Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

z-GAL: A NOEMA spectroscopic redshift survey of bright Herschel galaxies II. Dust properties

Ismail, D., Beelen, A., Buat, V., Berta, S., Cox, P., Stanley, F., Young, A., Jin, S., Neri, R., Bakx, T., Dannerbauer, H., Butler, K., Cooray, A., Nanni, A., Omont, A., Serjeant, S., van der Werf, P., Vlahakis, C., Weiß, A., Yang, C., Baker, A. J., Bendo, G., Borsato, E., Chartab, N., Dye, S., Eales, S., Gavazzi, R., Hughes, D., Ivison, R., Jones, B. M., Krips, M., Lehnert, M., Marchetti, L., Messias, H., Negrello, M. ORCID:, Perez-Fournon, I., Riechers, D. A. and Urquhart, S. 2023. z-GAL: A NOEMA spectroscopic redshift survey of bright Herschel galaxies II. Dust properties. Astronomy & Astrophysics 678 , A27. 10.1051/0004-6361/202346804

[thumbnail of aa46804-23.pdf] PDF - Published Version
Available under License Creative Commons Attribution.

Download (35MB)


We present the dust properties of 125 bright Herschel galaxies selected from the z-GAL NOEMA spectroscopic redshift survey. All the galaxies have precise spectroscopic redshifts in the range 1.3 < z < 5.4. The large instantaneous bandwidth of NOEMA provides an exquisite sampling of the underlying dust continuum emission at 2 and 3 mm in the observed frame, with flux densities in at least four sidebands for each source. Together with the available Herschel 250, 350, and 500 μm and SCUBA-2 850 μm flux densities, the spectral energy distribution (SED) of each source can be analyzed from the far-infrared to the millimeter, with a fine sampling of the Rayleigh-Jeans tail. This wealth of data provides a solid basis to derive robust dust properties, in particular the dust emissivity index (β) and the dust temperature (Tdust). In order to demonstrate our ability to constrain the dust properties, we used a flux-generated mock catalog and analyzed the results under the assumption of an optically thin and optically thick modified black body emission. The robustness of the SED sampling for the z-GAL sources is highlighted by the mock analysis that showed high accuracy in estimating the continuum dust properties. These findings provided the basis for our detailed analysis of the z-GAL continuum data. We report a range of dust emissivities with β ∼ 1.5 − 3 estimated up to high precision with relative uncertainties that vary in the range 7%−15%, and an average of 2.2 ± 0.3. We find dust temperatures varying from 20 to 50 K with an average of Tdust ∼ 30 K for the optically thin case and Tdust ∼ 38 K in the optically thick case. For all the sources, we estimate the dust masses and apparent infrared luminosities (based on the optically thin approach). An inverse correlation is found between Tdust and β with β ∝ Tdust−0.69, which is similar to what is seen in the local Universe. Finally, we report an increasing trend in the dust temperature as a function of redshift at a rate of 6.5 ± 0.5 K/z for this 500 μm-selected sample. Based on this study, future prospects are outlined to further explore the evolution of dust temperature across cosmic time.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Publisher: EDP Sciences
ISSN: 0004-6361
Date of First Compliant Deposit: 21 February 2024
Date of Acceptance: 5 July 2023
Last Modified: 21 Feb 2024 10:46

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics