相关论文: Studying 21cm power spectrum with one-point statis…
The cosmological 21cm signal offers a potential probe of the early Universe and the first ionizing sources. Current experiments probe the spatially-dependent variance (Gaussianity) of the signal through the power spectrum (PS). The signal…
The redshifted 21-cm signal is a unique probe of the early universe, particularly the Epoch of Reionization (EoR). While the 21-cm power spectrum has been the primary statistic for parameter inference, it fails to capture the non-Gaussian…
Using high redshift radio sources as background, the 21cm forest observations probe the neutral hydrogen absorption signatures of early structures along the lines of sight. Directly sensitive to the spin temperature, it complements the 21cm…
The residual gain errors add to the systematics of the radio interferometric observations. In case of the high dynamic range observations, these systematic effects dominates over the thermal noise of the observation. In this work, we…
In the most distant reaches of the Universe, the 21-cm hyperfine transition in neutral hydrogen provides one of the only available tracers of large-scale structure. A number of instruments have been working and planned to measure the 21-cm…
Accurate simulations of the 21-cm signal from the Epoch of Reionization require the generation of maps at specific frequencies given the values of astrophysical and cosmological parameters. The peculiar velocities of the hydrogen atoms…
Upon an expansion of all of the searches for redshifted HI 21-cm absorption (0.0021 < z 5.19), we update recent results regarding the detection of 21-cm in the non-local Universe. Specifically, we confirm that photo-ionisation of the gas is…
The Cosmic Dawn and Epoch of Reionisation, during which collapsed structures produce the first ionising photons and proceed to reionise the intergalactic medium, span a large range in redshift (z~30-6) and time (t_{age} ~ 0.1-1.0~Gyr).…
The exploration of the end of the Dark Ages will be one of the most exciting field of the next decade. While most of the proposed observations must await the next-generation telescopes, the observational window of the redshifted 21cm line…
The emission of 21-cm radiation from a neutral intergalactic medium (IGM) at high redshift is discussed in connection with the thermal and ionization history of the universe. The physical mechanisms that make such radiation detectable…
The measurement of the brightness temperature fluctuations of neutral hydrogen 21 cm lines from the Epoch of Reionisation (EoR) is expected to be a powerful tool for revealing the reionisation process. We study the 21 cm cross-correlation…
The cross-correlation between the 21 cm field and the galaxy distribution is a potential probe of the Epoch of Reionization (EoR). The 21 cm signal traces neutral gas in the intergalactic medium and, on large spatial scales, this should be…
The epoch of reionization (EoR) marks the last phase transition of hydrogen in our Universe, as it evolves from cold and neutral to hot and ionized in the intergalactic medium (IGM). While its endpoint and duration can be estimated from…
The 21cm line from the spin-flip transition of neutral hydrogen (HI) provides a unique window into the Epoch of Reionization (EoR), the final phase transition of our Universe. The Square Kilometre Array (SKA) enables precise measurements of…
Simulations estimating the differential brightness temperature of the redshifted 21-cm from the epoch of reionization (EoR) often assume that the spin temperature is decoupled from the background CMB temperature and is much larger than it.…
The power spectra of the redshifted 21-cm signal from the Epoch of Reionization (EoR) contain information about the ionization and thermal states of the intergalactic medium (IGM), and depend on the properties of the EoR sources. Recently,…
New observations over the next few years of the emission of distant objects will help unfold the chapter in cosmic history around the era of the first galaxies. These observations will use the neutral hydrogen emission or absorption at a…
Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to separate the weak signal from overwhelming foreground…
The 21\,cm transition of neutral hydrogen is opening an observational window into the cosmic dawn of the universe---the epoch of first star formation. We use 28\,hr of data from the Owens Valley Radio Observatory Long Wavelength Array…
Prior to the epoch of full reionization, the intergalactic medium and gravitationally collapsed systems will be detectable in 21-cm radiation. Physical mechanisms that would produce a 21-cm signature are discussed. These include Lya…