The dust emissivity index β in infrared-bright galaxies at 1.5 &lt; <i>z</i> &lt; 4.2
ABSTRACT We have measured the dust emissivity index $\beta$ for 21 infrared-bright sources (including several gravitationally lensed galaxies) at $1.5 &lt; z &lt; 4.2$ using Atacama Large Millimetre/submillimetre Array 101–199 GHz data sampling the Rayleigh–Jeans side of the spectral energy distribution. These data are largely insensitive to temperature variations and therefore should provide robust measurements of $\beta$. We obtain a mean $\beta$ of 2.2 with a standard deviation of 0.6 that is at the high end of the range of values that had previously been measured in many galactic and extragalactic sources. We find no systematic variation in $\beta$ versus redshift. We also demonstrate with a subset of our sources that these higher $\beta$ values have significant implications for modelling dust emission and in particular for calculating dust masses or the wavelength at which dust becomes optically thick.
Authors
- S. Urquhart (ORCID: https://orcid.org/0000-0001-9708-3831)
- Dominik A. Riechers
- P. Temi (ORCID: https://orcid.org/0000-0002-8341-342X)
- D. Ismail (ORCID: https://orcid.org/0009-0007-2281-4944)
- Stephen Serjeant (ORCID: https://orcid.org/0000-0002-0517-7943)
- Takafumi Tsukui (ORCID: https://orcid.org/0000-0002-1499-6377)
- Hiddo Algera (ORCID: https://orcid.org/0000-0002-4205-9567)
- G. J. Bendo (ORCID: https://orcid.org/0000-0001-9250-713X)
- S. Berta (ORCID: https://orcid.org/0000-0002-0320-1532)
- M. W. L. Smith (ORCID: https://orcid.org/0000-0002-3532-6970)
- Aristeidis Amvrosiadis (ORCID: https://orcid.org/0000-0002-4465-1564)
- Masato Hagimoto (ORCID: https://orcid.org/0000-0001-8083-5814)
- Tom J. L. C. Bakx
- P. Cox (ORCID: https://orcid.org/0000-0003-2027-8221)
- C. Vlahakis
- L. Bonavera (ORCID: https://orcid.org/0000-0001-8039-3876)
- G. de Zotti (ORCID: https://orcid.org/0000-0003-2868-2595)
- S. Eales
- J. González-Nuevo (ORCID: https://orcid.org/0000-0003-1354-6822)
Institutions
- Hiroshima University (JP)
- Australian National University (AU)
- Ames Research Center (US)
- Centre National de la Recherche Scientifique (FR)
- Institute of Astronomy and Astrophysics, Academia Sinica (TW)
- Universidad de Oviedo (ES)
- University of Cologne (DE)
- Durham University (GB)
- The Open University (GB)
- National Radio Astronomy Observatory (US)
- Institut d'Astrophysique de Paris (FR)
- Observatoire astronomique de Strasbourg (FR)
- University of Manchester (GB)
- Sorbonne Université (FR)
- Institut de Radioastronomie Millimétrique (FR)
- ARC Centre of Excellence for All-sky Astrophysics (AU)
- Osservatorio Astronomico di Padova (IT)
- National Astronomical Observatory of Japan (JP)
- Nagoya University (JP)
- Chalmers University of Technology (SE)
- Université de Strasbourg (FR)
- Cardiff University (GB)
- Netherlands Institute for Radio Astronomy (NL)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2025-05-19
- DOI
- https://doi.org/10.1093/mnras/staf816
- Citations
- 4
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 4.62
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- National Radio Astronomy Observatory
- Deutsche Forschungsgemeinschaft
- Korea Astronomy and Space Science Institute
- National Astronomical Observatory of Japan
- Science and Technology Facilities Council
- Japan Society for the Promotion of Science
- National Institutes of Natural Sciences
- Agencia Estatal de Investigación