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arXiv · 2205.03136

Improved background model for the Large Area X-ray Proportional Counter (LAXPC) instrument on-board AstroSat

H. M. Antia·P. C. Agrawal·Tilak Katoch·R. K. Manchanda·Kallol Mukerjee·Parag Shah
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Abstract

We present an improved background model for the Large Area X-ray Proportional Counter (LAXPC) detectors on-board AstroSat. Because of the large collecting area and high pressure, the LAXPC instrument has a large background count rate, which varies during the orbit. Apart from the variation with latitude and longitude during the orbit there is a prominent quasi-diurnal variation which has not been modelled earlier. Using over 5 years of background observations, we determined the period of the quasi-diurnal variation to be 84495 s and using this period, it is possible to account for the variation and also identify time intervals where the fit is not good. These lead to a significant improvement in the background model. The quasi-diurnal variation can be ascribed to the changes in charged particle flux in the near Earth orbit.

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H. M. Antia, P. C. Agrawal, Tilak Katoch, R. K. Manchanda, Kallol Mukerjee, Parag Shah. 2022-05-06. Improved background model for the Large Area X-ray Proportional Counter (LAXPC) instrument on-board AstroSat. https://doi.org/10.3847/1538-4365/ac6dd0

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