63 citations · 407 across the 35 of their papers we have counts for
36 papers
Can We Find the Emission Mechanism Behind the Extremely Bright GRB 230812B?
Utkarsh Pathak, Sameer K. Patil, Hitesh Tanenia +23
GRB 230812B is a bright long-duration GRB with a luminous, long-lived afterglow and an AstroSat/CZTI polarization measurement during the prompt phase, enabling a joint study of its…
Development of a one-dimensional position sensitive detector for Compton X-ray polarimeters
Abhay Kumar, Santosh V. Vadawale, N. P. S. Mithun +4
The scientific potential of X-ray polarimetry has long been recognized, but the challenges in measuring polarization have left it largely unexplored, particularly in the hard X-ray…
Spectro-polarimetry of GRB 180427A: evidence for distinct emission sites with varying polarisation
Rushikesh Sonawane, Shabnam Iyyani, Soumya Gupta +5
The dynamics of the origin of gamma-ray emissions in gamma-ray bursts (GRBs) remains an enigma. Through a joint analysis of GRB 180427A, observed by the Fermi Gamma-ray Space Teles…
Localisation of Gamma Ray Bursts using AstroSat Mass Model
Divita Saraogi, J Venkata Aditya, Varun Bhalerao +12
The Cadmium Zinc Telluride Imager (CZTI) aboard AstroSat has good sensitivity to Gamma Ray Bursts (GRBs), with close to 600 detections including about 50 discoveries undetected by…
The high-speed X-ray camera on AXIS
Eric D. Miller, Marshall W. Bautz, Catherine E. Grant +15
AXIS is a Probe-class mission concept that will provide high-throughput, high-spatial-resolution X-ray spectral imaging, enabling transformative studies of high-energy astrophysica…
High hard X-ray polarization in Cygnus X-1 confined to the intermediate hard state: evidence for a variable jet component
Tanmoy Chattopadhyay, Abhay Kumar, A. R. Rao +7
Cygnus X-1, the well-known accreting black hole system, exhibits several observational features hinting at an intricate interplay between the accretion disk, its atmosphere known a…
Demonstrating repetitive non-destructive readout (RNDR) with SiSeRO devices
Tanmoy Chattopadhyay, Sven Herrmann, Peter Orel +9
We demonstrate so-called repetitive non-destructive readout (RNDR) for the first time on a Single electron Sensitive Readout (SiSeRO) device. SiSeRO is a novel on-chip charge detec…
Improved noise performance from the next-generation buried-channel p-Mosfet SiSeROs
Tanmoy Chattopadhyay, Sven Herrmann, Matthew Kaplan +9
The Single electron Sensitive Read Out (SiSeRO) is a novel on-chip charge detector output stage for charge-coupled device (CCD) image sensors. Developed at MIT Lincoln Laboratory,…
Experimental verification of off-axis polarimetry with Cadmium Zinc Telluride detectors of AstroSat-CZT Imager
C. S. Vaishnava, N. P. S. Mithun, Santosh V. Vadawale +10
The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat consists of an array of a large number of pixellated CZT detectors capable of measuring the polarization of incident hard…
Extending the energy range of AstroSat-CZTI up to 380 keV with Compton Spectroscopy
Abhay Kumar, Tanmoy Chattopadhyay, Santosh V. Vadawale +4
The CZTI (Cadmium Zinc Telluride Imager) onboard AstroSat is a high energy coded mask imager and spectrometer in the energy range of 20 - 100 keV. Above 100 keV, the dominance of C…
Single electron Sensitive Readout (SiSeRO) X-ray detectors: Technological progress and characterization
Tanmoy Chattopadhyay, Sven Herrmann, Peter Orel +11
Single electron Sensitive Read Out (SiSeRO) is a novel on-chip charge detector output stage for charge-coupled device (CCD) image sensors. Developed at MIT Lincoln Laboratory, this…
Hard X-ray polarization catalog for a 5-year sample of Gamma-Ray Bursts using AstroSat CZT-Imager
Tanmoy Chattopadhyay, Soumya Gupta, Shabnam Iyyani +16
Cadmium Zinc Telluride Imager (CZTI) aboard AstroSat has been regularly detecting Gamma-Ray Bursts (GRBs) since its launch in 2015. Its sensitivity to polarization measurements at…
Gamma-Ray Polarimetry
Denis Bernard, Tanmoy Chattopadhyay, Fabian Kislat +1
While the scientific potential of high-energy X-ray and gamma-ray polarimetry has long been recognized, measuring the polarization of high-energy photons is challenging. To date, t…
Development and characterization of a fast and low noise readout for the next generation X-ray CCDs
Tanmoy Chattopadhyay, Sven Herrmann, Peter Orel +8
The broad energy response, low electronic read noise, and good energy resolution have made X-ray Charge-Coupled Devices (CCDs) an obvious choice for developing soft X-ray astronomi…
Probing into emission mechanisms of GRB 190530A using time-resolved spectra and polarization studies: Synchrotron Origin?
Rahul Gupta, S. Gupta, T. Chattopadhyay +47
Multi-pulsed GRB 190530A, detected by the GBM and LAT onboard \fermi, is the sixth most fluent GBM burst detected so far. This paper presents the timing, spectral, and polarimetric…
First results on SiSeRO (Single electron Sensitive Read Out) devices -- a new X-ray detector for scientific instrumentation
Tanmoy Chattopadhyay, Sven Herrmann, Barry Burke +11
We present an evaluation of a novel on-chip charge detector, called the Single electron Sensitive Read Out (SiSeRO), for charge-coupled device (CCD) image sensor applications. It u…
The AstroSat Mass Model: Imaging and Flux studies of off-axis sources with CZTI
Sujay Mate, Tanmoy Chattopadhyay, Varun Bhalerao +11
The Cadmium Zinc Telluride Imager (CZTI) on AstroSat is a hard X-ray coded-aperture mask instrument with a primary field of view of 4.6 x 4.6 degrees (FWHM). The instrument collima…
Hard X-ray Polarimetry -- An overview of the method, science drivers and recent findings
Tanmoy Chattopadhyay
The last decade has seen a leapfrog in the interest in X-ray polarimetry with a number of new polarization measurements in hard X-rays from AstroSat, POLAR, GAP, and PoGO+. The mea…
Sub-MeV spectroscopy with AstroSat-CZT Imager for Gamma Ray Bursts
Tanmoy Chattopadhyay, Soumya Gupta, Vidushi Sharma +10
Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat has been a prolific Gamma-Ray Burst (GRB) monitor. While the 2-pixel Compton scattered events (100 - 300 keV) are used to extr…
Exploring Sub-MeV Sensitivity of AstroSat-CZTI for ON-axis Bright Sources
Abhay Kumar, Tanmoy Chattopadhyay, Santosh V Vadawale +5
The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat is designed for hard X-ray imaging and spectroscopy in the energy range of 20 - 100 keV. The CZT detectors are of 5 mm thi…
Tiny-box: A tool for the versatile development and characterization of low noise fast X-ray imaging detectors
Tanmoy Chattopadhyay, Sven Herrmann, Steven Allen +8
X-ray Charge Coupled Devices (CCDs) have been the workhorse for soft X-ray astronomical instruments for the past quarter century. They provide broad energy response, extremely low…
Identifying charged particle background events in X-ray imaging detectors with novel machine learning algorithms
D. R. Wilkins, S. W. Allen, E. D. Miller +8
Space-based X-ray detectors are subject to significant fluxes of charged particles in orbit, notably energetic cosmic ray protons, contributing a significant background. We develop…
Spectro-polarimetric analysis of prompt emission of GRB 160325A: jet with evolving environment of internal shocks
Vidushi Sharma, Shabnam Iyyani, Dipankar Bhattacharya +3
GRB 160325A is the only bright burst detected by AstroSat CZT Imager in its primary field of view to date. In this work, we present the spectral and polarimetric analysis of the pr…
Time varying polarized gamma-rays from GRB 160821A: evidence for ordered magnetic fields
Vidushi Sharma, Shabnam Iyyani, Dipankar Bhattacharya +8
GRB 160821A is the third most energetic gamma ray burst observed by the {\it Fermi} gamma-ray space telescope. Based on the observations made by Cadmium Zinc Telluride Imager (CZTI…