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.
Large-scale structure of Universe
Galaxies: luminosity function
Mass function
Galaxies: ISM
Galaxies: star formation
Galaxies: high-redshift
Cosmic background radiation
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
Groupement d’Intérêt Scientifique French Center
Grenoble Alpes University
J. Bounmy
Groupement d’Intérêt Scientifique French Center
Grenoble Alpes University
M. Calvo
Grenoble Alpes University
Groupement d’Intérêt Scientifique French Center
A. Catalano
Grenoble Alpes University
Groupement d’Intérêt Scientifique French Center
S. Cora
National University of La Plata
D. Croton
Swinburne University of Technology
ARC Centre of Excellence for All-sky Astrophysics (CAASTRO)
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’Intérêt Scientifique French Center
C. Hoarau
Groupement d’Intérêt Scientifique French Center
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’Intérêt Scientifique French Center
Grenoble Alpes University
J. Marpaud
Grenoble Alpes University
Groupement d’Intérêt Scientifique French Center
G. Mellema
The Oskar Klein Centre
A. Monfardini
Grenoble Alpes University
Groupement d’Intérêt Scientifique French Center
Andrea Pallottini
Scuola Normale Superiore di Pisa
N. Ponthieu
Groupement d’Intérêt Scientifique French Center
Grenoble Alpes University
F. Prada
Spanish National Research Council (CSIC)
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 A16Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Signal Processing
DOI
10.1051/0004-6361/202245151