CONCERTO: Simulating the CO, [CII], and [CI] line emission of galaxies in a 117 deg2 field and the impact of field-to-field variance
Journal article, 2023

In the submillimeter regime, spectral line scans and line intensity mapping (LIM) are new promising probes for the cold gas content and star formation rate of galaxies across cosmic time. However, both of these two measurements suffer from field-to-field variance. We study the effect of field-to-field variance on the predicted CO and [CII] power spectra from future LIM experiments such as CONCERTO, as well as on the line luminosity functions (LFs) and the cosmic molecular gas mass density that are currently derived from spectral line scans. We combined a 117 deg2 dark matter lightcone from the Uchuu cosmological simulation with the simulated infrared dusty extragalactic sky (SIDES) approach. The clustering of the dusty galaxies in the SIDES-Uchuu product is validated by reproducing the cosmic infrared background anisotropies measured by Herschel and Planck. We find that in order to constrain the CO LF with an uncertainty below 20%, we need survey sizes of at least 0.1 deg2. Furthermore, accounting for the field-to-field variance using only the Poisson variance can underestimate the total variance by up to 80%. The lower the luminosity is and the larger the survey size is, the higher the level of underestimate. At z < 3, the impact of field-to-field variance on the cosmic molecular gas density can be as high as 40% for the 4.6 arcmin2 field, but drops below 10% for areas larger than 0.2 deg2. However, at z > 3 the variance decreases more slowly with survey size and for example drops below 10% for 1 deg2 fields. Finally, we find that the CO and [CII] LIM power spectra can vary by up to 50% in 1 deg2 fields. This limits the accuracy of the constraints provided by the first 1 deg2 surveys. In addition the level of the shot noise power is always dominated by the sources that are just below the detection thresholds, which limits its potential for deriving number densities of faint [CII] emitters. We provide an analytical formula to estimate the field-to-field variance of current or future LIM experiments given their observed frequency and survey size. The underlying code to derive the field-to-field variance and the full SIDES-Uchuu products (catalogs, cubes, and maps) are publicly available.

Galaxies: star formation

Cosmic background radiation

Galaxies: luminosity function

Large-scale structure of Universe

Mass function

Galaxies: high-redshift

Galaxies: ISM

Author

A. Gkogkou

Laboratoire d'Astrophysique de Marseille

Matthieu Béthermin

Laboratoire d'Astrophysique de Marseille

Observatoire Astronomique de Strasbourg

G. Lagache

Laboratoire d'Astrophysique de Marseille

M. Van Cuyck

Laboratoire d'Astrophysique de Marseille

E. Jullo

Laboratoire d'Astrophysique de Marseille

Manuel Aravena

Diego Portales University

A. Beelen

Laboratoire d'Astrophysique de Marseille

A. Benoit

Grenoble Alpes University

Groupement d'Interet Scientifique KID

J. Bounmy

Groupement d'Interet Scientifique KID

Grenoble Alpes University

M. Calvo

Grenoble Alpes University

Groupement d'Interet Scientifique KID

A. Catalano

Grenoble Alpes University

Groupement d'Interet Scientifique KID

S. Cora

National University of La Plata

D. Croton

Swinburne University of Technology

ARC Centre of Excellence for All-sky Astrophysics

S. De La Torre

Laboratoire d'Astrophysique de Marseille

A. Fasano

Laboratoire d'Astrophysique de Marseille

A. Ferrara

Scuola Normale Superiore di Pisa

J. Goupy

Grenoble Alpes University

Groupement d'Interet Scientifique KID

C. Hoarau

Groupement d'Interet Scientifique KID

Grenoble Alpes University

W. Hu

Laboratoire d'Astrophysique de Marseille

T. Ishiyama

Chiba University

Kirsten Knudsen

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

J. C. Lambert

Laboratoire d'Astrophysique de Marseille

J. F. Maciás-Pérez

Groupement d'Interet Scientifique KID

Grenoble Alpes University

J. Marpaud

Grenoble Alpes University

Groupement d'Interet Scientifique KID

G. Mellema

Oskar Klein Centre

A. Monfardini

Grenoble Alpes University

Groupement d'Interet Scientifique KID

Andrea Pallottini

Scuola Normale Superiore di Pisa

N. Ponthieu

Groupement d'Interet Scientifique KID

Grenoble Alpes University

F. Prada

Institute of Astrophysics of Andalusia (IAA)

Y. Roehlly

Laboratoire d'Astrophysique de Marseille

L. Vallini

Scuola Normale Superiore di Pisa

F. Walter

Max Planck Society

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 670 A16

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Signal Processing

DOI

10.1051/0004-6361/202245151

More information

Latest update

2/17/2023