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The nearby radio galaxy M87 is a very high-energy (VHE) gamma-ray emitter established by observations with ground-based gamma-ray detectors. Here we report the long-term monitoring of M87 from 2021 to 2024 with the Large High Altitude Air Shower Observatory (LHAASO). M87 has been detected by LHAASO with a statistical significance ∼ 9 σ . The observed energy spectrum extends to 20 TeV, with a possible hardening at ∼20 TeV and then a clear softening at higher energies. Assuming that the intrinsic spectrum is described by a single power law up to 20 TeV, a tight upper bound on the extragalactic background light intensity is obtained. A strong VHE flare lasting 8 days, with a rise time of ${\tau }_{r}^{\mathrm{rise}}=1.05\pm 0.49$ days and decay time of ${\tau }_{d}^{\mathrm{decay}}=2.17\pm 0.58$ days, was found in early 2022. A possible GeV flare is seen also in Fermi Large Area Telescope data during the VHE flare period. The variability time as short as 1 day seen in the LHAASO data suggests a compact emission region with a size of ∼3 × 10 ^15 δ cm ( δ being the Doppler factor of the emitting region), corresponding to a few Schwarzschild radii of the central supermassive black hole in M87. The continuous monitoring of the source reveals a duty cycle of ∼1% for VHE flares with a flux above 10 ^−11 erg cm ^−2 s ^−1 .

The first source catalog of the Large High Altitude Air Shower Observatory (LHAASO) reported the detection of a very high energy gamma-ray source, 1LHAASO J1219+2915. This Letter presents a further detailed study of the spectral and temporal behavior of this pointlike source. The best-fit position of the TeV source (R.A. = 185.°05 ± 0.°04, decl. = 29.°25 ± 0.°03) is compatible with NGC 4278 within ∼0.°03. Variation analysis shows an indication of variability on a timescale of a few months in the TeV band, which is consistent with low-frequency observations. Based on these observations, we report the detection of TeV γ -ray emissions from this low-luminosity active galactic nucleus. The observation by LHAASO's Water Cherenkov Detector Array during the active period has a significance level of 8.8 σ with a best-fit photon spectral index Γ = 2.56 ± 0.14 and a flux f _1–10 TeV = (7.0 ± 1.1 _sta ± 0.35 _syst ) × 10 ^−13 photons cm ^−2 s ^−1 , or approximately 5% of the Crab Nebula. The discovery of VHE gamma-ray emission from NGC 4278 indicates that compact, weak radio jets can efficiently accelerate particles and emit TeV photons.

We present cosmological constraints from the sample of Type Ia supernovae (SNe Ia) discovered and measured during the full 5 yr of the Dark Energy Survey (DES) SN program. In contrast to most previous cosmological samples, in which SNe are classified based on their spectra, we classify the DES SNe using a machine learning algorithm applied to their light curves in four photometric bands. Spectroscopic redshifts are acquired from a dedicated follow-up survey of the host galaxies. After accounting for the likelihood of each SN being an SN Ia, we find 1635 DES SNe in the redshift range 0.10 < z < 1.13 that pass quality selection criteria sufficient to constrain cosmological parameters. This quintuples the number of high-quality z > 0.5 SNe compared to the previous leading compilation of Pantheon+ and results in the tightest cosmological constraints achieved by any SN data set to date. To derive cosmological constraints, we combine the DES SN data with a high-quality external low-redshift sample consisting of 194 SNe Ia spanning 0.025 < z < 0.10. Using SN data alone and including systematic uncertainties, we find Ω _M = 0.352 ± 0.017 in flat ΛCDM. SN data alone now require acceleration ( q _0 < 0 in ΛCDM) with over 5 σ confidence. We find $({{\rm{\Omega }}}_{{\rm{M}}},w)=({0.264}_{-0.096}^{+0.074},-{0.80}_{-0.16}^{+0.14})$ in flat w CDM. For flat w _0 w _a CDM, we find $({{\rm{\Omega }}}_{{\rm{M}}},{w}_{0},{w}_{a})=({0.495}_{-0.043}^{+0.033},-{0.36}_{-0.30}^{+0.36},-{8.8}_{-4.5}^{+3.7})$ , consistent with a constant equation of state to within ∼2 σ . Including Planck cosmic microwave background, Sloan Digital Sky Survey baryon acoustic oscillation, and DES 3 × 2pt data gives (Ω _M , w ) = (0.321 ± 0.007, −0.941 ± 0.026). In all cases, dark energy is consistent with a cosmological constant to within ∼2 σ . Systematic errors on cosmological parameters are subdominant compared to statistical errors; these results thus pave the way for future photometrically classified SN analyses.

The systematic properties are largely unknown for the black hole X-ray binary Swift J151857.0–572147 newly discovered in the 2024 outburst. The nature of a black hole can be completely defined by specifying the mass and dimensionless spin parameter. Therefore, accurate measurement of the two fundamental parameters is important for understanding the nature of black holes. The joint spectral fitting of a reflection component with simultaneous observations from Insight-HXMT, NICER, and NuSTAR reveals for the first time a black hole dimensionless spin of ${0.84}_{-0.26}^{+0.17}$ and an inclination angle of ${21.1}_{-3.6}^{+4.5}$ degrees for this system. Monitoring of the soft state by NICER results in disk flux and temperature following ${F}_{\mathrm{disk}}\propto {T}_{\mathrm{in}}^{3.83\pm 0.17}$ . For the standard thin disk, ${L}_{\mathrm{disk}}\approx 4\pi {R}_{\mathrm{in}}^{2}\sigma {T}_{\mathrm{in}}^{4}$ , so the relationship between the flux and temperature of the disk we measured indicates that the inner radius of the disk is stable and the disk is in the innermost stable circular orbit. With an empirical relation built previously between the black hole outburst profile and the intrinsic power output, the source distance is estimated as 5.8 ± 2.5 kpc according to the outburst profile and peak flux observed by Insight-HXMT and NICER. Finally, a black hole mass of 3.67 ± 1.79–8.07 ± 4.20 M _⊙ can be inferred from a joint diagnostic of the aforementioned parameters measured for this system. This system is also consistent with most black hole X-ray binaries with high spin and a mass in the range of 5–20 M _⊙ .

Using new continuum and molecular line data from the Atacama Large Millimeter/submillimeter Array Three-millimeter Observations of Massive Star-forming Regions (ATOMS) survey and archival Very Large Array, 4.86 GHz data, we present direct observational evidence of hierarchical triggering relating three epochs of massive star formation in a ringlike H ii region, G24.47+0.49. We find from radio flux analysis that it is excited by a massive star(s) of spectral type O8.5V–O8V from the first epoch of star formation. The swept-up ionized ring structure shows evidence of secondary collapse, and within this ring, a burst of massive star formation is observed in different evolutionary phases, which constitutes the second epoch. ATOMS spectral line (e.g., HCO ^+ (1–0)) observations reveal an outer concentric molecular gas ring expanding at a velocity of ∼9 km s ^−1 , constituting the direct and unambiguous detection of an expanding molecular ring. It harbors twelve dense molecular cores with surface mass density greater than 0.05 g cm ^−2 , a threshold typical of massive star formation. Half of them are found to be subvirial and thus in gravitational collapse making them the third epoch of potential massive star-forming sites.

We present an energy-dependent analysis for the type-C quasiperiodic oscillations (QPOs) observed in the black hole X-ray binary Swift J1727.8–1613 using Insight-HXMT observations. We find that the QPO fractional rms at energies above 40 keV is significantly higher than that below 20 keV. This is the first report of a high energy (HE) rms excess in the rms spectrum of a black hole X-ray binary. In the high energy band, an extra hard component is observed in addition to the standard thermal Comptonization component at a similar energy band. The value of the QPO HE rms excess is not only correlated with the disk parameters and the photon index of the standard Comptonization component but also exhibits a moderate positive correlation with the flux of the additional hard spectral component. No features in the QPO phase-lag spectra are seen corresponding to the additional hard component. We propose that the additional hard component in the spectrum may originate from jet emission and the associated QPO HE rms excess can be explained by the precession of the jet base.

We present SN 2023zaw—a subluminous ( M _r = −16.7 mag) and rapidly evolving supernova ( t _1/2, _r = 4.9 days), with the lowest nickel mass (≈0.002 M _⊙ ) measured among all stripped-envelope supernovae discovered to date. The photospheric spectra are dominated by broad He i and Ca near-infrared emission lines with velocities of ∼10,000−12,000 km s ^−1 . The late-time spectra show prominent narrow He i emission lines at ∼1000 km s ^−1 , indicative of interaction with He-rich circumstellar material. SN 2023zaw is located in the spiral arm of a star-forming galaxy. We perform radiation-hydrodynamical and analytical modeling of the lightcurve by fitting with a combination of shock-cooling emission and nickel decay. The progenitor has a best-fit envelope mass of ≈0.2 M _☉ and an envelope radius of ≈50 R _⊙ . The extremely low nickel mass and low ejecta mass (≈0.5 M _⊙ ) suggest an ultrastripped SN, which originates from a mass-losing low-mass He-star (zero-age main-sequence mass < 10 M _⊙ ) in a close binary system. This is a channel to form double neutron star systems, whose merger is detectable with LIGO. SN 2023zaw underscores the existence of a previously undiscovered population of extremely low nickel mass (

The first-generation metal-free stars, referred to as Population III (Pop III) stars, are believed to be the first objects to form out of the pristine gas in the very early Universe. Pop III stars have different structures from the current generation of stars and are important for generating heavy elements and shaping subsequent star formation. However, it is very challenging to directly detect Pop III stars given their high redshifts and short lifetimes. In this Letter, we propose a novel method for detecting Pop III stars through their tidal disruption events (TDEs) by massive black holes. We model the emission properties and calculate the expected rates for these unique TDEs in the early Universe at z ∼ 10. We find that Pop III star TDEs have much higher mass fallback rates and longer evolution timescales compared to solar-type star TDEs in the local Universe, which enhances the feasibility of their detection, although a good survey strategy will be needed for categorizing these sources as transients. We further demonstrate that a large fraction of the flare emissions are redshifted to infrared wavelengths, which can be detected by the JWST and the Nancy Grace Roman Space Telescope (Roman). Last but not least, we find a promising Pop III star TDE detection rate of up to a few tens per year using Roman, based on our current understanding of the black hole mass function in the early Universe.

We study the spectral and temporal properties of the black hole (BH) X-ray transient binary SLX 1746–331 during the 2023 outburst with NICER, NuSTAR, and Insight-HXMT observations. Through the joint fitting of the spectra from NICER, NuSTAR, and Insight-HXMT, the spin and inclination angles are measured for the first time as 0.85 ± 0.03 and 53° ± 0.°5, respectively. Accordingly, the mass of the compact star is updated from the previous lower limit of 3.3 ± 2.1 M _⊙ to 5.5 ± 3.6 M _⊙ , which is consistent with 5.2 ± 4.5 M _⊙ measured with an empirical mass–luminosity correlation of BH samples. With more NICER observations covering the later decay of the outburst, we confirm that the entire outburst was dominated by the disk emissions, and the thermal spectrum follows $F\propto {T}_{\mathrm{in}}^{3.974\pm 0.003}$ , until a luminosity of over 2 magnitudes lower than the maximum of the outburst.

We propose a method based on the Hilbert–Huang transform (HHT) to recover the high-energy waveform of low-frequency quasiperiodic oscillations (QPOs). Based on the method, we successfully obtain the modulation of the phase-folded light curve above 170 keV using the QPO phase reconstructed at lower energies in MAXI J1535–571 with Insight-HXMT observations. A comprehensive simulation study is conducted to demonstrate that such modulation indeed originates from the QPO. Thus, the highest energies turn out to significantly exceed the upper limit of ∼100 keV for QPOs reported previously using the Fourier method, marking the first opportunity to study QPO properties above 100 keV in this source. Detailed analyses of these high-energy QPO profiles reveal different QPO properties between the 30–100 and 100–200 keV energy ranges: the phase lag remains relatively stable, and the amplitude slightly increases below ∼100 keV, whereas above this threshold, soft phase lags and a decrease in amplitude are observed. Given the reports of a hard-tail detection in broad spectroscopy, we propose that the newly discovered QPO properties above 100 keV are dominated by the hard-tail component, possibly stemming from a relativistic jet. Our findings also indicate a strong correlation between the QPOs originating from the jet and corona, supporting the scenario of jet–corona coupling precession. We emphasize that our proposed HHT-based method can serve as an efficient manner in expanding the high-energy band for studying QPOs, thereby enhancing our understanding of their origin.

In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow.

The Event Horizon Telescope observed the horizon-scale synchrotron emission region around the Galactic center supermassive black hole, Sagittarius A* (Sgr A*), in 2017. These observations revealed a bright, thick ring morphology with a diameter of 51.8 ± 2.3 μ as and modest azimuthal brightness asymmetry, consistent with the expected appearance of a black hole with mass M ≈ 4 × 10 ^6 M _⊙ . From these observations, we present the first resolved linear and circular polarimetric images of Sgr A*. The linear polarization images demonstrate that the emission ring is highly polarized, exhibiting a prominent spiral electric vector polarization angle pattern with a peak fractional polarization of ∼40% in the western portion of the ring. The circular polarization images feature a modestly (∼5%–10%) polarized dipole structure along the emission ring, with negative circular polarization in the western region and positive circular polarization in the eastern region, although our methods exhibit stronger disagreement than for linear polarization. We analyze the data using multiple independent imaging and modeling methods, each of which is validated using a standardized suite of synthetic data sets. While the detailed spatial distribution of the linear polarization along the ring remains uncertain owing to the intrinsic variability of the source, the spiraling polarization structure is robust to methodological choices. The degree and orientation of the linear polarization provide stringent constraints for the black hole and its surrounding magnetic fields, which we discuss in an accompanying publication.

High-latitude (∣ b ∣ > 30°) molecular clouds have virial parameters that exceed 1, but whether these clouds can form stars has not been studied systematically. Using JCMT SCUBA-2 archival data, we surveyed 70 fields that target high-latitude Planck Galactic cold clumps (HLPCs) to find dense cores with density of 10 ^5 –10 ^6 cm ^−3 and size of 1 × 10 ^21 cm ^−2 ). At an average rms of 15 mJy beam ^−1 , we detected Galactic dense cores in only one field, G6.04+36.77 (L183) while also identifying 12 extragalactic objects and two young stellar objects. Compared to the low-latitude clumps, dense cores are scarce in HLPCs. With synthetic observations, the densities of cores are constrained to be n _c ≲ 10 ^5 cm ^−3 should they exist in HLPCs. Low-latitude clumps, Taurus clumps, and HLPCs form a sequence where a higher virial parameter corresponds to a lower dense-core detection rate. If HLPCs were affected by the Local Bubble, the scarcity should favor turbulence-inhibited rather than supernova-driven star formation. Studies of the formation mechanism of the L183 molecular cloud are warranted.

We present the first polarimetric analysis of quasiperiodic oscillations (QPOs) in a black hole binary utilizing IXPE data. Our study focuses on Swift J1727.8–1613, which experienced a massive outburst that was observed by various telescopes across different wavelengths. The IXPE observation we studied was conducted during the hard-intermediate state. The polarization degree (PD) and polarization angle (PA) were measured at 4.28% ± 0.20% and 1.°9 ± 1.°4, respectively. Remarkably, significant QPO signals were detected during this observation, with a QPO frequency of approximately 1.34 Hz and a fractional rms amplitude of about 12.3%. Furthermore, we conducted a phase-resolved analysis of the QPO using the Hilbert–Huang transform technique. The photon index showed a strong modulation with respect to the QPO phase. In contrast, the PD and PA exhibit no modulations in relation to the QPO phase, which is inconsistent with the expectation of the Lense–Thirring precession of the inner flow. Further theoretical studies are needed to conform with the observational results.

Only a handful of massive starless core candidates have been discovered so far, but none of them have been fully confirmed. Within the MM1 clump in the filamentary infrared dark cloud G34.43+0.24 that was covered by the Atacama Large Millimeter/submillimeter Array (ALMA) ATOMS survey at Band 3 (∼2″, 6000 au) and the ALMA-QUARKS survey at Band 6 (∼0.″3, 900 au), two prestellar core candidates MM1-C and E1 with masses of 71 and 20 M _⊙ and radii of 2100–4400 au were discovered. The two cores show no obvious sign of star formation activities. In particular, MM1-C is a very promising massive prestellar core candidate with a total gas mass of 71 M _⊙ . Within MM1-C, we detected two extremely dense substructures, C1 and C2, as characterized by their high densities of ${n}_{{{\rm{H}}}_{2}}\sim {10}^{8\mbox{--}9}\,{\mathrm{cm}}^{-3}$ . Moreover, evidence of further fragmentation in C2 was also revealed. We have detected the primordial fragmentation in the earliest stage of massive star formation, and we speculate that MM1-C would be the birthplace of a massive multiple system. However, we cannot fully rule out the possibility that the massive prestellar core MM1-C will just form a cluster of low-mass stars if it undergoes further fragmentation.

Swift J1727.8–1613 is a black hole X-ray binary newly discovered in 2023. We perform spectral analysis with simultaneous Insight-HXMT, NICER, and NuSTAR observations when the source was approaching the hard intermediate state. Such a joint view reveals an additional hard component apart from the normally observed hard component with reflection in the spectrum, to be distinguished from the usual black hole X-ray binary systems. By including this extra component in the spectrum, we have measured a high spin of ${0.98}_{-0.07}^{+0.02}$ and an inclination of around ${40}_{-0.8}^{+1.2}$ °, which is consistent with NICER results reported before. However, we find that the additional spectral component cannot be exclusively determined due to the model degeneracy. Accordingly, a possible jet/corona configuration is adjusted to account for the spectral fitting with different model trials. The extra component may originate either from a relativistic jet or a jet base/corona underneath a slow jet.

We present the discovery of a new H i structure in the NGC 7194 group from the observations using the Karl G. Jansky Very Large Array. NGC 7194 group is a nearby ( z ∼ 0.027) small galaxy group with five quiescent members. The observations reveal a 200 kpc long H i plume that spans the entire group with a total mass of M _H I = 3.4 × 10 ^10 M _⊙ . The line-of-sight velocity of the H i gas gradually increases from south (7200 km s ^−1 ) to north (8200 km s ^−1 ), and the local velocity dispersion is up to 70 km s ^−1 . The structure is not spatially coincident with any member galaxies but it shows close associations with a number of blue star-forming knots. Intragroup H i gas is not rare, but this particular structure is still one of the unusual cases in the sense that it does not show any clear connection with sizable galaxies in the group. We discuss the potential origins of this large-scale H i gas in the NGC 7194 group and its relation with the intergalactic star-forming knots. We propose that this H i feature could have originated from tidal interactions among group members or the infall of a late-type galaxy into the group. Alternatively, it might be leftover gas from flyby intruders.

Since the last IAEA-FEC in 2021, significant progress on the development of long pulse steady state scenario and its related key physics and technologies have been achieved, including the reproducible 403 s long-pulse steady-state H-mode plasma with pure radio frequency (RF) power heating. A thousand-second time scale (∼1056 s) fully non-inductive plasma with high injected energy up to 1.73 GJ has also been achieved. The EAST operational regime of high β _P has been significantly extended ( H _98y2 > 1.3, β _P ∼ 4.0, β _N ∼ 2.4 and n _e / n _GW ∼ 1.0) using RF and neutral beam injection (NBI). The full edge localized mode suppression using the n = 4 resonant magnetic perturbations has been achieved in ITER-like standard type-I ELMy H-mode plasmas with q _95 ≈ 3.1 on EAST, extrapolating favorably to the ITER baseline scenario. The sustained large ELM control and stable partial detachment have been achieved with Ne seeding. The underlying physics of plasma-beta effect for error field penetration, where toroidal effect dominates, is disclosed by comparing the results in cylindrical theory and MARS-Q simulation in EAST. Breakdown and plasma initiation at low toroidal electric fields (

The physics potential of detecting ^8 B solar neutrinos will be exploited at the Jiangmen Underground Neutrino Observatory (JUNO), in a model-independent manner by using three distinct channels of the charged current (CC), neutral current (NC), and elastic scattering (ES) interactions. Due to the largest-ever mass of ^13 C nuclei in the liquid scintillator detectors and the expected low background level, ^8 B solar neutrinos are observable in the CC and NC interactions on ^13 C for the first time. By virtue of optimized event selections and muon veto strategies, backgrounds from the accidental coincidence, muon-induced isotopes, and external backgrounds can be greatly suppressed. Excellent signal-to-background ratios can be achieved in the CC, NC, and ES channels to guarantee the observation of the ^8 B solar neutrinos. From the sensitivity studies performed in this work, we show that JUNO, with 10 yr of data, can reach the 1 σ precision levels of 5%, 8%, and 20% for the ^8 B neutrino flux, ${\sin }^{2}{\theta }_{12}$ , and ${\rm{\Delta }}{m}_{21}^{2}$ , respectively. Probing the details of both solar physics and neutrino physics would be unique and helpful. In addition, when combined with the Sudbury Neutrino Observatory measurement, the world's best precision of 3% is expected for the measurement of the ^8 B neutrino flux.

We present the first catalog of very-high-energy and ultra-high-energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory. The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array from 2021 March to 2022 September and 933 days of data recorded by the Kilometer Squared Array from 2020 January to 2022 September. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering decl. from −20° to 80°. In total, the catalog contains 90 sources with an extended size smaller than 2° and a significance of detection at >5 σ . Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ( E > 100 TeV) emission at >4 σ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.

Additive manufacturing has emerged as a transformative technology for producing biomedical metals and implants, offering the potential to revolutionize patient care and treatment outcomes. This article reviews the recent advances in additive manufacturing (AM) of biomedical metal implants, especially load-bearing biomedical alloys, biodegradable alloys, novel metals, and 4D printing, whose properties are systematically assessed to facilitate material selection for specific medical applications. The applications of the most cutting-edge artificial intelligence in AM and surface functional modification are also presented. This article also explores the application of AM in various medical specialties, such as orthopedics, dentistry, cardiology, and neurosurgery, demonstrating its potential to solve complex clinical challenges and advance patient-centered healthcare solutions. Furthermore, it highlights the critical roles of AM in shaping the future of medical implant manufacturing. The optimistic outlook on the bright future of AM in medical metals delivers personalized, high-performance medical implants that improve patient treatment outcomes and well-being.

In this paper, we present a detailed analysis of the IRS 17 filament within the intermediate-mass protocluster IRAS 08448-4343 (of ∼10 ^3 L _⊙ ), using ALMA data from the ATOMS 3 mm and QUARKS 1.3 mm surveys. The IRS 17 filament, which spans ∼54,000 au (0.26 pc) in length and ∼4000 au (0.02 pc) in width, exhibits a complex, multicomponent velocity field and harbors hierarchical substructures. These substructures include three bundles of seven velocity-coherent fibers and 29 dense ( n ∼ 10 ^8 cm ^−3 ) condensations. The fibers have a median length of ∼4500 au and a median width of ∼1400 au. Among these fibers, four are identified as “fertile,” each hosting at least three dense condensations, which are regarded as the “seeds” of star formation. While the detected cores are randomly spaced within the IRS 17 filament based on the 3 mm dust continuum image, periodic spacing (∼1600 au) of condensations is observed in the fertile fibers according to the 1.3 mm dust map, consistent with the predictions of linear isothermal cylinder fragmentation models. These findings underscore the crucial role of fibers in star formation and suggest a hierarchical fragmentation process that extends from the filament to the fibers and, ultimately, to the smallest-scale condensations.

Bioengineered organs have been seen as a promising strategy to address the shortage of transplantable organs. However, it is still difficult to achieve heterogeneous structures and complex functions similar to natural organs using current bioengineering techniques. This work introduces the methods and dilemmas in organ engineering and existing challenges. Furthermore, a new roadmap for organ engineering, which uses a modular strategy with autologous bioreactors to create organ-level bioengineered constructions, is summarized based on the latest research advances. In brief, different functional modules of natural organs are constructed in vitro , and autologous bioreactors in vivo are utilized to facilitate inter-module assembly to form a complete bioengineered organ capable of replacing natural organ functions. There are bioengineered organs, such as biomimetic tracheas, which have been successfully fabricated following this roadmap. This new roadmap for organ engineering shows prospects in addressing the shortage of transplantable organs and has broad prospects for clinical applications.

The velocity-space distribution of the fast-ion loss in EAST neutral-beam injection (NBI) heating discharge is obtained both from Scintillator-based fast-ion loss detector (FILD) signals and by ASCOT5 and FILDSIM simulations. The results of simulations are in good agreement with the distribution of beam-ion losses measured with FILD of EAST and the correctness of the fast-ion loss distribution has been demonstrated. Simulations indicate that the beam-ion losses observed by the FILD probe are attributed to the fast ions from both the high-field side (HFS) and the low-field side (LFS). However, the beam-ion losses from the HFS (associated with NBI1L) have not been observed experimentally due to the limited detecting range of the FILD probe. Therefore, an upgrade and modification of the FILD probe was carried out in 2022 to enable the detection of fast-ion loss with smaller pitch angles. Comparative analysis is conducted in neutral-beam injection (NBI2R) discharges after the upgrade, which indicates that the velocity-space distribution of beam-ion losses from the HFS has strong agreement between experimental measurements and simulation results. However, the experimental and simulated results of the velocity-space distribution of beam-ion losses from the LFS shows inconsistencies, primarily because the BBNBI module in the simulation does not consider the contributions of boundary neutral particles to neutral-beam deposition (ionization reactions). These conclusions not only provide valuable references for improving the neutral-beam deposition model but also establish a fundamental basis for further exploring the mechanisms of fast-ion loss under various conditions on the EAST tokamak.

We analyze Spitzer spectra of 140 active galactic nuclei (AGN) detected in the hard X-rays (14–195 keV) by the Burst Alert Telescope on board Swift. This sample allows us to probe several orders of magnitude in black hole masses (10 ^6 –10 ^9 M _⊙ ), Eddington ratios (10 ^−3 –1), X-ray luminosities (10 ^42 –10 ^45 erg s ^−1 ), and X-ray column densities (10 ^20 –10 ^24 cm ^−2 ). The AGN emission is expected to be the dominant source of ionizing photons with energies ≳50 eV, and therefore, high-ionization mid-infrared (MIR) emission lines such as [Ne v ] 14.32, 24.32 μ m and [O iv ] 25.89 μ m are predicted to be good proxies of AGN activity, and robust against obscuration effects. We find high detection rates (≳85%–90%) for the MIR coronal emission lines in our AGN sample. The luminosities of these lines are correlated with the 14–150 keV luminosity (with a typical scatter of σ ∼0.4–0.5 dex), strongly indicating that the MIR coronal line (CL) emission is driven by AGN activity. CLs are also tightly correlated to the bolometric luminosity ( σ ∼0.2–0.3 dex), calculated from careful analysis of the spectral energy distribution. We find that the relationship between the CL strengths and L _14–150 keV is independent of black hole mass, AGN luminosity, and Eddington ratio, and mostly not affected by high X-ray column densities. This confirms that the MIR CLs can be used as unbiased tracers of the AGN power for X-ray luminosities in the 10 ^42 –10 ^45 erg s ^−1 range.

We present 850 μ m thermal dust polarization observations with a resolution of 14.″4 (∼0.13 pc) toward an infrared dark cloud G16.96+0.27 using James Clerk Maxwell Telescope/POL-2. The average magnetic field orientation, which roughly agrees with the larger-scale magnetic field orientation traced by the Planck 353 GHz data, is approximately perpendicular to the filament structure. The estimated plane-of-sky magnetic field strength is ∼96 μ G and ∼60 μ G using two variants of the Davis–Chandrasekhar–Fermi methods. We calculate the virial and magnetic critical parameters to evaluate the relative importance of gravity, the magnetic field, and turbulence. The magnetic field and turbulence are both weaker than gravity, but magnetic fields and turbulence together are equal to gravity, suggesting that G16.96+0.27 is in a quasi-equilibrium state. The alignment between the magnetic field and cloud is found to have a trend moving away from perpendicularity in the dense regions, which may serve as a tracer of potential fragmentation in such quiescent filaments.

The prompt emission mechanism of gamma-ray bursts (GRBs) is a long-standing open question, and GRBs have been considered as potential sources of high-energy neutrinos. Despite many years of search for the neutrino events associated with GRBs from IceCube, there were no results. However, the absence of search results for neutrinos provides a unique opportunity to constrain the parameter space of GRB jet models. In this paper, we chose four peculiar GRBs with two different types of jet composition to investigate neutrino emission. It is found that only GRB 211211A could be well constrained within the dissipative photosphere model. By adopting the specific parameters of the photosphere, one can obtain ε _p / ε _e < 8 for f _p > 0.2 from GRB 211211A. For the Internal-collision-induced Magnetic Reconnection and Turbulence (ICMART) model, we can effectively constrain neither GRB 230307A nor GRB 080916C. Moreover, we also investigate the detection prospects of high-energy neutrinos from GRBs and find that it is difficult to detect at least one high-energy neutrino associated with GRBs from the ICMART model even during the IceCube-Gen2 operation. For the GRB 211211A-like events, it is possible to detect at least one neutrino coincident with the gravitational wave during the IceCube-Gen2 operation, if such an event originated from mergers of compact stars within the photosphere dissipation.

The massive semidetached binary with a long-term decreasing orbital period may involve a rapid mass-transfer phase in Case A, and thus, they are good astrophysical laboratories for investigating the evolution of massive binary stars. In this work, by using the long-term observational light curves from the Optical Gravitational Lensing Experiment project and other data in the low-metallicity Large Magellanic Cloud, four semidetached massive binaries with long-term decreases in the orbital periods are detected from 165 EB-type close binaries. It is found that the more massive component in S07798 is filling its Roche lobe, where the period decrease is caused by mass transfer from the primary to the secondary. However, the other three (S03065, S12631, S16873) are semidetached binaries with a lobe-filling secondary where the mass transfer between the components should cause the period to increase if the angular momentum is conservative. The long-term period decreases in these three systems may be caused by angular momentum loss. Additionally, the orbital periods of three systems (S03065, S07798, S16873) are detected to show cyclic variation with periods shorter than 11 yr, which can be plausibly explained by the presence of close-in third bodies in these massive binaries. Based on all of these results, it is suggested that the detected four semidetached binaries almost have multiplicity. The companion stars are crucial for the origin and evolution of these massive close binaries.

The Rossby wave instability (RWI) is the fundamental nonaxisymmetric radial shear instability in disks. The RWI can facilitate disk accretion, set the shape of planetary gaps, and produce large vortices. It arises from density and/or temperature features, such as radial gaps, bumps, or steps. A general, sufficient condition to trigger the RWI is lacking, which we address by studying the linear RWI in a suite of simplified models, including incompressible and compressible shearing sheets and global, cylindrical disks. We focus on enthalpy amplitude and width as the fundamental properties of disk features with various shapes. We find analytic results for the RWI boundary and growth rates across a wide parameter space, in some cases with exact derivations and in others as a description of numerical results. Features wider than a scale height generally become unstable about halfway to Rayleigh instability, i.e., when the squared epicyclic frequency is about half the Keplerian value, reinforcing our previous finding. RWI growth rates approximately scale as enthalpy amplitude to the 1/3 power, with a weak dependence on width, across much of the parameter space. Global disk curvature affects wide planetary gaps, making the outer gap edge more susceptible to the RWI. Our simplified models are barotropic and height integrated, but the main results should carry over to more complex and realistic scenarios.

We present a comprehensive analysis of the timing and spectral properties of NGC 7314, a Seyfert 1.9 galaxy, using X-ray observations from XMM-Newton, NuSTAR, and RXTE/proportional counter array (PCA). The timing analysis reveals significant variability across different energy bands, with fractional variability values consistent with previous studies. The highly variable soft photons and comparatively less variable high-energy photons imply different origins of these two types. The soft energy photons come from a hot corona near the center, while the high-energy photons are produced by inverse Compton scattering of these primary X-ray photons in a hot plasma away from the central region. The spectral analysis employs various models to characterize the emission components. The results indicate the presence of a soft energy bump, Fe K α line emission, and a prominent reflection component. The long-term RXTE/PCA data analysis reveals temporal variations in the photon index (Γ) and power-law flux, suggesting evolving emission properties over time. The signature of both broad and narrow Fe K α emission line features suggested the broad, variable one coming from the accretion disk (∼10 ^−5 pc), while the nonevolving narrow line cannot be well constrained. The absorption feature could originate in a highly ionized region, possibly closer to the broad-line region. The evolution of the inner accretion properties indicates that NGC 7314 could be a potential changing-state active galactic nucleus.

Detecting the coalescences of massive black hole binaries (MBHBs) is one of the primary targets for space-based gravitational wave observatories such as laser interferometer space antenna, Taiji, and Tianqin. The fast and accurate parameter estimation of merging MBHBs is of great significance for the global fitting of all resolvable sources, as well as the astrophysical interpretation of gravitational wave signals. However, such analyses usually entail significant computational costs. To address these challenges, inspired by the latest progress in generative models, we explore the application of continuous normalizing flows (CNFs) on the parameter estimation of MBHBs. Specifically, we employ linear interpolation and trig interpolation methods to construct transport paths for training CNFs. Additionally, we creatively introduce a parameter transformation method based on the symmetry in the detector’s response function. This transformation is integrated within CNFs, allowing us to train the model using a simplified dataset, and then perform parameter estimation on more general data, hence also acting as a crucial factor in improving the training speed. In conclusion, for the first time, within a comprehensive and reasonable parameter range, we have achieved a complete and unbiased 11-dimensional rapid inference for MBHBs in the presence of astrophysical confusion noise using CNFs. In the experiments based on simulated data, our model produces posterior distributions comparable to those obtained by nested sampling.

Tungsten peaking is predicted in the core of a WEST plasma with total-f gyrokinetic simulations, including both collisional and turbulent transport. This prediction is validated with a synthetic diagnostic of the bolometry. Although nitrogen impurities are shown to reduce the neoclassical peaking of tungsten on-axis, the overall tungsten peaking increases when nitrogen impurities are present, as they reduce the turbulence screening off-axis. This finding is important for the plasma current ramp-up phase of ITER, where light impurities seeding will be desirable to achieve low temperatures at the plasma-facing components and reduce tungsten sputtering. It provides further argument for applying early ECRH heating to maintain margins on the core power balance. The neoclassical peaking factor is cross-verified between XGC and FACIT. The heat flux at separatrix and the heat load width are modeled by XGC and compared to WEST data.

Narrow emission lines in a galaxy’s spectrum that show double peaks indicate the presence of distinct gas components with different velocities, and its physical origin remains uncertain. This study uses galaxies from the final MaNGA data release to detect double-peaked narrow emission-line spaxels (DPSs) by examining the double Gaussian profiles of the H α -[N ii ] doublets across all MaNGA spaxels. A total of 5420 DPSs associated with 304 double-peaked narrow emission-line galaxies (DPGs) are identified, with each DPG containing a minimum of five DPSs and being free from overlap with other galaxies. We find that DPSs can be categorized into three groups according to their central distance r / R _e and the velocity difference Δ v between their two components: the inner low-Δ v , inner high-Δ v , and outer DPSs. By incorporating the physical characteristics of the DPGs into their DPSs, we demonstrate for the first time the existence of statistical correlations between barred DPGs and inner low-Δ v DPSs, AGN-hosting DPGs, and inner high-Δ v DPSs, as well as tidal DPGs and outer DPSs.

HOPS 87 is a Class 0 protostellar core known to harbor an extremely young bipolar outflow and a hot corino. We report the discovery of localized, chemically rich regions near the bases of the two-lobe bipolar molecular outflow in HOPS 87 containing molecules such as H _2 CO, ^13 CS, H _2 S, OCS, and CH _3 OH, the simplest complex organic molecule (COM). The locations and kinematics suggest that these localized features are due to jet-driven shocks rather than being part of the hot-corino region encasing the protostar. The COM compositions of the molecular gas in these jet-localized regions are relatively simpler than those in the hot-corino zone. We speculate that this simplicity is due to either the liberation of ice with a less complex chemical history or the effects of shock chemistry. Our study highlights the dynamic interplay between the protostellar bipolar outflow, disk, inner-core environment, and the surrounding medium, contributing to our understanding of molecular complexity in solar-like young stellar objects.