Hasil untuk "Prehistoric archaeology"

Marco Palla, Alessio Mucciarelli, Donatella Romano et al.

Context. In the context of galactic archaeology, the study of the Small Magellanic Cloud (SMC) is of crucial importance, as it represents a unique opportunity to study a nearby massive dwarf system. However, theoretical studies of the chemical evolution of this galaxy are strikingly lacking. Aims. In this study, we investigate the chemical enrichment of the SMC galaxy. Besides alpha and Fe-peak elements, we devote particular attention to the evolution of neutron-capture elements with different origin, namely r-process (Eu), weak s-process (Zr) and main s-process (Ba, La). Methods. We develop chemical evolution models that use as input the star formation histories obtained from colour-magnitude diagram fitting. We follow in detail the chemical feedback provided by a large variety of nucleosynthetic sources. Model predictions are compared with recent abundance measurements for the SMC. Results. The developed framework reproduces well all the observables for elements up to the Fe-peak. The abundance patterns of n-capture elements are simultaneously reproduced only by assuming an enhanced contribution from the delayed r-process at low metallicity and a top-lighter IMF relative to the reference IMF by Kroupa (2001). In this way, both the observed very high plateau in [Eu/Fe] and the rising trends in [s-process/Fe] ratios can be reproduced by the models. Conclusions. This study provides for the first time information on the evolution of several n-capture elements in a massive dwarf irregular galaxy, also providing insight on several ingredients driving galactic evolution. Moreover, this work provides a test-bed for further modelling of the SMC in the context of the numerous surveys that will target the Magellanic Clouds in the next years.

Barbara Huber, Marta Luciani, Ahmed M. Abualhassan et al.

Abstract The utilization of medicinal and psychoactive plants in the past represents a pivotal intersection of culture, health, and biodiversity. While such plants in Arabia have been known from classical and medieval textual records, this study provides material evidence of the use of one such plant for fumigation already in the Iron Age. Through metabolic profiling of organic residues recovered from archaeological artefacts at the oasis of Qurayyah, Northwest Arabia, we identified the drug plant Peganum harmala. Renowned for its antibacterial, psychoactive and multiple therapeutic properties, its presence highlights the deliberate utilization of local pharmacopeia by ancient communities. This discovery represents not only the first evidence for its use in Iron Age Arabia, but also the most ancient, radiometrically dated material evidence of Peganum harmala being used for fumigation globally. Beyond their health benefits, these plants were also valued for their sensory and affective properties. Documenting, understanding and preserving these ancient knowledge systems enriches our understanding of ancient traditions while safeguarding the region’s intangible cultural heritage.

Yunchen Tan, Junzo Uchiyama, Jesper Sjolte et al.

While the 8.2 ka abrupt cooling event is increasingly recognised as a major Holocene climatic anomaly, archaeological discussions of its cultural consequences have often been framed in terms of societal distress, including the collapse and abandonment of settlements. However, prehistoric communities must have responded in more diverse ways. This paper investigates the site-based socio-ecological adaptations at the Jiahu settlement in North China, which persisted throughout the entire 8.2 ka climatic downturn, offering insights into how some prehistoric settlements may have exhibited resilience in the face of abrupt environmental change. Drawing on the Baseline Resilience Indicator for Communities (BRIC) model, we integrate environmental and archaeological data to assess key resilience indicators within this prehistoric cultural sequence. Our results indicate that while many settlements across northern China suffered decline or complete abandonment during this interval, Jiahu offers an alternative response scenario, where systemic flexibility supported longer-term adaptation, enabling the local community to survive, endure and even evolve new strategies. Moreover, the abrupt environmental stress may also have displaced regional populations into similar kinds of more resilient environmental locales, generating population “packing”, increased inter-group exchange, and the localized innovation of new adaptive strategies. We argue that local social-ecological systems, buffered by robust natural and cultural resources, may have experienced the 8.2 ka downturn in terms of a catalyst that produced a cascade of wider social and behavioural adjustments. Our tentative conclusions underline the need to move beyond simplistic narratives of cultural decline driven by the sudden onset of harsh environmental conditions, and instead to examine the complex, varied and contingent ways in which prehistoric societies responded to abrupt environmental downturns.

Michaela Ecker, Sara Rhodes, Nils Andersen et al.

Abstract Sediment biomarkers are important archives of regional, and global climate signatures, particularly in regions which lack continuous terrestrial archives such as the semi-arid deserts of Africa. We measured carbon and hydrogen stable isotopes from plant wax n-alkanes recovered from the Holocene Later Stone Age (LSA) sedimentary sequence at Wonderwerk Cave (South Africa), that comprises several technocomplexes (Kuruman/Oakhurst, Wilton, Ceramic Wilton and Historic). The plant wax n-alkane results were integrated with published palaeoenvironment reconstructions from the cave based on faunal, botanical, geological and sedimentological proxies which provides a robust comparative framework. The findings match well with other proxy records from the same strata and indicate a semi-arid to semi-humid early Holocene, with a mix of woody C3 plants and C4 grasses. In contrast, the mid-late Holocene environment was increasingly arid, open and dominated by C4 grasses. A distinct humid period at 5300–6200 cal. BP is evident, associated with a high density of archaeological material and a change in cultural expression in the Wonderwerk record. This study provides a step forward in using stable isotopes from biomarkers to create terrestrial environmental records in semi-arid regions.

Leah Albrow, Michele T. Bannister, John C. Forbes et al.

Interstellar objects (ISOs) ejected from planetary systems carry kinematic signatures of their formation environments. The properties of these velocity distributions govern the ISOs' propagation and dynamical evolution in the Galactic potential. We investigate how planetary system architecture influences ISO production during post-gas-disc dynamical instabilities using N-body simulations. We explore the ISO production outcomes of 2461 randomly generated systems spanning total system masses of 300-800 Earth masses and multiplicities of 3-7 planets. By integrating planets embedded in a disc of test particles for 10 Myr, we find that evolving systems can be broadly divided into two distinct classes based on their initial architectures. Catastrophic systems are characterized by high multiplicities and orbitally compact configurations, or by high-mass planets in systems with large mass asymmetries. These systems eject a large fraction of their planetesimals (median 59 percent) and, depending on the ejection pathway, produce high-speed ISOs (median 2.9 km/s). In contrast, quiet systems have lower masses and multiplicities and do not undergo significant orbital rearrangement, yet still eject a median of 28 percent of planetesimals at lower velocities (median 1.6 km/s). This dichotomy points to distinct ejection pathways, involving either violent global instabilities or more gradual, diffusive processes. Overall, we find that ISO ejection velocities are typically low, on the order of a few km/s. Although ISOs subsequently experience dynamical heating as they orbit the Galaxy, their velocity distributions retain signatures of their progenitor systems' architectures and histories, underscoring the potential use of ISOs in Galactic archaeology.

R. I. El-Kholy, Z. M. Hayman

Stellar spectral classification according to the Morgan-Keenan (MK) system remains fundamental to astrophysical studies, yet modern surveys require automated, scalable tools. We present NutMaat, an open-source Python-based package inspired by MKCLASS, designed to automate MK classification while addressing scalability and usability limitations. It employs modern computational tools for batch processing and offers a modular architecture that enables efficient, platform-independent analysis of large spectral datasets. It also includes modules for detecting classical chemically peculiar stars, such as Am, Ap, and $λ$ Boo types, using internal consistency checks between different line diagnostics. Tested on the CFLIB and MILES libraries, NutMaat achieved spectral and luminosity classification accuracies comparable to MKCLASS, with minimal systematic offsets and a robust performance down to S/N $\le$ 10. NutMaat successfully identified chemically peculiar stars, tested on LAMOST DR7 ACV variables, and processed the SDSS-IV MaStar library -- which lacks native MK classifications -- to produce a stellar catalog, demonstrating survey readiness. Future development of NutMaat will focus on extending wavelength coverage beyond the 3800--5600 $Å$ range, computational acceleration via Cython, and refining peculiarity classification. Beyond its technical design, NutMaat can provide consistent, MK-standard classification across large-scale spectroscopic surveys, facilitating reliable stellar population analyses, identification of rare objects, and the construction of high-quality spectral catalogs essential for galactic archaeology and stellar evolution studies. As an open-source tool, NutMaat bridges traditional MK methods with modern data workflows, offering a scalable solution for current and future spectroscopic surveys.

Giuseppe Viterbo, Tobias Buck

Stellar streams offer one of the most sensitive probes of the Milky Way`s gravitational potential, as their phase-space morphology encodes both the tidal field of the host galaxy and the internal structure of their progenitors. In this work, we introduce a framework that leverages Flow Matching and Simulation-Based Inference (SBI) to jointly infer the parameters of the GD-1 progenitor and the global properties of the Milky Way potential. Our aim is to move beyond traditional techniques (e.g. orbit-fitting and action-angle methods) by constructing a fully Bayesian, likelihood-free posterior over both host-galaxy parameters and progenitor properties, thereby capturing the intrinsic coupling between tidal stripping dynamics and the underlying potential. To achieve this, we generate a large suite of mock GD-1-like streams using our differentiable N-body code \textsc{\texttt{Odisseo}}, sampling self-consistent initial conditions from a Plummer sphere and evolving them in a flexible Milky Way potential model. We then apply conditional Flow Matching to learn the vector field that transports a base Gaussian distribution into the posterior, enabling efficient, amortized inference directly from stream phase-space data. We demonstrate that our method successfully recovers the true parameters of a fiducial GD-1 simulation, producing well-calibrated posteriors and accurately reproducing parameter degeneracies arising from progenitor-host interactions. Flow Matching provides a powerful, flexible framework for Galactic Archaeology. Our approach enables joint inference on progenitor and Galactic parameters, capturing complex dependencies that are difficult to model with classical likelihood-based methods.

Barbara Voorhies, George H. Michaels

This article posits that the ancient Maya were uniquely advantaged by the limestone bedrock of their homeland, the Yucatán Peninsula. This happenstance was unintentional, but limestone provided a resource that helped promote Maya society to become a civilization. The most significant innovation was the elevation of one cultivated plant, maize, to the role of a dietary staple, which was made possible by nixtamalization, an innovative processing technology that increased the plant’s nutritional value. Nixtamalization relies on soaking maize kernels in an alkaline solution, which the Maya usually made with burned limestone. Before maize became a staple, earlier prehistoric Maya likely cultivated many crops, with maize among them. The consequent dietary and intense cultural focus on maize by later prehistoric Maya blinded researchers from recognizing that the earliest Maya on the peninsula were broad-spectrum farmers.

Kevin L. Beeson, Janez Kos, Richard de Grijs et al.

The ability to measure precise and accurate stellar effective temperatures ($T_{\rm{eff}}$) and surface gravities ($\log(g)$) is essential in determining accurate and precise abundances of chemical elements in stars. Measuring $\log(g)$ from isochrones fitted to colour-magnitude diagrams of open clusters is significantly more accurate and precise compared to spectroscopic $\log(g)$. By determining the ranges of ages, metallicity, and extinction of isochrones that fit the colour-magnitude diagram, we constructed a joint probability distribution of $T_{\rm{eff}}$ and $\log(g)$. The joint photometric probability shows the complex correlations between $T_{\rm{eff}}$ and $\log(g)$, which depend on the evolutionary stage of the star. We show that by using this photometric prior while fitting spectra, we can acquire more precise spectroscopic stellar parameters and abundances of chemical elements. This reveals higher-order abundance trends in open clusters like traces of atomic diffusion. We used photometry and astrometry provided by the \textit{Gaia} DR3 catalogue, Padova isochrones, and Galactic Archaeology with HERMES (GALAH) DR4 spectra. We analysed the spectra of 1979 stars in nine open clusters, using MCMC to fit the spectroscopic abundances of 26 elements, $T_{\rm{eff}}$, $\log(g)$, $v_{\rm{mic}}$, and $v_{\rm{broad}}$. We found that using photometric priors improves the accuracy of abundances and $\log(g)$, which enables us to view higher-order trends of abundances caused by atomic diffusion in M67 and Ruprecht 147.

Pradosh Barun Das, Daniel B. Zucker, Gayandhi M. De Silva et al.

Analysing stellar parameters and abundances from nearly one million Gaia Data Release 3 (DR3) Radial Velocity Spectrometer (RVS) spectra poses challenges due to the limited spectral coverage (restricted to the infrared Ca II triplet) and variable signal-to-noise ratios of the data. To address this, we use The Cannon, a data-driven method, to transfer stellar parameters and abundances from the GALAH (GALactic Archaeology with HERMES) DR4 (R ~ 28,000) catalogue to the lower resolution Gaia DR3 RVS spectra (R ~ 11,500). Our model, trained on 14,484 common targets, predicts parameters such as $T_{\text{eff}}$, $\log g$, and $[\text{Fe/H}]$, along with several other elements across approximately 800,000 Gaia RVS spectra. We utilise stars from open and globular clusters present in the Gaia RVS catalogue to validate our predicted mean $[\text{Fe/H}]$ with high precision (~0.02-0.10 dex). Additionally, we recover the bimodal distribution of $[\text{Ti/Fe}]$ versus $[\text{Fe/H}]$, reflecting the high and low $α$-components of Milky Way disc stars, demonstrating The Cannon's capability for accurate stellar abundance determination from medium-resolution Gaia RVS spectra. The methodologies and resultant catalogue presented in this work highlight the remarkable potential of the RVS dataset, which by the end of the Gaia mission will comprise spectra of over 200 million stars.

Michał Auch, Tomasz Dzieńkowski, Irka Hajdas et al.

W artykule zaprezentowano wyniki datowania radiowęglowego wczesnośredniowiecznej ceramiki z dwóch pieców odkrytych na stanowisku nr 35 w Gródku nad Bugiem. „Tradycyjne” datowanie wskazuje na XI w., podczas gdy uzyskane daty 14C są o około 150 lat starsze. Stratygraficzny związek próbek i ceramiki nie budzi wątpliwości, należy zatem omawiane wyniki potraktować jako głos w dyskusji dotyczącej różnych rytmów przemian warsztatu garncarskiego na ziemiach Polski wschodniej, rozpatrywanych dotąd wyłącznie w odniesieniu do wielkopolskiego centrum państwa Piastów.

Katja Höflich, Gerhard Hobler, Frances I. Allen et al.

The focused ion beam (FIB) is a powerful tool for the fabrication, modification and characterization of materials down to the nanoscale. Starting with the gallium FIB, which was originally intended for photomask repair in the semiconductor industry, there are now many different types of FIB that are commercially available. These instruments use a range of ion species and are applied broadly in materials science, physics, chemistry, biology, medicine, and even archaeology. The goal of this roadmap is to provide an overview of FIB instrumentation, theory, techniques and applications. By viewing FIB developments through the lens of the various research communities, we aim to identify future pathways for ion source and instrumentation development as well as emerging applications, and the scope for improved understanding of the complex interplay of ion-solid interactions. We intend to provide a guide for all scientists in the field that identifies common research interests and will support future fruitful interactions connecting tool development, experiment and theory. While a comprehensive overview of the field is sought, it is not possible to cover all research related to FIB technologies in detail. We give examples of specific projects within the broader context, referencing original works and previous review articles throughout.

Andrzej Pelisiak

The Neolithic and Bronze Age communities that settled the eastern Carpathian Forelands and Carpathian Foothills used a variety of local and non-local siliceous raw materials. Raw materials identified in the archaeological record differ in quality and usefulness for making tools. Obsidian, Jurassic flint from the Cracow-Częstochowa Upland, chocolate flint, or Świeciechów and Volhynian flints represent the best quality. On the other hand, some local raw materials were also in use, most popular among them being siliceous marls and cherts. Sources of siliceous marls and cherts are known from many locations in the Dynów, Strzyżów and Przemyśl foothills. Moreover, systematic field surveys in this area have provided new information on the availability of cherts and siliceous marls at many new locations in the region. They appear in the primary autochthonous, secondary autochthonous, and more rarely in sub-autochthonous or residual, sources. Exposures on steep hill slopes and dissected river valleys provide easy access to the best quality raw materials in the primary autochthonous sources. Raw materials from secondary autochthonous sources in the riverbeds were also available, but they were of lesser quality than those from the exposures. The aim of this paper is to present natural exposures of siliceous marls and cherts and discuss them as a potential source of raw materials for the Neolithic and Bronze Age communities inhabiting loess areas of the eastern Carpathian foreland (Rzeszów Settlement Region).

Arturo Ruiz Taboada

El conjunto de Tornerías lo forman dos edificios en uno, de épocas y estilos diferentes con reformas y añadidos que siempre han dificultado su lectura. Las excavaciones desarrolladas entre 2017 y 2020 han aportado nuevas evidencias que permiten definir tanto las fases como la funcionalidad y diseño de la arquitectura. Sobre un importante paquete estratigráfico se construyen dos edificios de forma consecutiva. El más antiguo fechado entre los siglos VII y VIII, denominado A, con estructura en piedra, tiene planta basilical y ábside. El más moderno fechado entre los siglos IX y X, o B, está cimentado en la parte conservada del edificio A. Este último posee dos plantas, la primera en origen dedicada a mezquita y la baja a tiendas, además de una torre o alminar adosado a su fachada oeste. La enorme cantidad de datos procesados prueba que la arqueología urbana, pese a sus limitaciones, se está consolidando como una disciplina científica fundamental para entender la evolución histórica de nuestras ciudades.

Shengchun Xiong, Xiangru Li, Caixiu Liao

This work proposes a Residual Recurrent Neural Network (RRNet) for synthetically extracting spectral information, and estimating stellar atmospheric parameters together with 15 chemical element abundances for medium-resolution spectra from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). The RRNet consists of two fundamental modules: a residual module and a recurrent module. The residual module extracts spectral features based on the longitudinally driving power from parameters, while the recurrent module recovers spectral information and restrains the negative influences from noises based on Cross-band Belief Enhancement. RRNet is trained by the spectra from common stars between LAMOST DR7 and APOGEE-Payne catalog. The 17 stellar parameters and their uncertainties for 2.37 million medium-resolution spectra from LAMOST DR7 are predicted. For spectra with S/N >= 10, the precision of estimations Teff and log g are 88 K and 0.13 dex respectively, elements C, Mg, Al, Si, Ca, Fe, Ni are 0.05 dex to 0.08 dex, and N, O, S, K, Ti, Cr, Mn are 0.09 dex to 0.14 dex, while that of Cu is 0.19 dex. Compared with StarNet and SPCANet, RRNet shows higher accuracy and robustness. In comparison to Apache Point Observatory Galactic Evolution Experiment and Galactic Archaeology with HERMES surveys, RRNet manifests good consistency within a reasonable range of bias. Finally, this work releases a catalog for 2.37 million medium-resolution spectra from the LAMOST DR7, the source code, the trained model and the experimental data respectively for astronomical science exploration and data processing algorithm research reference.

Aarya A. Patil, Gwendolyn M. Eadie, Joshua S. Speagle et al.

Asteroseismic time-series data have imprints of stellar oscillation modes, whose detection and characterization through time-series analysis allows us to probe stellar interior physics. Such analyses usually occur in the Fourier domain by computing the Lomb-Scargle (LS) periodogram, an estimator of the power spectrum underlying unevenly-sampled time-series data. However, the LS periodogram suffers from the statistical problems of (1) inconsistency (or noise) and (2) bias due to high spectral leakage. Here, we develop a multitaper power spectrum estimator using the Non-Uniform Fast Fourier Transform (mtNUFFT) to tackle the inconsistency and bias problems of the LS periodogram. Using a simulated light curve, we show that the mtNUFFT power spectrum estimate of solar-like oscillations has lower variance and bias than the LS estimate. We also apply our method to the Kepler-91 red giant, and combine it with PBjam peakbagging to obtain mode parameters and a derived age estimate of $3.97 \pm 0.52$ Gyr. PBjam allows the improvement of age precision relative to the $4.27 \pm 0.75$ Gyr APOKASC-2 (uncorrected) estimate, whereas partnering mtNUFFT with PBjam speeds up peakbagging thrice as much as LS. This increase in efficiency has promising implications for Galactic archaeology, in addition to stellar structure and evolution studies. Our new method generally applies to time-domain astronomy and is implemented in the public Python package tapify, available at https://github.com/aaryapatil/tapify.

Derek Shank, Timothy C. Beers, Vinicius M. Placco et al.

Orbital characteristics based on Gaia Early Data Release 3 astrometric parameters are analyzed for ${\sim} 1700$ $r$-process-enhanced (RPE; [Eu/Fe] $> +0.3$) metal-poor stars ([Fe/H] $\leq -0.8$) compiled from the $R$-Process Alliance, the GALactic Archaeology with HERMES (GALAH) DR3 survey, and additional literature sources. We find dynamical clusters of these stars based on their orbital energies and cylindrical actions using the \HDBSCAN ~unsupervised learning algorithm. We identify $36$ Chemo-Dynamically Tagged Groups (CDTGs) containing between $5$ and $22$ members; $17$ CDTGs have at least $10$ member stars. Previously known Milky Way (MW) substructures such as Gaia-Sausage-Enceladus, the Splashed Disk, the Metal-Weak Thick Disk, the Helmi Stream, LMS-1 (Wukong), and Thamnos are re-identified. Associations with MW globular clusters are determined for $7$ CDTGs; no recognized MW dwarf galaxy satellites were associated with any of our CDTGs. Previously identified dynamical groups are also associated with our CDTGs, adding structural determination information and possible new identifications. Carbon-Enhanced Metal-Poor RPE (CEMP-$r$) stars are identified among the targets; we assign these to morphological groups in the Yoon-Beers $A$(C)$_{c}$ vs. [Fe/H] Diagram. Our results confirm previous dynamical analyses that showed RPE stars in CDTGs share common chemical histories, influenced by their birth environments.

Velichka Mazanova, Tatiana Mishina, Stoilka Terziyska-Ignatova

The article summarizes the accumulated information from the investigated 11 houses of the last Late Chalcolithic settlement at Tell Yunatsite. The Late Chalcolithic house is discussed both as a functional and a symbolically arranged place where real and mystical (profane and sacred) intertwine. The contextual method that was applied allows for identifying the various functions of the house. The residential function was the primary one. The everyday activities of the inhabitants took place in the house: childbirth, raising the children, preparing food, and several other household and economic activities. On the other hand, inside the house the individual felt in a secure space, protected by the household deities that prevented the penetration of evil forces. The settlement was burnt down and the inhabitants of the houses fell victim to the attackers and the fire. The survivors returned and buried those who died outside the buildings. Those who were buried under the ruins were left as they were. The survivors performed a complex burial ritual: they covered symbolically with soil not only the houses, but also the space between them. In this way, they ‘closed down’ and put an end to the life cycle of the houses and transformed the settlement into a cemetery of those who died in the military clash.

H. Ibarra-Medel, V. Avila-Reese, I. Lacerna et al.

We apply stellar population synthesis analysis to obtain spatially-resolved archaeological inferences for a large sample of "red and dead" Elliptical galaxies (Classical Ellipticals; CLEs) from the MaNGA/SDSS-IV DR15 survey. From their 2D stellar light and mass maps, we explore the differences between the radial mass and light distributions in the rest-frame bands $g,$ $r,$ and $i$ as functions of look-back time, $t_{\rm lb}$, or redshift, $z$. We characterize these differences through the ratios between the following mass- and light-derived global properties: sizes, concentrations, and effective surface densities. We find that the mass-to-light ratios of these properties change with $t_{\rm lb}$, more the more massive the galaxies are. The CLE galaxy archaeological progenitors are, on average, less compact, concentrated, and dense in light than in mass as $z$ decreases. However, at later times, when also the evolution of the progenitors becomes passive at all radii, there is an upturn in these trends and the differences between mass and light in compactness/concentration decrease towards $z\sim 0$. The trends in the ratios of mass to light sizes agree qualitatively with results from direct observations in galaxy surveys at different redshifts. We discuss the caveats and interpretations of our results, and speculate that the strong structural evolution found in some previous studies for early-type galaxies could be explained partially by photometric changes rather than by intrinsic structural changes.

Damien de Mijolla, Melissa K. Ness

Identification of chemically similar stars using elemental abundances is core to many pursuits within Galactic archaeology. However, measuring the chemical likeness of stars using abundances directly is limited by systematic imprints of imperfect synthetic spectra in abundance derivation. We present a novel data-driven model that is capable of identifying chemically similar stars from spectra alone. We call this Relevant Scaled Component Analysis (RSCA). RSCA finds a mapping from stellar spectra to a representation that optimizes recovery of known open clusters. By design, RSCA amplifies factors of chemical abundance variation and minimizes those of non-chemical parameters, such as instrument systematics. The resultant representation of stellar spectra can therefore be used for precise measurements of chemical similarity between stars. We validate RSCA using 185 cluster stars in 22 open clusters in the APOGEE survey. We quantify our performance in measuring chemical similarity using a reference set of 151,145 field stars. We find that our representation identifies known stellar siblings more effectively than stellar abundance measurements. Using RSCA, 1.8% of pairs of field stars are as similar as birth siblings, compared to 2.3% when using stellar abundance labels. We find that almost all of the information within spectra leveraged by RSCA fits into a two-dimensional basis, which we link to [Fe/H] and alpha-element abundances. We conclude that chemical tagging of stars to their birth clusters remains prohibitive. However, using the spectra has noticeable gain, and our approach is poised to benefit from larger datasets and improved algorithm designs.