The dust emissivity index β in infrared-bright galaxies at 1.5 < z < 4.2
Journal article, 2025
We have measured the dust emissivity index for 21 infrared-bright sources (including several gravitationally lensed galaxies) at <![CDATA[$1.5 < z 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. We obtain a mean 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 versus redshift. We also demonstrate with a subset of our sources that these higher values have significant implications for modelling dust emission and in particular for calculating dust masses or the wavelength at which dust becomes optically thick.
submillimetre: galaxies
galaxies: ISM
infrared: galaxies
galaxies: high-redshift
Author
G. J. Bendo
University of Manchester
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
H. Algera
National Astronomical Observatory of Japan
Hiroshima University
Academia Sinica
A. Amvrosiadis
Durham University
S. Berta
Institut de Radioastronomie Millimétrique (IRAM)
L. Bonavera
Instituto Universitario de Ciencias y Tecnologías Espaciales de Asturias (ICTEA)
University of Oviedo
P. Cox
Institut d 'Astrophysique de Paris
G. De Zotti
Istituto nazionale di astrofisica (INAF)
S. Eales
Cardiff University
J. González-Nuevo
Instituto Universitario de Ciencias y Tecnologías Espaciales de Asturias (ICTEA)
University of Oviedo
Masato Hagimoto
Nagoya University
D. Ismail
Observatoire Astronomique de Strasbourg
D. A. Riechers
University of Cologne
S. Serjeant
Open University
M. W.L. Smith
Cardiff University
P. Temi
National Aeronautics and Space Administration (NASA)
Takafumi Tsukui
Australian National University
S. Urquhart
Open University
C. Vlahakis
National Radio Astronomy Observatory
Monthly Notices of the Royal Astronomical Society
00358711 (ISSN) 13652966 (eISSN)
Vol. 540 2 1560-1577Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1093/mnras/staf816