysis (source dependent or independent), and variables used in the RF.

Example

• lstchain-0.7.6.dev242+g2086cb9

• source-indep (diffuse gamma, src_r<3deg, disp_norm)

/fefs/aswg/workspace/seiya.nozaki/data/MC/v0.7.5/tailcut84_dynamic_bllac/srcindep/RF/lstchain_standard_config.json

• source-dep

/fefs/aswg/workspace/seiya.nozaki/data/MC/v0.7.5/tailcut84_dynamic_bllac/srcdep/RF/lstchain_src_dep_config.json

DL2 data

Information about your DL2 data and settings such as: specifc versions of lstchain, specfic .json version used.

Example:

• lstchain-0.7.6.dev242+g2086cb9

• source-indep

/fefs/aswg/workspace/seiya.nozaki/data/MC/v0.7.5/tailcut84_dynamic_bllac/srcindep/DL2/data/
/fefs/aswg/workspace/seiya.nozaki/data/BLLac/v0.7.3/tailcut84_dynamic_v075/srcindep/DL2/data/dl2_LST-1.Run0XXXX_merged.h5

• source-dep

/fefs/aswg/workspace/seiya.nozaki/data/MC/v0.7.5/tailcut84_dynamic_bllac/srcdep/DL2/data/ 
/fefs/aswg/workspace/seiya.nozaki/data/BLLac/v0.7.3/tailcut84_dynamic_v075/srcdep/DL2/data/dl2_LST-1.Run0XXXX_merged.h5

DL3 data selection

Information about your DL3 data selection.

Example

• intensity > 50
• r: [0, 1 ]
• wl: [0.1, 1 ]
• leakage_intensity_width_2: [0, 0.2 ]

• source-indep
  • fixed_gh_cut: 0.3
  • fixed_theta_cut: 0.2

• source-dep
  • fixed_gh_cut: 0.7
  • fixed_alpha_cut: 10

High-level analysis

Please put any information about the production of higher level analysis here.

Example

• Science Tool: gammapy 0.18.2
• Point-like IRF, 1D analysis

Analysis Results

Please place higher-level analysis results (Spectra, SkyMaps, Lightcurves, etc) here. If the alert was observed for several nights please add plots for each night separately and all data together.