Saptashwa Bhattacharyya

Towards a foundation model for astrophysical source detection: An End-to-End Gamma-Ray Data Analysis Pipeline Using Deep Learning Open

Judit Pérez-Romero, Saptashwa Bhattacharyya, S. Caron, D. Malyshev, Robert Nicolas , et al. · 2025

The increasing volume of gamma-ray data demands new analysis approaches that can handle large-scale datasets while providing robustness for source detection. We present a Deep Learning (DL) based pipeline for detection, localization, and c…

The birth of Be star disks Open

J. Labadie-Bartz, A. C. Carciofi, A. C. Rubio, D. Baade, Robert J. Siverd , et al. · 2025

Context. Classical Be stars are well known to eject mass to build up a disk, but the details governing the initial distribution and subsequent evolution of this matter into a disk are in general poorly constrained through observations. Aim…

Very High-energy Gamma-Ray Episodic Activity of Radio Galaxy NGC 1275 in 2022–2023 Measured with MACE Open

S. Godambe, N. Mankuzhiyil, C. Borwankar, B. Ghosal, A. Tolamatti , et al. · 2024

The radio galaxy NGC 1275, located at the central region of Perseus cluster, is a well-known very high-energy (VHE) gamma-ray emitter. The Major Atmospheric Cherenkov Experiment Telescope has detected two distinct episodes of VHE ( E > 80 …

Prospects for a survey of the galactic plane with the Cherenkov Telescope Array Open

S. Abe, J. Abhir, A. Abhishek, F. Acero, A. Acharyya , et al. · 2024

Approximately one hundred sources of very-high-energy (VHE) gamma rays are known in the Milky Way, detected with a combination of targeted observations and surveys. A survey of the entire Galactic Plane in the energy range from a few tens …

Dark matter line searches with the Cherenkov Telescope Array Open

S. Abe, J. Abhir, A. Abhishek, F. Acero, A. Acharyya , et al. · 2024

Monochromatic gamma-ray signals constitute a potential smoking gun signature for annihilating or decaying dark matter particles that could relatively easily be distinguished from astrophysical or instrumental backgrounds. We provide an upd…

AutoSourceID-Classifier Open

Fiorenzo Stoppa, Saptashwa Bhattacharyya, Roberto Ruiz de Austri, P. Vreeswijk, S. Caron , et al. · 2023

Aims. Traditional star-galaxy classification techniques often rely on feature estimation from catalogs, a process susceptible to introducing inaccuracies, thereby potentially jeopardizing the classification’s reliability. Certain galaxies,…

AutoSourceID-FeatureExtractor Open

Fiorenzo Stoppa, Roberto Ruiz de Austri, P. Vreeswijk, Saptashwa Bhattacharyya, S. Caron , et al. · 2023

Aims . In astronomy, machine learning has been successful in various tasks such as source localisation, classification, anomaly detection, and segmentation. However, feature regression remains an area with room for improvement. We aim to d…

Chasing Gravitational Waves with the Cherenkov Telescope Array Open

Jarred Gershon Green, M. Seglar-Arroyo, CTA Consortium, NULL AUTHOR_ID, Kazuki Abe , et al. · 2023

The detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of m…

Variability studies of active galactic nuclei from the long-term monitoring program with the Cherenkov Telescope Array Open

G. Grolleron, Josefa Becerra Gonzalez, J. Biteau, M. Cerruti, Roger Grau Haro , et al. · 2023

Blazars are active galactic nuclei (AGN) with a relativistic jet oriented toward the observer. This jet is composed of accelerated particles which can display emission over the entire electromagnetic spectrum. Spectral variability has been…

Potential of the Cherenkov Telescope Array for studying the young nearby supernova remnants Open

Dmitry A. Prokhorov, S.-H. Lee, Shigehiro Nagataki, Jacco Vink, Donald C. Ellison , et al. · 2023

Modern imaging atmospheric Cherenkov telescopes have extensively observed young nearby supernova remnants (SNRs), with ages of about 1000 years or less, in the very-high-energy (VHE) gamma-ray band. These efforts resulted in the detection …

Chasing Gravitational Waves with the Cherenkov Telescope Array Open

Jarred Gershon Green, A. Carosi, Lara Nava, B. Patricelli, F. Schüßler , et al. · 2023

The detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of m…

Investigating the VHE Gamma-ray Sources Using Deep Neural Networks Open

Veronika Vodeb, Saptashwa Bhattacharyya, G. Principe, G. Zaharijaš, Roberto Ruiz de Austri , et al. · 2023

The upcoming Cherenkov Telescope Array (CTA) will dramatically improve the point-source sensitivity compared to the current Imaging Atmospheric Cherenkov Telescopes (IACTs). One of the key science projects of CTA will be a survey of the wh…

ctapipe - Prototype Open Event Reconstruction Pipeline for the Cherenkov Telescope Array Open

Maximilian Linhoff, Kazuki Abe, Shotaro Abe, A. Acharyya, R. Adam , et al. · 2023

The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based gamma-ray observatory currently under construction.\n It will improve over the current generation of imaging atmospheric Cherenkov telescopes (IACTs) by a…

Expected exclusion limits to TeV dark matter from the Perseus Cluster with the Cherenkov Telescope Array Open

Sergio Hernández Cadena, Kazuki Abe, Shotaro Abe, A. Acharyya, R. Adam , et al. · 2023

Clusters of galaxies are the largest gravitationally-bound structures in the Universe. They are composed of galaxies and gas (approximately 15% of the total mass) mostly dark matter (DM, accounts up to 85% of the total mass). If the DM is …

AutoSourceID-Classifier. Star-Galaxy Classification using a Convolutional Neural Network with Spatial Information Open

Fiorenzo Stoppa, Saptashwa Bhattacharyya, Roberto Ruiz de Austri, P. M. Vreeswijk, S. Caron , et al. · 2023

Aims. Traditional star-galaxy classification techniques often rely on feature estimation from catalogues, a process susceptible to introducing inaccuracies, thereby potentially jeopardizing the classification's reliability. Certain galaxie…

Interpolation of Instrument Response Functions for the Cherenkov Telescope Array in the Context of pyirf Open

Rune Michael Dominik, Kazuki Abe, Shotaro Abe, A. Acharyya, R. Adam , et al. · 2023

The Cherenkov Telescope Array (CTA) will be the next generation ground-based\n very-high-energy gamma-ray observatory, constituted by tens of Imaging Atmospheric\n Cherenkov Telescopes at two sites once its construction and commissioning a…

Dark matter searches in dwarf spheroidal galaxies with the Cherenkov Telescope Array Open

Francesco Gabriele Saturni, Gonzalo Rodríguez-Fernández, Kazuki Abe, Shotaro Abe, A. Acharyya , et al. · 2023

Dark matter (DM) is one of the major components in the Universe. However, at present its existence is still only inferred through indirect astronomical observations. DM particles can annihilate or decay, producing final-state Standard Mode…

Performance update of an event-type based analysis for the Cherenkov Telescope Array Open

Juan Bernete Medrano, O. Gueta, T. Hassan, Maximilian Linhoff, G. Maier , et al. · 2023

The Cherenkov Telescope Array (CTA) will be the next-generation observatory in the field of very-high-energy (20 GeV to 300 TeV) gamma-ray astroparticle physics. The traditional approach to data analysis in this field is to apply quality c…

Pybkgmodel - a background modelling toolbox for the CTA Open

Marcel C. Strzys, Kazuki Abe, Shotaro Abe, A. Acharyya, R. Adam , et al. · 2023

Despite the advancement in background rejection techniques, observation of the very-high-energy gamma-ray sky by imaging atmospheric Cherenkov telescopes (IACTs) are subject to an irreducible background from gamma-like hadron- or electron-…

Sensitivity of the Cherenkov Telescope Array to the gamma-ray emission from neutrino sources detected by IceCube Open

O. Sergijenko, A. M. Brown, Damiano F. G. Fiorillo, Alberto Rosales de León, K. Satalecka , et al. · 2023

Gamma-ray observations of the astrophysical neutrino sources are fundamentally important for understanding the underlying neutrino production mechanism. We investigate the Cherenkov Telescope Array (CTA) ability to detect the very-high-ene…

AutoSourceID-FeatureExtractor. Optical image analysis using a two-step mean variance estimation network for feature estimation and uncertainty characterisation Open

Fiorenzo Stoppa, Roberto Ruiz de Austri, P. M. Vreeswijk, Saptashwa Bhattacharyya, S. Caron , et al. · 2023

Aims. In astronomy, machine learning has been successful in various tasks such as source localisation, classification, anomaly detection, and segmentation. However, feature regression remains an area with room for improvement. We aim to de…

Sensitivity of the Cherenkov Telescope Array to spectral signatures of hadronic PeVatrons with application to Galactic Supernova Remnants Open

F. Acero, A. Acharyya, R. Adam, Arnau Aguasca-Cabot, I. Agudo , et al. · 2023

Contrasting X-ray/UV time-lags in Seyfert 1 galaxies NGC 4593 and NGC 7469 using AstroSat observations Open

Kavita Kumari, G. C. Dewangan, I. E. Papadakis, Max W. J. Beard, I. M. McHardy , et al. · 2023

We study accretion disk-corona connection in Seyfert 1 galaxies using simultaneous UV/X-ray observations of NGC 4593 (July 14-18, 2016) and NGC 7469 (October 15-19, 2017) performed with AstroSat. We use the X-ray (0.5-7.0 keV) data acquire…

Detecting Fermi LAT Gamma-ray Sources with Neural Networks Open

Diana Horangic, E. Orlando, A. W. Strong, Saptashwa Bhattacharyya · 2023

The Fermi Large Area Telescope (LAT) has been in orbit of Earth since 2008 collecting gamma rays. One challenge in analyzing LAT data is detecting sources and knowing the various classes of gamma-ray sources and how many there are. Neural …

Time-Series Analysis of Oxygen as an Important Environmental Parameter for Monitoring Diversity Hotspot Ecosystems: An Example of a River Sinking into the Karst Underground Open

Saptashwa Bhattacharyya, Janez Mulec, Andreea Oarga-Mulec · 2023

Predicting variations in dissolved oxygen concentration (DO) is important for management and environmental monitoring of aquatic ecosystems. Regression analyses and univariate and multivariate time-series analyses based on autoregressive m…

Prospects for $\gamma$-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array Open

The Cherenkov Telescope Array Consortium, NULL AUTHOR_ID, K. Abe, S. Abe, F. Acero , et al. · 2023

Galaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's formation history. Accordingly, they are excellent targets to search for signals of DM an…

Commissioning of the MACE gamma-ray telescope at Hanle, Ladakh, India Open

K. K. Yadav, N. Chouhan, R. Thubstan, S. Norlha, J. Hariharan , et al. · 2022

The MACE telescope has recently been commissioned at Hanle, Ladakh

AutoSourceID-Light. Fast Optical Source Localization via U-Net and Laplacian of Gaussian Open

Fiorenzo Stoppa, P. M. Vreeswijk, S. Bloemen, Saptashwa Bhattacharyya, G. Jóhannesson , et al. · 2022

$\textbf{Aims}$. With the ever-increasing survey speed of optical wide-field telescopes and the importance of discovering transients when they are still young, rapid and reliable source localization is paramount. We present AutoSourceID-Li…

Localisation and classification of gamma ray sources using neural networks Open

Chris van den Oetelaar, Saptashwa Bhattacharyya, B. Panes, S. Caron, G. Zaharijaš , et al. · 2021

\n Contains fulltext :\n 236393.pdf (Publisher’s version ) (Open Access)\n

Interpretation of the CALET Electron+Positron Spectrum concerning Dark Matter Signatures Open

Holger Motz, Y. Asaoka, Saptashwa Bhattacharyya · 2019

CALET (CALorimetric Electron Telescope) is in operation on the ISS since October 2015 and directly measures the electron+positron cosmic-ray spectrum up into the TeV-region with fine energy resolution and good proton rejection. Interpretat…

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