Geminga

General information

• Name of the source: Geminga
• Brief description of the source: Radio-quiet middle-aged gamma-ray pulsar
  • Object type : Pulsar
  • Other relevant information: Third pulsar detected by IACTs
  • RA: 06 33 54.15 (hh mm ss), Dec: +17 46 12.9 (dd mm ss)
  • RA, Dec in deg (ICRS): 98.48 17.77
  • Galactic coordinates: l=195.13 b=+04.27

People involved

• Álvaro Mas-Aguilar (alvmas@ucm.es)
• Marcos López-Moya (marcos@gae.ucm.es)
• Giulia Brunelli (giulia.brunelli@inaf.it)
• Rubén López-Coto (rlopezcoto@iaa.es)
• Giovanni Ceribella (ceribell@mpp.mpg.de)
• Paul K. H. Yeung (pkh91yg@icrr.u-tokyo.ac.jp)

Data-taking information

Geminga has been observed with standard wobble observations (offset = 0.4 deg), in dark and good weather conditions:

• TNG dust < 0.5 ug/m3
• No clouds both from satellite images and all sky camera
• Rate_LL around 5.5 kHz
• Lidar trans@9km >= 0.85

Runs per each day

• 2022

 20-12-2022: [11533 11534 11535 11536 11537 11538 11539 11540 11541]
 22-12-2022: [11580 11581 11582 11583 11584 11585]

• 2023

 14-01-2023: [11645 11646 11647 11648]
 15-01-2023: [11664 11665 11666]
 17-01-2023: [11693 11694 11695 11696 11697 11698]
 18-01-2023: [11715]
 20-01-2023: [11732 11733 11734 11735 11736 11737]
 21-01-2023: [11761 11762]
 24-01-2023: [11818 11819 11820 11821 11822 11823 11824 11825]
 25-01-2023: [11850 11851 11852 11853 11854 11855]
 26-01-2023: [11884 11885 11886 11887]
 28-01-2023: [11950 11951 11952]
 11-02-2023: [11959 11960]
 13-02-2023: [11972 11973 11974 11975 11976]
 14-02-2023: [11983 11984 11985 11986 11987 11988 11989]
 18-02-2023: [11998]
 20-02-2023: [12018 12019 12020 12021 12022 12023 12024]
 22-02-2023: [12041 12042 12043 12044]
 24-02-2023: [12070 12071 12072 12073 12074]
 10-03-2023: [12139 12141]
 13-03-2023: [12152 12153 12154 12155 12156 12157 12158 12159 12160]
 15-03-2023: [12178 12179 12180 12181]
 16-03-2023: [12197 12198 12199 12200 12201]
 18-03-2023: [12248 12249 12250 12251 12252 12253]
 19-03-2023: [12283 12284 12285 12286 12287 12288]
 21-03-2023: [12340 12341 12342 12343 12344]
 22-03-2023: [12373 12374 12375 12376 12377]
 23-03-2023: [12385 12386]
 24-03-2023: [12415 12416 12417 12418 12419 12420 12421]
 07-12-2023: [15867 15868 15869 15870 15871 15872]
 08-12-2023: [15899 15900 15901 15902 15903 15904 15905 15906 15907]
 09-12-2023: [15931 15932 15933 15934 15935 15936 15937 15938 15939]
 10-12-2023: [15960 15961 15962 15963 15964 15965 15966 15967 15968]
 12-12-2023: [16029 16030 16031 16032 16033 16034 16035 16036 16037]
 13-12-2023: [16067 16068]
 14-12-2023: [16100 16101 16102 16103 16104 16105 16106 16107 16108 16109]
 15-12-2023: [16138 16139 16140 16141 16142 16143 16144 16145 16146]
 17-12-2023: [16210 16211 16212 16213 16214 16215]
 18-12-2023: [16232 16233 16234 16235]
 19-12-2023: [16252 16253 16254]

• 2024

 09-01-2024: [16282 16283 16284]
 10-01-2024: [16310 16311]
 14-01-2024: [16370 16371 16372 16373 16374 16375 16376]
 01-02-2024: [16459 16460 16461 16462 16463 16464 16465 16466 16467 16468]
 04-02-2024: [16549 16550 16551 16552 16553 16554 16555]
 05-02-2024: [16578 16579 16580 16581]
 06-02-2024: [16584 16585 16586 16588 16589]
 11-02-2024: [16700 16701 16702 16703 16704 16705 16706 16707 16708 16709]

Total observational time without any selection: 79.25h

The quality selection was based on the differential intensity spectra of the detected showers, dR/dI (events/s/p.e.), see reference notebook here. A zenith cut Zd<50deg was also applied.

Final list of selected runs:

[11533, 11534, 11535, 11536, 11537, 11538, 11539, 11580, 11581, 11582, 11583, 11584, 11585, 11645, 11646, 11647, 11648, 11664, 11665, 11666,
 11693, 11694, 11695, 11696, 11697, 11698, 11715, 11732, 11733, 11734, 11735, 11736, 11737, 11761, 11762, 11818, 11819, 11820, 11821, 11822,
 11823, 11824, 11825, 11850, 11851, 11852, 11853, 11854, 11855, 11884, 11885, 11886, 11887, 11950, 11959, 11960, 11972, 11973, 11974, 11976,
 11983, 11984, 11985, 11986, 11987, 11988, 11989, 12018, 12041, 12042, 12043, 12044, 12139, 12141, 12152, 12153, 12154, 12155, 12156, 12157,
 12158, 12159, 12197, 12198, 12199, 12200, 12201, 12248, 12249, 12250, 12251, 12252, 12283, 12284, 12285, 12286, 12287, 12288, 12340, 12341,
 12342, 12343, 15867, 15868, 15869, 15870, 15871, 15872, 15899, 15900, 15901, 15902, 15903, 15904, 15905, 15906, 15907, 15931, 15932, 15933,
 15934, 15935, 15936, 15937, 15938, 15961, 15962, 15963, 15964, 15965, 15966, 15967, 15968, 16029, 16030, 16031, 16032, 16033, 16034, 16035,
 16036, 16037, 16067, 16068, 16100, 16101, 16102, 16103, 16104, 16105, 16106, 16107, 16108, 16109, 16138, 16139, 16140, 16141, 16142, 16143,
 16144, 16145, 16146, 16210, 16211, 16212, 16213, 16214, 16215, 16232, 16233, 16234, 16235, 16282, 16283, 16284, 16459, 16460, 16461, 16462,
 16463, 16465, 16466, 16467, 16468, 16549, 16550, 16551, 16552, 16553, 16554, 16579, 16580, 16584, 16586, 16588, 16589, 16700, 16701, 16702,
 16703, 16704, 16705, 16706, 16707, 16708]

Total good-quality observational time: 60.1h

Data analysis

Low-level analysis

Software version used: lstchain v0.10.7

Approach: source-dependent

DL1 to DL2

The analysis started from the DL1a files produced by LSTOSA:

/fefs/aswg/data/real/DL1/20*/v0.10/tailcut84/dl1*.h5

A dedicated source-dependent production of Monte Carlo data was required (see here). The MCs were produces at dec=22.76deg and with NSB tuned on Geminga. The corresponding RF models used for the DL2 production were stored in:

/fefs/aswg/data/models/AllSky/20240126_v0.10.4_src6_dec2276_tuned/dec_2276/

Path to the DL2 files:

/fefs/aswg/workspace/giulia.brunelli/data/real/Geminga/src_dependent_v0.10/DL2/ 

DL2 to IRF

The corresponding MC Testing Dataset was used for the IRF production:

/fefs/aswg/data/mc/DL2/AllSky/20240126_v0.10.4_src6_dec2276_tuned/TestingDataset/dec_2276/

The point-like IRFs were computed using a linear interpolation, with the following cuts

• gh-efficiency=70%
• alpha-containment=70%
• intensity > 50 p.e.

specified in the configuration file

/fefs/aswg/workspace/giulia.brunelli/data/real/Geminga/src_dependent_v0.10/irf_tool_config.json

Path to the IRFs:

/fefs/aswg/workspace/giulia.brunelli/data/real/Geminga/src_dependent_v0.10/IRFs/

DL2 to DL3

The same configuration file was used for the DL3 production.

Path to the DL3 files:

/fefs/aswg/workspace/giulia.brunelli/data/real/Geminga/src_dependent_v0.10/DL3/