Shriharsh P. Tendulkar
A5030668506- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- High-pressure geophysics and materials
- Astronomy and Astrophysical Research
- Radio Astronomy Observations and Technology
- GNSS positioning and interference
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- earthquake and tectonic studies
- Cosmology and Gravitation Theories
- Mechanics and Biomechanics Studies
- Inertial Sensor and Navigation
- Galaxies: Formation, Evolution, Phenomena
- Particle Detector Development and Performance
- Astrophysics and Star Formation Studies
- Calibration and Measurement Techniques
- Space Satellite Systems and Control
- Astro and Planetary Science
- Particle Accelerators and Free-Electron Lasers
- Seismology and Earthquake Studies
- Atomic and Subatomic Physics Research
Tata Institute of Fundamental Research
2021-2025
National Centre for Radio Astrophysics
2021-2024
Canadian Institute for Advanced Research
2023-2024
McGill University
2016-2021
University of California, Santa Barbara
2018
California Institute of Technology
2011-2016
AdTech Optics (United States)
2012
Optica
2012
Indian Institute of Technology Bombay
2008
The precise localization of the repeating fast radio burst (FRB 121102) has provided first unambiguous association (chance coincidence probability $p\lesssim3\times10^{-4}$) an FRB with optical and persistent counterpart. We report on imaging spectroscopy counterpart find that it is extended ($0.6^{\prime\prime}-0.8^{\prime\prime}$) object displaying prominent Balmer [OIII] emission lines. Based spectrum line ratios, we classify as a low-metallicity, star-forming, $m_{r^\prime} = 25.1$ AB...
We present the results of a Palomar Transient Factory (PTF) archival search for blue transients which lie in magnitude range between "normal" core-collapse and superluminous supernovae (i.e. with $-21\,{\leq}M_{R\,(peak)}\,{\leq}-19$). Of six events found after excluding all interacting Type~IIn Ia-CSM supernovae, three (PTF09ge, 09axc 09djl) are coincident centers their hosts, one (10iam) is offset from center, two (10nuj 11glr) precise can not be determined. All central have similar rise...
We report on the discovery of eight repeating fast radio burst (FRB) sources found using Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These span a dispersion measure (DM) range 103.5 to 1281 pc cm$^{-3}$. They display varying degrees activity: six were detected twice, another three times, and one ten times. FRBs likely represent bright and/or high-rate end distribution infrequently sources. For all sources, we determine sky coordinates with uncertainties...
Abstract The millisecond-duration radio flashes known as fast bursts (FRBs) represent an enigmatic astrophysical phenomenon. Recently, the sub-arcsecond localization (∼100 mas precision) of FRB 121102 using Very Large Array has led to its unambiguous association with persistent and optical counterparts, identification host galaxy. However, even more precise is needed in order probe direct physical relationship between millisecond themselves associated emission. Here, we report...
We present a catalog of 536 fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project between 400 and 800 MHz from 2018 July 25 to 2019 1, including 62 18 previously reported repeating sources. The represents first large sample, repeaters non-repeaters, observed in single survey with uniform selection effects. This facilitates comparative absolute studies FRB population. show that apparent non-repeaters have sky locations...
We conducted a survey of nearby binary systems composed main sequence stars spectral types F and G in order to improve our understanding the hierarchical nature multiple star systems. Using Robo-AO, first robotic adaptive optics instrument, we collected high angular resolution images with deep well-defined detection limits Sloan Digital Sky Survey i' band. A total 695 components belonging 595 were observed. prioritized observations faint secondary separations over 10'' quantify still poorly...
Abstract We report on the discovery and analysis of bursts from nine new repeating fast radio burst (FRB) sources found using Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These span a dispersion measure (DM) range 195–1380 pc cm −3 . detect two three sources, four one source, five source. determine sky coordinates all with uncertainties ∼10′. Faraday rotation measures (RMs) for values −20(1) −499.8(7) rad m −2 , that are substantially lower than RM derived emitted by FRB...
Millisecond radio pulsars acquire their rapid rotation rates through mass and angular momentum transfer in a low-mass X-ray binary system. Recent studies of PSR J1824−2452I J1023+0038 have observationally demonstrated this link, they also shown that such systems can repeatedly transition back-and-forth between the millisecond pulsar states. This suggests fraction are not newly born but rather suspended back-and-forth, state-switching phase, perhaps for gigayears. XSS J12270−4859 has been...
ABSTRACT We report on radio and X-ray observations of the only known repeating Fast Radio Burst (FRB) source, FRB 121102. have detected six additional bursts from this source: five with Green Bank Telescope at 2 GHz, one 1.4 GHz Arecibo Observatory, for a total 17 source. All dispersion measures consistent single value (∼559 pc cm −3 ) that is three times predicted maximum Galactic contribution. The highly variable spectra like those indicating frequency structure seen across individual...
We present radio and γ-ray observations, which, along with concurrent X-ray reveal that the binary millisecond pulsar (MSP)/low-mass transition system PSR J1023+0038 has undergone a transformation in state. Whereas until recently harbored bright pulsar, pulsations at frequencies between 300 to 5000 MHz have now become undetectable. Concurrent this disappearance, flux of quintupled. conclude that, though is currently not detectable, mechanism still active wind, as well newly formed accretion...
We report on the discovery of FRB 20200120E, a repeating fast radio burst (FRB) with low dispersion measure (DM), detected by Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB project. The source DM 87.82 pc cm$^{-3}$ is lowest recorded from an to date, yet significantly higher than maximum expected Milky Way interstellar medium in this direction (~ 50 cm$^{-3}$). have three bursts and one candidate over period 2020 January-November. baseband voltage data for event January 20...
Abstract We present a synthesis of fast radio burst (FRB) morphology (the change in flux as function time and frequency) detected the 400–800 MHz octave by FRB project on Canadian Hydrogen Intensity Mapping Experiment (CHIME/FRB), using events from first CHIME/FRB catalog. The catalog consists 62 bursts 18 repeating sources, plus 474 one-off FRBs, between 2018 July 25 2019 2. identify four observed archetypes (“simple broadband,” “simple narrowband,” “temporally complex,” “downward...
We present results of the coordinated observing campaign that made first subarcsecond localization a Fast Radio Burst, FRB 121102. During this campaign, we simultaneous detection an burst by multiple telescopes: VLA at 3 GHz and Arecibo Observatory 1.4 GHz. Of nine bursts detected Very Large Array GHz, four had coverage other observatories. use multi-observatory constraints modeling seen only to confirm earlier showing spectra are not well modeled power law. find characterized ~500 MHz...
We report the first detections of repeating fast radio burst source FRB 121102 above 5.2 GHz. Observations were performed using 4$-$8 GHz receiver Robert C. Byrd Green Bank Telescope with Breakthrough Listen digital backend. present spectral, temporal and polarization properties 21 bursts detected within 60 minutes a total 6-hour observations. These observations comprise highest density yet reported in literature, 18 being 30 minutes. A few clearly show sub-structures distinct spectral...
Abstract FRB 121102 is the only known repeating fast radio burst source. Here we analyze a wide-frequency-range (1–8 GHz) sample of high signal-to-noise, coherently dedispersed bursts detected using Arecibo and Green Bank telescopes. These reveal complex time–frequency structures that include subbursts with finite bandwidths. The frequency-dependent structure complicates determination dispersion measure (DM); argue it appropriate to use DM metric maximizes frequency-averaged pulse structure,...