A. Chatterjee
A5061751493- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Radiation Detection and Scintillator Technologies
- Planetary Science and Exploration
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Geophysics and Gravity Measurements
- Space Exploration and Technology
- Astronomy and Astrophysical Research
- Particle Accelerators and Free-Electron Lasers
- Laser-induced spectroscopy and plasma
- Gyrotron and Vacuum Electronics Research
- SAS software applications and methods
- Atmospheric Ozone and Climate
- Plasma Diagnostics and Applications
- Calibration and Measurement Techniques
- Astronomical Observations and Instrumentation
- Nuclear physics research studies
- Geochemistry and Geologic Mapping
Tata Institute of Fundamental Research
2017-2023
Saha Institute of Nuclear Physics
1975-2019
TU Dortmund University
2018
Institute for High Energy Physics
2017
Institute of Space Sciences
2017
Universidad Complutense de Madrid
2017
Centro Brasileiro de Pesquisas Físicas
2017
University of Maryland, College Park
2017
Physical Research Laboratory
2017
Jet Propulsion Laboratory
2011
[1] The NASA Discovery Moon Mineralogy Mapper imaging spectrometer was selected to pursue a wide range of science objectives requiring measurement composition at fine spatial scales over the full lunar surface. To these objectives, broad spectral with high uniformity and signal-to-noise ratio capable measuring compositionally diagnostic absorption features from variety known possible materials required. For this purpose designed developed that measures 430 3000 nm 10 sampling through 24...
Abstract A neutrino with energy ∼290 TeV, IceCube-170922A, was detected in coincidence the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, chance being rejected at ∼3 σ level. We monitored very-high-energy (VHE) band Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes for ∼41 hr from 1.3 to 40.4 days after detection. Day-timescale variability is clearly resolved. interpret quasi-simultaneous and broadband electromagnetic observations a novel one-zone...
The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with significance 25.5σ using the MAGIC telescopes. Together gravitationally lensed blazar QSO B0218+357 (z 0.944), most distant very high energy (VHE) to date. observations were triggered by an outburst in 2015 April seen energies Large Area Telescope on board Fermi. Multi-wavelength suggest subdivision state into two distinct flux states. In band covered MAGIC, variability timescale...
It is widely believed that the bulk of Galactic cosmic rays are accelerated in supernova remnants (SNRs). However, no observational evidence presence particles PeV energies SNRs has yet been found. The young historical SNR Cassiopeia A (Cas A) appears as one best candidates to study acceleration processes. Between December 2014 and October 2016 we observed Cas with MAGIC telescopes, accumulating 158 hours good-quality data. We derived spectrum source from 100 GeV 10 TeV. also analysed...
Context. QSO B0218+357 is a gravitationally lensed blazar located at redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated 10–12 day delay. In July 2014, experienced violent flare observed Fermi-LAT and followed MAGIC telescopes.
Aims. We aim to characterize the multiwavelength emission from Markarian 501 (Mrk 501), quantify energy-dependent variability, study potential multiband correlations, and describe temporal evolution of broadband within leptonic theoretical scenarios. Methods. organized a campaign take place between March July 2012. Excellent coverage was obtained with more than 25 instruments, including MAGIC, FACT VERITAS Cherenkov telescopes, instruments on board Swift Fermi spacecraft, telescopes operated...
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 1 April and 10 August 2013, including first detailed characterization synchrotron peak with Swift NuSTAR. During campaign, nearby BL Lac object was observed in both a quiescent an elevated state. The campaign includes NuSTAR, MAGIC, VERITAS, Fermi Large Area Telescope (LAT), X-ray UV Optical Telescope, various ground-based optical instruments, GASP-WEBT program, as well radio by OVRO,...
Clusters of galaxies are expected to be reservoirs cosmic rays (CRs) that should produce diffuse gamma-ray emission due their hadronic interactions with the intra-cluster medium. The nearby Perseus cool-core cluster, identified as most promising target search for such an emission, has been observed MAGIC telescopes at very-high energies (VHE, E>100 GeV) a total 253 hr from 2009 2014. active nuclei NGC 1275, central dominant galaxy and IC 310, lying about 0.6$^\circ$ centre, have detected...
We report on the detection of flaring activity from Fanaroff-Riley I radio galaxy NGC 1275 in very-high-energy (VHE, E $>$ 100 GeV) gamma rays with MAGIC telescopes. Observations were performed between 2016 September and 2017 February as part a monitoring program. The brightest outburst $\sim1.5$ times Crab Nebula flux above GeV (C.U.) was observed during night December 31 January 1 (fifty higher than mean previously measured two observational campaigns 2009 2011). Significant variability...
The dwarf spheroidal galaxy Ursa Major II (UMaII) is believed to be one of the most dark-matter dominated systems among Milky Way satellites and represents a suitable target for indirect dark matter (DM) searches. MAGIC telescopes carried out deep observation campaign on UMaII between 2014 2016, collecting almost hundred hours good-quality data. This enlarges pool DM targets observed at very high energy (E ≳ 50 GeV) in search signatures annihilation wide mass range ∼100 GeV TeV. To this end,...
We present periodicity search analyses on the $\gamma$-ray lightcurve of TeV blazar PKS 1510-089 observed by \textit{Fermi} Large Area Telescope. report detection two transient quasi-periodic oscillations: a 3.6-day QPO during outburst in 2009 that lasted five cycles (MJD 54906--54923); and 92 days spanning over 650 from 2018 to 2020 58200--58850), which for seven cycles. employed Lomb-Scargle periodogram, Weighted Wavelet Z-transform, REDFIT, Monte Carlo simulation techniques find any...
Context. PKS 1510-089 is one of only a few flat spectrum radio quasars detected in the VHE (very-high-energy, > 100 GeV) gamma-ray band. Aims. We study broadband spectral and temporal properties emission during high state. Methods. performed observations with MAGIC telescopes long state May 2015. In order to perform modelling source, we have also gathered contemporaneous multiwavelength data radio, IR, optical photometry polarization, UV, X-ray GeV ranges. construct energy distribution...
We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during multi-instrument campaign spanning from 2009 March 15 to August 1 which includes, among other instruments, MAGIC, VERITAS, Whipple 10-m, Fermi-LAT, RXTE, Swift, GASP-WEBT and VLBA. find increase in fractional variability with energy, while no significant interband correlations flux changes are found acquired set. The higher very high energy (>100 GeV, VHE) gamma-ray emission lack correlation X-ray...
Context. The gamma-ray binary LS I +61°303 is a well-established source from centimeter radio up to very high energy (VHE; E> 100 GeV). broadband emission shows periodicity of ~26.5 days, coincident with the orbital period. A longer (super-orbital) period 1667 ± 8 days was proposed variability and confirmed using optical high-energy (HE; MeV) observations. In this paper, we report on four-year campaign performed by MAGIC together archival data concentrating search for long-timescale...
The extragalactic VHE gamma-ray sky is rich in blazars. These are jetted active galactic nuclei viewed at a small angle to the line-of-sight. Only handful of objects larger known so far emit above 100 GeV. Multi-wavelength studies such up highest energies provide new insights into particle and radiation processes nuclei. We report results from first multi-wavelength campaign observing TeV detected nucleus galaxy IC 310, whose jet observed moderate viewing 10 deg - 20 deg. multi-instrument...
The Geminga pulsar, one of the brighest gamma-ray sources, is a promising candidate for emission very-high-energy (VHE > 100 GeV) pulsed gamma rays. Also, detection large nebula have been claimed by water Cherenkov instruments. We performed deep observations with MAGIC telescopes, yielding 63 hours good-quality data, and searched from pulsar wind nebula. did not find any significant detection, derived 95% confidence level upper limits. resulting limits 5.3 x 10^{-13} TeV cm^{-2} s^{-1}...
The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes observed the BL Lac object H1722+119 (redshift unknown) for six consecutive nights between 2013 May 17 and 22, a total of 12.5 h. observations were triggered by high activity in optical band measured KVA (Kungliga Vetenskapsakademien) telescope. source was first time detected very energy (VHE, $E > 100$ GeV) $\gamma$-ray with statistical significance 5.9 $\sigma$. integral flux above 150 GeV is estimated to be $(2.0\pm...
We present a long term optical $R$ band light curve analysis of the gravitationally lensed blazar AO 0235+164 in time span 1982 - 2019. Several methods lead to result that there is periodicity ~8.13 years these data. In addition, each five major flares are apparently double-peaked, with secondary peak following primary one by ~2 years. Along well known system, OJ 287, our finding constitutes most secure cases quasi-periodic behaviour ever found. A binary supermassive black hole system...
Aims. The very high energy (VHE ≳100 GeV) γ -ray MAGIC observations of the blazar S4 0954+65, were triggered by an exceptionally flux state emission in optical. This has a disputed redshift z = 0.368 or ≥ 0.45 and uncertain classification among subclasses. exceptional source described here makes for excellent opportunity to understand physical processes jet 0954+65 thus contribute its classification. Methods. We investigated multiwavelength (MWL) light curve spectral distribution (SED)...
Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray bands, where broadband spectral energy distributions usually peak. In this work, we report on three "target-of-opportunity" (ToO) observations Mrk 421, one brightest TeV blazars, triggered by strong flaring event energies 2014. These feature long, continuous,...
A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MC) has been discovered as strong GeV gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space (Fermi-LAT). The recent observations the Suzaku X-ray satellite have revealed that some these emitting SNRs, such IC443, W49B, W44, and G359.1-0.5, overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR MC. It was observed in gamma rays Fermi-LAT well 0.3 $-$ 10.0...
The MAGIC telescopes observed S2 0109+22 in 2015 July during its flaring activity high energy gamma rays by Fermi-LAT. We analyse the data to characterise very (VHE) gamma-ray emission of 0109+22, which belongs subclass intermediate synchrotron peak (ISP) BL Lac objects. study multi-frequency order investigate source classification. Finally, we compare long-term behaviour other VHE emitting (TeV) blazars. performed a temporal and spectral analysis centred around interval observation (MJD...
The BL Lac object 1ES 1011+496 was discovered at very high energy (VHE, E > 100GeV) γ-rays by Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) in Spring 2007. Before that the source little studied different wavelengths. Therefore, a multiwavelength (MWL) campaign organized 2008. Along MAGIC, MWL included Metsähovi Radio Observatory, Bell and Kungliga Vetenskapsakademien (KVA) optical telescopes Swift AGILE satellites. MAGIC observations span from 2008 March to May for total of 27.9 h,...