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相关论文: HI intensity mapping with MeerKAT: forecast for de…

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Intensity mapping of the neutral hydrogen (HI) is a new observational tool that can be used to efficiently map the large-scale structure of the Universe over wide redshift ranges. The power spectrum of the intensity maps contains…

宇宙学与河外天体物理 · 物理学 2016-03-23 L. Wolz , C. Tonini , C. Blake , J. S. B. Wyithe

Several experimental efforts are underway to measure the power spectrum of 21cm fluctuations from the Epoch of Reionization (EoR) using low-frequency radio interferometers. Experiments like the Hydrogen Epoch of Reionization Array (HERA)…

天体物理仪器与方法 · 物理学 2019-06-19 Adam E. Lanman , Jonathan C. Pober

We present the first measurement of the HI mass function (HIMF) using data from MeerKAT, based on 276 direct detections from the MIGHTEE Survey Early Science data covering a period of approximately a billion years ($0 \leq z \leq 0.084 $).…

Neutral hydrogen (HI) will soon be the dark matter tracer observed over the largest volumes of Universe thanks to the 21 cm intensity mapping technique. To unveil cosmological information it is indispensable to understand the HI…

宇宙学与河外天体物理 · 物理学 2017-12-06 Aurélie Pénin , Obinna Umeh , Mario Santos

An interesting probe of the nature of dark energy is the measure of its sound speed, $c_s$. We review the significance for constraining sound speed models of dark energy using large neutral hydrogen (HI) surveys with the Square Kilometre…

天体物理学 · 物理学 2009-01-08 A. Torres-Rodriguez , C. M. Cress , K. Moodley

The emission from neutral hydrogen (HI) clouds in the post-reionization era (z < 6), too faint to be individually detected, is present as a diffuse background in all low frequency radio observations below 1420 MHz. The angular and frequency…

天体物理学 · 物理学 2009-10-29 Somnath Bharadwaj , Shiv K. Sethi , Tarun Deep Saini

We forecast constraints on cosmological parameters in the interacting dark energy models using the mock data generated for neutral hydrogen intensity mapping (IM) experiments. In this work, we only consider the interacting dark energy…

宇宙学与河外天体物理 · 物理学 2021-09-13 Ming Zhang , Bo Wang , Peng-Ju Wu , Jing-Zhao Qi , Yidong Xu , Jing-Fei Zhang , Xin Zhang

The precise characterization and mitigation of systematic effects is one of the biggest roadblocks impeding the detection of the fluctuations of cosmological 21cm signals. Missing data in radio cosmological experiments, often due to radio…

Neutral hydrogen intensity mapping can in principle deliver rapid and large-volume cosmological surveys with exquisitely accurate redshifts that are determined directly from imaging. However, intensity maps suffer from very strong…

宇宙学与河外天体物理 · 物理学 2024-05-30 Rahul Kothari , Roy Maartens

Radio holographic measurements using the MeerKAT telescope are presented for each of its supported observing bands, namely UHF (544--1087 MHz), L (856--1711 MHz) and S (1750--3499 MHz). Because the UHF-band receiver design is a scaled…

天体物理仪器与方法 · 物理学 2023-02-08 Mattieu de Villiers

The proposed ICAL experiment at INO aims to identify the neutrino mass hierarchy from observations of atmospheric neutrinos, and help improve the precision on the atmospheric neutrino mixing parameters. While the design of ICAL is primarily…

高能物理 - 唯象学 · 物理学 2015-06-22 Moon Moon Devi , Tarak Thakore , Sanjib Kumar Agarwalla , Amol Dighe

The MeerKAT Large Area Synoptic Survey (MeerKLASS) collaboration has acquired multiple passes of L-band (856-1712 MHz) scanning observations over a 268 deg$^2$ sky region. This scanning enables efficient, large-area sky surveys by…

The Large Survey Project (LSP) "MeerKAT Absorption Line Survey" (MALS) is a blind HI 21-cm and OH 18-cm absorption line survey in the L- and UHF-bands, with the primary goal to better determine the occurrence of atomic and molecular gas in…

Radio Frequency Interference (RFI) is unwanted noise that swamps the desired astronomical signal. Radio astronomers have always had to deal with RFI detection and excision around telescope sites, but little has been done to understand the…

天体物理仪器与方法 · 物理学 2022-11-17 Isaac Sihlangu , Nadeem Oozeer , Bruce Bassett

Sensing with undetected photons enables the measurement of absorption and phase shifts at wavelengths different from those detected. Here, we experimentally map the balance and loss parameter space in a non-degenerate nonlinear…

We present a Bayesian framework to establish a power-spectrum space decomposition of frequency tomographic (PSDFT) data for future intensity mapping (IM) experiments. Different from most traditional component-separation methods which work…

天体物理仪器与方法 · 物理学 2023-08-30 Chang Feng , Filipe B. Abdalla

Line-intensity mapping observations will find fluctuations of integrated line emission are attenuated by varying degrees at small scales due to the width of the line emission profiles. This attenuation may significantly impact estimates of…

A detection of the 21 cm signal can provide a unique window of opportunity for uncovering complex astrophysical phenomena at the epoch of reionization and placing constraints on cosmology at high redshifts, which are usually elusive to…

宇宙学与河外天体物理 · 物理学 2024-06-21 Danial Baradaran , Boryana Hadzhiyska , Martin J. White , Noah Sailer

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy models may have similar expansion rates as…

天体物理学 · 物理学 2014-11-18 Kazuhiro Yamamoto , David Parkinson , Takashi Hamana , Robert C. Nichol , Yasushi Suto

Dark matter interactions with massless or very light Standard Model particles, as photons or neutrinos, may lead to a suppression of the matter power spectrum at small scales and of the number of low mass haloes. Bounds on the dark matter…

宇宙学与河外天体物理 · 物理学 2019-01-30 Laura Lopez-Honorez , Olga Mena , Pablo Villanueva-Domingo