ALMACAL VII: First Interferometric Number Counts at 650 μm

Klitsch, A.; Zwaan, M.A.; Smail, I.; Péroux, C.; Biggs, A.D.; Chen, C-C.; Ivison, R.J.; Popping, G.; Lagos, C.; Béthermin, M.; Swinbank, A.M.; Hamanowicz, A.; Dutta, R.

Abstract

Measurements of the cosmic far-infrared background (CIB) indicate that emission from many extragalactic phenomena, including star formation and black hole accretion, in the Universe can be obscured by dust. Resolving the CIB to study the population of galaxies in which this activity takes place is a major goal of submillimetre astronomy. Here, we present interferometric 650휇m submillimetre number counts. Using the Band 8 data from the ALMACAL survey, we have analysed 81 ALMA calibrator fields together covering a total area of 5.5 arcmin2 . The typical central rms in these fields is ∼ 100휇Jy beam−1 with the deepest maps reaching 휎 = 47휇Jy beam−1 at sub-arcsec resolution. Multi-wavelength coverage from ALMACAL allows us to exclude contamination from jets associated with the calibrators. However, residual contamination by jets and lensing remain a possibility. Using a signal-to-noise threshold of 4.5휎, we find 21 dusty, star-forming galaxies with 650휇m flux densities of ≥ 0.7mJy. At the detection limit we resolve ' 100 per cent of the CIB at 650휇m, a significant improvement compared to low resolution studies at similar wavelength. We have therefore identified all the sources contributing to the EBL at 650 microns and predict that the contribution from objects with flux 0.7

Citation

Klitsch, A., Zwaan, M., Smail, I., Péroux, C., Biggs, A., Chen, C.-C., Ivison, R., Popping, G., Lagos, C., Béthermin, M., Swinbank, A., Hamanowicz, A., & Dutta, R. (2020). ALMACAL VII: First Interferometric Number Counts at 650 μm. Monthly Notices of the Royal Astronomical Society, 495(2), 2332-2341. https://doi.org/10.1093/mnras/staa1315

• Journal Article Type: Article
• Acceptance Date: May 1, 2020
• Online Publication Date: May 12, 2020
• Publication Date: Jun 30, 2020
• Deposit Date: May 13, 2020
• Publicly Available Date: May 13, 2020
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 495
• Issue: 2
• Pages: 2332-2341
• DOI: https://doi.org/10.1093/mnras/staa1315
• Public URL: https://durham-repository.worktribe.com/output/1302298