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21cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Adrian Liu , Max Tegmark

We explore the constraining power of future 21cm intensity mapping (IM) observations at the SKAO, focusing primarily on the sum of neutrino masses, $\Sigma m_\nu$. We forecast observations of the 21cm IM auto-power spectrum as well as the…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-29 Gabriele Autieri , Maria Berti , Marta Spinelli , Balakrishna Sandeep Haridasu , Matteo Viel

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…

Deep wide spectral line surveys with the Square Kilometre Array (SKA) will expand the cosmic frontiers of neutral atomic hydrogen (HI) in galaxies. However, at cosmologically significant redshifts ($z \gtrsim 0.5$), detections will…

Astrophysics of Galaxies · Physics 2025-02-12 Charissa Button , Roger Deane

Characterizing the epoch of reionization (EoR) at $z\gtrsim 6$ via the redshifted 21 cm line of neutral Hydrogen (HI) is critical to modern astrophysics and cosmology, and thus a key science goal of many current and planned low-frequency…

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Paolo Comaschi , Andrea Ferrara

Only in recent years has the realization emerged that galaxies do not dominate the universal baryon budget but are merely the brightest pearls of an underlying Cosmic Web. Although the gas in these inter-galactic filaments is moderately to…

Astrophysics · Physics 2009-11-10 Robert Braun

The geosynchronous (GSO) debris environment is continually evolving. Regular monitoring of the region is consequently of great importance, though the trade-off between coverage and sensitivity makes this challenging for the population of…

The Square Kilometre Array (SKA) is a planned radio interferometer of unprecedented scale that will revolutionize low-frequency radio astronomy when completed. In particular, one of its core science drivers is the systematic mapping of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-11 Nichole Barry , Gianni Bernardi , Bradley Greig , Nicholas Kern , Florent Mertens

Automatic image matting (AIM) refers to estimating the soft foreground from an arbitrary natural image without any auxiliary input like trimap, which is useful for image editing. Prior methods try to learn semantic features to aid the…

Computer Vision and Pattern Recognition · Computer Science 2021-07-16 Jizhizi Li , Jing Zhang , Dacheng Tao

The distribution of 21 cm emission from neutral hydrogen is a powerful cosmological and astrophysical probe, as it traces the underlying dark matter and cold gas distributions throughout cosmic times. However, the prediction of observable…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Satvik Mishra , Roberto Trotta , Matteo Viel

The 21 cm spectral line emission of atomic neutral hydrogen (HI) is one of the primary wavelengths observed in radio astronomy. However, the signal is intrinsically faint and the HI content of galaxies depends on the cosmic environment,…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 J. A. Barkai , M. A. W. Verheijen , E. T. Martínez , M. H. F. Wilkinson

We discuss the prospects of using the redshifted 21~cm emission from neutral hydrogen in the post-reionization epoch to study our universe. The main aim of the article is to highlight the efforts of Indian scientists in this area with the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-27 Tapomoy Guha Sarkar , Anjan A Sen

HI 21~cm absorption spectroscopy provides an excellent probe of the neutral gas content of absorbing galaxies, yielding information on their kinematics, mass, physical size and ISM conditions. The high sensitivity, unrivaled frequency…

Astrophysics · Physics 2009-11-10 N. Kanekar , F. H. Briggs

In this short contribution we consider what types of surveys might be optimally pursued with path-finding instruments of 1%, 10% and finally 100% of the projected SKA sensitivity from the perspective of scientific applications that utilize…

Astrophysics · Physics 2007-05-23 Robert Braun

We report an improved technique for diffuse foreground minimization from Cosmic Microwave Background (CMB) maps using a new multi-phase iterative internal-linear-combination (ILC) approach in harmonic space. The new procedure consists of…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-18 Vipin Sudevan , Pavan K. Aluri , Sarvesh Kumar Yadav , Rajib Saha , Tarun Souradeep

The all-sky 408 MHz map of Haslam et al. is one the most important total-power radio surveys. It has been widely used to study diffuse synchrotron radiation from our Galaxy and as a template to remove foregrounds in cosmic microwave…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. Remazeilles , C. Dickinson , A. J. Banday , M. -A. Bigot-Sazy , T. Ghosh

We present an implementation of a blind source separation algorithm to remove foregrounds off millimeter surveys made by single-channel instruments. In order to make possible such a decomposition over single-wavelength data: we generate…

We compare multiple foreground-cleaning pipelines for estimating the tensor-to-scalar ratio, $r$, using simulated maps of the planned CMB-S4 experiment within the context of the South Pole Deep Patch. To evaluate robustness, we analyze bias…

Line intensity mapping (LIM) is a rapidly emerging technique for constraining cosmology and galaxy formation using multi-frequency, low angular resolution maps. Many LIM applications crucially rely on cross-correlations of two line…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-29 Emmanuel Schaan , Martin White