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Sm3+-activated Y(2)O(2)S red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y(2)O(2)S:Sm3+, Ti4+, Mg2+ samples prepared by these two methods are pure hexagonal crystals in structure with a trivial change due to dopants. Scanning electron microscopy (SEM) results show that the product presents an almond-like sheet in uniform size. Under the excitation of 269 nm ultraviolet light, Y(2)O(2)S:Sm3+ samples fabricated by these two methods exhibit three main groups of red emission lines located at 564, 604, and 656 nm, respectively, which are attributed to the transitions of 4G(5/2) ->6H(5/2), 4G(5/2) ->6H(7/2), 4G(5/2) ->6H9/2, respectively. The samples prepared by microemulsion are seven times higher in fluorescent emission intensity and half time longer in afterglow time than that prepared by combustion.

The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest γ-ray duration (20 hours), and one of the largest isotropie energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.

We report the discovery of GRB 221009A, the highest flux gamma-ray burst (GRB) ever observed by the Fermi Gamma-ray Burst Monitor (Fermi-GBM). This GRB has continuous prompt emission lasting more than 600 s, which smoothly transitions to afterglow emission visible in the Fermi-GBM energy range (8 keV–40 MeV), and total energetics higher than any other burst in the Fermi-GBM sample. By using a variety of new and existing analysis techniques we probe the spectral and temporal evolution of GRB 221009A. We find no emission prior to the Fermi-GBM trigger time (t 0; 2022 October 9 at 13:16:59.99 UTC), indicating that this is the time of prompt emission onset. The triggering pulse exhibits distinct spectral and temporal properties suggestive of the thermal, photospheric emission of shock breakout, with significant emission up to ∼15 MeV. We characterize the onset of external shock at t 0 + 600 s and find evidence of a plateau region in the early-afterglow phase, which transitions to a slope consistent with Swift-XRT afterglow measurements. We place the total energetics of GRB 221009A in context with the rest of the Fermi-GBM sample and find that this GRB has the highest total isotropic-equivalent energy (E γ,iso = 1.0 × 1055 erg) and second highest isotropic-equivalent luminosity (L γ,iso = 9.9 × 1053 erg s–1) based on its redshift of z = 0.151. These extreme energetics are what allowed us to observe the continuously emitting central engine of Fermi-GBM from the beginning of the prompt emission phase through the onset of early afterglow.

It is generally believed that long-duration gamma-ray bursts (GRBs) are associated with massive star core collapse 1 , whereas short-duration GRBs are associated with mergers of compact star binaries 2 . However, growing observations 3 – 6 have suggested that oddball GRBs do exist, and several criteria (prompt emission properties, supernova/kilonova associations and host galaxy properties) rather than burst duration only are needed to classify GRBs physically 7 . A previously reported long-duration burst, GRB 060614 (ref.  3 ), could be viewed as a short GRB with extended emission if it were observed at a larger distance 8 and was associated with a kilonova-like feature 9 . As a result, it belongs to the type I (compact star merger) GRB category and is probably of binary neutron star (NS) merger origin. Here we report a peculiar long-duration burst, GRB 211211A, whose prompt emission properties in many aspects differ from all known type I GRBs, yet its multiband observations suggest a non-massive-star origin. In particular, substantial excess emission in both optical and near-infrared wavelengths has been discovered (see also ref.  10 ), which resembles kilonova emission, as observed in some type I GRBs. These observations point towards a new progenitor type of GRBs. A scenario invoking a white dwarf (WD)–NS merger with a post-merger magnetar engine provides a self-consistent interpretation for all the observations, including prompt gamma rays, early X-ray afterglow, as well as the engine-fed 11 , 12 kilonova emission. Analysis of the long-duration GRB 211211A led to observations of emission properties differing from all known type I bursts, yet its multiband behaviour suggests a non-massive-star origin, pointing towards a new progenitor type.

Persistent luminescent phosphors can store light energy in advance and release it with a long-lasting afterglow emission. With their ability to eliminate in situ excitation and store energy for long periods of time, they are promising for broad applications, including background-free bioimaging, high-resolution radiography, conformal electronics imaging and multilevel encryption. This Review provides an overview of various strategies for trap manipulation in persistent luminescent nanomaterials. We highlight key examples in the design and preparation of nanomaterials with tunable persistent luminescence, particularly in the near-infrared range. In subsequent sections, we cover the most current developments and trends concerning the use of these nanomaterials in biological applications. Moreover, we assess their advantages and disadvantages compared with conventional luminescent materials for biological applications. We also discuss future research directions and challenges, such as insufficient brightness at the single-particle level, and possible solutions to these challenges.Persistent luminescent phosphors are promising for applications from bioimaging to multilevel encryption. Here, the authors review the design and preparation of persistent luminescence nanomaterials, developments in biological applications and outstanding challenges.

We conducted a comprehensive investigation of the brightest-of-all-time GRB 221009A, using new insights from very high-energy (VHE) observations from LHAASO and a complete multiwavelength afterglow data set. Through data fitting, we imposed constraints on the jet structure, radiation mechanisms, and burst environment of GRB 221009A. Our findings reveal a structured jet morphology characterized by a core+wing configuration. A smooth transition of energy within the jet takes place between the core and wing, but with a discontinuity in the bulk Lorentz factor. The jet structure differs from both the case of the short GRB 170817A and the results of numerical simulations for long-duration bursts. The VHE emission can be explained by the forward shock synchrotron self-Compton radiation of the core component, but requiring a distinctive transition of the burst environment from uniform to wind-like, suggesting the presence of complex pre-burst mass ejection processes. The low-energy multiwavelength afterglow is mainly governed by the synchrotron radiation from the forward and reverse shocks of the wing component. Our analysis indicates a magnetization factor of 5 for the wing component. Additionally, by comparing the forward shock parameters of the core and wing components, we find a potential correlation between the electron acceleration efficiency and both the Lorentz factor of the shock and the magnetic field equipartition factor. We discuss the significance of our findings, potential interpretations, and remaining issues.

Organic room temperature phosphorescence (RTP) materials with persistent afterglow exhibit good biocompatibility, high signal to noise ratio and time resolved imaging characteristics in bio-applications. Moreover, they can serve as hypoxia detection probes and photodynamic therapy agents for the sensitivity of triplet excitons toward oxygen in the surroundings. In this review, the recent progress of in vitro and in vivo afterglow bioimaging is presented by utilizing organic RTP materials. The strategies of molecular design and controlling methods of molecular packing were summarized, to prompt this new rising research field, with the emphasis on high intensity, ultralong lifetimes and red-shifted wavelengths of phosphorescence emission.

We present a comprehensive study of 29 short gamma-ray bursts (SGRBs) observed ≈0.8−60 days postburst using Chandra and XMM-Newton. We provide the inferred distributions of the SGRB jet opening angles and true event rates to compare against neutron star merger rates. We perform a uniform analysis and modeling of their afterglows, obtaining 10 opening angle measurements and 19 lower limits. We report on two new opening angle measurements (SGRBs 050724A and 200411A) and eight updated values, obtaining a median value of 〈θ j〉 ≈ 6.°1 [−3.°2, +9.°3] (68% confidence on the full distribution) from jet measurements alone. For the remaining events, we infer θ j ≳ 0.°5–26°. We uncover a population of SGRBs with wider jets of θ j ≳ 10° (including two measurements of θ j ≳ 15°), representing ∼28% of our sample. Coupled with multiwavelength afterglow information, we derive a total true energy of 〈E true,tot〉 ≈ 1049–1050 erg, which is consistent with magnetohydrodynamic jet launching mechanisms. Furthermore, we determine a range for the beaming-corrected event rate of Rtrue≈360−1800 Gpc−3 yr−1, set by the inclusion of a population of wide jets on the low end, and the jet measurements alone on the high end. From a comparison with the latest merger rates, our results are consistent with the majority of SGRBs originating from binary neutron star mergers. However, our inferred rates are well above the latest neutron star–black hole merger rates, consistent with at most a small fraction of SGRBs originating from such mergers.

The fabrication of chiral molecules into macroscopic systems has many valuable applications, especially in the fields of optical displays, data encryption, information storage, and so on. Here, we design and prepare a serious of supramolecular glasses (SGs) based on Zn-L-Histidine complexes, via an evaporation-induced self-assembly (EISA) strategy. Metal-ligand interactions between the zinc(II) ion and chiral L-Histidine endow the SGs with interesting circularly polarized afterglow (CPA). Multicolored CPA emissions from blue to red with dissymmetry factor as high as 9.5 × 10 −3 and excited-state lifetime up to 356.7 ms are achieved under ambient conditions. Therefore, this work not only communicates the bulk SGs with wide-tunable afterglow and large circular polarization, but also provides an EISA method for the macroscopic self-assembly of chiral metal–organic hybrids toward photonic applications. Material designs with multicolor circularly polarized emissions are desirable for photonic applications. Here, the authors report supramolecular glasses based on self-assembled chiral metal–organic complexes with color-tunable circularly polarized afterglow.

We present realistic expectations for the number and properties of neutron star binary mergers to be detected as multi-messenger sources during the upcoming fourth observing run (O4) of the LIGO-Virgo-KAGRA gravitational-wave (GW) detectors, with the aim of providing guidance for the optimization of observing strategies. Our predictions are based on a population synthesis mode, which includes the GW signal-to-noise ratio, the kilonova (KN) optical and near-infrared light curves, the relativistic jet gamma-ray burst (GRB) prompt emission peak photon flux, and the afterglow light curves in radio, optical, and X-rays. Within our assumptions, the rate of GW events to be confidently detected during O4 is 7.7−5.7+11.9 yr−1 (calendar year), 78% of which will produce a KN, and a lower 52% will also produce a relativistic jet. The typical depth of current optical electromagnetic search and follow-up strategies is still sufficient to detect most of the KNæ in O4, but only for the first night or two. The prospects for detecting relativistic jet emission are not promising. While closer events (within z ≲ 0.02) will likely still have a detectable cocoon shock breakout, most events will have their GRB emission (both prompt and afterglow) missed unless seen under a small viewing angle. This reduces the fraction of events with detectable jets to 2% (prompt emission, serendipitous) and 10% (afterglow, deep radio monitoring), corresponding to detection rates of 0.17−0.13+0.26 and 0.78−0.58+1.21 yr−1, respectively. When considering a GW subthreshold search triggered by a GRB detection, our predicted rate of joint GW+GRB prompt emission detections increases up to a more promising 0.75−0.55+1.16 yr−1.