Publications (39)
Scintillation of PSR B1508+55 -- the view from a 10,000-km baseline
V. R. Marthi, D. Simard, R. A. Main +6
We report on the simultaneous Giant Metrewave Radio Telescope (GMRT) and Algonquin Radio Observatory (ARO) observations at 550-750 MHz of the scintillation of PSR B1508+55, resulti…
The second data release from the European Pulsar Timing Array: IV. Implications for massive black holes, dark matter and the early Universe
J. Antoniadis, P. Arumugam, S. Arumugam +111
The European Pulsar Timing Array (EPTA) and Indian Pulsar Timing Array (InPTA) collaborations have measured a low-frequency common signal in the combination of their second and fir…
Simultaneous single-pulse observations of radio pulsars - IV. Flux density spectra of individual pulses
M. Kramer, A. Karastergiou, Y. Gupta +3
In this paper we demonstrate that a large, unexplored reservoir of information about pulsar emission exists, that is directly linked to the radiating particles and their radiation…
On the aberration-retardation effects in pulsars
K. Krzeszowski, D. Mitra, Y. Gupta +3
The magnetospheric locations of pulsar radio emission region are not well known. The actual form of the so--called radius--to--frequency mapping should be reflected in the aberrati…
Tracking pulsar dispersion measures using the GMRT
A. L. Ahuja, Y. Gupta, D. Mitra +1
In this paper, we describe a novel experiment for the accurate estimation of pulsar dispersion measures using the Giant Metre-wave Radio Telescope. This experiment was carried out…
Discovery and timing of three millisecond pulsars in radio and gamma-rays with the GMRT and Fermi-LAT
B. Bhattacharyya, J. Roy, T. J. Johnson +14
We performed deep observations to search for radio pulsations in the directions of 375 unassociated Fermi Large Area Telescope (LAT) gamma-ray sources using the Giant Metrewave Rad…
The central point source in G76.9+1.0
V. R. Marthi, J. N. Chengalur, Y. Gupta +2
We describe the serendipitous discovery of a radio point source in a 618 MHz image of the supernova remnant(SNR) G76.9+1.0. The SNR has a bipolar structure and the point source is…
Turn-over in pulsar spectra around 1 GHz
J. Kijak, Y. Gupta, K. Krzeszowski
The main aim is to investigate the possibility of a high frequency turn-over in the radio spectrum of pulsars. Using the GMRT, multi-frequency flux density measurements of several…
The Expanded Giant Metrewave Radio Telescope
N. N. Patra, N. Kanekar, J. N. Chengalur +22
With 30 antennas and a maximum baseline length of 25 km, the Giant Metrewave Radio Telescope (GMRT) is the premier low-frequency radio interferometer today. We have carried out a s…
GMRT discovery of PSR J1544+4937, an eclipsing black-widow pulsar identified with a Fermi LAT source
B. Bhattacharyya, J. Roy, P. S. Ray +17
Using the Giant Metrewave Radio Telescope (GMRT) we performed deep observations to search for radio pulsations in the directions of unidentified Fermi Large Area Telescope (LAT) ga…
Simultaneous single-pulse observations of radio pulsars: II. Orthogonal polarization modes in PSR B1133+16
A. Karastergiou, M. Kramer, S. Johnston +3
In this paper, we present a study of orthogonal polarization modes in the radio emission of PSR B1133+16, conducted within the frame of simultaneous, multi-frequency, single-pulse…
Frequency dependence of pulsar radiation patterns
J. Gil, Y. Gupta, I. B. Ghothoskar +1
We report on new results from simultaneous, dual frequency, single pulse observation of PSR B0329+54 using the Giant Metrewave Radio Telescope. We find that the longitude separatio…
The geometry of PSR B0031-07
R. Smits, D. Mitra, B. Stappers +4
Here we present the results from an analysis of a multifrequency simultaneous observation of PSR B003107. We have constructed a geometrical model, based on an empirical relation…
Simultaneous Single-Pulse Observations of Radio Pulsars: V. On the Broadband Nature of The Pulse Nulling Phenomenon in PSR B1133+16
N. D. R. Bhat, Y. Gupta, M. Kramer +3
We revisit the phenomenon of pulse nulling using high-quality single-pulse data of PSR B1133+16 from simultaneous multifrequency observations. Observations were made at 325, 610, 1…
The Geometry of PSR B0031-07
J. M. Smits, D. Mitra, B. W. Stappers +4
PSR B0031-07 is well known to exhibit three different modes of drifting sub-pulses (mode A, B and C). It has recently been shown that in a multifrequency observation, consisting of…
Flux-density spectral analysis for several pulsars and two newly-identified gigahertz-peaked spectra
M. Dembska, J. Kijak, A. Jessner +3
In this paper we present results from flux density measurements for 21 pulsars over a wide frequency range, using the Giant Metrewave Radio Telescope (GMRT) and the Effelsberg tele…
Discovery of a remarkable subpulse drift pattern in PSR B0818-41
B. Bhattacharyya, Y. Gupta, J. Gil +1
We report the discovery of a remarkable subpulse drift pattern in the relatively less studied wide profile pulsar, B0818-41, using high sensitivity GMRT observations. We find simul…
NGC 1851A: Revealing an ongoing three-body encounter in a dense globular cluster
A. Dutta, P. C. C. Freire, T. Gautam +16
PSR J05144002A is a binary millisecond pulsar located in the globular cluster NGC 1851. The pulsar has a spin period of 4.99 ms, an orbital period of 18.8 days, and is in a very…
The second data release from the European Pulsar Timing Array V. Search for continuous gravitational wave signals
J. Antoniadis, P. Arumugam, S. Arumugam +97
We present the results of a search for continuous gravitational wave signals (CGWs) in the second data release (DR2) of the European Pulsar Timing Array (EPTA) collaboration. The m…
The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
J. Antoniadis, P. Arumugam, S. Arumugam +95
We present the results of the search for an isotropic stochastic gravitational wave background (GWB) at nanohertz frequencies using the second data release of the European Pulsar T…
Understanding the effects of geometry and rotation on pulsar intensity profiles
R. M. C. Thomas, Y. Gupta, R. T. Gangadhara
We have developed a method to compute the possible distribution of radio emission regions in a typical pulsar magnetosphere, taking into account the viewing geometry and rotational…
The second data release from the European Pulsar Timing Array II. Customised pulsar noise models for spatially correlated gravitational waves
J. Antoniadis, P. Arumugam, S. Arumugam +95
The nanohertz gravitational wave background (GWB) is expected to be an aggregate signal of an ensemble of gravitational waves emitted predominantly by a large population of coalesc…
Radio Searches of Fermi LAT Sources and Blind Search Pulsars: The Fermi Pulsar Search Consortium
P. S. Ray, A. A. Abdo, D. Parent +29
We present a summary of the Fermi Pulsar Search Consortium (PSC), an international collaboration of radio astronomers and members of the Large Area Telescope (LAT) collaboration, w…
Comparing recent PTA results on the nanohertz stochastic gravitational wave background
The International Pulsar Timing Array Collaboration, G. Agazie, J. Antoniadis +242
The Australian, Chinese, European, Indian, and North American pulsar timing array (PTA) collaborations recently reported, at varying levels, evidence for the presence of a nanohert…
The discovery of PSR J1833-1034 : the pulsar associated with the supernova remnant G21.5-0.9
Y. Gupta, D. Mitra, D. A. Green +1
We report the discovery of a young pulsar associated with the supernova remnant G21.5-0.9, using the Giant Metrewave Radio Telescope (GMRT) located near Pune, India. Discovered at…
Pulsars with gigahertz-peaked spectra
J. Kijak, W. Lewandowski, O. Maron +2
We investigate a high frequency turn-over effect in radio spectra for pulsars with positive or flat spectral index. Using GMRT and Effelsberg observatory, we estimated the flux den…
LOFAR Detection of 110-188 MHz Emission and Frequency-Dependent Activity from FRB 20180916B
Z. Pleunis, D. Michilli, C. G. Bassa +32
FRB 20180916B is a well-studied repeating fast radio burst source. Its proximity (~150 Mpc), along with detailed studies of the bursts, have revealed many clues about its nature --…
Detection of fast transients with radio interferometric arrays
N. D. R. Bhat, J. N. Chengalur, P. J. Cox +7
Next-generation radio arrays, including the Square Kilometre Array (SKA) and its pathfinders, will open up new avenues for exciting transient science at radio wavelengths. Their in…
High-Performance Computing for SKA Transient Search: Use of FPGA based Accelerators -- a brief review
R. Aafreen, R. Abhishek, B. Ajithkumar +34
This paper presents the High-Performance computing efforts with FPGA for the accelerated pulsar/transient search for the SKA. Case studies are presented from within SKA and pathfin…
Discovery of a radio nebula around PSR J0855-4644
C. Maitra, S. Roy, F. Acero +1
We report the discovery of a diffuse radio emission around PSR J0855--4644 using an upgraded GMRT (uGMRT) observation at 1.35 GHz. The radio emission is spatially coincident with t…
Understanding the radio emission geometry of PSR B0329+54
R. T. Gangadhara, Y. Gupta
We have analyzed high-quality single pulse data of PSR B0329+54 at 325 MHz and 606 MHz to study the structure of the emission beam. Using the window-threshold technique, which is s…
Unraveling the drift behaviour of the remarkable pulsar PSR B0826-34
Y. Gupta, J. Gil, J. Kijak +1
We present new results from high sensitivity GMRT observations of PSR B0826-34. We provide a model to explain the observed subpulse drift properties of this pulsar, including the a…
The Frequency Evolution of Interstellar Pulse Broadening from Radio Pulsars
O. Loehmer, D. Mitra, Y. Gupta +2
In this paper we report multi-frequency measurements of pulse broadening times (tau_d) for nine medium dispersion measure (DM pc cm) pulsars observed over…
Detection of new emission components in PSR B0329+-54
R. T. Gangadhara, Y. Gupta, D. R. Lorimer
To study the structure of emission beam, we have analysed the single pulse data of PSR B0329+-54 at 325 and 606 MHz. In order to unambiguously detect the weak emission components,…
Upgraded GMRT survey for pulsars in globular clusters. I: Discovery of a millisecond binary pulsar in NGC 6652
T. Gautam, A. Ridolfi, P. C. C. Freire +6
Globular clusters contain a unique pulsar population, with many exotic systems that can form only in their dense stellar environments. The leap in sensitivity of the upgraded Giant…
Turn-over in pulsar spectra above 1 GHz
J. Kijak, Y. Gupta, K. Krzeszowski
We present the first direct evidence for turn-over in pulsar radio spectra at high frequencies. Two pulsars are now shown to have a turn-over frequency > 1GHz. We also find some ev…
Understanding the radio emission geometry of multi-component radio pulsars from retardation and aberration effects
Y. Gupta, R. T. Gangadhara
We have conducted a detailed analysis of the emission geometry of a handful of radio pulsars that have prominent, multiple-component profiles at meter wavelengths. From careful det…
Results from multi-frequency observations of PSR B0826-34
B. Bhattacharyya, Y. Gupta, J. Gil
We report new results obtained from multi-frequency observations of PSR B0826-34 with the Giant Metrewave Radio Telescope (GMRT). (1) We find no evidence of weak emission during th…
The PSR J0514-4002A binary system in NGC 1851
P. C. C. Freire, Y. Gupta, S. M. Ransom +1
Using the Giant Metrewave Radio Telescope (GMRT), we have discovered PSR J0514-4002A, a binary millisecond pulsar in the globular cluster NGC 1851. This pulsar has a rotational per…