Publisher Correction: The evolution of dust attenuation in z ≈ 2–12 galaxies observed by JWST
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Anthropogenic sulfate-climate interactions suppress dust activity over East Asia
Observational evidences indicate a significant decline in dust storm frequencies over the East Asian arid-semiarid region during recent decades, which creates a strong contrast with a great increase in sulfate emissions over monsoonal Asia. However, the causes for decline of dust activities are still controversial. Through conducting a set of idealized sensitivity experiments of regional aerosol perturbations, here we show that anthropogenic sulfate aerosols over monsoonal Asia remarkably suppress the regional dust activities over East Asia. Southward shift of Asian westerly jet stream induced by sulfate aerosols results in increasing precipitation and weakening surface wind speeds over the arid-semiarid region, thereby suppressing local dust emission fluxes. Further, the latest Sixth Coupled Model Intercomparison Project simulations indicate that anthropogenic aerosols partly drive the recent weakening in regional dust activities and that future change of regional dust activities will likely depend on emissions scenarios of Asian anthropogenic aerosols and greenhouse gases.
Photometric detection at 7.7 μm of a galaxy beyond redshift 14 with JWST/MIRI
The James Webb Space Telescope (JWST) has spectroscopically confirmed numerous galaxies at z > 10. While weak rest-frame ultraviolet emission lines have only been seen in a handful of sources, the stronger rest-frame optical emission lines are highly diagnostic and accessible at mid-infrared wavelengths with the Mid-Infrared Instrument (MIRI) of JWST. We report the photometric detection of the distant spectroscopically confirmed galaxy JADES-GS-z14-0 at (z=14.3{2}_{-0.20}^{+0.08}) with MIRI at 7.7 μm. The most plausible solution for the stellar-population properties is that this galaxy contains half a billion solar masses in stars with a strong burst of star formation in the most recent few million years. For this model, at least one-third of the flux at 7.7 μm originates from the rest-frame optical emission lines Hβ and/or [O iii]λλ4959, 5007. The inferred properties of JADES-GS-z14-0 suggest rapid mass assembly and metal enrichment during the earliest phases of galaxy formation. This work demonstrates the unique power of mid-infrared observations in understanding galaxies at the redshift frontier.
Mass and particle size distribution of household dust on children’s hands
Children are vulnerable to household dust exposure; however, to date, a handful of studies simultaneously report both the mass and particle size of household dust found on children’s hands after natural indoor play activities.
Observationally derived magnetic field strength and 3D components in the HD 142527 disk
The magnetic fields in protoplanetary disks around young stars play an important role in disk evolution and planet formation. Measuring the polarized thermal emission from magnetically aligned grains is a reliable method for tracing magnetic fields. However, it has been difficult to observe magnetic fields from dust polarization in protoplanetary disks because other polarization mechanisms involving grown dust grains become efficient. Here we report multi-wavelength (0.87, 1.3, 2.1 and 2.7 mm) observations of polarized thermal emission in the protoplanetary disk around HD 142527, which shows a lopsided dust distribution. We revealed that smaller dust particles still exhibit magnetic alignment in the southern part of the disk. Furthermore, angular offsets between the observed magnetic field and the disk azimuthal direction were discovered. These offsets can be used to measure the relative strengths of each component of a three-dimensional magnetic field (radial (Br), azimuthal (Bϕ) and vertical (Bz)). Applying this method, we derived the magnetic field around a 200 au radius from the protostar as ∣Br∣:∣Bϕ∣:∣Bz∣ ≈ 0.26:1:0.23 with a strength of ~0.3 mG. Our observations provide some key parameters of magnetic activities, including the plasma beta, which has had to be assumed in theoretical studies. In addition, the radial and vertical angular momentum transfers were found to be comparable, which poses a challenge to theoretical studies of protoplanetary disks.
Abundant water from primordial supernovae at cosmic dawn
Primordial (or population III) supernovae were the first nucleosynthetic engines in the Universe, and they forged the heavy elements required for the later formation of planets and life. Water, in particular, is thought to be crucial to the cosmic origins of life as we understand it, and recent models have shown that water can form in low-metallicity gas like that present at high redshifts. Here we present numerical simulations that show that the first water in the Universe formed in population III core-collapse and pair-instability supernovae at redshifts z ≈ 20. The primary sites of water production in these remnants are dense molecular cloud cores, which in some cases were enriched with primordial water to mass fractions that were only a factor of a few below those in the Solar System today. These dense, dusty cores are also probable candidates for protoplanetary disk formation. Besides revealing that a primary ingredient for life was already in place in the Universe 100–200 Myr after the Big Bang, our simulations show that water was probably a key constituent of the first galaxies.
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