We present high-spatial-resolution (less than or similar to 1 .'' 0), multiwavelength observations of UGC 2369S, a nearby luminous infrared galaxy showing three distinct cores separated on kiloparsec scales in near-infrared (NIR) imaging with significant X-ray emission. Utilizing optical/NIR adaptive optics, radio, Chandra X-ray, as well as archival Hubble Space Telescope imaging, we perform a comprehensive study of active galactic nuclei (AGN) activity, obscuration, and host properties. As one of the clearest cases of a triple-nucleus merger at similar or equal to 3 kpc separations, UGC 2369S is the first to be studied with high-resolution observations at multiple wavelengths. We find that the northern core, having possibly the most massive black hole (BH) in the system (M-BH similar or equal to 10(8)M(circle dot)), is consistent with a heavily obscured AGN. However, its high dust extinction (A(v) > 5), hydrogen column density (N-H greater than or similar to 10(25) cm(-2)), and nondetection of optical coronal lines and coronal X-ray emission leave the identification inconclusive. The other two cores show no evidence for black-hole activity and instead exhibit signatures of tidal disruption. From stellar mass surface density and stellar velocity dispersion maps, we infer that the strongly varying gravitational potential in this three-body system may have cannibalized the stellar bulge of the southwestern core, leaving a metal-enriched remnant. An ongoing survey focusing on similar triple systems could help us understand how they evolve and help benchmark numerical simulations, providing insight into gravitational wave predictions and the formation of the most massive BHs.

Haystack and Owens Valley Radio Observatory observations recently revealed strong, intermittent, sinusoidal total flux-density variations that maintained their coherence between 1975 and 2021 in the blazar PKS 2131−021 ( z = 1.283). This was interpreted as possible evidence of a supermassive black hole binary (SMBHB). Extended observations through 2023 show a coherence over 47.9 yr, with an observed period P _15 GHz = (1739.8 ± 17.4) days. We reject, with p -value = 2.09 × 10 ^−7 , the hypothesis that the variations are due to random fluctuations in the red noise tail of the power spectral density. There is clearly a physical phenomenon in PKS 2131−021 producing coherent sinusoidal flux-density variations. We find the coherent sinusoidal intensity variations extend from below 2.7 GHz to optical frequencies, from which we derive an observed period P _optical = (1764 ± 36) days. Across this broad frequency range, there is a smoothly varying monotonic phase shift in the sinusoidal variations with frequency. Hints of periodic variations are also observed at γ -ray energies. The importance of well-vetted SMBHB candidates to searches for gravitational waves is pointed out. We estimate the fraction of blazars that are SMBHB candidates to be >1 in 100. Thus, monitoring programs covering tens of thousands of blazars could discover hundreds of SMBHB candidates.

Since their discovery more than 60 years ago, accreting supermassive black holes in active galactic nuclei (AGN) have been recognized as highly variable sources, requiring an extremely compact, dynamic environment. Their variability is related to several phenomena, including changing accretion rates, temperature changes, foreground absorbers and structural changes to the accretion disk. Spurred by a new generation of time-domain surveys, the extremes of black hole variability are now being probed. Here we describe the discovery of an extreme flare by the AGN J224554.84+374326.5, which brightened by more than a factor of 40 in 2018. The source has slowly faded since then. The total emitted ultraviolet and optical energy to date is similar to 10(54) erg, which represents the complete conversion of approximately one solar mass into electromagnetic radiation. This flare is 30 times more powerful than the previous most powerful AGN transient. Very few physical events in the Universe can liberate this much electromagnetic energy. We discuss potential mechanisms, including the tidal disruption of a high-mass star (>30 M-circle dot), gravitational lensing of an AGN flare or supernova, or a supermassive (pair-instability) supernova in the accretion disk of an AGN. We favour the tidal disruption of a massive star in a prograde orbit in an AGN disk.

Models of active galactic nuclei (AGN) often invoke a close physical association between the broad-line region (BLR) and the accretion disk. We evaluate this theoretical expectation by investigating the relationship between the inclination angle of the BLR ( θ _BLR ) and the inclination angle of the inner accretion disk ( θ _disk ). For a sample of eight AGN that have published values of θ _BLR estimated from dynamical modeling of the BLR based on velocity-resolved reverberation mapping experiments, we analyze high-quality, joint XMM-Newton and NuSTAR X-ray observations to derive new, robust measurements of θ _disk through broadband (0.3–78 keV) reflection spectroscopy. Mock spectra demonstrate that the results are generally not strongly affected by warm absorbers or the model used to fit the soft-band data. We find a strong, positive correlation between θ _BLR and θ _disk (Pearson correlation coefficient 0.856, p -value 0.007), although Monte Carlo simulations indicate that the level of significance is only marginal (<3 σ ). Nevertheless, the nearly linear relation between θ _BLR and θ _disk suggests a possible physical alignment between the accretion disk and the BLR. Future studies with a larger and more homogeneous sample are needed to confirm the correlation and refine our understanding of the structure and dynamics of the central regions of active galaxies.

Luminous accretion disks around black holes are expected to have densities of similar to 1015-1022 cm-3, which are high enough that plasma physics effects become important. Many of these effects have been traditionally neglected in the calculation of atomic parameters, and therefore in photoionization models and ultimately also in X-ray reflection models. In this paper, we describe updates to the atomic rates used by the xstar code, which is in turn part of the xillver disk reflection model. We discuss the effect of adding necessary high-density corrections into the xillver code. Specifically, we find that the change of recombination rates plays an important role, dominating the differences between model versions. With synthetic spectra, we show that, even in a highly ionized state, high-density slabs can produce strong iron (similar to 6.5-9 keV) and oxygen (similar to 0.6-0.8 keV) resonance features. The significant iron emission could address the problem of the supersolar iron abundances found in some sources.

ABSTRACT Cyclotron resonant scattering features (CRSFs) are the absorption features in the X-ray spectra of strongly magnetized accretion neutron stars (NSs), which are probably the most reliable probe to the surface magnetic fields of NSs. The high-mass X-ray binary GX 301–2 exhibits a very wide, variable, and complicated CRSF in the average spectra, which should be two absorption lines based on Nuclear Spectroscopic Telescope Array (NuStar) and Hard X-ray Modulation Telescope (Insight-HXMT) observations. With the Insight-HXMT frequent observations, we performed the phase-resolved spectroscopy and confirmed two cyclotron absorption lines in the phase-resolved spectra, with their centroid energy ratio ∼1.6–1.7 in the supercritical luminosity case. A major hindrance in understanding those CRSFs is the very poorly constrained magnetic inclination angle, which is also a fundamental property of an NS and key to understanding the emission characteristics of a pulsar. Comparing the phase-resolved CRSF with simulated X-ray spectra, the magnetic inclination angle is found to be ≳70°, i.e. nearly orthogonal between the NS’s spin and magnetic axis. The implications of an orthogonal rotator and magnetic structure evolution in the accreting X-ray binary are also discussed.

The inclination angle of substructures in active galaxies gives insights into physical components from scales of the vicinity of the central black hole to the entire host galaxy. We use the self-consistent reflection spectral model RELXILL to measure the inclination of the inner region of accretion disks with broadband (0.3–78 keV) X-ray observations, systematically studying the reliability of this methodology. To test the capability of the model to return statistically consistent results, we analyze multiepoch joint XMM-Newton and NuSTAR data of the narrow-line Seyfert 1 galaxy I Zwicky 1 and the broad-line radio galaxy 3C 382, which exhibit different degrees of spectral complexity and reflection features. As expected, we find that adding more data for analysis narrows the confidence interval and that multiepoch joint observations return optimal measurements; however, even single-epoch data can be well fitted if the reflection component is sufficiently dominant. Mock spectra are used to test the capability of RELXILL to recover input parameters from typical single-epoch joint observations. We find that inclination is well recovered at 90% confidence, with improved constraints at higher reflection fraction and higher inclination. Higher iron abundance and corona temperature tighten the constraints as well, but the effect is not as significant as a higher reflection fraction. The spin, however, has little effect in reflection-based inclination measurements. We conclude that broadband reflection spectroscopy can reliably measure inner accretion disk inclination.

MAXI J1803-298 is a transient black hole candidate discovered in 2021 May during an outburst that lasted several months. Multiple X-ray observations reveal recurring "dipping" intervals in several of its light curves, particularly during the hard/intermediate states, with a typical recurrence period of similar to 7 hr. We report analysis of four NuSTAR observations of the source, supplemented with NICER data where available, over the duration of the outburst evolution covering the hard, intermediate, and the soft states. Reflection spectroscopy reveals the black hole to be rapidly spinning (a * = 0.990 +/- 0.001) with a near edge-on viewing angle (i = 70 degrees +/- 1 degrees). Additionally, we show that the light-curve dips are caused by photoelectric absorption from a moderately ionized absorber whose origin is not fully understood, although it is likely linked to material from the companion star impacting the outer edges of the accretion disk. We further detect absorption lines in some of the spectra, potentially associated with Fe xxv and Fe xxvi, indicative of disk winds with moderate to extreme velocities. During the intermediate state and just before transitioning into the soft state, the source showed a sudden flux increase, which we found to be dominated by soft disk photons and consistent with the filling of the inner accretion disk, at the onset of state transition. In the soft state, we show that models of disk self-irradiation provide a better fit and a preferred explanation to the broadband reflection spectrum, consistent with previous studies of other accreting sources.

Objective: To investigate the clinicopathological features of glomuvenous malformation (GVM). Methods: Thirty-one cases of GVM diagnosed at the Henan Provincial People's Hospital from January 2011 to December 2021 were collected. Their clinical and pathological features were analyzed. The expression of relevant markers was examined using immunohistochemistry. The patients were also followed up. Results: There were 16 males and 15 females in this study, with an average age of 11 years (range, 1-52 years). The locations of the disease included 13 cases in the limbs (8 cases in the upper limbs, 5 cases in the lower limbs), 9 cases in the trunks, and 9 cases in the foot (toes or subungual area). Twenty-seven of the cases were solitary and 4 were multifocal. The lesions were characterized by blue-purple papules or plaques on the skin surface, which grew slowly. The lumps became larger and appeared to be conspicuous. Microscopically, GVM mainly involved the dermis and subcutaneous tissue, with an overall ill-defined border. There were scattered or clustered irregular dilated vein-like lumens, with thin walls and various sizes. A single or multiple layers of relatively uniform cubic/glomus cells were present at the abnormal wall, with scattered small nests of the glomus cells. The endothelial cells in the wall of abnormal lumen were flat or absent. Immunohistochemistry showed that glomus cells strongly expressed SMA, h-caldesmon, and collagen IV. Malformed vascular endothelial cells expressed CD31, CD34 and ERG. No postoperative recurrence was found in the 12 cases. Conclusions: GVM is an uncommon type of simple venous malformation in the superficial soft tissue and different from the classical glomus tumor. Morphologically, one or more layers of glomus cells grow around the dilated venous malformation-like lumen, which can be combined with common venous malformations.

We present a detailed X-ray spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, for which a sequence of X-ray flares were detected during a long, simultaneous observation acquired with XMM-Newton and NuSTAR. We determine the key parameters of the inner accretion disk and hot corona in the context of the disk reflection model, which successfully captures the evolution of the X-ray corona during the X-ray flare. Using a thermal Comptonization continuum model, we confirm that the corona rapidly cooled from ∼200 to ∼15 keV, likely a consequence of strong pair production and runaway in a disk-like corona during the X-ray flare, when the nonthermal electron fraction rapidly increased. We detect multiple variable blueshifted absorption features arising from outflowing material along the line of sight to I Zwicky 1, which we associated with ionized winds and ultrafast outflows. One of the ionized winds may be newly launched just after the X-ray flare. During the 5 days of NuSTAR observations, the ionization state and velocity of these outflows followed a relation of the form ξ ∼ v w 3.24 , as expected from a super-Eddington wind. Comparison with molecular gas and warm ionized gas observations suggests that the kinematics of the ionized winds are consistent with a sufficiently cooled, momentum-driven outflow. Considering the dynamical feedback from these outflows can account for the significantly undermassive black hole in I Zwicky 1.

This study presents the alloy development of a new class of L12-strengthened Co-Al-Nb-based alloys with high γ′-solvus temperatures together with superb strengths at both ambient and elevated temperatures. The L12-Co3(Al, Nb) phase was found to be in equilibrium with the γ-Co matrix and the B2-CoAl phase in the ternary Co-10Al-3Nb alloy after an isothermal aging at 700 °C; however, it transformed into the Laves phase as the aging temperature increased to 800 °C. Alloying additions of Ni helped to suppress the B2 phase formation, resulting in a clean γ-γ′ dual-phase microstructure. Ti and Ta elements further stabilized the L12 structure and increased the γ′-solvus temperature to 1150 °C without inducing the formation of any other deleterious intermetallic phases. The newly developed Co-Al-Nb-Ni-Ti-Ta multicomponent Co-rich alloy has demonstrated outstanding yield strengths at both ambient and elevated temperatures, reaching 1023 ± 27 MPa at 25 °C and 897 ± 53 MPa at 700 °C, respectively. Furthermore, electron microscopy analyses uncovered unique deformation substructures, in which plasticity is predominantly carried out via nanoscale matrix-channel-confined stacking faults. As determined by the first-principle calculations, the absence of particle shearing upon deformation at ambient temperature is ascribed to the ultrahigh planar fault energies of the multicomponent γ′ precipitates. High-density superlattice-stacking-fault shearing and their interactions are responsible for the yield anomaly at 700 °C. These findings not only provide the fundamental understanding of the deformation behavior of the L12-strengthened alloys, but also demonstrate the great potential for developing next-generation high-temperature structural materials based on the multicomponent Co-rich alloy systems.

目的:探讨发生于浅表软组织的普通静脉畸形（common venous malformation，CVM）临床病理特点及基因变异特征。方法:收集河南省人民医院2020年1月至11月确诊的CVM共75例，采用免疫组织化学、荧光PCR法检测相关指标情况。结果:本组男性31例，女性44例，年龄1~69岁，平均年龄17岁，发病部位包括四肢（上肢13例，下肢34例）、躯干（14例）和头面部（14例）。51例出生时即发现，其余病例在幼年或青少年时被发现。病变表现为可触及的质软包块，肢体外观粗大并不同程度疼痛，累及浅表皮肤者皮损呈蓝色至深蓝色或暗红色至紫色。大体多呈暗红色质软组织，可见海绵状区域。镜下见不规则扩张的畸形脉管腔，呈网状、蜂窝状、海绵状或散在分布，位于真皮层、皮下筋膜层或肌层内，病变边界大多不清；畸形管腔管壁厚薄不一，壁内平滑肌细胞排列紊乱，可见黏液样变性；少部分病例可见化生性骨或软骨形成。血管内皮细胞表达CD31、CD34、ERG，管壁内肌纤维表达平滑肌肌动蛋白，弹力纤维染色畸形血管呈阴性；13例存在PIK3CA突变（突变率23.6%，13/55），突变类型E545K、E542K和H1047R。结论:发生于浅表软组织的CVM属于常见的单纯性血管畸形，无自愈性；形态学由大小不等的扩张静脉样管腔构成，遗传学上存在PIK3CA突变，提示CVM中可能存在PI3K信号通路异常，并可能参与疾病的发生发展。

This study presents the alloy development of a new class of L1 2 -strengthened Co-Al-Nb-based alloys with high gamma ' -solvus temperatures together with superb strengths at both ambient and elevated temperatures. The L1 2 -Co 3 (Al, Nb) phase was found to be in equilibrium with the gamma -Co matrix and the B2-CoAl phase in the ternary Co-10Al-3Nb alloy after an isothermal aging at 700 degrees C; however, it transformed into the Laves phase as the aging temperature increased to 800 degrees C. Alloying additions of Ni helped to suppress the B2 phase formation, resulting in a clean gamma - gamma ' dual-phase microstructure. Ti and Ta elements further stabilized the L1 2 structure and increased the gamma ' -solvus temperature to 1150 degrees C without inducing the formation of any other deleterious intermetallic phases. The newly developed Co-Al-Nb-Ni-Ti-Ta multicomponent Co-rich alloy has demonstrated outstanding yield strengths at both ambient and elevated temperatures, reaching 1023 +/- 27 MPa at 25 degrees C and 897 +/- 53 MPa at 700 degrees C, respectively. Furthermore, electron microscopy analyses uncovered unique deformation substructures, in which plasticity is predominantly carried out via nanoscale matrix-channel-confined stacking faults. As determined by the first-principle calculations, the absence of particle shearing upon deformation at ambient temperature is ascribed to the ultrahigh planar fault energies of the multicomponent gamma ' precipitates. High-density superlattice-stackingfault shearing and their interactions are responsible for the yield anomaly at 700 degrees C. These findings not only provide the fundamental understanding of the deformation behavior of the L1 2 -strengthened alloys, but also demonstrate the great potential for developing next-generation high-temperature structural materials based on the multicomponent Co-rich alloy systems.

We present a detailed study of the high mass X-ray binary Vela X-1, using observations performed by Insight-HXMT in 2019 and 2020, concentrating on timing analysis and spectral studies including pulse phase-resolved spectroscopy. The cyclotron line energy is found to be at ~21-27 keV and 43-50 keV for the fundamental and first harmonic, respectively. We present the evolution of spectral parameters and find that two line centroid energy ratio E2/E1 evolved from ~2 before MJD 58900 to ~1.7 after that. The harmonic cyclotron line energy has no relation to the luminosity but the fundamental line energy shows a positive correlation with X-ray luminosity, suggesting that Vela X-1 is located in the sub-critical accreting regime. In addition, the pulse phase-resolved spectroscopy in Vela X-1 is performed. Both the CRSF and continuum parameters show strong variability over the pulse phase with the ratio of two line energies about 2 near the peak phases, and down to ~1.6 around off-peak phases. Long-term significant variations of the absorption column density and its evolution over the pulse phase may imply the existence of the clumpy wind structure near the neutron star.

In this paper, wavelet analysis is used to study spectral-timing properties of MAXI J1535-571 observed by Insight-HXMT. The low-frequency quasi-periodic oscillations (QPOs) are detected in nine observations. Based on wavelet analysis, the time intervals with QPO and non-QPO are isolated separately, and the corresponding spectra with QPO and non-QPO are analyzed. We find that the spectra with QPO (hereafter QPO spectra) are softer than those without QPO (hereafter non-QPO spectra) in the hard intermediate state (HIMS). While in the soft intermediate state (SIMS), the QPO spectra are slightly harder. The disk temperature of QPO regime is slightly lower during HIMS, but becomes higher during SIMS. The cutoff energies of QPO spectra and non-QPO spectra do not show significant differences. The flux ratio of the disk to total flux is higher for the time intervals with non-QPO than that of QPO regime. We propose that these differences in the spectral properties between QPO and non-QPO regimes could be explained in the scenario of Lense-Thirring precession, and the reversal of the QPO/non-QPO behavior between HIMS and SIMS may be associated with appearance/disappearance of a type-B QPO which might origin from the precession of the jet.

目的:探讨原发性心脏血管肉瘤（primary cardiac angiosarcoma，PCAS）临床病理及遗传学特点。方法:收集河南省人民医院确诊的PCAS共9例，采用免疫组织化学和二代测序技术检测蛋白和基因突变情况。结果:本组患者男性7例，女性2例；年龄18~53岁；6例位于右心房，2例位于心包，1例位于右房室沟。9例伴心包积液，3例伴胸腔积液，4例伴肺多发转移。细胞学见肿瘤细胞呈腺样、乳头状排列，上皮样形态，酷似腺癌细胞；组织学见肿瘤组织呈高-中等分化，见不规则血管腔样结构，瘤细胞鞋钉样或乳头状，部分区域呈片状、束状排列，细胞胖梭形，核深染不规则，异型性明显，病理性核分裂象易见；免疫标记显示肿瘤细胞强表达CD34、CD31、ERG。伴多发肺转移结节和浆膜腔积液病例存在TP53错义突变（p.R273C），且肿瘤细胞p53蛋白强阳性。结论:PCAS早期即存在浆膜腔积液和肺多发转移，组织形态呈高-中等分化，细胞学极易误诊为腺癌，免疫组织化学有助于鉴别诊断；且TP53突变可能与肿瘤的高侵袭性生物学行为相关。

The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments 1 , 2 . The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys 3 —including gum metals 4 , 5 and strain glass alloys 6 , 7 —may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation 3 . Recently, chemically complex alloys, such as ‘high-entropy’ alloys 8 , have attracted tremendous research interest owing to their promising properties 9 – 15 . In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10 −4 ) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.

Conventional crystalline alloys usually possess a low atomic size difference in order to stabilize its crystalline structure. However, in this article, we report a single phase chemically complex alloy which possesses a large atomic size misfit usually unaffordable to conventional alloys. Consequently, this alloy develops a rather complex atomic-scale chemical order and a highly distorted crystalline structure. As a result, this crystalline alloy displays an unusually high elastic strain limit (~2%), about ten times of that of conventional alloys, and an extremely low internal friction (<2E-4) at room temperature. More interestingly, this alloy firmly maintains its elastic modulus even when the testing temperature rises from room temperature to 900 K, which is unmatched by the existing alloys hitherto reported. From an application viewpoint, our discovery may open up new opportunities to design high precision devices usable even under an extreme environment.

Background: Cholangiocarcinoma (CCA) presents tremendously high mortality. Its prognosis is unfavorable because of lacking in potential biomarkers for prognostic prediction. Methods: CCA patients in GEO cohort were categorized into two subtypes. Differentially expressed and methylated genes were identified, and the impact of DNA methylation in trans-regulating gene expression were investigated. Finally, a CIMP-related methylation signature for CCA (CMSC) was trained in GEO and validated in Tongji cohort. Results: A subset of patients with CIMP-H were identified, correlated with unfavorable prognosis. Gene enrichment analysis implied the potential mechanism of CIMP as a promoter in carcinogenesis via regulating proliferation. The trans-regulation among differentially methylation CpG sites and genes, with the same changing trends was positively correlated, while the contrary circumstances was predominantly dominated by negative correlation. Notably, CMSC based on four genes could significantly classified CCA patients into low- and high-risk groups in GEO cohort and the robustness of CMSC was validated in Tongji cohort. The result based on receiver operating characteristic analysis further indicated the CMSC presented highly sensitive and specific prediction of prognosis in CCA. Conclusion: our work highlighted the clinical significance of CMSC in predicting the prognosis of CCA.

ABSTRACT We report the orbital X-ray variability of the high-mass X-ray binary (HMXB) GX 301−2. GX 301−2 underwent a spin-up process in 2018–2020 with the period evolving from ∼685–670 s. The energy-resolved pulse profiles of the pulsar at 1–60 keV varied from single-peaked and sinusoidal shapes to multipeaked ones across different orbital phases. Pulse fractions evolving over the orbit had negative correlations with the X-ray flux. The broad-band X-ray energy spectrum of the pulsar can be described with a partially covered negative–positive cut-off power-law continuum model. Near the periastron passage of the pulsar we found strong variation in the additional column density ($N_{\mathrm{H}_{2}}$), which correlated with variation of the flux. Curves of growth for both Fe Kα and Fe Kβ lines were plotted to investigate the distribution of matter around the neutron star. We also found evidence for two cyclotron absorption lines in the phase-averaged spectra in GX 301−2, with one line of 30–42 keV and the other line varying over 48–56 keV. The centroid energies of both lines show a similar relationship with X-ray luminosity: positive correlation in the lower luminosity range, and a negative relation above a critical luminosity of $10^{37}\, \rm erg\, s^{-1}$. We estimate the surface magnetic field of the neutron star in GX 301−2 to be ∼(0.5–2) × 1013 G. The two cyclotron line energies have a nearly fixed ratio of ∼1.63 while having a low strength ratio (∼0.05), suggesting that these two features may actually be one line.