We explore the phenomenology of the “Dark Walker”—an SU(3) theory with eight flavors of massless fundamental fermions in the dark sector. During inflation, its walking dynamics generate primordial non-Gaussianities through the exchange of unparticles, while accounting for the current dark matter relic abundance if we consider freeze-in of Dark Walker coupled to the Standard Model through the Higgs portal. This provides a simple yet predictive example linking strongly coupled inflationary dynamics to present-day dark matter.

Observations from Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) continue to reveal gravitationally magnified high-redshift star candidates, resulting in a rising demand for accurate stellar bolometric corrections to facilitate comparisons between theoretical stellar evolutionary models and observational data. To address this need, we updated our YBC stellar bolometric correction database by incorporating bolometric corrections for cosmologically redshifted stars, now called the zYBC database. These bolometric corrections were derived by redshifting stellar spectra from public stellar spectral libraries, attenuated by the extinction curves for both the dust in the host galaxy and the Milky Way, followed by convolution with the transmission curves of various photometric filters. Our methodology naturally incorporates the effects due to the cosmological K-correction and the dust. In addition to the existing stellar spectral libraries in the previous version of YBC, we included stellar spectral libraries from non-local thermodynamic equilibrium models (PoWR, TLUSTY, and CMFGEN) for O, B stars, which are more appropriate for hot massive stars. In particular, the PoWR and CMFGEN models include the modelling of stellar wind. The database supports key photometric systems for high-redshift studies, such as HST/WFC3 wide-band filters, JWST/NIRCam, and Chinese Space-station Survey Telescope (CSST) equipped with its Main Survey Camera (MSC) and Multi-Channel Imager (MCI), which are pivotal facilities for the current and future observational studies of high-redshift stars. The database maintains the flexibility to incorporate additional photometric systems upon request. As examples, we present colours as functions of log Teff at various redshifts for several photometric systems, which exhibit non-monotonic behaviours and demonstrate the necessity for a dedicated modelling. In particular, we find that the relations show larger dispersions at high redshifts than in the zero redshift case. This indicates that the stellar parameters of high-redshift stars can be better determined than those of their local counterparts, given their redshifts can be reliably determined through other methods (e.g. from their host galaxies) and their photometric data are of high enough quality for physical parameter determinations via spectral-fitting methods. We also demonstrate the difference in the effects brought on by the variety in the amounts of extinctions. This updated database represents a valuable resource for high-redshift star research.

Observations show that multiple stellar populations (MPs) are ubiquitous in globular clusters. The Hubble Space Telescope (HST) has been a pivotal tool for previous photometric studies of MPs. The Chinese Space Station Survey Telescope (CSST) is a 2 m telescope scheduled for launch. One of its imaging instruments, the Survey Camera (SC), combines ultraviolet sensitivity comparable to that of HST with a significantly larger field of view, making it well-suited for conducting large-scale photometric surveys of MPs within extensive stellar stream structures. In this work, we perform mock observations of the stellar stream Palomar 5 to assess the feasibility of detecting MPs with the CSST/SC. The results indicate that the CSST/SC cannot resolve MPs in stellar streams at distances comparable to Palomar 5 (greater than or similar to 20 kpc) with one or 10 150 s exposures. This fundamental limitation arises from the absence of the precise proper motions required to disentangle stream members. We estimate that successful resolution would require the target stream to be less than or similar to 8 kpc under a 150 s exposure. Furthermore, using theoretical color-magnitude diagrams, we find that the CSST/SC g band provides an optimal balance between contamination rate and completeness rate for member identification in the cluster's core. However, this approach fails in the stream due to severe field star contamination. Therefore, future CSST observations of Palomar 5 and its tidal tails will employ multiple epochs across several bands to obtain the deep photometry and proper motion data for a definitive MP analysis.

The Chinese Space Station Survey Telescope (CSST) is a flagship space mission, supported by the China Manned Space Project, designed to carry out a large-area sky survey to explore the nature of dark matter and dark energy in the Universe. The onboard multi-band imaging and slitless spectroscopic modules will enable us to obtain photometric data for billions of galaxies and stars, as well as hundreds of millions of spectroscopic measurements, advancing various scientific analyses such as galaxy clustering and weak gravitational lensing. To support the image simulations for the main survey of the CSST mission, we present a mock catalog of stars and galaxies. For stars, the mock catalog is generated using either Galaxia or TRILEGAL , both of which provide a range of stellar properties to meet the requirements of CSST image simulations. For galaxies, we built a mock light-cone up to redshift z ∼ 3.5 from the cosmological N -body simulation and populated the mock galaxy catalog from the dark matter haloes using a semi-analytical galaxy formation model. We then performed a full-sky ray-tracing simulation of weak gravitational lensing to obtain lensing shear at the position of each galaxy in the light-cone. To support both multi-band imaging and slitless spectroscopic simulations, we computed the spectral energy distribution (SED) for each galaxy based on its star formation history using a supervised deep learning model and determined the magnitudes in each band using the CSST throughputs. Finally, the properties of our mock galaxies include positions, redshifts, stellar masses, shapes, sizes, SEDs, lensing shears and magnifications. We have validated our mock catalog against observational data and theoretical models, with results showing good overall agreement. The catalog provides a flexible data set for the development of CSST image processing and can support a wide range of cosmological analyses within the CSST mission.

The growing density of robotic fiber positioners (RFPs) in modern multi-object spectroscopic telescopes, such as the phase II system of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), makes real-time collision prediction increasingly important, particularly as future instruments are expected to integrate 8000-12,000 RFPs within highly overlapping workspaces. To enhance operational safety and maximize observational efficiency in such high-density configurations, we developed a real-time collision prediction system tailored for astronomical fiber positioning systems. Integrating a field-programmable gate array-based vision system with a lightweight spatiotemporal deep learning model, our method achieves high-precision dynamic RFP trajectory prediction to further forecast potential collisions. The system captures positional variations via optical flow and centroid tracking, enabling reliable motion inference through the deep learning model under realistic observing conditions. Experimental validation using LAMOST observational data shows a 48.19% improvement in trajectory prediction accuracy over the standard Transformer baseline, as measured by final displacement error. Collision-prediction experiments in both simulation and on a real platform further verified the effectiveness and robustness of the proposed framework. On the real platform, our approach achieved 98.98% precision and 99.85% recall. Under batched GPU array-level inference, the total latency remains well below the 6 s prediction horizon. These results demonstrate that our approach can provide accurate and low-latency collision-risk prediction for dense robotic fiber positioning systems, offering a reliable early-warning capability and a practical basis for future collision-avoidance systems in large-scale telescopes equipped with high-density fiber positioners.

Observations from HST JWST continue to reveal gravitationally magnified high-redshift star candidates, resulting in increasing demand for accurate stellar bolometric corrections to compare stellar models with observational data. We update YBC stellar bolometric correction database by incorporating bolometric corrections for cosmologically redshifted stars, called zYBC. The bolometric corrections are derived by redshifting stellar spectra from libraries, attenuated by extinction curves for both the dust in the host galaxy and the Milky Way, and followed by convolution with the transmission curves of photometric filters. Our methodology incorporates the effects due to the cosmological K-correction and the dust. Besides the spectral libraries in earlier YBC, we add NLTE-based spectral libraries for O, B stars, which are better suited for hot massive stars, particularly wind-included PoWR and CMFGEN models. The database supports key photometric systems for high-redshift studies, such as HST/WFC3, JWST/NIRCam, and CSST's MSC and MCI, and maintains the flexibility to incorporate additional photometric systems upon request. As examples, we present colors as functions of Teff at various redshifts for several photometric systems, which exhibit non-monotonic behaviors and demonstrate the necessity for a dedicated modelling. In particular, we find that the relations show larger dispersions at high redshift than the zero redshift case. This indicates that the stellar parameters of high redshift stars can be better determined than those of their local counterparts, given their redshifts reliably determined through other methods and their photometric data are of high enough quality for physical parameter determination through spectral-fitting. We also show the difference in the effect brought by the different amount of extinctions. zYBC represents a valuable resource for high-redshift star research.

The Chinese Space Station Survey Telescope (CSST) is a flagship space-based observatory. Its main survey camera is designed to conduct high spatial resolution near-ultraviolet to near-infrared imaging and low-resolution spectroscopic surveys. To maximize the scientific output of CSST, we have developed a comprehensive, high-fidelity simulation pipeline for reproducing both imaging and spectroscopic observations. This paper presents an overview of the simulation framework, detailing its implementation and components. Built upon the GalSim package and incorporating the latest CSST instrumental specifications, our pipeline generates pixel-level mock observations that closely replicate the expected instrumental and observational conditions. The simulation suite integrates realistic astrophysical object catalogs, instrumental effects, point-spread function modeling, and observational noises to produce accurate synthetic data. We describe the key processing stages of the simulation, from constructing the input object catalogs to modeling the telescope optics and detector responses. Furthermore, we introduce the most recent release of simulated datasets, which provide a crucial testbed for data processing pipeline developments, calibration strategies, and scientific analyses, ensuring that CSST will meet its stringent requirements. Our pipeline serves as a vital tool for optimizing CSST main survey strategies and ensuring robust cosmological measurements.

Chinese Space Station Telescope (CSST), which will begin its scientific operations around 2027, is going to survey the sky area of the median-to-high Galactic latitude and median-to-high ecliptic latitude. The high astrometric precision of the CSST Survey Camera for faint objects enables the detection of a number of giant planets and brown dwarfs around M dwarfs and brown dwarfs via differential astrometry in its optical survey. In this paper, we predict the number of giant planets and brown dwarfs around stars and brown dwarfs detectable with CSST astrometry. We generate synthetic samples of CSST stellar and substellar sources, and carry out companion injection-recovery simulations in the samples using different occurrence rates for FGK dwarfs, M dwarfs, and brown dwarfs. We calculate companion yields based on CSST astrometric precision. Our analysis reveals that over its 10 yr mission, the CSST Survey Camera could barely discover giant planets and low-mass BDs around FGK dwarfs, but is projected to detect 20−170 giant planets and low-mass brown dwarfs around M dwarfs within 300 pc, and 300−570 brown dwarf binaries within 600 pc. Therefore, CSST astrometry is likely to significantly increase the current sample of substellar companions around M dwarfs and brown dwarfs. This sample will deepen our understanding of planet formation and evolution around low-mass stars and brown dwarfs.

Very metal-poor (VMP; [Fe/H] < -2) stars are critical tracers for understanding early star formation and Galactic chemical evolution. However, identifying these rare objects from the massive datasets generated by the Dark Energy Spectroscopic Instrument (DESI) presents significant challenges in efficiency and precision due to the scarcity of high-fidelity labels and low signal-to-noise ratios in the metal-poor regime. To address this, we propose a novel dual-model deep learning framework that integrates a 1D-ResNet binary classifier with a specialized parameter regression model. Leveraging a transfer learning strategy with high-quality labels from APOGEE and the Large Sky Area Multi-object Fiber Spectroscopic Telescope, we optimized the framework for DESI spectra. The classification model achieves an accuracy of 97.87%, while the regression model predicts stellar metallicity with an rms error of 0.093 dex. Applying this framework to the high-quality DESI-HQ-DATA dataset and applying a strict temperature cut (T-eff >= 4500 K) to avoid extrapolation in the cool dwarf regime, we constructed a highly purified catalog of 2569 high-confidence VMP candidates. Internal validation demonstrates a significant improvement in consistency between DESI pipeline measurements, and external crossmatching with Gaia XP spectra confirms the reliability of our metallicity estimates. Finally, compared to existing compilations, this work contributes 1377 new VMP candidates, providing a robust and statistically significant sample for future studies of the Galactic halo and ancient stellar populations.

We present the first deployment of an end-to-end autonomous control system driven by a large language model (LLM) on an operational solar telescope-the Solar Full-disk Multi-layer Magnetograph (SFMM), named JW-ASTClaw. This system employs a multi-agent framework adopting a decoupled three-layer architecture (perception-decision-execution) interconnected through the Model Context Protocol (MCP), which addresses real-time adaptive scheduling under complex environmental conditions while achieving high portability: the perception and decision logic are reused unchanged across instruments, requiring only telescope-specific command interfaces to be adapted. Three perception agents-data-quality-agent, cloud-analyzer-agent, and flare-detector-agent-encode senior observer expertise, including wind jitter detection via limb-ring standard deviation, projected-circle zonal cloud analysis, and multi-band active region identification, as LLM-callable rules, while a central reasoning engine performs multi-source fusion and conflict resolution. The system supports graceful degradation from cloud LLM to local inference and finally to rule-based fallback, designed for remote field stations with unstable connectivity. Cross-season validation on archival data demonstrates 100

Individual stars located near the caustics of galaxy clusters can undergo extreme magnification when crossing micro-caustics, rendering them observable even at cosmological distances. Though most massive stars are likely reside in binary systems rather than as single star, the influence of binary star system on magnification events is severely under-explored. In this work, we simulate the light curves produced by detached binary stars crossing micro-caustics, aiming to characterize their unique observational signatures.Using high-resolution magnification maps generated by the GPU-PMO-CAUSTIC algorithm and PARSEC stellar models with red-shifted magnitude, we examined the impact of binary star parameters and crossing geometries on microlensing magnification patterns. Our simulations reveal that binary stars produce diverse light curve features, including overlapping peaks, plateau-like structures, and time-variable color-magnitude differences. These features, particularly the distinct temporal variations in spectral energy distributions, offer diagnostic tools for distinguishing binary systems from single stars.We further demonstrate the potential of multi-band photometry using the Chinese Space Station Telescope's Multi-Channel Imager (CSST-MCI) to capture these variations.Our findings provide theoretical support for identifying binary systems in future caustic-crossing events, enabling more accurate characterization of high-redshift stellar populations.

Open clusters offer unique opportunities to study stellar dynamics and evolution under the influence of their internal gravity, the Milky Way's gravitational field, and the interactions with encounters. Using the Gaia DR3 data for a catalog of open clusters within 500 parsecs that exhibit tidal features reported by the literature, we applied a novel method based on 3D principal component analysis to select a ``golden sample'' of nearby open clusters with minimal line-of-sight distortions. This approach ensures a systematic comparison of 3D and 2D structural parameters for tidally perturbed clusters. The selected golden sample includes Blanco 1, Melotte 20, Melotte 22, NGC 2632, NGC 7092, NGC 1662, Roslund 6, and Melotte 111. We analyzed these clusters by fitting both 2D and 3D King Profiles to their stellar density distributions. Our results reveal systematic discrepancies, with most of the golden sample clusters exhibiting larger 3D tidal radii compared to their 2D counterparts, demonstrating that the 2D projection effects bias the measured cluster size. Furthermore, the 3D density profiles show stronger deviations from the King profiles at the tidal radii (Δ ρ_ 3D > Δ ρ_ 2D ), highlighting enhanced sensitivity to tidal disturbances. Additionally, we investigated the spatial distribution of cluster members relative to their bulk motion in the Galactic plane. We find that some clusters exhibit tidal features oriented perpendicular to their direction of motion, which can be attributed to the fact that the current surveys only detect the curved inner regions of the tidal features. In conclusion, this work offers a golden sample of nearby open clusters that are most reliable for 3D structure analysis and underscores the necessity of 3D analysis when characterizing OC morphological asymmetries, determining cluster size, and identifying tidal features.

This paper statistically analyzes the seeing data at the Lenghu site Platform C from 2018 to 2024, during which extensive construction modified the original landscape. The study focuses on the impacts of meteorological factors and building obstructions. The results reveal a progressive degradation in seeing as the monitoring setup passively changed: the median values were 0.'' 76 (the original location), 0.'' 83 during the Terrace, and 0 .'' 99 at the new Dome (temporarily considered the permanent monitoring location). Once the instruments are fully deployed, wind speed and wind direction critically affect seeing quality, with optimal conditions occurring when the wind speed is 2-6 m s(-1) and the wind direction is between 180 degrees and 270 degrees. However, in 2023 and 2024, the wind speeds decreased, and the prevailing wind direction shifted from southwest to northwest, correlating with poorer seeing. Computational Fluid Dynamics simulations reveal that the construction of the Wide Field Survey Telescope altered the local wind field, increasing turbulence around the Dome, especially when the winds blow from 225 degrees to 255 degrees. In contrast, Platform A, located in a higher and more open area, consistently maintained better seeing, particularly after midnight, likely due to fewer obstructions and lower nocturnal heat release.

The C statistic is a widely used likelihood-ratio statistic for model fitting and goodness-of-fit assessments with Poisson data in high-energy physics and astrophysics. Although it enjoys convenient asymptotic properties, the statistic is routinely applied in cases where its nominal null distribution relies on unwarranted assumptions. Because researchers do not typically carry out robustness checks, their scientific findings are left vulnerable to misleading significance calculations. With an emphasis on low-count scenarios, we present a comprehensive study of the theoretical properties of C statistics and related goodness-of-fit algorithms. We focus on common ``plug-in'' algorithms where moments of C are obtained by assuming the true parameter equals its estimate. To correct such methods, we provide a suite of new principled user-friendly algorithms and well-calibrated p-values that are ready for immediate deployment in the (astro)physics data-analysis pipeline. Using both theoretical and numerical results, we show (a) standard $χ^2$-based goodness-of-fit assessments are invalid in low-count settings, (b) naive methods (e.g., vanilla bootstrap) result in biased null distributions, and (c) the corrected Z-test based on conditioning and high-order asymptotics gives the best precision with low computational cost. We illustrate our methods via a suite of simulations and applied astrophysical analyses. An open-source Python package is provided in a GitHub repository.

There has been growing evidence that the rich star clusters in the Magellanic Clouds contain significant fractions of rapidly rotating stars. In this work, we aim to constrain these fractions by studying the colour-magnitude diagrams of four star clusters, selected among those with the most striking signatures of fast rotators. Using isochrones derived from parsec v2.0 stellar tracks, we generate distinct stellar populations, each covering a limited interval of initial rotation rates omega(i), referred to as 'Partial Models' (PMs). Using optimization algorithms and Monte Carlo Markov Chains, PMs are combined to create the final best-fitting model. In our analysis, we adopt two key assumptions: a uniform age and an isotropic distribution of stellar spin axes within each cluster. The solutions are allowed to explore the entire range of omega(i), and different values of age, metallicity, distance, and foreground extinction. We find that the rotational velocity distributions in all four clusters reveal a high fraction of stars with omega(i) close to the break-up value, in all cases. Specifically, the fraction of stars with omega(i )> 0.7 exceeds 80 per cent in the clusters NGC 419 of the Small Magellanic Cloud (SMC) and NGC 1831 and NGC 1866 of the Large Magellanic Cloud (LMC). For NGC 2203 of the LMC, this fraction is smaller, although it still exceeds 50 per cent, confirming that also this cluster is mainly populated by fast-rotating stars.

Recent literature reports a color deviation between observed Gaia color-magnitude diagrams (CMDs) and theoretical model isochrone predictions, particularly in the very low-mass regime. To assess its impact on cluster age determination via isochrone fitting, we quantified the color deviations for three benchmark clusters, Hyades, Pleiades, and Praesepe, both for the Gaia color (BP-RP) and (G-RP). In general, the (G-RP) color deviations are smaller than the (BP-RP) ones. Empirical color correction functions based on these benchmarks are derived for the currently available MIST and PARSEC 1.2S isochrone models. Applying the correction functions to 31 additional open clusters and 3 moving groups results in a significantly improved alignment between the isochrones and observed CMDs. With our empirical corrections, isochrones provide age estimates consistent with literature values obtained through the spectral Lithium Depletion Boundary method, validating the effectiveness of our approach. The corresponding metallicities with PARSEC 1.2S also show a good agreement with the spectroscopic results. The empirical color correction function we present in this work offers a tool for a consistent age determination within the full mass range of stellar clusters using the isochrone fitting method.

Open clusters (OCs) are the primary contributors to the native stellar population of the Milky Way disk. Neutron stars (NSs) -- remnants of massive stars -- in the disk should also originate from OCs, along with the resulting pulsars. However, no NS associated with any OC has been validated, presumably due to high-velocity kicks, exceeding the OC's escape velocity, imparted by supernova explosions. We have achieved arcsec-level localization (~1/1000 of the OC's tidal radius) to place the newly found pulsar PSR J1921+3745 in the tidal tail as well as near the tidal radius edge of NGC 6791, one of the oldest and most massive Galactic OCs. Our N-body simulation shows that, for an OC like NGC 6791, a substantial fraction of NSs with low-velocity kicks, peaking around 3 km/s in our calculation, remain in the cluster's tidal tails. The radio PSR J1921+3745 in the cluster tidal tail thus represents a snapshot of an escaping NS from an OC to the Galactic disk field. Further identification and characterization of pulsars associated with OCs are crucial to probe the origin of Galactic disk neutron stars and their co-evolution with the clusters.

We investigate the nebular emission produced by young stellar populations using the new GALSEVN model based on the combination of the SEVN population-synthesis code including binary-star processes and the GALAXEV code for the spectral evolution of stellar populations. Photoionization calculations performed with the CLOUDY code confirm that accounting for binary-star processes strongly influences the predicted emission-line properties of young galaxies. In particular, we find that our model naturally reproduces the strong HeII/Hb ratios commonly observed at high Hb equivalent widths in metal-poor, actively star-forming galaxies, which have proven challenging to reproduce using previous models. Including bursty star formation histories broadens the agreement with observations, while the most extreme HeII equivalent widths can be reproduced by models dominated by massive stars. GALSEVN also enables us to compute, for the first time in a way physically consistent with stellar emission, the emission from accretion discs of X-ray binaries (XRBs) and radiative shocks driven by stellar winds and supernova explosions. We find that these contributions are unlikely to prominently affect the predicted HeII/Hb ratio, and that previous claims of a significant contribution by XRBs to the luminosities of high-ionization lines are based on models predicting improbably high ratios of X-ray luminosity to star formation rate, inconsistent with the observed average luminosity function of XRBs in nearby galaxies. The results presented here provide a solid basis for a more comprehensive investigation of the physical properties of observed galaxies with GALSEVN using Bayesian inference.

Using archival Fermi-LAT data with a time span of ∼12 yr, we study the population of Millisecond Pulsars (MSPs) in Globular Clusters (GlCs) and investigate their dependence on cluster dynamical evolution in the Milky Way. We show that the γ -ray luminosity ( L γ ) and emissivity (i.e., ϵ γ = L γ / M , with M the cluster mass) are good indicators of the population and abundance of MSPs in GlCs, and they are highly dependent on the dynamical evolution history of the host clusters. Specifically speaking, the dynamically older GlCs with more compact structures are more likely to have larger L γ and ϵ γ , and these trends can be summarized as strong correlations with cluster stellar encounter rate Γ and the specific encounter rate (Λ = Γ/ M ), with L γ ∝ Γ 0.70±0.11 and ϵ γ ∝ Λ 0.73±0.13 for dynamically normal GlCs. However, as GlCs evolve into deep core collapse, these trends are found to be reversed, implying that strong encounters may have lead to the disruption of Low-Mass X-ray Binaries and ejection of MSPs from core-collapsed systems. Besides, the GlCs are found to exhibit larger ϵ γ with increasing stellar mass function slope ( ϵ γ ∝ 10 (0.57±0.1) α ), decreasing tidal radius ( ϵ γ ∝ R t − 1.0 ± 0.22 ) and distances from the Galactic Center (GC, ϵ γ ∝ R gc − 1.13 ± 0.21 ). These correlations indicate that, as GlCs losing kinetic energy and spiral in toward the GC, tidal stripping and mass segregation have a preference in leading to the loss of normal stars from GlCs, while MSPs are more likely to concentrate to cluster center and be deposited into the GC. Moreover, we gauge ϵ γ of GlCs is ∼10–1000 times larger than the Galactic bulge, the latter is thought to reside thousands of unresolved MSPs and may be responsible for the GC γ -ray excess, which supports that GlCs are generous contributors to the population of MSPs in the GC.

Starting from the Gaia DR3 HR diagram, we derive the star formation history (SFH) as a function of distance from the Galactic Plane within a cylinder centred on the Sun with a 200~pc radius and spanning 1.3~kpc above and below the Galaxy's midplane. We quantify both the concentration of the more recent star formation in the Galactic Plane, and the age-related increase in the scale height of the Galactic Disc stellar component, which is well-described by power-laws with indices ranging from $1/2$ to $2/3$. The vertically-integrated star formation rate falls from $(1.147 \pm 0.039)\times10^{-8}\, \text{M}_{\odot} \text{yr}^{-1} \text{pc}^{-2}$ at earlier times down to $(6.2 \pm 3.0) \times10^{-9}\, \text{M}_{\odot} \text{yr}^{-1} \text{pc}^{-2}$ at present times, but we find a significant peak of star formation in the 2 to 3 Gyr age bin. The total mass of stars formed per unit area over time is $118.7 \pm 6.2\, \text{M}_{\odot} \text{pc}^{-2}$, which is nearly twice the present stellar mass derived from kinematics within 1~kpc from the Galactic Plane, implying a high degree of matter recycling in successive generations of stars. The method is then modified by adopting an age-dependent correlation between the SFH across the different slices, which results in less noisy and more symmetrical results without significantly changing the previously mentioned quantities. This appears to be a promising way to improve SFH recovery in external galaxies.