Measurement of background radiations and spectra of X-ray sources using low-cost stratospheric balloon missions

Abstract

In small balloon missions, some in situ radiation is added to the targeted strong persistent astronomical sources (such as, the Sun, Crab, Cygnus X-1, etc.) or transient sources, such as solar flares, gamma-ray bursts, etc., during their detection, i.e., the background radiation. For measurement and modeling of background radiation, we use the data of the low-cost, small, stratospheric, high-altitude balloon-borne missions conducted by Indian Centre for Space Physics. In this paper, we show several models to estimate the background counts where the strong X-ray sources are detected at the altitude range of $\sim 35\text{–}42$ km even in the absence of onboard pointing system and severe atmospheric absorption. For all data analysis purposes, the photons detected in the detector are in the energy range of $10\text{–}80$ keV. Moreover, we found that the observed data is within $\pm 1\sigma$ of the calculated background model. Finally, using these background models, we estimate the spectra and luminosity of the Crab nebula and the black hole candidate Cygnus X-1, which agree with the previously published results.