The Herschel-SPIRE Dark Field - II. A P(D) fluctuation analysis of the deepest Herschel image of the submillimetre universe
File(s)
Published version
Author(s)
Varnish, Thomas WO
Wu, Xinni
Pearson, Chris
Clements, David L
Parmar, Ayushi
Type
Journal Article
Abstract
The Herschel-SPIRE Dark Field is the deepest field produced by the SPIRE instrument pushing down below the galaxy confusion limit in each of the 250, 350, 500 μm bands. Standard source extraction techniques inevitably fail because of this, and we must turn to statistical methods. Here, we present a P(D) – probability of deflection – analysis of a 12' diameter region of uniform coverage at the centre of the Herschel-SPIRE Dark Field. Comparing the distribution of pixel fluxes from our observations to the distributions predicted by current literature models, we find that none of the most recent models can accurately recreate our observations. Using a P(D) analysis, we produce a fitted differential source count spline with a bump in the source counts at faint flux densities, followed by a turnover at fainter fluxes, required to fit the observations. This indicates a possible missing component from the current literature models that could be interpreted perhaps as a new population of galaxies, or a missing aspect of galaxy evolution. Taking our best-fitting results, we also calculate the contribution to the cosmic infrared background (CIB) in each of the bands, which all agree with the Planck CIB measurements in this field.
Date Issued
2025-05-01
Date Acceptance
2025-02-10
Citation
Monthly Notices of the Royal Astronomical Society, 2025, 539 (1), pp.347-354
ISSN
0035-8711
Publisher
Oxford University Press
Start Page
347
End Page
354
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
539
Issue
1
Copyright Statement
© 2025 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
10.1093/mnras/staf318
Subjects
Astronomy & Astrophysics
ATLAS
cosmology: observations
EVOLUTION
galaxies: evolution
GALAXY NUMBER COUNTS
HERMES
INFRARED-EMISSION
MU-M
Physical Sciences
Science & Technology
submillimetre: diffuse background
submillimetre: galaxies
Publication Status
Published
Date Publish Online
2025-04-10