English
Related papers

Related papers: The Correlation Calibration of PAPER-64 data

200 papers

Observations of the HI 21cm transition line promises to be an important probe into the cosmic dark ages and epoch of reionization. One of the challenges for the detection of this signal is the accuracy of the foreground source removal. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Datta , S. Bhatnagar , C. L. Carilli

Foreground power dominates the measurements of interferometers that seek a statistical detection of highly-redshifted HI emission from the Epoch of Reionization (EoR). The chromaticity of the instrument creates a boundary in the Fourier…

The precise form of the foregrounds for sky-averaged measurements of the 21-cm line during and before the epoch of reionization is unknown. We suggest that the level of complexity in the foreground models used to fit global 21-cm data…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-26 Geraint Harker

Cosmic baryon evolution during the Cosmic Dawn and Reionization results in redshifted 21-cm spectral distortions in the cosmic microwave background (CMB). These encode information about the nature and timing of first sources over redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-04 Mayuri Sathyanarayana Rao , Ravi Subrahmanyan , N Udaya Shankar , Jens Chluba

We perform a Fisher analysis to estimate the expected constraints on the Epoch of Reionization (EoR) model parameters (i.e., minimum virial temperature, the ionizing efficiency and the mean free path of ionizing photons) taking into account…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-04 Hayato Shimabukuro , Shintaro Yoshiura , Keitaro Takahashi , Shuichiro Yokoyama , Kiyotomo Ichiki

Intensity mapping of the HI 21 cm line and the CO 2.61 mm line from the epoch of reionization has emerged as powerful, complementary, probes of the high-redshift Universe. However, both maps and their cross-correlation are dominated by…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-11 Meng Zhou , Jianrong Tan , Yi Mao

We present a catalog of spectral measurements covering a 100-200 MHz band for 32 sources, derived from observations with a 64-antenna deployment of the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) in South…

A number of experiments are currently working towards a measurement of the 21 cm signal from the Epoch of Reionization. Whether or not these experiments deliver a detection of cosmological emission, their limited sensitivity will prevent…

A detection of the 21-cm signal power spectrum from the Epoch of Reionization is imminent, thanks to consistent advancements from telescopes such as LOFAR, MWA, and HERA, along with the development of SKA. In light of this progress, it is…

We present an efficient method to generate large simulations of the Epoch of Reionization (EoR) without the need for a full 3-dimensional radiative transfer code. Large dark-matter-only simulations are post-processed to produce maps of the…

Redshifted H{\sc\,i} 21 cm emission from unresolved low-redshift large scale structure is a promising window for ground-based Baryon Acoustic Oscillations (BAO) observations. A major challenge for this method is separating the cosmic signal…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Hee-Jong Seo , Christopher M. Hirata

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

Detection of the redshifted 21cm-line signal from neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR) is complicated by intense foregrounds such as galactic synchrotron and extragalactic radio galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-31 Kenji Kubota , Shintaro Yoshiura , Keitaro Takahashi , Kenji Hasegawa , Hidenobu Yajima , Masami Ouchi , B. Pindor , R. L. Webster

Spectral measurements of the 21 cm monopole background have the promise of revealing the bulk energetic properties and ionization state of our universe from z ~ 6-30. Synchrotron foregrounds are orders of magnitude larger than the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-08 Eric R. Switzer , Adrian Liu

The GMRT Epoch of Reionization (EoR) experiment is an ongoing effort to measure the power spectrum from neutral hydrogen at high redshift. We have previously reported an upper limit of (70 mK)^2 at wavenumbers of k=0.65 h/Mpc using a basic…

We test the hypothesis that limitations in the sky model used to calibrate an interferometric radio telescope, where the model contains extended radio sources, will generate bias in the Epoch of Reionisation (EoR) power spectrum. The…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 Cathryn M. Trott , Randall B. Wayth

The Epoch of Reionization (EoR) remains a poorly understood cosmic era for the most part. Yet, efforts are still going on to probe and understand this epoch. We present a review of the latest developments in the techniques (especially…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-26 Chandra Shekhar Murmu , Raghunath Ghara , Suman Majumdar , Kanan K. Datta

The primary challenge for experiments measuring the neutral hydrogen power spectrum from the Epoch of Reionization (EoR) are mode-mixing effects where foregrounds from very bright astrophysical sources interact with the instrument to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Bryna J. Hazelton , Miguel F. Morales , Ian S. Sullivan

Confidence calibration is critical for the safe deployment of machine learning models in the real world. However, such issue in vision-language models like CLIP, particularly after fine-tuning, has not been fully addressed. In this work, we…

Machine Learning · Computer Science 2025-05-30 Shuoyuan Wang , Yixuan Li , Hongxin Wei

The cross-correlation between 21-cm intensity mapping experiments and photometric surveys of galaxies (or any other cosmological tracer with a broad radial kernel) is severely degraded by the loss of long-wavelength radial modes due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-19 Caroline Guandalin , Isabella P. Carucci , David Alonso , Kavilan Moodley