Zobrazeno 1 - 10
of 23
pro vyhledávání: '"Sk. Saiyad Ali"'
Autor:
Abinash Kumar Shaw, Arnab Chakraborty, Mohd Kamran, Raghunath Ghara, Samir Choudhuri, Sk. Saiyad Ali, Srijita Pal, Abhik Ghosh, Jais Kumar, Prasun Dutta, Anjan Kumar Sarkar
The redshifted 21-cm radiation from the atomic hydrogen (HI) provides an excellent direct probe to study the evolution of HI in IGM and thus reveal the nature of the first luminous objects, their evolution and role during Cosmic Dawn (CD) and Epoch o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e18e3377b2532f399ca2859947836742
http://arxiv.org/abs/2211.05512
http://arxiv.org/abs/2211.05512
Publikováno v:
Monthly Notices of the Royal Astronomical Society, 494(2), 1936-1945
Measurements of the Galactic synchrotron emission is relevant for the 21-cm studies from the Epoch of Reionization. The study of the synchrotron emission is also useful to quantify the fluctuations in the magnetic field and the cosmic ray electron de
Autor:
Srijita Pal, Kh Md Asif Elahi, Somnath Bharadwaj, Sk Saiyad Ali, Samir Choudhuri, Abhik Ghosh, Arnab Chakraborty, Abhirup Datta, Nirupam Roy, Madhurima Choudhury, Prasun Dutta
The post-reionization $(z \le 6)$ neutral hydrogen (HI) 21-cm intensity mapping signal holds the potential to probe the large scale structures, study the expansion history and constrain various cosmological parameters. Here we apply the Tapered Gridd
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ff99d57e703d87aac5de0bab6d86f09b
Autor:
Nirupam Roy, Sk. Saiyad Ali, Abhik Ghosh, Samir Choudhuri, Suman Chatterjee, Somnath Bharadwaj
Publikováno v:
Monthly Notices of the Royal Astronomical Society, 463(4), 4093-4107. Oxford University Press
We present the improved visibility based Tapered Gridded Estimator (TGE) for the power spectrum of the diffuse sky signal. The visibilities are gridded to reduce the computation, and tapered through a convolution to suppress the contribution from the
Publikováno v:
Monthly Notices of the Royal Astronomical Society, 459(1), 151-156. Oxford University Press
It is important to correctly subtract point sources from radio-interferometric data in order to measure the power spectrum of diffuse radiation like the Galactic synchrotron or the Epoch of Reionization 21-cm signal. It is computationally very expens
Publikováno v:
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (ISSN 0035-8711), 470, L11-L15
Characterizing the diffuse Galactic synchrotron emission at arcminute angular scales is needed to reliably remove foregrounds in cosmological 21-cm measurements. The study of this emission is also interesting in its own right. Here, we quantify the f
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4b10d71613b875f25c96f0f9b4699091
http://arxiv.org/abs/1704.08642
http://arxiv.org/abs/1704.08642
We use the Fisher matrix formalism to predict the prospects of measuring the redshifted 21-cm power spectrum in different $k$-bins using observations with the upcoming Ooty Wide Field Array (OWFA) which will operate at $326.5 {\rm MHZ}$. This corresp
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9e3e489b47ffe424158be97c6cafe2a5
http://arxiv.org/abs/1703.00634
http://arxiv.org/abs/1703.00634
The "Tapered Gridded Estimator" (TGE) is a novel way to directly estimate the angular power spectrum from radio-interferometric visibility data that reduces the computation by efficiently gridding the data, consistently removes the noise bias, and su
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f279b8f43bb0dc7caf369a931b9aa598
Prospects for Detecting the 326.5 MHz Redshifted 21-cm HI Signal with the Ooty Radio Telescope (ORT)
Autor:
Sk. Saiyad Ali, Somnath Bharadwaj
Publikováno v:
Journal of Astrophysics and Astronomy. 35:157-182
Observations of the redshifted 21 cm HI fluctuations promise to be an important probe of the post-reionization era. In this paper we calculate the expected signal and foregrounds for the upgraded Ooty Radio Telescope (ORT) which operates at frequency
The diffuse Galactic synchrotron emission (DGSE) is the most important diffuse foreground component for future cosmological 21-cm observations. The DGSE is also an important probe of the cosmic ray electron and magnetic field distributions in the tur
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3cee896124457b79f3a297287c043c24