Cosmic Infrared Background

Cosmic Infrared Background
Name	Cosmic Infrared Background
Wavelength	Infrared (near-IR to far-IR)
Discovered	Late 20th century
Instruments	COBE, Spitzer, Herschel, Planck, JWST

Cosmic Infrared Background

The Cosmic Infrared Background is the diffuse extragalactic infrared radiation field that integrates emission from unresolved sources across cosmic time. It is studied to constrain formation histories associated with Hubble Space Telescope, James Webb Space Telescope, Spitzer Space Telescope, Herschel Space Observatory and missions like Cosmic Background Explorer and Planck. Measurements involve collaborations among institutions such as NASA, European Space Agency, Jet Propulsion Laboratory, and observatories including Keck Observatory, Very Large Telescope and Atacama Large Millimeter Array.

Introduction

The Cosmic Infrared Background (CIB) traces cumulative radiation from dusty star-forming galaxies, active galactic nuclei and early structures during epochs probed by surveys from Infrared Astronomical Satellite to Wide-field Infrared Survey Explorer and follow-ups by Subaru Telescope and Palomar Observatory. Studies connect to landmark programs like the Great Observatories Origins Deep Survey, the Hubble Ultra-Deep Field and the CANDELS project. Investigations often reference theoretical frameworks developed by researchers affiliated with California Institute of Technology, Harvard–Smithsonian Center for Astrophysics, Max Planck Institute for Astronomy and Institute of Astronomy, Cambridge.

Observational Measurements and Instruments

Direct detection and fluctuation analysis of the CIB rely on data from Cosmic Background Explorer (COBE) instruments such as DIRBE, on results from Spitzer Space Telescope instruments like IRAC and MIPS, and on far-infrared maps from Herschel instruments PACS and SPIRE. Balloon-borne experiments such as BLAST and submillimeter facilities like South Pole Telescope and James Clerk Maxwell Telescope contributed. Recent high-resolution work uses Atacama Large Millimeter/submillimeter Array (ALMA) and deep surveys by James Webb Space Telescope (JWST), coordinated by teams from European Southern Observatory and Space Telescope Science Institute. Absolute photometry links to calibration efforts from National Institute of Standards and Technology and cross-correlation studies with Sloan Digital Sky Survey and Two Micron All Sky Survey catalogs.

Origin and Contributors

Principal contributors to the CIB include populations of dusty star-forming galaxies, luminous infrared galaxies cataloged by surveys like IRAS and submillimeter galaxies identified by SCUBA, and obscured accretion onto supermassive black holes in active galactic nuclei characterized in Chandra X-ray Observatory and XMM-Newton surveys. High-redshift contributors tie to constraints from observations targeting the Epoch of Reionization and candidates found in Frontier Fields and lensing studies by Hubble Space Telescope and Spitzer. Modeling efforts draw on stellar population synthesis codes developed at University of Arizona, radiative transfer work from Max Planck Institute for Astrophysics, and semi-analytic galaxy formation frameworks used by groups at University of Cambridge and Princeton University.

Spectrum and Anisotropies

The spectral energy distribution of the CIB spans near-infrared through far-infrared and submillimeter bands probed by instruments on COBE, Spitzer, Herschel and Planck. Angular power spectra and anisotropy measurements exploit techniques developed in analyses of the Cosmic Microwave Background by collaborations such as the WMAP team and Planck Collaboration. Cross-power analyses with galaxy catalogs from Sloan Digital Sky Survey and weak lensing maps from Dark Energy Survey provide constraints on bias and clustering, with theoretical interpretation informed by models from Santa Cruz Galaxy Formation Group and simulation suites like the Illustris and EAGLE projects.

Cosmological and Astrophysical Implications

CIB observations inform star-formation rate density histories quantified in studies by Madau and Dickinson compilations and constrain dust-obscured growth of structures relevant to models at Institute for Advanced Study and Lawrence Berkeley National Laboratory. Cross-correlation with Cosmic Microwave Background lensing maps from Planck and Atacama Cosmology Telescope probes matter distribution and halo occupation models developed by researchers at Columbia University and University of Chicago. Limits on Population III star formation, early black hole accretion, and feedback scenarios tie to theoretical work at Kavli Institute for Cosmology and to predictions from numerical simulations by groups at Los Alamos National Laboratory.

Methods of Separation from Foregrounds

Separating the CIB from foregrounds requires modeling of zodiacal light measured by missions like IRAS and COBE/DIRBE, Galactic cirrus emission characterized using Infrared Astronomical Satellite (IRAS) and Planck dust maps, and point-source masking guided by catalogs from Two Micron All Sky Survey (2MASS) and Wide-field Infrared Survey Explorer (WISE). Component-separation algorithms adapt methods from Planck Collaboration and techniques used in WMAP analysis, while independent component analysis and cross-correlation pipelines are implemented by teams at University of California, Berkeley and Institut d'Astrophysique de Paris. Ground-based subtraction uses atmospheric modeling approaches developed for South Pole Telescope and Atacama Cosmology Telescope programs.

Category:Extragalactic background light