Astronomical Observatory

The management of observing proposals is a critical operational component for modern astronomical facilities. As missions grow in complexity, the demand for efficient, fair, and adaptable proposal handling systems is increasingly pressing. Existing systems are often monolithic and tightly coupled to a specific observatory, lacking the flexibility to be easily adapted. This paper introduces AstroPropose, a novel, general-purpose framework for creating and managing astronomical observing proposal systems, derived from the architecture of the operational Einstein Probe Observing Proposal System (EOPS). AstroPropose is centered on a powerful visual workflow engine, enabling administrators to define and deploy entire proposal workflows through a graphical interface. Key features include a dynamic form builder, a configurable workflow engine, and a flexible role-based access control (RBAC) system. We present the complete architecture and data model. As validation, we detail how the framework’s design principles are embodied in EOPS, which has successfully managed two annual proposal cycles and handles daily time-critical Target of Opportunity (ToO) submissions for the Einstein Probe mission. To further demonstrate the framework’s generalizability, we present a second case study: its adaptation as the proposal management prototype for the Chinese Space Station Telescope (CSST), a multi-instrument survey mission with a dual-phase review process. AstroPropose, validated through the successful operation of EOPS and the rapid prototyping of the CSST system, is being prepared for an open-source release to the astronomical community.

We present a systematic evaluation of modern multimodal large language models (LLMs) for the classification of mean-motion and secular resonances from images of resonant arguments. Four benchmark datasets (RB-TEST, RB-PILOT, RB-SMALL, RB-FULL) were constructed to cover clear, ambiguous, and transient cases, with both binary and three-class outputs. Using standardized prompts (a full prompt for large models and a simplified variant for small models that cannot process complex instructions), we tested flagship commercial models, large open-source models, and small locally runnable models. Commercial LLMs reach [Formula: see text] on simple cases and up to [Formula: see text] on the three-class RB-SMALL dataset, while the best open-source models also reach [Formula: see text] on unambiguous cases and [Formula: see text] on the complex ones. On the full binary benchmark, open-source models approach commercial performance ([Formula: see text]-[Formula: see text]). Most errors occur in transient and resonance-sticking regimes. The results show that LLMs can perform resonance classification at levels comparable to those of classical or machine-learning methods without training or fine-tuning, and that even small open-source models achieve practically useful accuracy. The released benchmarks establish a reproducible standard for evaluating LLMs on dynamical astronomy tasks.

Silver nanoparticles (AgNP), which have a wide range of applications in technical and biological fields, are produced in hundreds of tons annually and are eventually released into water, air, and soil. In this study, the effects of AgNPs on Phanerochaete chrysosporium, a white-rot fungus that plays a key role in wood waste degradation, were investigated. The AgNP were synthesized at high temperature with gallic acid under different pH conditions: near-neutral pH (~7.5), notation AgNP@GA-1, and alkaline pH (~10.5), notation AgNP@GA-2, focusing on their ability to cope with oxidative stress. The samples were characterized by fine granularity (particle diameter of 12 and 11 nm, respectively), specific plasmonic features (characteristic band at 425 and 408 nm), hydrodynamic diameter of 93 and 133 nm, respectively, and Zeta potential of −34 to −44 mV, which gave them stability over a period of three months. The fungal cultures exposed to AgNP concentrations of 40–100 µL/mL (approximately 4–11 µg/mL) presented superoxide dismutase (SOD) activity, which increased by approximately 45% at 40 µL/mL for AgNP@GA-1 after 7 days, whereas AgNP@GA-2 decreased SOD activity by up to 40% at 60 µL/mL. Both AgNP types strongly stimulated catalase (CAT) biosynthesis, with two- to three-fold increased activity on the 7th day at 100 µL/mL. CAT activity remained significantly elevated for AgNP@GA-1 on the 14th day at 60–80 µL/mL, whereas for AgNP@GA-2 it decreased by 40–60% compared with the control. Variations in malondialdehyde content indicated moderate lipid peroxidation, suggesting relatively low cytotoxic effects on fungal cells. Overall, the results demonstrate that P. chrysosporium exhibits adaptive biochemical responses to AgNP-induced oxidative stress while maintaining metabolic functionality, highlighting the potential compatibility of AgNPs with white-rot fungi involved in environmental wood waste biodegradation processes.

Abstract We conducted a H i 21 cm absorption study of a sample of 147 nearby ( z < 0.1) low-power radio sources with 10 mJy < S 1.4 GHz < 30 mJy and log ( P 1.4 GHz / W Hz − 1 ) = 20.5 – 23.7 , using the Five-hundred-meter Aperture Spherical radio Telescope. By investigating the origin and kinematics of H i absorbing gas, we aim to study the interplay between the active galactic nucleus (AGN) and its surrounding interstellar medium. Our observations detect 12 new absorbers, combining results from the pilot survey (three absorbers out of 26 sources), yielding a detection rate of ∼ 10 . 2 − 2.0 + 3.1 % . The detection rate in our sample is lower than in higher-power samples, which is likely due to emission dilution and the dominance of extended sources, indicating a gas-rich and star-forming-dominated population in low-power sources. Among new detections, most line profiles are narrow and show velocities close to systemic ones, consistent with rotating disks, while four show disturbed kinematics indicative of inflows or outflows. The fraction of outflow candidates rises with radio power, while the fraction of inflow ones remains constant, suggesting the effect of radio emission on driving H i outflows. In our sample, compact sources show a higher H i detection rate than extended sources. Contrary to expectations from higher-power samples, MIR-bright sources at low-power radio do not exhibit a higher H i detection rate or more disturbed kinematics. In low-power radio sources, blueshifted absorption occurs only in Seyferts and low-ionization nuclear emitting regions, indicating the connection between atomic outflows and the ionization state of AGN.

Early-type galaxies host low-luminosity active galactic nuclei, as indicated by radio emission spanning up to several orders of magnitude in terms of the physical scale, ranging from compact parsec-scale to extended kiloparsec-scale radio morphology. We investigate the Eddington-scaled radio luminosity distribution of nearby early-type galaxies in a large sample of 117 sources to confirm whether this distribution is bimodal, as previously inferred for a smaller sample of 62 galaxies. We also consider whether the bimodality can be attributed to specific host galaxy properties. We compiled a sample of early-type galaxies with black hole masses measured using direct methods, as well as the radio flux densities at 1.4,GHz and 3,GHz. We used statistical tests to confirm whether the Eddington-scaled radio luminosities are bimodal. We investigated the properties of radio-dim and -bright sources, assessed the presence of extended jets with VLASS imaging, and examined host galaxy kinematics and central stellar structure. We confirm, using a twice larger sample of all known 1.4,GHz-detected early-type galaxies with directly measured black hole masses (117 galaxies), that the distribution of ̊m 1.4,GHz /L_ Edd is bimodal, with a characteristic antimode at L_ ̊m 1.4,GHz /L_ Edd ≈ -8.6, which disappears when considering the subset of sources with black hole masses obtained using the M_ ̊m BH -σ_⋆ relation. The radio-bright peak is dominated by galaxies hosting resolved jets, while radio-dim systems show compact nuclear emission with many showing excess radio emission relative to that expected from star formation as indicated by the well-known far-infrared and radio (FIR-radio) correlation. Moreover, we find that radio-bright galaxies are primarily slow rotators with depleted stellar cores, whereas radio-dim galaxies are predominantly fast rotators. We show that nearby early-type galaxies with direct black hole mass measurements exhibit a clear bimodality in Eddington-scaled radio luminosity, separating radio-dim nuclei with compact emission from radio-bright systems hosting extended jets. The dichotomy correlates strongly with host-galaxy kinematics and central structure, suggesting that the ability to sustain jet production is governed primarily by galaxy assembly history and feeding mode, rather than by black hole mass or accretion rate alone. In this term, the radio output of radio-dim sources likely reflects modest, intermittent supplies of magnetized gas delivered to the accretion flow through stochastic processes and, most plausibly, the tidal disruption of giant-branch stars passing through the immediate vicinity of the supermassive black hole (SMBH).

Compelling observational evidence indicates that the disc population in galaxy clusters has undergone rapid evolution, transitioning from a dominance of blue spirals to red lenticular galaxies (S0s) over the past sim7 We built a simplified cluster evolutionary model in the standard cosmological framework to constrain the characteristic timescales of this transformation. In our model, all field spirals joining the cluster at various redshifts are subject to ram-pressure stripping (RPS), which removes their gas reservoir leading to the quenching of their star formation on a timescale, t_ s, and to an (initially) unspecified mechanism that transforms them into S0s on a timescale, t_ m. We assume that t_̊m s and t_̊m m are independent and both power-law functions of the galaxy-to-cluster mass ratio, M_⋆/M_̊m cl. We constrained our model using the observed distribution of spirals and S0s in a colour-mass plane from the OmegaWINGS and EDisCS cluster surveys at z and z respectively. Our best-fit model reproduces the data remarkably well, especially at low redshift, and predicts evolutionary trends for the main morphological fractions in agreement with previous studies. We find typical t_̊m s values between 0.1 and 1 compatible with previous estimates, supporting RPS as the most efficient quenching mechanisms in clusters. A surprisingly strong anti-correlation between t_̊m s and M_⋆/M_̊m cl is required in order to suppress the formation of red, low-mass spirals at low redshift, which we interpret as being driven by orbit anisotropy. Conversely, t_̊m m depends very weakly on M_⋆/M_̊m cl and has typical values of a few Gyr. The inferred morphological evolution is compatible with that resulting from the ageing of the stellar populations in galaxies that have been abruptly quenched by ram pressure stripping: we confirm spectrophotometric ageing as a key channel for the spiral-to-S0 transition in galaxy clusters, with secular evolution playing a secondary role.

Context . Stellar activity remains one of the main limitations in the detection of Earth-like planets using radial velocity (RV) measurements. The Sun, as the only star for which surface features can be spatially resolved, offers a unique testbed for studying the impact of active regions on RV and photometric variability. Aims . Using SOAPv4 (Spot Oscillation And Planet), we modelled solar RV and photometric variability induced by spots and faculae over long timescales. Our goal is to verify whether present-day, state-of-the-art models of the cross-correlation function correctly reproduce the observed variability. Moreover, we aim to assess how the choice of input data and identification technique influences the agreement between simulated and observed signals. Methods . To simulate solar RV and photometric time series, we first identified active regions in SDO images. This was done using mathematical morphological transforms applied to SDO/HMI and AIA images. Mathematical morphological identification was validated against other state-of-the-art identification methods. Using these inputs, we ran SOAPv4 to simulate solar RVs and photometry, and we validated the results with HARPS-N RV observations, as well as with VIRGO/SPM photometric measurements. Results . The simulations that use mathematical morphological identification achieved the best match with the observed RV time series, yielding residuals with a measured standard deviation of ~0.91 m/s. Other state-of-the-art methods produced higher filling factors and, consequently, larger discrepancies. The photometric simulations reproduced the overall variability trends. Conclusions . We demonstrate that mathematical morphological transforms accurately identify solar active regions. Using these inputs, SOAPv4 reproduces the observed solar RV variability with a measured standard deviation of the residuals of ~0.91 m/s. Photometric simulations capture the overall variability trends, confirming that SOAP can reliably model the impact of both spots and faculae on solar RVs and photometry.

ABSTRACT Filaments are crucial components of the cosmic web, representing the extensive and aligned distributions of galaxies and gas. Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we report the detection of a filament in the Ursa Major supergroup using atomic-hydrogen (H i) observations. This filament consists of sixteen various types of galaxies and five starless gas clumps, spanning a length of approximately 0.9 Mpc. Notably, it is extremely thin, with a thickness comparable to the diameter of a galaxy. We observed a galaxy-filament spin alignment and a velocity gradient within the filament. These findings strongly suggest a cold accretion flow along the filament, potentially contributing to the formation and growth of the galaxies. The thin filament, as a small group, is likely to be merged into the Ursa Major supergroup in the context of hierarchical structure formation.

ABSTRACT The first four all-sky surveys with eROSITA the soft X-ray instrument on board the Spektrum–Roentgen–Gamma (SRG) satellite revealed a new X-ray source, eRASSU J012422.9–724248, in the Magellanic Bridge, near the Eastern Wing of the Small Magellanic Cloud (SMC). We performed a broad-band timing and spectral analysis using the optical and X-ray data of eRASSU J012422.9–724248. Using the X-ray observations with eROSITA, Swift, NuSTAR and optical data from the optical Gravitational Lensing Experiment (OGLE) and the Las Cumbres Observatory (LCO), we confirm the nature of eRASSU J012422.9–724248as a Be/X-ray binary (BeXRB) pulsar in the Magellanic Bridge. The position is coincident with that of an early-type star (OGLE ID SMC732.10.7). We detect the spin period at 341.71 s in NuSTAR data and infer a period of 63.65 d from the 15 yr monitoring with OGLE, that we interpret as the orbital period of the system. A tentative CRSF at $\sim$12.3 keV is identified in NuSTAR spectra with $\sim 1.8\sigma$. The source appears to show a persistent X-ray luminosity and an optical magnitude transition on the long timescale. We propose eRASSU J012422.9–724248is a new member of the class of persistent BeXRBs.