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相关论文: An HI intensity mapping survey with a Phased Array…

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Intensity mapping surveys will provide access to a coarse view of the cosmic large-scale structure in unprecedented large volumes at high redshifts. Given the large fractions of the sky that can be efficiently scanned using emission from…

宇宙学与河外天体物理 · 物理学 2019-01-09 Oliver Leicht , Cora Uhlemann , Francisco Villaescusa-Navarro , Sandrine Codis , Lars Hernquist , Shy Genel

We use a large N-body simulation to examine the detectability of HI in emission at redshift z ~ 1, and the constraints imposed by current observations on the neutral hydrogen mass function of galaxies at this epoch. We consider three…

宇宙学与河外天体物理 · 物理学 2015-05-20 Nishikanta Khandai , Shiv K. Sethi , Tiziana Di Matteo , Rupert A. C. Croft , Volker Springel , Anirban Jana , Jeffrey P. Gardner

Using the Parkes radio telescope, we study the 21cm neutral hydrogen (HI) properties of a sample of galaxies with redshifts z<0.13 extracted from the optical 2dF Galaxy Redshift Survey (2dFGRS). Galaxies at 0.04<z<0.13 are studied using new…

宇宙学与河外天体物理 · 物理学 2013-10-24 Jacinta Delhaize , Martin Meyer , Lister Staveley-Smith , Brian Boyle

The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory (SARAO) Square…

天体物理仪器与方法 · 物理学 2022-01-19 Devin Crichton , Moumita Aich , Adam Amara , Kevin Bandura , Bruce A. Bassett , Carlos Bengaly , Pascale Berner , Shruti Bhatporia , Martin Bucher , Tzu-Ching Chang , H. Cynthia Chiang , Jean-Francois Cliche , Carolyn Crichton , Romeel Dave , Dirk I. L. de Villiers , Matt A. Dobbs , Aaron M. Ewall-Wice , Scott Eyono , Christopher Finlay , Sindhu Gaddam , Ken Ganga , Kevin G. Gayley , Kit Gerodias , Tim Gibbon , Austin Gumba , Neeraj Gupta , Maile Harris , Heiko Heilgendorf , Matt Hilton , Adam D. Hincks , Pascal Hitz , Mona Jalilvand , Roufurd Julie , Zahra Kader , Joseph Kania , Dionysios Karagiannis , Aris Karastergiou , Kabelo Kesebonye , Piyanat Kittiwisit , Jean-Paul Kneib , Kenda Knowles , Emily R. Kuhn , Martin Kunz , Roy Maartens , Vincent MacKay , Stuart MacPherson , Christian Monstein , Kavilan Moodley , V. Mugundhan , Warren Naidoo , Arun Naidu , Laura B. Newburgh , Viraj Nistane , Amanda Di Nitto , Deniz Ölçek , Xinyu Pan , Sourabh Paul , Jeffrey B. Peterson , Elizabeth Pieters , Carla Pieterse , Aritha Pillay , Anna R. Polish , Liantsoa Randrianjanahary , Alexandre Refregier , Andre Renard , Edwin Retana-Montenegro , Ian H. Rout , Cyndie Russeeawon , Alireza Vafaei Sadr , Benjamin R. B. Saliwanchik , Ajith Sampath , Pranav Sanghavi , Mario G. Santos , Onkabetse Sengate , J. Richard Shaw , Jonathan L. Sievers , Oleg M. Smirnov , Kendrick M. Smith , Ulrich Armel Mbou Sob , Raghunathan Srianand , Pieter Stronkhorst , Dhaneshwar D. Sunder , Simon Tartakovsky , Russ Taylor , Peter Timbie , Emma E. Tolley , Junaid Townsend , Will Tyndall , Cornelius Ungerer , Jacques van Dyk , Gary van Vuuren , Keith Vanderlinde , Thierry Viant , Anthony Walters , Jingying Wang , Amanda Weltman , Patrick Woudt , Dallas Wulf , Anatoly Zavyalov , Zheng Zhang

We present a simulation experiment of a pipeline based on machine learning algorithms for neutral hydrogen (HI) intensity mapping (IM) surveys with different telescopes. The simulation is conducted on HI signals, foreground emission,…

天体物理仪器与方法 · 物理学 2022-09-14 Lin-Cheng Li , Yuan-Gen Wang

21cm intensity mapping experiments aim to observe the diffuse neutral hydrogen (HI) distribution on large scales which traces the Cosmic structure. The Square Kilometre Array (SKA) will have the capacity to measure the 21cm signal over a…

The epoch of reionization power spectrum is expected to evolve strongly with redshift, and it is this variation with cosmic history that will allow us to begin to place constraints on the physics of reionization. The primary obstacle to the…

In Paper III of our series "A Uniform Analysis of the Ly-alpha forest at z=0 - 5", we presented a set of 270 quasar spectra from the archives of the Faint Object Spectrograph on the Hubble Space Telescope. A total of 151 of these spectra,…

天体物理学 · 物理学 2009-11-07 Jennifer Scott , Jill Bechtold , Miwa Morita , Adam Dobrzycki , Varsha Kulkarni

We have carried out an extremely long integration-time (9000 s/beam) 21-cm blind survey of 60 square degrees in Centaurus using the Parkes multibeam system. We find that the noise continues to fall as sqrt(t) throughout, enabling us to…

We present the first results of the HI intensity mapping power spectrum analysis with the MeerKAT International GigaHertz Tiered Extragalactic Exploration (MIGHTEE) survey. We use data covering $\sim$4 square degrees in the COSMOS field…

宇宙学与河外天体物理 · 物理学 2025-06-13 Aishrila Mazumder , Laura Wolz , Zhaoting Chen , Sourabh Paul , Mario Santos , Matt Jarvis , Junaid Townsend , Srikrishna Sekhar , Russ Taylor

We present the results of a search for associated 21 cm HI absorption at redshift 0.42 < z < 1.00 in radio-loud galaxies from three Galaxy And Mass Assembly (GAMA) survey fields. These observations were carried out as part of a pilot survey…

We model the distribution of neutral hydrogen (HI) in the post-reionization era and investigate its detectability in 21 cm intensity mapping with the future SKA radio telescope. We rely on high resolution hydrodynamical N-body simulations.…

宇宙学与河外天体物理 · 物理学 2015-06-19 Francisco Villaescusa-Navarro , Matteo Viel , Kanan K. Datta , T. Roy Choudhury

It is shown that 21 cm intensity mapping could be used in the near term to make cosmologically useful measurements. Large scale structure could be detected using existing radio telescopes, or using prototypes for dedicated redshift survey…

宇宙学与河外天体物理 · 物理学 2010-10-13 Kiyoshi Wesley Masui , Patrick McDonald , Ue-Li Pen

We present the results of a pilot survey for neutral hydrogen (HI) 21 cm absorption in the Arecibo Legacy Fast Arecibo L-Band Feed Array (ALFALFA) Survey. This project is a wide-area "blind" search for HI absorption in the local universe,…

宇宙学与河外天体物理 · 物理学 2015-05-30 Jeremy Darling , Erin P. Macdonald , Martha P. Haynes , Riccardo Giovanelli

The cross-correlation of a foreground density field with two different background convergence fields can be used to measure cosmographic distance ratios and constrain dark energy parameters. We investigate the possibility of performing such…

宇宙学与河外天体物理 · 物理学 2015-11-11 Alkistis Pourtsidou , David Bacon , Robert Crittenden

Where dust and gas are uniformly mixed, atomic hydrogen can be traced through the detection of far-infrared (FIR) or UV emission of dust. We considered, for the origin of discrepancies observed between various direct and indirect tracers of…

星系天体物理 · 物理学 2022-11-30 Jean-Marc Casandjian , Jean Ballet , Isabelle Grenier , Quentin Remy

We use cosmological simulations of reionization to predict the effect of large HII regions around individual high-redshift quasars on the possible signal from the redshifted 21cm line of neutral hydrogen in the pre-reionization era. We show…

天体物理学 · 物理学 2009-11-10 Katharina Kohler , Nickolay Y. Gnedin , Jordi Miralda-Escude , Peter A. Shaver

Neutral hydrogen (HI) intensity mapping traces the large-scale distribution of matter in the Universe and therefore should correlate with the gamma-ray emission originated from particle dark matter annihilation or from active galactic…

宇宙学与河外天体物理 · 物理学 2020-09-03 Elena Pinetti , Stefano Camera , Nicolao Fornengo , Marco Regis

The redshifted 1420 MHz emission from the HI in unresolved damped Lyman-\alpha clouds at high z will appear as a background radiation in low frequency radio observations. This holds the possibility of a new tool for studying the universe at…

天体物理学 · 物理学 2009-10-31 Somnath Bharadwaj , Biman B. Nath , Shiv K. Sethi

At present neutral atomic hydrogen (HI) gas in galaxies at redshifts above $z \sim 0.3$ (the extent of 21-cm emission surveys in individual galaxies) and below $z \sim 1.7$ (where the Lyman-$\alpha$ line is not observable with ground-based…