GRB240502A

Alert Information

• Name/type of the alert:
• GCN notice: [1]
• Triggered by: INTEGRAL
• Alert coordinates:
  • RA: 7 34 30.96 (hh mm ss), Dec: 16 43 27.48 (dd mm ss)
  • RA, Dec in deg (ICRS): 113.629deg, 16.7243deg
• Alert arrival time: 2024-05-02 05:28:47UTC
• Other relevant information:
  • Redshift (z): not available

LST Observations

• Dates of data-taking: 2024-05-02
  • 2024-05-102
    • Zenith range (deg): 48 --> 70
    • Transmission9km: tbd
    • Observation condition: moon and dark
    • Observation mode: std wobbles
    • Runs: 17225 - 17233
    • Joint observations with MAGIC? : yes (17225-17229)
    • ELOG link:[ http://www.lst1.iac.es/elog/LST+commissioning/3347]
    • Important comments: first run (17225) interrupted due Calibox issue

General information

• Name of the source: GRB 240502A
• Brief description of the source:
  • Object type : GRB
  • Redshift (z) : ?
  • Other relevant information
  • RA: 7 34 30.960 (hh mm ss), Dec: +16 43 27.480 (dd mm ss)
  • RA, Dec in deg (ICRS): 113.629, 16.7243

• Analysis by:
  • Irene Jiménez Martínez (MPP - irenejm@mpp.mpg.de or irene.jimenez@cta-consortium.org)

Data-taking information

• Dates of data-taking:
  • Date (time of observation h)
    • ZD range (deg): 46 - 70 deg
    • AZ range (deg): 266 - 278 deg
    • Transmission9km:
    • Observations:

'2024-05-02': [17225 , 17226 , 17227, 17228, 17229, 17230, 17231, 17232, 17233] 1.7 h (no cuts)

600 px

• Data quality selection applied on above data sample: run 17225 was interrupted due to Calibox issue. Run 17230 was missing in RTA. DTs changed to medium after run 17233. Data quality selection could not be performed due to problem with run summary. Got errors for runs 17227 and 17231: Effective area is all zero at [113d37m44.4s 16d43m27.48s]. No safe energy band can be defined for the dataset '17227': setting `mask_safe` to all False. and Effective area is all zero at [113d37m44.4s 16d43m27.48s]. No safe energy band can be defined for the dataset '17231': setting `mask_safe` to all False.
• Joint observations with MAGIC? : Yes for runs 17225-17229, no for runs 17230-17233.
• Information on data-taking (observations summaries): https://www.lst1.iac.es/datacheck/observation_overview/2024/05/run_summary_2024_05_02.pdf

General analysis information

• source-independent analysis
• lstchain version: v0.10.7 (software school)
• DL1b standard production (v0.10/tailcut84), run-wise merged files in:

/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17225.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17226.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17227.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17228.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17229.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17230.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17231.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17232.h5
/fefs/aswg/data/real/DL1/20240502/v0.10/tailcut84/dl1_LST-1.Run17233.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_2276

Random forest

Path to the models used:

/fefs/aswg/data/models/AllSky/20240131_allsky_v0.10.5_all_dec_base/dec_2276

DL2 data

Config file:

/fefs/aswg/data/models/AllSky/20240131_allsky_v0.10.5_all_dec_base/dec_2276/lstchain_config_2024-01-31.json

Files in:

/fefs/aswg/workspace/irene.jimenez/FOA/GRB240502A_20240502_data/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

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

Stacked observations

• 2024-05-02

Spectral results

• 2024-05-02

Spectral parameters: PL , DO NOT TRUST (low signal, see LC for the full night)

  type      name         value         unit        error       min     max frozen is_norm link
--------  ----------  ----------  --------------  --------- ---------  --- ------ ------- ----
spectral       index  2.1595e+00                  6.359e-01       nan  nan  False   False 
spectral   amplitude  1.9915e-11  TeV-1 s-1 cm-2  3.235e-11       nan  nan  False    True  
spectral   reference  3.0000e+02             TeV  0.000e+00       nan  nan   True   False 

Integral flux E > 100 GeV: 5.5179e-05 s-1 cm-2 DO NOT TRUST (low signal, see LC for the full night)

DO NOT TRUST (low signal, see LC for full night):

Light curve

• 2024-05-02

LC for the full night: