SearcharxivSearch

arXiv · 0706.1544

Novel technique for monitoring the performance of the LAT instrument on board the GLAST satellite

Abstract

The Gamma-ray Large Area Space Telescope (GLAST) is an observatory designed to perform gamma-ray astronomy in the energy range 20 MeV to 300 GeV, with supporting measurements for gamma-ray bursts from 10 keV to 25 MeV. GLAST will be launched at the end of 2007, opening a new and important window on a wide variety of high energy astrophysical phenomena . The main instrument of GLAST is the Large Area Telescope (LAT), which provides break-through high-energy measurements using techniques typically used in particle detectors for collider experiments. The LAT consists of 16 identical towers in a four-by-four grid, each one containing a pair conversion tracker and a hodoscopic crystal calorimeter, all covered by a segmented plastic scintillator anti-coincidence shield. The scientific return of the instrument depends very much on how accurately we know its performance, and how well we can monitor it and correct potential problems promptly. We report on a novel technique that we are developing to help in the characterization and monitoring of LAT by using the power of classification trees to pinpoint in a short time potential problems in the recorded data. The same technique could also be used to evaluate the effect on the overall LAT performance produced by potential instrumental problems.

Explore related subjects

Keep this discovery

BibTeXRIS

D. Paneque, A. Borgland, A. Bovier, E. Bloom, Y. Edmonds, S. Funk, G. Godfrey, R. Rando, L. Wai, P. Wang. 2007-06-11. Novel technique for monitoring the performance of the LAT instrument on board the GLAST satellite. https://doi.org/10.1063/1.2757452

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

A Computer Program to Visualize Gravitational Lenses

Gravitational lenses are presently playing an important role in astrophysics. By means of these lenses the parameters of the deflector such as its mass, ellipticity, etc. and Hubble's constant can be determined. Using C, Xforms, Mesa and Imlib a computer program to visualize this lens effect has been developed. This program has been applied to generate sequences of images of a source object and its corresponding images. It has also been used to visually test different models of gravitational lenses.

astro-ph

2MTF I. The Tully-Fisher Relation in the 2MASS J, H and K Bands

The 2 Micron All-Sky Survey (2MASS) Tully-Fisher Survey (2MTF) aims to measure Tully-Fisher (TF) distances to all bright inclined spirals in the 2MASS Redshift Survey (2MRS). Essential to this project is a universal calibration of the TF relation in the 2MASS J (1.2 um), H (1.6 um) and K (2.2 um) bands. We present the first bias corrected or universal TF template in these bands. We find that the slope of the TF relation becomes steeper as the wavelength increases being close to L \propto v^4 in K-band and L \propto v^3.6 in J and H-bands. We also investigate the dependence on galaxy morphology showing that in all three bands the relation is steeper for later type spirals which also have a dimmer TF zeropoint than earlier type spirals. We correct the final relation to that for Sc galaxies. Finally we study the scatter from the TF relation fitting for a width dependent intrinsic scatter which is not found to vary significantly with wavelength.

astro-ph

Effect of Peculiar Motion in Weak Lensing

We study the effect of peculiar motion in weak gravitational lensing. We derive a fully relativistic formula for the cosmic shear and the convergence in a perturbed Friedmann Universe. We find a new contribution related to galaxies peculiar velocity. This contribution does not affect cosmic shear in a measurable way, since it is of second order in the velocity. However, its effect on the convergence (and consequently on the magnification, which is a measurable quantity) is important, especially for redshifts z < 1. As a consequence, peculiar motion modifies also the relation between the shear and the convergence.

astro-ph