Zobrazeno 1 - 10
of 26
pro vyhledávání: '"Marthi, Visweshwar Ram"'
Autor:
Marthi, Visweshwar Ram, Maan, Yogesh
We report the first, direct measurement of the electron density turbulence parameter $C_1$, enabled by 550-750 MHz observations with the upgraded Giant Metrewave Radio Telescope. The parameter $C_1$ depends on the power law index of the wavenumber sp
Externí odkaz:
http://arxiv.org/abs/2411.19330
Pulsars have been primarily detected by their narrow pulses or periodicity in time domain data. Interferometric surveys for pulsars are challenging due to the trade-off between beam sensitivity and beam size and the corresponding tradeoff between sur
Externí odkaz:
http://arxiv.org/abs/2407.17764
Autor:
Lin, Hsiu-Hsien, Main, Robert, Pen, Ue-Li, Wharton, Robert, Bause, Marlon Luis, Bethapudi, Suryarao, Li, Dongzi, Lin, Fang Xi, Marthi, Visweshwar Ram, Spitler, Laura G
We present DM-power, a new method for precisely determining the dispersion measure (DM) of radio bursts, and apply it to the Fast Radio Burst (FRB) source FRB~20180916B. Motivated by the complex structure on multiple time scales seen in FRBs, DM-powe
Externí odkaz:
http://arxiv.org/abs/2208.13677
Autor:
Marthi, Visweshwar Ram, Gautam, Tasha, Li, Dongzi, Lin, Hsiu-Hsien, Main, Robert, Naidu, Arun Kumar, Pen, Ue-Li, Wharton, Robert
We report the findings of a uGMRT observing campaign on FRB 180916.J0158+65, discovered recently to show a 16.35-day periodicity of its active cycle. We observed the source at 550-750 MHz for $\sim 2$ hours each during three successive cycles at the
Externí odkaz:
http://arxiv.org/abs/2007.14404
Publikováno v:
Monthly Notices of the Royal Astronomical Society, Volume 500, Issue 4, February 2021, Pages 4398-4413
Considering the upcoming OWFA, we use simulations of the foregrounds and the $z = 3.35$ HI 21-cm intensity mapping signal to identify the $(k_{\perp},k_{\parallel})$ modes where the expected 21-cm power spectrum $P(k_{\perp},k_{\parallel})$ is substa
Externí odkaz:
http://arxiv.org/abs/1911.05372
Pulsar scintillation allows a glimpse into small-scale plasma structures in the interstellar medium, if we can infer their properties from the scintillation pattern. With Very Long Baseline Interferometry and working in delay-delay rate space, where
Externí odkaz:
http://arxiv.org/abs/1810.07231
Simulations play a vital role in testing and validating HI 21-cm power spectrum estimation techniques. Conventional methods use techniques like N-body simulations to simulate the sky signal which is then passed through a model of the instrument. This
Externí odkaz:
http://arxiv.org/abs/1709.03984
Foreground removal is the most important step in detecting the large-scale redshifted HI 21-cm signal. Modelling foreground spectra is challenging and is further complicated by the chromatic response of the telescope. We present a multi-frequency ang
Externí odkaz:
http://arxiv.org/abs/1707.05335
Autor:
Marthi, Visweshwar Ram
One of the scientific objectives of the Ooty Wide Field Array(OWFA) is to observe the redshifted HI emission from z ~ 3.35. Although predictions spell out optimistic outcomes in reasonable integration times, these studies were based purely on analyti
Externí odkaz:
http://arxiv.org/abs/1703.00643
For radio interferometric arrays with a sufficient number of redundant spacings the multiplicity of measurements of the same sky visibility can be used to determine both the antenna gains as well as the true visibilities. Many of the earlier approach
Externí odkaz:
http://arxiv.org/abs/1310.1449