English
Related papers

Related papers: Simulated multi-tracer analyses with HI intensity …

200 papers

Multiple tracers of the cosmic density field, with different bias, number and luminosity evolution, can be used to measure the large-scale properties of the Universe. We show how an optimal combination of tracers can be used to detect…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 David Alonso , Pedro G. Ferreira

We investigate the feasibility of measuring the effects of peculiar velocities in large-scale structure using the dipole of the redshift-space cross-correlation function. We combine number counts of galaxies with brightness-temperature…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-01 Alex Hall , Camille Bonvin

We investigate the prospect of constraining scalar field dark energy models using HI 21-cm intensity mapping surveys. We consider a wide class of coupled scalar field dark energy models whose predictions about the background cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Azam Hussain , Shruti Thakur , Tapomoy Guha Sarkar , Anjan A Sen

The 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR) but suffers from contamination by spectrally smooth foregrounds, which obscure the large-scale signal along the line of sight. We explore the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Wenzer Qin , Kai-Feng Chen , Katelin Schutz , Adrian Liu

After reionization, neutral hydrogen (HI) traces the large-scale structure (LSS) of the Universe, enabling HI intensity mapping (IM) to capture the LSS in 3D and constrain key cosmological parameters. We present a new framework utilizing…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-10 Eishica Chand , Arka Banerjee , Simon Foreman , Francisco Villaescusa-Navarro

Using multiple tracers of large-scale structure allows to evade the limitations imposed by sampling variance for some parameters of interest in cosmology. We demonstrate the optimal way of carrying out a multitracer analysis in a galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-22 Nico Hamaus , Uroš Seljak , Vincent Desjacques

We investigate the effect of radio-frequency interference (RFI) excision in estimating the cosmological \hi\ 21 cm power spectrum. Flagging of RFI-contaminated channels results in a non-uniform sampling of the instrumental bandpass…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 Arnab Chakraborty , Abhirup Datta , Aishrila Mazumder

Cross-correlations between 21cm observations and galaxy surveys provide a powerful probe of reionization by reducing foreground sensitivity while linking ionization morphology to galaxies. We quantify the constraining power of 21cm-Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Yannic Pietschke , Anne Hutter , Caroline Heneka

We present a comprehensive set of forecasts for the cross-correlation signal between 21cm intensity mapping and galaxy redshift surveys. We focus on the data sets that will be provided by the SKAO for the 21cm signal, DESI and Euclid for…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-10 Maria Berti , Marta Spinelli , Matteo Viel

Intensity mapping experiments survey the spectrum of diffuse line radiation rather than detect individual objects at high signal-to-noise. Spectral maps of unresolved atomic and molecular line radiation contain three-dimensional information…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-19 Eric R. Switzer , Tzu-Ching Chang , Kiyoshi W. Masui , Ue-Li Pen , Tabitha C. Voytek

Measuring the total neutrino mass is one of the most exciting opportunities available with next-generation cosmological data sets. We study the possibility of detecting the total neutrino mass using large-scale clustering in 21cm intensity…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 Mario Ballardini , Roy Maartens

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

Line intensity mapping using atomic hydrogen (HI) has the potential to efficiently map large volumes of the universe if the signal can be successfully separated from overwhelmingly bright radio foreground emission. This motivates…

We conduct the first case study towards developing optimal foreground mitigation strategies for neutral hydrogen (HI) intensity mapping using radio interferometers at low redshifts. A pipeline for simulation, foreground mitigation and power…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-08 Zhaoting Chen , Laura Wolz , Richard Battye

Next-generation cosmological surveys will observe larger cosmic volumes than ever before, enabling us to access information on the primordial Universe, as well as on relativistic effects. We consider forthcoming 21cm intensity mapping…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-08 Jan-Albert Viljoen , José Fonseca , Roy Maartens

Removing contaminants is a delicate, yet crucial step in neutral hydrogen (HI) intensity mapping and often considered the technique's greatest challenge. Here, we address this challenge by analysing HI intensity maps of about $100$ deg$^2$…

A detection of the predicted anticorrelation between 21cm and either Ly-alpha or H-alpha from the Epoch of Reionization (EOR) would be a powerful probe of the first galaxies. While 3D intensity maps isolate foregrounds in low k_\parallel…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-06 Abraham R. Neben , Brian Stalder , Jacqueline N. Hewitt , John L. Tonry

Foreground removal is the most important step in detecting the large-scale redshifted HI 21-cm signal. Modelling foreground spectra is challenging and is further complicated by the chromatic response of the telescope. We present a…

Instrumentation and Methods for Astrophysics · Physics 2017-07-19 Visweshwar Ram Marthi , Suman Chatterjee , Jayaram Chengalur , Somnath Bharadwaj

Estimating the auto power spectrum of cosmological tracers from line-intensity mapping (LIM) data is often limited by instrumental noise, residual foregrounds, and systematics. Cross-power spectra between multiple lines offer a robust…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 Debanjan Sarkar , Ella Iles , Adrian Liu