Search

Circularly polarized luminescence (CPL) materials are promising candidates for future display technology. However, such highly efficient emitters suffer from the issues of difficult chiral separation and low photoluminescence quantum yield (PLQY). In this work, the chiral 4,4′‐biphenanthrene‐3,3′‐diol (BIPOL) unit was introduced into a thermally activated delayed fluorescence (TADF) framework for the first time. We presented two series of enantiomers, R/S‐o‐DCzBPNCN and R/S‐p‐DCzBPNCN, and the synthesis of enantiopure BIPOL can be prepared via normal column chromatography. Notably, o‐DCzBPNCN showed narrow singlet‐triplet gap of 0.05 eV, efficient TADF, and high PLQYs of 82 % in doped films. In addition, R/S‐o‐DCzBPNCN exhibited high luminescence dissymmetry factor (gPL) values of −1.94×10−2/+1.91×10−2 in doped films. The strategy of BIPOL introduction offers a new approach to organic emitters with stereospecific synthesis, TADF, and chiroptical properties. [ABSTRACT FROM AUTHOR]

The systematic targeting of extended Ly α emission around high-redshift quasars resulted in the discovery of rare and bright Enormous Ly α Nebulae (ELANe) associated with multiple active galactic nuclei (AGNs). We initiate here “a multiwavelength study of ELAN environments” (AMUSE2) focusing on the ELAN around the z ∼ 3 quasar SDSS J1040+1020, aka the Fabulous ELAN. We report on VLT/HAWK-I, APEX/LABOCA, JCMT/SCUBA-2, SMA/850 ÎĽ m, and ALMA CO(5-4), and 2 mm observations and compare them to previously published VLT/MUSE data. The continuum and line detections enable a first estimate of the star formation rates, dust, stellar, and molecular gas masses in four objects associated with the ELAN (three AGNs and one Ly α emitter), confirming that the quasar host is the most star-forming (star formation rate of ∼500 M ⊙ yrâˆ'1) and massive galaxy (M star ∼ 1011 M ⊙) in the system, and thus can be assumed as central. All four embedded objects have similar molecular gas reservoirs ( M H 2 ∼ 10 10 M ⊙), resulting in short depletion timescales. This fact together with the estimated total dark matter halo mass, M DM = (0.8â€"2) Ă— 1013 M ⊙, imply that this ELAN will evolve into a giant elliptical galaxy. Consistently, the constraint on the baryonic mass budget for the whole system indicates that the majority of baryons should reside in a massive warm/hot reservoir (up to 1012 M ⊙), needed to complete the baryons count. Additionally, we discuss signatures of gas infall on the compact objects as traced by Ly α radiative transfer effects and the evidence for the alignment between the satellites’ spins and their directions to the central. [ABSTRACT FROM AUTHOR]

Submillimeter dust polarization measurements of a sample of 50 star-forming regions, observed with the Submillimeter Array (SMA) and the Caltech Submillimeter Observatory (CSO) covering parsec-scale clouds to milliparsec-scale cores, are analyzed in order to quantify the magnetic field importance. The magnetic field misalignment δ—the local angle between magnetic field and dust emission gradient—is found to be a prime observable, revealing distinct distributions for sources where the magnetic field is preferentially aligned with or perpendicular to the source minor axis. Source-averaged misalignment angles 〈 |δ|〉 fall into systematically different ranges, reflecting the different source-magnetic field configurations. Possible bimodal 〈 |δ|〉 distributions are found for the separate SMA and CSO samples. Combining both samples broadens the distribution with a wide maximum peak at small 〈 |δ|〉 values. Assuming the 50 sources to be representative, the prevailing source-magnetic field configuration is one that statistically prefers small magnetic field misalignments |δ|. When interpreting |δ| together with a magnetohydrodynamics force equation, as developed in the framework of the polarization-intensity gradient method, a sample-based log-linear scaling fits the magnetic field tension-to-gravity force ratio 〈 ΣB〉 versus 〈 |δ|〉 with 〈 ΣB〉 = 0.116 · exp (0.047 · 〈 |δ|〉 ) ± 0.20 (mean error), providing a way to estimate the relative importance of the magnetic field, only based on measurable field misalignments |δ|. The force ratio ΣB discriminates systems that are collapsible on average (〈 ΣB〉 < 1) from other molecular clouds where the magnetic field still provides enough resistance against gravitational collapse (〈 ΣB〉 > 1). The sample-wide trend shows a transition around 〈 |δ|〉 ≈ 45°. Defining an effective gravitational force ∼1 – 〈 ΣB〉 , the average magnetic-field-reduced star formation efficiency is at least a factor of two smaller than the free-fall efficiency. For about one fourth of the sources the average efficiency drops to zero. The force ratio ΣB can further be linked to the normalized mass-to-flux ratio, yielding an estimate for the latter one without the need of field strength measurements. Across the sample, a transition from magnetically supercritical to subcritcal is observed with growing misalignment 〈 |δ|〉 . [ABSTRACT FROM AUTHOR]