MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY皇家天文学会月刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY(英文缩写 MON NOT R ASTRON SOC),ISSN 0035-8711,eISSN 1365-2966,中文译名:皇家天文学会月刊 是一本学术期刊。本页汇总该期刊的最新影响因子、分区信息以及最新收录于 PubMed 的文献,帮助您快速了解期刊全貌。
发文量统计区间：2025-09-28 至 2026-09-28，按本站收录文献的发表日期统计。
期刊介绍
历年影响因子趋势
| JCR 数据年份 | 影响因子 | JCR 分区 |
|---|---|---|
| 2021 | 5.235 | Q1 |
| 2022 | 4.800 | Q1 |
| 2023 | 4.700 | Q1 |
| 2024 | 4.800 | Q1 |
| 2025 | 5.200 | Q1 |
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 最新收录文献
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1. The abundance and radial distribution of faint and ultra-faint dwarfs in galaxy clusters.
PMID:日期:2026-10-01Cosmological simulations of galaxy clusters are unable to resolve dwarf galaxies due to limited numerical resolution, which drives the artificial disruption of dark matter substructures. We address these limitations by combining the results of the cosmological hydrodynamical simulation TNG50 in CDM with an empirical model of tidal evolution of cluster galaxies calibrated using high-resolution idealized N-body simulations. Applied to the three most massive clusters in TNG50, our model allows us to study the stellar mass and radial distribution of dwarfs well below the formal resolution limit of the parent simulation. We find that, at , clusters with virial mass [Formula: see text] [Formula: see text] host a vast population of dwarf galaxies within the virial radius, amounting to 2000-7000 systems with [Formula: see text] [Formula: see text]. Taken together, these satellites follow a radial distribution that matches the underlying dark matter profile of the host. However, applying a minimum mass or luminosity threshold for detection, as expected in observational studies, tends to exclude the most heavily stripped objects, which tend to populate the inner regions. Future surveys targeting ultra-faint galaxies in group and cluster environments, such as those made possible by the , Rubin, or telescope, will be fundamental to refute or confirm this prediction.
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2. The Cluster Completeness Correction Calculator (c-4): a neural-network framework and pilot application to the LEGUS survey of NGC 628.
PMID:日期:2026-08-01Integrated-light star cluster catalogues in external galaxies are subject to complex, often poorly characterized selection effects that can bias inferred cluster demographics and introduce significant uncertainties, limiting the physical parameter space accessible to analysis. To mitigate this problem, here we introduce the Cluster Completeness Correction Calculator (c-4): a new software tool to quantify and predict these effects in both physical and photometric parameter spaces. c-4 adds artificial star clusters to observed galaxy images, processes these images through the same detection and filtering steps used to construct the original cluster catalogue, and then trains multilayer perceptron neural networks to learn the resulting selection function. The trained neural networks provide continuous, differentiable completeness functions that can be used for direct completeness corrections or incorporated into forward models. We present a pilot application of c-4 to NGC 628, demonstrating that the learned selection operator is highly accurate and successfully captures the strongly non-separable dependence of completeness on mass, age, and extinction. Applying the completeness correction to NGC 628 extends the range of cluster demographic analyses by roughly an order of magnitude in both mass and age, and removes artificial flattening in the observed cluster mass and age distributions. These results establish neural-network-based completeness modelling as a powerful and general approach for recovering intrinsic cluster populations, and provide a scalable framework for modelling high-dimensional selection functions in resolved stellar population studies.
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3. Formation time-scales for stellar bars in diverse galactic discs.
PMID:日期:2026-04-01We study the formation of stellar bars using 145 simulations of disc galaxies embedded in live and static dark matter haloes. We use the exponential bar growth time-scale, [Formula: see text], to quantify how disc structure and kinematics regulate the onset and rate of secular bar formation. We extend previous work to thicker and more turbulent discs, motivated by those observed at high redshift ([Formula: see text]). By revisiting several commonly used disc stability criteria - the Efstathiou-Lake-Negroponte parameter ([Formula: see text]), the Ostriker-Peebles ratio ([Formula: see text]), and the disc stellar mass fraction within 2.2 disc scale radii ([Formula: see text]) - we find that [Formula: see text], when expressed in terms of the disc's orbital period, follows a tight power law with each criteria. In Milky Way-like discs embedded in live haloes, bars form within a Hubble time if [Formula: see text], [Formula: see text], and [Formula: see text]. We show discs with higher velocity dispersion experience delayed bar growth and introduce an empirical relation that correctly describes the bar formation time-scales of all our live halo models. Bars in static haloes grow at roughly half the rate of those in live haloes and require substantially greater disc instability to do so.
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4. Origins and lifetimes of secular and tidal bars in simulated disc galaxies.
PMID:日期:2026-04-01We analyse 307 Milky Way-mass disc galaxies in the TNG50 cosmological simulation to study the formation and evolution of stellar bars through secular processes and tidal interactions. About 90 per cent of these galaxies form at least one bar during their cosmic evolution. Most bars form rapidly in dynamically cold discs shortly after the central stellar mass exceeds that of dark matter (inside the stellar half-mass radius). In these cases, bar formation is consistent with secular instabilities driven by the disc's self-gravity, which organizes stellar orbits into a coherent bar structure. However, about 24 per cent of barred galaxies are dark matter-dominated at the time of bar formation. We trace the origin of these bars to tidal perturbations from passing or accreting satellites and streams, and introduce a new metric, [Formula: see text], to quantify the total external tidal field acting on each galaxy. We find that [Formula: see text] correlates negatively with the central stellar-to-dark matter mass ratio at the time of bar formation: the more dark-matter-dominated a disc, the stronger the tidal perturbation required to trigger a bar. Bars that form in dark matter-dominated discs under tidal perturbations are typically transient - disappearing in a few Gyr - unlike their counterparts which form in stellar-dominated discs. After a few orbital times, the properties of all bars are broadly similar, though their host galaxies differ: secular bars arise in thin, compact discs, whereas tidally induced bars can form in thicker, more extended discs whose properties closely resemble those of unbarred galaxies.
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5. Discs no more: the morphology of low-mass simulated galaxies in FIREbox.
PMID:日期:2025-12-01We study the morphology of hundreds of simulated central galaxies in the stellar mass range [Formula: see text] 10-10 [Formula: see text] from the FIREbox cosmological volume. We demonstrate that FIREbox is able to predict a wide variety of morphologies, spanning from disc-dominated objects to spheroidal galaxies supported by stellar velocity dispersion. However, the simulations predict a strong relation between morphology (degree of rotational support) and stellar mass: galaxies comparable to the Milky Way are often disc-dominated while the presence of stellar discs mostly vanishes for dwarfs with [Formula: see text][Formula: see text]. This defines a 'morphology transition' regime for galaxies with [Formula: see text] in which discs become increasingly common, but below which discs are rare. We show that burstiness in the star formation history and the deepening of the gravitational potential strongly correlate in our simulations with this transition regime, with discs forming in objects with lower levels of burstiness in the last [Formula: see text] Gyr and haloes with mass [Formula: see text] and above. While observations support a transition towards thicker discs in the regime of dwarfs, our results are in partial disagreement with observations of at least some largely rotationally supported gas discs in dwarfs with [Formula: see text][Formula: see text]. This study highlights dwarf morphology as a fundamental benchmark for testing future galaxy formation models.
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6. Tracing chemical depletion in evolved binaries hosting second-generation transition discs.
PMID:日期:2025-04-01The mechanisms responsible for chemical depletion across diverse astrophysical environments are not yet fully understood. In this paper, we investigate chemical depletion in post-AGB/post-RGB binary stars hosting second-generation transition discs using high-resolution optical spectra from HERMES/Mercator and UVES/VLT. We performed a detailed chemical abundance analysis of six post-AGB/post-RGB stars and six post-AGB/post-RGB candidates with transition discs in the Galaxy and in the Large Magellanic Cloud. The atmospheric parameters and elemental abundances were obtained through 1D LTE analysis of chemical elements from C to Eu, and 1D NLTE corrections were incorporated for elements from C to Fe. Our results confirmed that depletion efficiency, traced by the [S/Ti] abundance ratio, is higher in post-AGB/post-RGB binaries with transition discs compared to the overall sample of post-AGB/post-RGB binaries. We also examined correlations between derived abundances and binary system parameters (astrometric, photometric, orbital, pulsational). Additionally, we compared the depletion patterns in our sample to those observed in young stars with transition discs and in the interstellar medium. We confirmed that the depletion is significantly stronger in post-AGB/post-RGB binaries with transition discs than in young stars with transition discs. Furthermore, we found that [X/Zn] abundance ratio trends of volatile and refractory elements in post-AGB/post-RGB binaries with transition discs generally resemble similar trends in the interstellar medium (except for trends of [Si/Zn] and [Mg/Zn] ratios). These findings, although based on a limited sample, provide indirect constraints for depletion mechanism in circumbinary discs around post-AGB/post-RGB stars.
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7. Battle of the CH motions: aliphatic versus aromatic contributions to astronomical PAH emission and exploration of the aliphatic, aromatic, and ethynyl CH stretches.
PMID:日期:2024-12-01Strong anharmonic coupling between vibrational states in polycyclic aromatic hydrocarbons (PAH) produces highly mixed vibrational transitions that challenge the current understanding of the nature of the astronomical mid-infrared PAH emission bands. Traditionally, PAH emission bands have been characterized as either aromatic or aliphatic, and this assignment is used to determine the fraction of aliphatic carbon in astronomical sources. In reality, each of the transitions previously utilized for such an attribution is highly mixed with contributions from both aliphatic and aromatic CH motions as well as non-CH motions such as CC stretches. High-resolution gas-phase IR absorption measurements of the spectra of the aromatic molecules indene and 2-ethynyltoluene at the Canadian Light Source combined with high-level anharmonic quantum chemical computations reveal the complex nature of these transitions, implying that the use of these features as a marker for the aliphatic fraction in astronomical sources is not uniquely true or actually predictive. Further, the presence of aliphatic, aromatic, and ethynyl CH groups in 2-ethynyltoluene provides an internally consistent opportunity to simultaneously study the spectroscopy of all three astronomically important groups. Finally, this study makes an explicit connection between fundamental quantum mechanical principles and macroscopic astronomical chemical physics, an important link necessary to untangle the lifecycle of stellar and planetary systems.
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8. AHKASH: a new Hybrid particle-in-cell code for simulations of astrophysical collisionless plasma.
PMID:日期:2024-11-01We introduce Astrophysical Hybrid-Kinetic simulations with the flash code ([Formula: see text]) - a new Hybrid particle-in-cell (PIC) code developed within the framework of the multiphysics code flash. The new code uses a second-order accurate Boris integrator and a predictor-predictor-corrector algorithm for advancing the Hybrid-kinetic equations, using the constraint transport method to ensure that magnetic fields are divergence-free. The code supports various interpolation schemes between the particles and grid cells, with post-interpolation smoothing to reduce finite particle noise. We further implement a [Formula: see text] method to study instabilities in weakly collisional plasmas. The new code is tested on standard physical problems such as the motion of charged particles in uniform and spatially varying magnetic fields, the propagation of Alfvén and whistler waves, and Landau damping of ion acoustic waves. We test different interpolation kernels and demonstrate the necessity of performing post-interpolation smoothing. We couple the turbgen turbulence driving module to the new Hybrid PIC code, allowing us to test the code on the highly complex physical problem of the turbulent dynamo. To investigate steady-state turbulence with a fixed sonic Mach number, it is important to maintain isothermal plasma conditions. Therefore, we introduce a novel cooling method for Hybrid PIC codes and provide tests and calibrations of this method to keep the plasma isothermal. We describe and test the 'hybrid precision' method, which significantly reduces (by a factor [Formula: see text]) the computational cost, without compromising the accuracy of the numerical solutions. Finally, we test the parallel scalability of the new code, showing excellent scaling up to 10,000 cores.
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9. Automation of finding strong gravitational lenses in the Kilo Degree Survey with U - DenseLens (DenseLens + Segmentation).
PMID:日期:2024-09-01In the context of upcoming large-scale surveys like Euclid, the necessity for the automation of strong lens detection is essential. While existing machine learning pipelines heavily rely on the classification probability (P), this study intends to address the importance of integrating additional metrics, such as Information Content (IC) and the number of pixels above the segmentation threshold ([Formula: see text]), to alleviate the false positive rate in unbalanced data-sets. In this work, we introduce a segmentation algorithm (U-Net) as a supplementary step in the established strong gravitational lens identification pipeline (Denselens), which primarily utilizes [Formula: see text] and [Formula: see text] parameters for the detection and ranking. The results demonstrate that the inclusion of segmentation enables significant reduction of false positives by approximately 25 per cent in the final sample extracted from DenseLens, without compromising the identification of strong lenses. The main objective of this study is to automate the strong lens detection process by integrating these three metrics. To achieve this, a decision tree-based selection process is introduced, applied to the Kilo Degree Survey (KiDS) data. This process involves rank-ordering based on classification scores ([Formula: see text]), filtering based on Information Content ([Formula: see text]), and segmentation score ([Formula: see text]). Additionally, the study presents 14 newly discovered strong lensing candidates identified by the U-Denselens network using the KiDS DR4 data.
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10. An asymptotically correct implicit-explicit time integration scheme for finite volume radiation-hydrodynamics.
PMID:日期:2024-06-01Numerical radiation-hydrodynamics (RHD) for non-relativistic flows is a challenging problem because it encompasses processes acting over a very broad range of time-scales, and where the relative importance of these processes often varies by orders of magnitude across the computational domain. Here, we present a new implicit-explicit method for numerical RHD that has a number of desirable properties that have not previously been combined in a single method. Our scheme is based on moments and allows machine-precision conservation of energy and momentum, making it highly suitable for adaptive mesh refinement applications; it requires no more communication than hydrodynamics and includes no non-local iterative steps, making it highly suitable for massively parallel and Graphics Processing Unit (GPU)-based systems where communication is a bottleneck; and we show that it is asymptotically accurate in the streaming, static diffusion, and dynamic diffusion limits, including in the so-called asymptotic diffusion regime where the computational grid does not resolve the photon mean-free path. We implement our method in the GPU-accelerated RHD code quokka and show that it passes a wide range of numerical tests.