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We present a catalogue of HI sources extracted from the MIGHTEE survey data cubes covering the COSMOS field. The catalogue contains 293 sources in the redshift range of 0.004 < z < 0.093. In addition to HI masses and velocity widths, the…

We present methods and results from "21-cm Spectral Line Observations of Neutral Gas with the EVLA" (21-SPONGE), a large survey for Galactic neutral hydrogen (HI) absorption with the Karl G. Jansky Very Large Array (VLA). With the upgraded…

Detecting neutral Hydrogen (H\,{\sc i}) via the 21~cm line emission from the intergalactic medium at $z\gtrsim 6$ has been identified as one of the most promising probes of the epoch of cosmic reionization -- a major phase transition of the…

宇宙学与河外天体物理 · 物理学 2018-07-04 Nithyanandan Thyagarajan , Chris Carilli , Bojan Nikolic

This paper describes the Duchamp source finder, a piece of software designed to find and describe sources in 3-dimensional, spectral-line data cubes. Duchamp has been developed with HI (neutral hydrogen) observations in mind, but is widely…

天体物理仪器与方法 · 物理学 2012-04-12 Matthew T. Whiting

We have selected a sample of 80 candidates for obscured radio-loud active galactic nuclei and presented their basic optical/near-infrared (NIR) properties in Paper 1. In this paper, we present both high-resolution radio continuum images for…

星系天体物理 · 物理学 2016-03-16 Ting Yan , John T. Stocke , Jeremy Darling , Emmanuel Momjian , Soniya Sharma , Nissim Kanekar

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

Large Scale Structures (LSS) in the universe can be traced using the neutral atomic hydrogen HI through its 21cm emission. Such a 3D matter distribution map can be used to test the Cosmological model and to constrain the Dark Energy…

宇宙学与河外天体物理 · 物理学 2015-05-30 R. Ansari , J. E. Campagne , P. Colom , J. M. Le Goff , C. Magneville , J. M. Martin , M. Moniez , J. Rich , C. Yèche

Extracting the neutral hydrogen (HI) signal is a great challenge for cosmological 21cm experiments, both the astrophysical foregrounds and the receiver noise are typically several orders of magnitude greater than the 21cm signal. However,…

宇宙学与河外天体物理 · 物理学 2019-06-14 Qizhi Huang , Fengquan Wu , Reza Ansari , Xuelei Chen

Modern large radio continuum surveys have high sensitivity and resolution, and can resolve previously undetected extended and diffuse emissions, which brings great challenges for the detection and morphological classification of extended…

天体物理仪器与方法 · 物理学 2023-06-27 Baoqiang Lao , Sumit Jaiswal , Zhen Zhao , Leping Lin , Junyi Wang , Xiaohui Sun , Shengli Qin

Different physical processes in galaxy evolution, such as galaxy mergers that lead to coalescence of dual Active Galactic Nuclei (AGN) and outflows emanating from the narrow line region, can leave their imprint on the optical spectra of AGN…

星系天体物理 · 物理学 2022-09-08 Rajeshwari Dutta , Raghunathan Srianand

We present and discuss European VLBI Network UHF band spectral line observations, made to localise the redshifted 21cm HI absorption known to occur in the subgalactic sized compact steep spectrum galaxies 3C 49 and 3C 268.3. We have…

天体物理学 · 物理学 2009-11-11 A. Labiano , R. C. Vermeulen , P. D. Barthel , C. P. O'Dea , J. F. Gallimore , S. Baum , W. de Vries

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the…

星系天体物理 · 物理学 2022-01-05 Emily F. Kerrison , Vanessa A. Moss , Elaine M. Sadler , James R. Allison

Neutral Hydrogen (HI) provides a very important fuel for star formation, but is difficult to detect at high redshift due to weak emission, limited sensitivity of modern instruments, and terrestrial radio frequency interference (RFI) at low…

星系天体物理 · 物理学 2016-07-20 Lucas R. Hunt , D. J. Pisano , Stanislav S. Edel

We have undertaken a survey for HI 21-cm absorption within the host galaxies of z ~ 1.2 - 1.5 radio sources, in the search of the cool neutral gas currently "missing" at z > 1. This deficit is believed to be due to the optical selection of…

宇宙学与河外天体物理 · 物理学 2015-06-12 S. J. Curran , M. T. Whiting , A. Tanna , E. M. Sadler , M. B. Pracy , R. Athreya

The upcoming Square Kilometre Array Observatory (SKAO) will produce images of neutral hydrogen distribution during the epoch of reionization by observing the corresponding 21-cm signal. However, the 21-cm signal will be subject to…

Observations of neutral hydrogen can provide a wealth of information about the kinematics of galaxies. To learn more about the large scale structures and accretion processes, the extended environment of galaxies have to be observed.…

宇宙学与河外天体物理 · 物理学 2015-05-20 Attila Popping , Robert Braun

The 21 cm hyperfine transition of the atomic hydrogen (HI) in ground state is a powerful probe of the neutral gas content of the universe. This radio frequency transition has been used routinely for decades to observe, both in emission and…

星系天体物理 · 物理学 2019-11-26 Preetha Saha , Nirupam Roy , Mukul Bhattacharya

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…

天体物理仪器与方法 · 物理学 2024-11-04 Jack Phelps

We present the MUSE Hubble Ultra Deep Survey, a mosaic of nine MUSE fields covering 90\% of the entire HUDF region with a 10-hour deep exposure time, plus a deeper 31-hour exposure in a single 1.15 arcmin2 field. The improved observing…

The low-frequency component of the upcoming Square Kilometre Array Observatory (SKA-Low) will be sensitive enough to construct 3D tomographic images of the 21-cm signal distribution during reionisation. However, foreground contamination…