We present the first results from Chemical Evolution Constrained Using Ionized Lines in Interstellar Aurorae (CECILIA), a Cycle 1 JWST NIRSpec/MSA program that uses ultra-deep ∼30 hr G235M/F170LP observations to target multiple electron temperature-sensitive auroral lines in the spectra of 33 galaxies at
We investigate the effect of uncertainty in water vapor continuum absorption at terrestrial wavenumbers on CO2forcing , longwave feedback
- PAR ID:
- 10533251
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Advances in Modeling Earth Systems
- Volume:
- 16
- Issue:
- 7
- ISSN:
- 1942-2466
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
Abstract z ∼ 1–3. Using a subset of 23 galaxies, we construct two ∼600 object-hour composite spectra, both with and without the stellar continuum, and use these to investigate the characteristic rest-optical (λ rest≈ 5700–8500 Å) spectrum of star-forming galaxies at the peak epoch of cosmic star formation. Emission lines of eight different elements (H, He, N, O, Si, S, Ar, and Ni) are detected, with most of these features observed to be ≲3% the strength of Hα . We report the characteristic strength of three auroral features ([Nii ]λ 5756, [Siii ]λ 6313, and [Oii ]λ λ 7322, 7332), as well as other semi-strong and faint emission lines, including forbidden [Niii ]λ λ 7380, 7414 and permitted Oi λ 8449, some of which have never before been observed outside of the local Universe. Using these measurements, we findT e [Nii ] = 13,630 ± 2540 K, representing the first measurement of electron temperature using [Nii ] in the high-redshift Universe. We also see evidence for broad line emission with a FWHM ofα is 6.01%–28.31% the strength of the narrow component and likely arises from star-formation-driven outflows. Finally, we briefly comment on the feasibility of obtaining large samples of faint emission lines using JWST in the future. -
more » « less
Abstract We investigated the effect of the cation‐π interaction on the susceptibility of a tryptophan model system toward interaction with singlet oxygen, that is, type II photooxidation. The model system consists of two indole units linked to a lariat crown ether to measure the total rate of removal of singlet oxygen by the indole units in the presence of sodium cations (i.e. indole units subject to a cation‐π interaction) and in the absence of this interaction. We found that the cation‐π interaction significantly decreases the total rate of removal of singlet oxygen (
k T) for the model system, that is, (k T = 2.4 ± 0.2) × 108m −1 s−1without sodium cationvs (k T = 6.9 ± 0.9) × 107m −1 s−1upon complexation of sodium cation to the crown ether. Furthermore, we found that the indole moieties undergo type I photooxidation processes with triplet excited methylene blue; this effect is also inhibited by the cation‐π interaction. The chemical rate of reaction of the indole groups with singlet oxygen is also slower upon complexation of sodium cation in our model system, although we were unable to obtain an exact ratio due to differences of the chemical reaction rates of the two indole moieties. -
more » « less
Abstract The discovery of superconductivity at 260 K in hydrogen-rich compounds like LaH10re-invigorated the quest for room temperature superconductivity. Here, we report the temperature dependence of the upper critical fields
μ 0H c2(T ) of superconducting H3S under a record-high combination of applied pressures up to 160 GPa and fields up to 65 T. We find thatH c2(T ) displays a linear dependence on temperature over an extended range as found in multigap or in strongly-coupled superconductors, thus deviating from conventional Werthamer, Helfand, and Hohenberg (WHH) formalism. The best fit ofH c2(T ) to the WHH formalism yields negligible values for the Maki parameterα and the spin–orbit scattering constantλ SO. However,H c2(T ) is well-described by a model based on strong coupling superconductivity with a coupling constantλ ~ 2. We conclude that H3S behaves as a strong-coupled orbital-limited superconductor over the entire range of temperatures and fields used for our measurements. -
more » « less
Abstract Single‐crystal X‐ray diffraction and Brillouin spectroscopy experiments were performed on a natural Cr‐pyrope (Prp71.0Alm12.6Sps0.7Grs3.5Uvr12.2) at high pressure and high temperature up to 11.0 GPa and 800 K. Fitting the collected data to the third‐order finite strain equation yields bulk modulus (
K S 0), shear modulus (G 0), their pressure ((∂K S /∂P )T and (∂G /∂P )T ) and temperature ((∂K S /∂T )Pand (∂G/∂T )P) derivatives,K S 0 = 167.7(8) GPa,G 0 = 91.5(5) GPa, (∂K S /∂P )T = 4.3(1), (∂G /∂P )T = 1.4(1), (∂K S /∂T )P =− 0.0175(1) GPa/K and (∂G/∂T )P =− 0.0073(1) GPa/K. Using the obtained results, we examined whether the elastic properties of the Cr‐pyrope can be accurately calculated from those of endmembers including pyrope, almandine, grossular, and uvarovite assuming a linear relationship between elastic properties and composition (end‐member model). The results indicate that the end‐member model provides a sufficient approximation for the elastic properties of Cr‐pyrope in calculating the density and velocity of the subcontinental lithospheric mantle (SCLM). We modeled the densities and velocities of three typical types of SCLM (Archon, Proton, and Tecton) in order to investigate how the variation of chemical composition influences the SCLM. We obtained that the compositional change from the Archon to the Tecton increases the density of the SCLM significantly, which can be an important prerequisite for SCLM delamination. However, the compositional variation only slightly changes the velocity of the SCLM and the change is within the uncertainty of the calculation. Moreover, in comparison to the velocity,ρ /V P andρ /V S are much more sensitive to the compositional change of the SCLM. -
more » « less
ABSTRACT Triplet arylnitrenes may provide direct access to aryl azo‐dimers, which have broad commercial applicability. Herein, the photolysis of
p ‐azidostilbene (1 ) in argon‐saturated methanol yielded stilbene azo‐dimer (2 ) through the dimerization of tripletp ‐nitrenostilbene (31N ). The formation of31N was verified by electron paramagnetic resonance spectroscopy and absorption spectroscopy (λ max ~ 375 nm) in cryogenic 2‐methyltetrahydrofuran matrices. At ambient temperature, laser flash photolysis of1 in methanol formed31N (λ max ~ 370 nm, 2.85 × 107 s−1). On shorter timescales, a transient absorption (λ max ~ 390 nm) that decayed with a similar rate constant (3.11 × 107 s−1) was assigned to a triplet excited state (T) of1 . Density functional theory calculations yielded three configurations for T of1 , with the unpaired electrons on the azido (TA) or stilbene moiety (TTw, twisted and TFl, flat). The transient was assigned to TTwbased on its calculated spectrum. CASPT2 calculations gave a singlet–triplet energy gap of 16.6 kcal mol−1for1 N ; thus, intersystem crossing of11N to31N is unlikely at ambient temperature, supporting the formation of31N from T of1 . Thus, sustainable synthetic methods for aryl azo‐dimers can be developed using the visible‐light irradiation of aryl azides to form triplet arylnitrenes.
