Astronomy & Astrophysics最新文献

{"title":"The ESO SupJup Survey","authors":"S. de Regt, I. A. G. Snellen, N. F. Allard, D. González Picos, S. Gandhi, N. Grasser, R. Landman, P. Mollière, E. Nasedkin, T. Stolker, Y. Zhang","doi":"10.1051/0004-6361/202453190","DOIUrl":"https://doi.org/10.1051/0004-6361/202453190","url":null,"abstract":"<i>Context.<i/> Brown dwarfs at the L–T transition likely experience an inhomogeneous clearing of the clouds in their atmospheres. The resulting surface of thin and thick cloudy patches has been put forward to explain the observed variability, <i>J<i/>-band brightening, and re-emergence of FeH absorption.<i>Aims.<i/> We studied the closest binary brown dwarfs, Luhman 16A and B, in an effort to constrain their chemical and cloud compositions. As this binary consists of an L7.5 and a T0.5 component, we gain insight into the atmospheric properties at the L–T transition.<i>Methods.<i/> As part of the ESO SupJup Survey, we observed Luhman 16AB at high spectral resolution in the <i>J<i/> band (1.1–1.4 μm) using CRIRES<sup>+<sup/>. To analyse the spectra, we employed an atmospheric retrieval framework, coupling the radiative transfer code petitRADTRANS with the MultiNest sampling algorithm.<i>Results.<i/> For both objects, we report detections of H<sub>2<sub/>O, K, Na, FeH, and, for the first time in the <i>J<i/> band, hydrogen fluoride (HF). The K doublet at 1250 nm shows asymmetric absorption in the blue line wings, which are reproduced via pressure- and temperature-dependent shifts in the line cores. We find evidence of clouds in both spectra and place constraints on an FeH depletion in the Luhman 16A photosphere. The inferred over-abundance of FeH for Luhman 16B is in contradiction with its predicted rainout into iron clouds. A two-column model, which emulates the patchy surface expected at the L–T transition, is weakly preferred (~1.8<i>σ<i/>) for component B but disfavoured for A (~5.5<i>σ<i/>).<i>Conclusions.<i/> The results suggest a uniform surface on Luhman 16A, which is in good agreement with the reduced variability observed for this L-type component. While the presented evidence is not sufficient to allow us to draw conclusions about any inhomogeneity on Luhman 16B, future observations covering a broader wavelength range could help us test the cloud-clearing hypothesis.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"24 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing the morphology of molecular clouds without supervision","authors":"Pablo Richard, Erwan Allys, François Levrier, Antoine Gusdorf, Constant Auclair","doi":"10.1051/0004-6361/202451493","DOIUrl":"https://doi.org/10.1051/0004-6361/202451493","url":null,"abstract":"Molecular clouds are astrophysical objects whose complex nonlinear dynamics are reflected in their complex morphological features. Many studies investigating the bridge between higher-order statistics and physical properties have highlighted the value of non-Gaussian morphological features in capturing physical information. Yet, as this bridge is usually characterized in the supervised world of simulations, transferring it to observations can be hazardous, especially when the discrepancy between simulations and observations remains unknown. In this paper, we aim to evaluate, directly from the observation data, the discriminating ability of a set of statistics. To do so, we developed a test that allowed us to compare the informative power of two sets of summary statistics for a given unlabeled dataset. Contrary to supervised approaches, this test does not require knowledge of any class label or parameter associated with the data. Instead, it evaluates and compares the degeneracy levels of the summary statistics based on a notion of statistical compatibility. We applied this test to column density maps of 14 nearby molecular clouds observed by <i>Herschel<i/> and iteratively compared different sets of typical summary statistics. We show that a standard Gaussian description of these clouds is highly degenerate but can be substantially improved when being estimated on the logarithm of the maps. This illustrates that low-order statistics, when properly used, remain a very powerful tool. We further show that such descriptions still exhibit a small quantity of degeneracies, some of which are lifted by the higher-order statistics provided by reduced wavelet scattering transforms. These degeneracies quantitatively differ between observations and state-of-the-art simulations of dense molecular cloud collapse, and they are not present for log-fractional Brownian motion models. Finally, we show how the summary statistics identified can be cooperatively used to build a morphological distance, which is evaluated visually and gives convincing results.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"68 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breaking long-period resonance chains with stellar flybys","authors":"C. Charalambous, N. Cuello, C. Petrovich","doi":"10.1051/0004-6361/202553710","DOIUrl":"https://doi.org/10.1051/0004-6361/202553710","url":null,"abstract":"<i>Context.<i/> Planetary migration models predict multiple planets captured into a chain of mean-motion resonances during the disk phase. Over a dozen systems have been observed in these configurations, with nearly all close-in planets with a lack of resonant chains for planets with orbital periods longer than 300 days.<i>Aims.<i/> Dynamical studies often overlook the fact that stars do not evolve in isolation. In this work, we explore the possibility that the absence of giant planets in long-period resonant chains may be due to post-formation disruption caused by stellar flybys.<i>Methods.<i/> For planets in the 2:1-2:1 and 3:2-3:2 resonant chains, we evaluated the long-term stability after varying parameters such as the planet masses, as well as the inclination, pericentric distance, and mass of the flyby star.<i>Results.<i/> Our integrations show that the 2:1-2:1 resonant chain is significantly more resilient to a stellar flyby than for the 3:2-3:2 configuration. The nature of the instability is different in both scenarios; the 2:1-2:1 becomes unstable quickly, soon after a penetrative close encounter. Instead, planets in the 3:2-3:2 chain become unstable in long timescales due to more distant flybys (up to <i>q<i/>/<i>a<i/><sub>out<sub/> 25 for Jupiter-mass planets) that only provide small perturbations for the system to chaotically dissolve.<i>Conclusions.<i/> If an encounter occurs between a star hosting planets and a passing star, Jupiter-mass systems with three planets in a 3:2-3:2 resonant chain or more compact initial configurations are likely to be disrupted.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"70 1","pages":"A175"},"PeriodicalIF":6.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The enigmatic magnetic field of the planet hosting Herbig Ae/Be star HD 169142","authors":"S. Hubrig, S. P. Järvinen, I. Ilyin, M. Schöller","doi":"10.1051/0004-6361/202453225","DOIUrl":"https://doi.org/10.1051/0004-6361/202453225","url":null,"abstract":"<i>Context.<i/> Recent observations of the accretion disk around the Herbig Ae/Be star HD 169142 have revealed its complex and asymmetric morphology that indicates the presence of planets. The knowledge of the magnetic field structure in host stars is indispensable for our understanding of the magnetospheric interaction between the central stars, the circumstellar (CS) environment, and the planetary companions.<i>Aims.<i/> We want to study the geometry of the magnetic field of HD 169142.<i>Methods.<i/> We measured the mean longitudinal magnetic field from high-resolution ESPaDOnS and HARPSpol spectra of HD 169142 using the least-squares deconvolution technique. Additionally, the spectral variability of hydrogen lines is studied using dynamical spectra.<i>Results.<i/> Our analysis of the Stokes <i>V<i/> spectra reveals the presence of definitely detected narrow Zeeman features observed using line masks with neutral iron lines. On two observing epochs, we also obtain marginally detected broad Zeeman features. To explain the simultaneous appearance of narrow and broad Zeeman features, we discuss different scenarios, including one scenario related to a non-photospheric origin of the narrow Zeeman features due to magnetospheric interaction with warm CS matter. In an environment such as a wind or an accretion disk, spectral lines may form over a relatively large volume, and the field topology may therefore be complex not only in latitude and azimuth, but in radius as well. Dynamical plots of the H<i>β<i/> line show an intriguing very complex structure with appearing and disappearing absorption features, which can be related to the complex morphology of the CS matter with asymmetric dust clump structures. The profiles of spectral lines belonging to different elements are variable, indicating the presence of chemical spots.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"13 1","pages":"L15"},"PeriodicalIF":6.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Bulge Cluster Origin (BulCO) survey at the ESO-VLT: Probing the early history of the Milky Way assembly. Design and first results in Liller 1★","authors":"F. R. Ferraro, L. Chiappino, A. Bartolomei, L. Origlia, C. Fanelli, B. Lanzoni, C. Pallanca, M. Loriga, S. Leanza, E. Valenti, D. Romano, A. Mucciarelli, D. Massari, M. Cadelano, E. Dalessandro, C. Crociati, R. M. Rich","doi":"10.1051/0004-6361/202554092","DOIUrl":"https://doi.org/10.1051/0004-6361/202554092","url":null,"abstract":"We present the scientific goals and the very first results of the Bulge Cluster Origin (BulCO) survey. This survey has been specifically designed to perform an unprecedented chemical screening of stellar systems orbiting the Milky Way bulge, with the aim to unveil their true origin. It takes advantage of the improved performances of the spectrograph CRIRES+ operating at the ESO Very Large telescope in the near-infrared domain. Due to the complex evolutionary history of the Milky Way, a variety of relics tracing different phenomena is expected to populate the bulge: Globular clusters formed in situ or accreted from outside the Galaxy, nuclear star clusters of cannibalized structures, and possibly a few remnants of the proto-bulge formation process (the so-called bulge fossil fragments). The signatures of the different origins are imprinted in the chemical properties of these stellar systems because specific abundance patterns provide authentic chemical DNA tests that unequivocally trace the enrichment process, and therefore, the environment in which the stellar population formed. Thus, each system can provide a new piece of information on the bulge formation and evolutionary history. As first results of the survey, we discuss the α−element and iron abundances of a sample of stars that was observed in the stellar system Liller 1, which is proposed to be a bulge fossil fragment. By combining this dataset with a recently published sample of high- to medium-resolution spectra, we show that the overall chemical properties of the stellar populations in Liller1 prove its tight link with the Galactic bulge and provide new constraints on its star formation history.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing two orthogonally polarized spectral components in Vela X-1 with IXPE","authors":"Sofia V. Forsblom, Sergey S. Tsygankov, Valery F. Suleimanov, Alexander A. Mushtukov, Juri Poutanen","doi":"10.1051/0004-6361/202553867","DOIUrl":"https://doi.org/10.1051/0004-6361/202553867","url":null,"abstract":"Polarimetric observations of X-ray pulsars (XRPs) have provided us with the key to unlocking their geometrical properties. Thanks to the Imaging X-ray Polarimetry Explorer (IXPE), the geometries of several XRPs have been determined, providing new insights into their emission mechanisms and magnetic field structures. The polarimetric properties of Vela X-1 have a clear dependence on energy, showing a 90° swing in the polarization angle (PA) between low and high energies. Due to the complex energy-dependent nature of the polarization properties, until now it was not possible to determine the pulsar geometry. In this work we present the results of a detailed analysis of the pulse-phase-resolved polarization properties of Vela X-1 at different energies. By separating the polarimetric analysis into low and high energy ranges, we are able to disentangle the contributions of the soft and hard spectral components to the polarization, revealing the pulse phase dependence of the polarization degree and PA in each energy band. The PA pulse-phase dependence at high energies (5−8 keV) allows us, for the first time, to determine the pulsar geometry in Vela X-1. Based on the fit with the rotating vector model, we estimate the pulsar spin position angle to be around 127° and the magnetic obliquity to be 13°. We discuss two possible scenarios that could explain the 90° swing in the PA between high and low energies: a two-component spectral model and vacuum resonance.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":"A224"},"PeriodicalIF":6.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionization memory of plasma emitters in a solar prominence","authors":"E. Wiehr, H. Balthasar, G. Stellmacher, M. Bianda","doi":"10.1051/0004-6361/202451526","DOIUrl":"https://doi.org/10.1051/0004-6361/202451526","url":null,"abstract":"<i>Aims.<i/> In the low-collisional, partially ionized plasma (PIP) of solar prominences, uncharged emitters might show different signatures of magnetic line broadening than charged emitters. We investigate if the widths of weak metal emissions in prominences exceed the thermal line broadening by a different amount for charged and for uncharged emitters.<i>Methods.<i/> We simultaneously observe five optically thin, weak metal lines in the brightness center of a quiescent prominence and compare their observed widths with the thermal broadening.<i>Results.<i/> The inferred nonthermal broadening of the metal lines does not indicate systematic differences between the uncharged Mg b<sub>2<sub/> and Na D<sub>1<sub/> and the charged Fe II emitters, only Sr II is broader.<i>Conclusions.<i/> The additional line broadening of charged emitters can reasonably be attributed to magnetic forces. That of uncharged emitters can then come from their temporary state as ions before recombination. Magnetically induced velocities will be retained some time after recombination. Modelling PIPs then requires consideration of a memory of previous ionization states.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2 1","pages":"A209"},"PeriodicalIF":6.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The persistent nature of the Be X-ray binary pulsar 4U 0728-25","authors":"N. La Palombara, L. Sidoli, S. Mereghetti, P. Esposito, G. L. Israel","doi":"10.1051/0004-6361/202554103","DOIUrl":"https://doi.org/10.1051/0004-6361/202554103","url":null,"abstract":"We report the results obtained with a <i>XMM–Newton<i/> observation, performed in April 2023, of the poorly known Galactic Be X-ray binary pulsar 4U 0728-25. It was revealed at a flux level (not corrected for the absorption) <i>f<i/><sub>X<sub/>(0.2–12 keV) = 1.7×10<sup>−11<sup/> erg cm<sup>−2<sup/> s<sup>−1<sup/>, which implies an unabsorbed source luminosity <i>L<i/><sub>X<sub/>≃1.3×10<sup>35<sup/> erg s<sup>−1<sup/>: this is the minimum luminosity ever observed for this source. We measured a pulse period <i>P<i/><sub>spin<sub/> = 103.301(5) s, a value ≃0.15% longer than that estimated in 2016 with <i>AstroSat<i/>. The pulse profile shows a broad single peak at all energies, with a limited energy dependence and a small increase in the pulsed fraction with energy. The time-averaged <i>EPIC<i/> spectrum can be described equally well by four different emission models, either with a single non-thermal component (a partially covered power law or a cut-off power law), or with a thermal component in addition to the non-thermal one (a black body plus a power law, or a collisionally ionised gas plus a cut-off power law). All of them provided an equally good fit and, in the case of the power–law plus black–body model, the thermal component is characterized by a high temperature (<i>kT<i/><sub>BB<sub/>≃1.5 keV) and a small size (<i>R<i/><sub>BB<sub/>≃240 m), comparable with that of the neutron-star polar caps. A spectral variability along the pulse phase is present, which suggests a flux variation of the black-body component. These results show that, for its luminosity level, flux variabilty over long time scales, and spectral properties, 4U 0728-25 is very similar to most of the persistent Be X-ray binaries. Therefore, it can be considered a member of this class of sources.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"6 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"JWST observations of exogenic species on Jupiter: HCN, H2O, and CO2","authors":"Pablo Rodríguez-Ovalle, Thierry Fouchet, Thibault Cavalié, Emmanuel Lellouch, Leigh N. Fletcher, Jake Harkett, Vincent Hue, Bilal Benmahi, Imke de Pater","doi":"10.1051/0004-6361/202453575","DOIUrl":"https://doi.org/10.1051/0004-6361/202453575","url":null,"abstract":"<i>Context<i/>. The impact of the Shoemaker-Levy 9 (SL9) comet on Jupiter in 1994 opened up a new field of study focused on the exogenic species within Jupiter’s atmosphere. Among these species, we find H<sub>2<sub/>O, CO, and HCN. It is thought that these species coexist at the same pressure level (∼3 mbar in 2022) and that the interaction between some of them creates daughter molecules such as CO<sub>2<sub/>. However, understanding their complex meridional distributions is still a matter of debate.<i>Aims<i/>. We measured the meridional distribution of H<sub>2<sub/>O, HCN, and CO<sub>2<sub/> to understand the chemistry and dynamics leading to these distributions.<i>Methods<i/>. We used James Webb Space Telescope (JWST) Mid InfraRed Instrument (MIRI) medium-resolution spectroscopy observations from 17<sup>∘<sup/>S to 26<sup>∘<sup/>S, and from 45<sup>∘<sup/>S towards the south pole for CO<sub>2<sub/>, H<sub>2<sub/>O, and HCN. We used a radiative transfer code coupled with an inversion algorithm to retrieve the temperature using the CH<sub>4<sub/> <i>v<i/><sub>4<sub/> band and the abundance of the species for the different latitudes.<i>Results<i/>. We found an increase in H<sub>2<sub/>O in the south polar region, while CO<sub>2<sub/> is found to be depleted, which points towards an exchange of oxygen between H<sub>2<sub/>O and CO<sub>2<sub/> happening in the southern auroral region. The HCN abundance decreases towards the pole, and abundance values are similar to the ones obtained with ALMA in 2017. The depletion of HCN may be due to heterogeneous chemistry related to stratospheric polar aerosols.<i>Conclusions<i/>. The exogenic molecules analysed seem to be influenced either by polar aerosols produced by ion-neutral chemistry (e.g. HCN) or by particle precipitation occurring in the auroral regions (e.g. H<sub>2<sub/>O and CO<sub>2<sub/>). These measurements provide new insights into chemical evolution at a small spatial scale, revealing previously undetected localized trends.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"219 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematics of metallicity populations in Omega Centauri using the Gaia Focused Product Release and Hubble Space Telescope","authors":"N. Vernekar, S. Lucatello, P. Kuzma, L. Spina","doi":"10.1051/0004-6361/202453187","DOIUrl":"https://doi.org/10.1051/0004-6361/202453187","url":null,"abstract":"<i>Context<i/>. Omega Cen is the largest known globular cluster in the Milky Way. It is also a quite complex object with a large metallicity spread and multiple stellar populations. Despite a number of studies over the past several decades, the series of events that led to the formation of this cluster is still poorly understood. One of its peculiarities is the presence of a metal-rich population that does not show the phenomenon of light-element anti-correlations (C-N, Na-O, Mg-Al), a trait that is considered characteristic of Galactic globular clusters and present among more metal-poor Omega Cen stars. This leads to speculation that such an anomalous population was accreted by the cluster.<i>Aims<i/>. We aim to investigate the kinematics of Omega Cen populations to gain insight into the formation scenario of the cluster.<i>Methods<i/>. Using the newly released <i>Gaia<i/> FPR and DR3 catalogue, we conducted a detailed kinematical analysis of cluster members within Omega Cen. The cluster members were divided into four metallicity populations, and their mean proper motion in radial and tangential components were compared with each other. We also performed Gaussian-mixture model fitting on the metallicity distribution to estimate the number of populations within our sample and an independent analysis of the Hubble Space Telescope catalogue as confirmation.<i>Results<i/>. The mean proper motions (<i>μ<i/><sub><i>r<i/><sub/> and <i>μ<i/><sub><i>t<i/><sub/>) of the metallicity populations do not show any significant differences. It is also not dependent on the approach chosen to determine the number of metallicity populations. We do find a clear signature of rotation in all of the populations (including the metal-rich one) with similar velocities.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"13 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}