Accurate dust temperature determination in a z = 7.13 galaxy

• We report ALMA Band 9 continuum observations of the normal, dusty star-forming galaxy A1689-zD1 at z = 7.13, resulting in a ∼4.6 σ detection at 702 GHz. For the first time, these observations probe the far-infrared spectrum shortward of the emission peak of a galaxy in the Epoch of Reionization (EoR). Together with ancillary data from earlier works, we derive the dust temperature, Td, and mass, Md, of A1689-zD1 using both traditional modified blackbody spectral energy density fitting, and a new method that relies only on the [C ii] 158 μm line and underlying continuum data. The two methods give Td = (42+13-7, 40+13-) K, and Md} = (1.7+1.3-0.7, 2.0+1.8-1.0), ×, 107, M⊙. Band 9 observations improve the accuracy of the dust temperature (mass) estimate by ∼50 per cent (6 times). The derived temperatures confirm the reported increasing Td-redshift trend between z = 0 and 8; the dust mass is consistent with a supernova origin. Although A1689-zD1 is a normal UV-selected galaxy, our results, implying that ∼85 per cent of its star-formation rate is obscured, underline the non-negligible effects of dust in EoR galaxies.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

dust, extinction

galaxies: evolution

galaxies: individual: (A1689-zD1)

galaxies: formation

submillimetre: galaxies

galaxies: high-redshift

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)