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Related papers: HI intensity mapping with MeerKAT: forecast for de…

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HI intensity mapping is a promising technique to probe large-scale structure, traditionally analyzed via two-point statistics such as the angular power spectrum. This technique has proven very powerful but may miss key non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Pauline Gorbatchev , Jean-Luc Starck , Stefano Camera , Marta Spinelli

Radio interferometric data are used to estimate the sky brightness distributions in radio frequencies. Here we focus on estimators of the large-scale structure and the power spectrum of the sky brightness distribution inferred from radio…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Prasun Dutta , Meera Nandakumar

We present a survey strategy to detect the neutral hydrogen (HI) power spectrum at $5<z<6$ using the SKA-Low radio telescope in presence of foregrounds and instrumental effects. We simulate observations of the inherently weak HI signal…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-27 Zhaoting Chen , Emma Chapman , Laura Wolz , Aishrila Mazumder

A critical challenge in measuring the power spectrum of 21cm emission from cosmic reionization is compensating for the frequency dependence of an interferometer's sampling pattern, which can cause smooth-spectrum foregrounds to appear…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Aaron R. Parsons , Jonathan C. Pober , James E. Aguirre , Christopher L. Carilli , Daniel C. Jacobs , David F. Moore

Holography is an established technique for measuring the wavefront of optical signals through interferometric combination with a reference wave. Conventionally the integration time of a hologram is limited by the interferometer coherence…

Optics · Physics 2023-12-13 Guillaume Thekkadath , Duncan England , Benjamin Sussman

We have considered the prospects for measuring the cross Warm Dark Matter (WDM) power spectrum of the redshifted HI 21-cm signal and the Lyman-$\alpha$ forest and thereby constraining WDM mass using observations with upcoming…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Anjan Kumar Sarkar , Ashis Kumar Pal , Tapomoy Guha Sarkar

Sub-milliarcsecond imaging of nearby main sequence stars and binary systems can provide critical information on stellar phenomena such as rotational deformation, accretion effects, and the universality of starspot (sunspot) cycles.…

Instrumentation and Methods for Astrophysics · Physics 2018-01-22 Dave Kieda , Nolan Matthews

Future total-power single-dish HI intensity mapping (HI IM) surveys have the potential to provide unprecedented insight into late time ($z < 1$) cosmology that are competitive with Stage IV dark energy surveys. However, redshifts between $0…

Instrumentation and Methods for Astrophysics · Physics 2019-03-29 Stuart Harper , Clive Dickinson

In order to study the "Cosmic Dawn" and the Epoch of Reionization with 21 cm tomography, we need to statistically separate the cosmological signal from foregrounds known to be orders of magnitude brighter. Over the last few years, we have…

The 21-cm signal provides a novel avenue to measure the thermal state of the universe during cosmic dawn and reionization (redshifts $z\sim 5-30$), and thus to probe energy injection from decaying or annihilating dark matter (DM). These DM…

High Energy Physics - Phenomenology · Physics 2023-12-20 Yitian Sun , Joshua W. Foster , Hongwan Liu , Julian B. Muñoz , Tracy R. Slatyer

In this paper we compare the performance of multi and single-mode interferometry for the estimation of the phase of the complex visibility. We provide a theoretical description of the interferometric signal which enables to derive the phase…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 E. Tatulli , N. Blind , J. P. Berger , A. Chelli , F. Malbet

HI Intensity Mapping (IM) will be used to do precision cosmology using many existing and upcoming radio observatories. The signal will be contaminated due to absorption, the largest component of which will be the flux absorbed by the HI…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Sambit Roychowdhury , Clive Dickinson , Ian W. A. Browne

The MeerKAT UltraDeep HI Survey aims to observe the 21 cm emission line of neutral hydrogen gas out to a redshift of z=1 and beyond. From both direct detections and stacked signal, we will address the HI mass function, the cosmic neutral…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-26 B. W. Holwerda , S-L. Blyth

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,…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Lin-Cheng Li , Yuan-Gen Wang

Upcoming and future neutral hydrogen Intensity Mapping surveys offer a great opportunity to constrain cosmology in the post-reionization Universe, provided a good accuracy is achieved in the separation between the strong foregrounds and the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-02 Siyambonga D. Matshawule , Marta Spinelli , Mario G. Santos , Sibonelo Ngobese

Considering the upcoming OWFA, we use simulations of the foregrounds and the $z = 3.35$ HI 21-cm intensity mapping signal to identify the $(k_{\perp},k_{\parallel})$ modes where the expected 21-cm power spectrum $P(k_{\perp},k_{\parallel})$…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-21 Suman Chatterjee , Somnath Bharadwaj , Visweshwar Ram Marthi

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…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Pascal M. Keller , Bojan Nikolic , Nithyanandan Thyagarajan , Chris L. Carilli , Gianni Bernardi , Ntsikelelo Charles , Landman Bester , Oleg M. Smirnov , Nicholas S. Kern , Joshua S. Dillon , Bryna J. Hazelton , Miguel F. Morales , Daniel C. Jacobs , Aaron R. Parsons , Zara Abdurashidova , Tyrone Adams , James E. Aguirre , Paul Alexander , Zaki S. Ali , Rushelle Baartman , Yanga Balfour , Adam P. Beardsley , Tashalee S. Billings , Judd D. Bowman , Richard F. Bradley , Philip Bull , Jacob Burba , Steven Carey , Carina Cheng , David R. DeBoer , Eloy de Lera Acedo , Matt Dexter , Nico Eksteen , John Ely , Aaron Ewall-Wice , Nicolas Fagnoni , Randall Fritz , Steven R. Furlanetto , Kingsley Gale-Sides , Brian Glendenning , Deepthi Gorthi , Bradley Greig , Jasper Grobbelaar , Ziyaad Halday , Jacqueline N. Hewitt , Jack Hickish , Austin Julius , MacCalvin Kariseb , Joshua Kerrigan , Piyanat Kittiwisit , Saul A. Kohn , Matthew Kolopanis , Adam Lanman , Paul La Plante , Adrian Liu , Anita Loots , Yin-Zhe Ma , David Harold Edward MacMahon , Lourence Malan , Cresshim Malgas , Keith Malgas , Bradley Marero , Zachary E. Martinot , Andrei Mesinger , Mathakane Molewa , Tshegofalang Mosiane , Steven G. Murray , Abraham R. Neben , Hans Nuwegeld , Robert Pascua , Nipanjana Patra , Samantha Pieterse , Jonathan C. Pober , Nima Razavi-Ghods , James Robnett , Kathryn Rosie , Mario G. Santos , Peter Sims , Craig Smith , Hilton Swarts , Pieter Van Wyngaarden , Peter K. G. Williams , Haoxuan Zheng

Astronomical intensity interferometry enables quantitative measurements of the source geometry by measuring the photon fluxes in individual telescopes and correlating them, rather than correlating the electromagnetic waves' amplitudes. This…

Instrumentation and Methods for Astrophysics · Physics 2023-06-16 Andreas Zmija , Naomi Vogel , Gisela Anton , Dmitry Malyshev , Thilo Michel , Adrian Zink , Stefan Funk

Full-polarization primary beam patterns of MeerKAT antennas have been measured in L-band (856 to 1711 MHz) by means of radio holography using celestial targets. This paper presents the observed frequency dependent properties of these beams,…

Instrumentation and Methods for Astrophysics · Physics 2022-02-21 Mattieu de Villiers , William Cotton

Filaments stand as pivotal structures within the cosmic web. However, direct detection of the cold gas content of the filaments remains challenging due to its inherent low brightness temperature. With the TNG hydrodynamical simulations, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-10 Diyang Liu , Yichao Li , Denis Tramonte , Furen Deng , Jiaxin Wang , Yougang Wang , Xin Zhang , Xuelei Chen
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