LIGHTS: Limitations of far-infrared tracers for Galactic cirrus mitigation in the era of ultra-deep imaging
Year: 2026
Type: article
Abstract: Current and forthcoming deep optical imaging surveys reach surface brightness levels fainter than 30 mag/arcsec 2 , where Galactic cirrus emission becomes a significant contaminant. This poses a major challenge for the study of extremely low-surface-brightness extragalactic structures. We investigated the relationship between far-infrared emission, as traced by the Herschel 250 μm band, and optical surface brightness in the Sloan g and r bands. We find that, for Galactic cirrus with μ g ≳ 27 mag/arcsec 2 , a linear relation is consistent with the data, assuming optically thin dust, with optical cirrus emission amounting to ∼0.1% of the far-infrared flux. Using Herschel far-infrared data to trace Galactic cirrus enables its identification over wide areas but at the cost of significantly reducing spatial resolution. This limitation introduces source confusion and restricts the effective surface brightness depth that can be robustly probed in optical data. We show that, when cirrus emission is modeled using Herschel 250 μm data, the limiting surface brightness is μ V ∼ 28 mag/arcsec 2 . This is substantially shallower than the nominal depth of surveys such as LIGHTS or the 10-year co-added LSST ( μ V ∼ 30.5 mag/arcsec 2 ). These results highlight a fundamental limitation in the use of currently available far-infrared data for cirrus mitigation in ultra-deep optical imaging and emphasize the need for higher-resolution cirrus tracers to fully exploit the depth of upcoming surveys.
Source: Astronomy and Astrophysics
Authors: Ouldouz Kaboud, Ignacio Trujillo, Ignacio Ruiz Cejudo, S. Zahra Hosseini-ShahiSavandi, Mireia Montes, Sergio Guerra Arencibia, Mauro D’Onofrio, Dennis Zaritsky, Javier Román, Nushkia Chamba, Giulia Golini, Chen-Yu Chuang, Minh Ngoc Le, Carlos Marrero-de la Rosa, Zahra Sharbaf, Richard Donnerstein, Sepideh Eskandarlou, Raúl Infante-Sainz, Garreth Martin, Samane Raji, Nafise Sedighi
Institutions: Institute of Space Sciences, University of Padua, Universidad de La Laguna, Instituto de Astrofísica de Canarias, University of Arizona, University of Córdoba, Ames Research Center, UNSW Sydney, Centro de Estudios de Física del Cosmos de Aragón, University of Nottingham, Universidad de Valladolid
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: Ohio State University, University of Minnesota, University of Arizona, University of Notre Dame, Arizona Board of Regents, European Commission, Ministerio de Ciencia e Innovación, Istituto Nazionale di Astrofisica, Universidad de Córdoba, Leibniz-Institut für Astrophysik Potsdam, Instituto de Astrofísica de Canarias, European Centre for Medium-Range Weather Forecasts, HORIZON EUROPE Framework Programme, Leibniz-Gemeinschaft, Agencia Estatal de Investigación
Awards: G1401168639, G1855990336, G2257393230, G2309174360, G252646220, G2660406951, Unravelling the Dark Universe from the Canary Islands Observatories, G2971730108, G3518538256, G4267812785, G430777504, G5049803760, G5195188938, G5421974903, G5622099616, Excellence in Galaxies - Twinning the IAC, G8575141037, G8920660035, G9000451760, G99296377
OpenAlex ID: W7215887566