311 citations · 2.2k across the 66 of their papers we have counts for
8 papers · 1 filter
Degree-Scale Galactic Radio Emission at 122 MHz around the North Celestial Pole with LOFAR-AARTFAAC
B. K. Gehlot, L. V. E. Koopmans, A. R. Offringa +11
Aims: Contamination from bright diffuse Galactic thermal and non-thermal radio emission poses crucial challenges in experiments aiming to measure the 21-cm signal of neutral hydrog…
A numerical study of 21-cm signal suppression and noise increase in direction-dependent calibration of LOFAR data
M. Mevius, F. Mertens, L. V. E. Koopmans +14
We investigate systematic effects in direction dependent gain calibration in the context of the Low-Frequency Array (LOFAR) 21-cm Epoch of Reionization (EoR) experiment. The LOFAR…
Large HI optical depth and Redshifted 21-cm signal from cosmic dawn
Kanan K. Datta, Raghunath Ghara, Ariful Hoque +1
The HI 21-cm optical depth () can be considerably large as the kinetic and spin temperature of the inter-galactic medium (IGM) is expected to be very low during cosmic dawn. I…
Astrophysical information from the Rayleigh-Jeans Tail of the CMB
Raghunath Ghara, Garrelt Mellema, Saleem Zaroubi
One of the explanations for the recent EDGES-LOW band 21-cm measurements of a strong absorption signal around 80~MHz is the presence of an excess radio background to the Cosmic Mic…
Probing IGM Physics during Cosmic Dawn using the Redshifted 21-cm Bispectrum
Mohd Kamran, Suman Majumdar, Raghunath Ghara +5
With the advent of the first luminous sources at Cosmic Dawn (CD), the redshifted 21-cm signal, from the neutral hydrogen in the Inter-Galactic Medium (IGM), is predicted to underg…
Constraining the state of the intergalactic medium during the Epoch of Reionization using MWA 21-cm signal observations
Raghunath Ghara, Sambit K. Giri, Benedetta Ciardi +2
The Murchison Widefield Array (MWA) team has derived new upper limits on the spherically averaged power spectrum of the 21-cm signal at six redshifts in the range $z \approx 6.5-8.…
Redshifted 21-cm bispectrum II: Impact of the spin temperature fluctuations and redshift space distortions on the signal from the Cosmic Dawn
Mohd Kamran, Raghunath Ghara, Suman Majumdar +5
We present a study of the 21-cm signal bispectrum (which quantifies the non-Gaussianity in the signal) from the Cosmic Dawn (CD). For our analysis, we have simulated the 21-cm sign…
Prospects of constraining reionization model parameters using Minkowski tensors and Betti numbers
Akanksha Kapahtia, Pravabati Chingangbam, Raghunath Ghara +2
We explore the possibility of constraining model parameters of the Epoch of Reionization (EoR) from 21cm brightness temperature maps, using a combination of morphological descripto…