The on-orbit calibration of the Fermi Large Area Telescope

Journal Article · Sun Sep 06 00:00:00 EDT 2009 · Astroparticle Physics

DOI:https://doi.org/10.1016/j.astropartphys.2009.08.002· OSTI ID:1357429

Abdo, A. A.; Ackermann, M.; Ajello, M.; Ampe, J.; Anderson, B.; Atwood, W. B.; Axelsson, M.; Bagagli, R.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bartelt, J.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bédérède, D.; Bellardi, F.; Bellazzini, R.; Belli, F.; Berenji, B. ; Bisello, D.; Bissaldi, E.; Bloom, E. D.; Bogaert, G.; Bogart, J. R.; Bonamente, E.; Borgland, A. W.; Bourgeois, P.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Busetto, G.; Caliandro, G. A.; Cameron, R. A.; Campell, M.; Caraveo, P. A.; Carius, S.; Carlson, P.; Casandjian, J. M.; Cavazzuti, E.; Ceccanti, M.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chipaux, R.; Cillis, A. N.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Condamoor, S.; Conrad, J.; Corbet, R.; Cutini, S.; Davis, D. S.; DeKlotz, M.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Digel, S. W.; Dizon, P.; Dormody, M.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Edmonds, Y.; Fabiani, D.; Farnier, C.; Favuzzi, C.; Ferrara, E. C.; Ferreira, O.; Fewtrell, Z.; Flath, D. L.; Fleury, P.; Focke, W. B.; Fouts, K.; Frailis, M.; Freytag, D.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Goodman, J.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hakimi, M.; Haller, G.; Hanabata, Y.; Hart, P. A.; Hascall, P.; Hays, E.; Huffer, M.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kavelaars, A.; Kelly, H.; Kerr, M.; Klamra, W.; Knödlseder, J.; Kocian, M. L.; Kuehn, F.; Kuss, M.; Latronico, L.; Lavalley, C.; Leas, B.; Lee, B.; Lee, S. -H.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Lung, D. K.; Madejski, G. M.; Makeev, A.; Marangelli, B.; Marchetti, M.; Massai, M. M.; May, D.; Mazzenga, G.; Mazziotta, M. N.; McEnery, J. E.; McGlynn, S.; Meurer, C.; Michelson, P. F.; Minuti, M.; Mirizzi, N.; Mitra, P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nelson, D.; Nilsson, L.; Nishino, S.; Nolan, P. L.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paccagnella, A.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Picozza, P.; Pinchera, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Rapposelli, E.; Raynor, W.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Reyes, L. C.; Ritz, S.; Robinson, S.; Rochester, L. S.; Rodriguez, A. Y.; Romani, R. W.; Roth, M.; Ryde, F.; Sacchetti, A.; Sadrozinski, H. F. -W.; Saggini, N.; Sanchez, D.; Sander, A.; Sapozhnikov, L.; Saxton, O. H.; Saz Parkinson, P. M.; Sellerholm, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, J. -L.; Stephens, T. E.; Strickman, M. S.; Strong, A. W.; Sugizaki, M.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Tenze, A.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Turri, M.; Usher, T. L.; Vilchez, N.; Virmani, N.; Vitale, V.; Wai, L. L.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, D. L.; Wood, K. S.; Yasuda, H.; Ylinen, T.; Ziegler, M.

The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope began its on-orbit operations on June 23, 2008. Calibrations, defined in a generic sense, correspond to synchronization of trigger signals, optimization of delays for latching data, determination of detector thresholds, gains and responses, evaluation of the perimeter of the South Atlantic Anomaly (SAA), measurements of live time, of absolute time, and internal and spacecraft boresight alignments. Here in this work, we describe on-orbit calibration results obtained using known astrophysical sources, galactic cosmic rays, and charge injection into the front-end electronics of each detector. Instrument response functions will be described in a separate publication. This paper demonstrates the stability of calibrations and describes minor changes observed since launch. Lastly, these results have been used to calibrate the LAT datasets to be publicly released in August 2009.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Contributing Organization: Fermi LAT Collaboration
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1357429
• Journal Information: Astroparticle Physics, Vol. 32, Issue 3-4; ISSN 0927-6505
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
GLAST
Fermi
FGST
LAT
Telescope
Gamma-ray
Calibrations