Related papers: 21 cm Intensity Mapping with the DSA-2000
Following the first two annual intensity mapping workshops at Stanford in March 2016 and Johns Hopkins in June 2017, we report on the recent advances in theory, instrumentation and observation that were presented in these meetings and some…
Observations of the neutral Hydrogen (\HI ) 21-cm signal hold the potential of allowing us to map out the cosmological large scale structures (LSS) across the entire post-reionization era ($z \leq 6$). Several experiments are planned to map…
Line intensity mapping is a superb tool to study the collective radiation from early galaxies. However, the method is hampered by the presence of strong foregrounds, mostly produced by low-redshift interloping lines. We present here a…
The large-scale structure of the Universe supplies crucial information about the physical processes at play at early times. Unresolved maps of the intensity of 21 cm emission from neutral hydrogen HI at redshifts z~1-5 are the best hope of…
The 21cm line of neutral hydrogen (HI) opens a new avenue in our exploration of the structure and evolution of the Universe. It provides complementary data to the current large-scale structure observations with different systematics, and…
The abundance of cold molecular gas plays a crucial role in models of galaxy evolution. While deep spectroscopic surveys of CO emission lines have been a primary tool for measuring this abundance, the difficulty of these observations has…
The cosmic "Dark Ages" is the period between the last scattering of the Cosmic Microwave Background (CMB) and the appearance of the first luminous sources, spanning redshifts $1100\gtrsim z\gtrsim 30$. The only way to observe this period is…
We present projected constraints on modified gravity models from the observational technique known as 21 cm intensity mapping, where cosmic structure is detected without resolving individual galaxies. The resulting map is sensitive to both…
Understanding dark energy requires precision measurements of the expansion history of the universe and the growth of large-scale structure. The 21 cm intensity mapping (21 cm IM) technique enables rapid large-area surveys that can deliver…
Spectral distortions in the cosmic microwave background over the 40--200~MHz band are imprinted by neutral hydrogen in the intergalactic medium prior to the end of reionization. This signal, produced in the redshift range $z = 6-34$ at the…
The Square Kilometre Array will be a revolutionary instrument for the study of gas in the distant Universe. SKA1 will have sufficient sensitivity to detect and image atomic 21 cm HI in individual galaxies at significant cosmological…
This study presents the methodology for creating a cost-efficient radio astronomy telescope that can be used to detect 21 cm emissions (1420.405 MHz) and determine the distribution and kinematics of neutral hydrogen specifically in the…
Detection of the redshifted 21cm-line signal from neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR) is complicated by intense foregrounds such as galactic synchrotron and extragalactic radio galaxies.…
We analyze the formation of the signal in the 21 cm hydrogen line of the Dark Ages ($30\le z\le300$) in different cosmological models and discuss the possibility of its detection by decameter-wavelength radio telescopes. To study the…
We present Giant Metrewave Radio Telescope (GMRT) HI 21cm emission images of the z=0.009 damped Lyman-alpha (DLA) absorber towards the QSO HS 1543+5921. The DLA has been earlier identified as a low surface brightness galaxy SBS 1543+593 at…
The hyperfine structure absorption lines of neutral hydrogen in spectra of high-redshift radio sources, known collectively as the 21-cm forest, have been demonstrated as a sensitive probe to the small-scale structures governed by the dark…
21-cm intensity mapping (IM) is a powerful technique to probe the large-scale distribution of neutral hydrogen (HI) and extract cosmological information such as the baryon acoustic oscillation feature. A key challenge lies in recovering the…
Line intensity mapping (LIM) is a promising observational method to probe large-scale fluctuations of line emission from distant galaxies. Data from wide-field LIM observations allow us to study the large-scale structure of the universe as…
Line intensity mapping (LIM) is an emerging technique with a unique potential to probe a wide range of scales and redshifts. Realizing the full potential of LIM, however, relies on accurate modeling of the signal. We introduce an extended…
Spatial variations in the Lyman-$\alpha$ forest opacity at $z<6$ seem to require a late end to cosmic reionization. In this picture, the universe contains neutral hydrogen 'islands' of up to 100 cMpc$/h$ in extent down to redshifts as low…