Informatics Publishing Limited

M. C. Ramadevi ¹, S. Seetha ², Dipankar Bhattacharya ³, B. T. Ravishankar ¹, N. Sitaramamurthy ¹, G. Meena ¹, M. Ramakrishna Sharma ¹, Ravi Kulkarni ¹, V. Chandra Babu ¹, Kumar ¹, Brajpal Singh ¹, Anand Jain ¹, Reena Yadav ¹, S. Vaishali ¹, B. N. Ashoka ¹, Anil Agarwal ¹, K. Balaji ⁴, Manoj Kumar ⁵, Prashanth Kulshresta ⁵, Pankaj Agarwal ⁶, Mathew Sebastian ⁶

Affiliations
1 Space Astronomy Group, SSIF, ISITE Campus, Karthik Nagar, Outer Ring Road, ISRO Satellite Centre, Bengaluru 560 037, IN
2 Indian Space Research Organisation Headquarters, Department of Space, Antariksh Bhavan, New BEL Road, Bengaluru 560 231, IN
3 Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411 007, IN
4 Spacecraft Mechanisms Group, ISAC, Old Airport Road, Vimanapura Post, Bengaluru 560 017, IN
5 Control and Digital Electronics Group, ISAC, Old Airport Road, Vimanapura Post, Bengaluru 560 017, IN
6 Vikram Sarabhai Space Center, Thiruvananthapuram 695 022, IN

Abstract

Scanning Sky Monitor (SSM) on-board AstroSat is a wide-field imager to monitor the X-ray sky in the energy band 2.5-10 keV. The primary science objective of SSM is to detect and locate transient X-ray sources in the sky. Once detected the information is to be provided to the astronomical community for follow-up observations to do a more detailed study of the source. Long-term monitoring of known X-ray transient sources is also one of the science objectives of SSM. The instrument constitutes three units of 1D positionsensitive propotional counters with coded masks on each, all three mounted on a platform capable of rotation to scan about 50% of the sky in one full rotation. The angular resolution of each unit in SSM is 12' x 2.5°. Sensitivity of SSM is ~30 milliCrab at 3 sigma in 10 min integration time. This article briefly discusses the instrument and a few early results since the launch of AstroSat.

Keywords

AstroSat, Crab, Scanning Sky Monitor, X-Ray Transient Sources.

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