Astronomy & Astrophysics最新文献

{"title":"Dark matter fraction derived from the M 31 rotation curve","authors":"F. Hammer, Y. B. Yang, P. Amram, L. Chemin, G. A. Mamon, J. L. Wang, I. Akib, Y. J. Jiao, H. F. Wang","doi":"10.1051/0004-6361/202452753","DOIUrl":"https://doi.org/10.1051/0004-6361/202452753","url":null,"abstract":"Mass estimates of a spiral galaxy derived from its rotation curve must account for the galaxy’s past accretion history. There are several lines of evidence indicating that M31 experienced a major merger 2 to 3 Gyr ago. In this work, we generated a dynamical model of M31 as a merger remnant that reproduces most of its properties, including from the central bar to the outskirts. The model accounts for M31’s past major merger and reproduces the details of its rotation curve, including its 14 kpc bump and the observed increase of velocity beyond 25 kpc. We find non-equilibrium and oscillatory motions in the gas of the merger-remnant outskirts caused by material in a tidal tail returning to the merger remnant. A total dynamical M31 mass of 4.5 × 10<sup>11<sup/> <i>M<i/><sub>⊙<sub/> within 137 kpc was obtained after scaling it to the observed HI rotation curve. Within this radial distance, we find that 68% of the total dynamical mass is dark.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"61 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077601","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":"KOBE-1: The first planetary system from the KOBE survey","authors":"O. Balsalobre-Ruza, J. Lillo-Box, A. M. Silva, S. Grouffal, J. Aceituno, A. Castro-González, C. Cifuentes, M. R. Standing, J. P. Faria, P. Figueira, A. Santerne, E. Marfil, A. Abreu, A. Aguichine, L. González-Ramírez, J. C. Morales, N. Santos, N. Huélamo, E. Delgado Mena, D. Barrado, V. Adibekyan, S. C. C. Barros, Á. Berihuete, M. Morales-Calderón, E. Nagel, E. Solano, S. G. Sousa, J. F. Agüí Fernández, M. Azzaro, G. Bergond, S. Cikota, A. Fernández-Martín, J. Flores, S. Góngora, A. Guijarro, I. Hermelo, V. Pinter, J. I. Vico Linares","doi":"10.1051/0004-6361/202452631","DOIUrl":"https://doi.org/10.1051/0004-6361/202452631","url":null,"abstract":"<i>Context<i/>. K-dwarf stars are promising targets in the exploration of potentially habitable planets. Their properties, falling between G and M dwarfs, provide an optimal trade-off between the prospect of habitability and ease of detection. The KOBE experiment is a blind-search survey exploiting this niche, monitoring the radial velocity of 50 late-type K-dwarf stars. It employs the CARMENES spectrograph, with an observational strategy designed to detect planets in the habitable zone of their system.<i>Aims<i/>. In this work, we exploit the KOBE data set to characterize planetary signals in the K7 V star HIP 5957 (KOBE-1) and to constrain the planetary population within its habitable zone.<i>Methods<i/>. We used 82 CARMENES spectra over a time span of three years. We employed a generalized Lomb–Scargle periodogram to search for significant periodic signals that would be compatible with Keplerian motion on KOBE-1. We carried out a model comparison within a Bayesian framework to ensure the significance of the planetary model over alternative configurations of lower complexity. We also inspected two available TESS sectors in search of planetary signals.<i>Results<i/>. We identified two signals: at <i>P<i/><sub>b<sub/> = 8.5 d and <i>P<i/><sub>c<sub/> = 29.7 d. We confirmed their planetary nature through ruling out other non-planetary configurations. Their minimum masses are 8.80 ± 0.76 M<sub>⊕<sub/> (KOBE-1 b), and 12.4 ± 1.1 M<sub>⊕<sub/> (KOBE-1 c), corresponding to absolute masses within the planetary regime at a high certainty (>99.7%). By analyzing the sensitivity of the CARMENES time series to additional signals, we discarded planets above 8.5 M<sub>⊕<sub/> within the habitable zone. We identified a single transit-like feature in TESS, whose origin is still uncertain, but still compatible within 1<i>σ<i/> with a transit from planet c.<i>Conclusions<i/>. The KOBE-1 multi-planetary system, consisting of a relatively quiet K7-dwarf hosting two sub-Neptune-minimum- mass planets, establishes the first discovery from the KOBE experiment. We have explored future prospects for characterizing this system, concluding that <i>Gaia<i/> DR4 will be insensitive to their astrometric signature. Meanwhile, nulling interferometry with the Large Interferometer For Exoplanets (LIFE) mission could be capable of directly imaging both planets and characterizing their atmospheres in future studies.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"39 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077604","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":"Effects of secular growth and mergers on the evolution of metallicity gradients and azimuthal variations in a Milky Way-like galaxy","authors":"Florent Renaud, Bridget Ratcliffe, Ivan Minchev, Misha Haywood, Paola Di Matteo, Oscar Agertz, Alessandro B. Romeo","doi":"10.1051/0004-6361/202452219","DOIUrl":"https://doi.org/10.1051/0004-6361/202452219","url":null,"abstract":"We analyzed the evolution of the radial profiles and the azimuthal variations of the stellar metallicities from the VINTERGATAN simulation of a Milky Way-like galaxy. We find that negative gradients exist as soon as the disk settles at high redshift, and are maintained throughout the long-term evolution of the galaxy, including during major merger events. The inside-out growth of the disk and an overall outward radial migration tend to flatten these gradients in time. Major merger events only have a moderate and shortlived imprint on the [Fe/H] distributions with almost no radial dependence. The reason lies in the timescale for enrichment in Fe being significantly longer than the duration of the starbursts episodes, themselves slower than dynamical mixing during typical interactions. It results in signatures of major mergers becoming undetectable in [Fe/H] only a few megayears after pericenter passages. We note that considering other tracers like the warm interstellar medium, or monitoring the evolution of the metallicity gradient as a single value instead of a radial full profile could lead to different interpretations; we warn against oversimplifying this complex problem.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"27 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077606","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":"Anatomy of a z = 6 Lyman-α emitter down to parsec scales","authors":"M. Messa, E. Vanzella, F. Loiacono, P. Bergamini, M. Castellano, B. Sun, C. Willott, R. A. Windhorst, H. Yan, G. Angora, P. Rosati, A. Adamo, F. Annibali, A. Bolamperti, M. Bradač, L. D. Bradley, F. Calura, A. Claeyssens, A. Comastri, C. J. Conselice, J. C. J. D’Silva, M. Dickinson, B. L. Frye, C. Grillo, N. A. Grogin, C. Gruppioni, A. M. Koekemoer, M. Meneghetti, U. Meštrić, R. Pascale, S. Ravindranath, M. Ricotti, J. Summers, A. Zanella","doi":"10.1051/0004-6361/202451695","DOIUrl":"https://doi.org/10.1051/0004-6361/202451695","url":null,"abstract":"We present a detailed JWST/NIRSpec and NIRCam analysis of a gravitationally lensed galaxy (<i>μ<i/> = 17 − 21) at a redshift of 6.14 magnified by the Hubble Frontier Field galaxy cluster MACS J0416. The target galaxy is a typical compact and UV-faint (<i>M<i/><sub>UV<sub/> = −17.8) Lyman-<i>α<i/> emitter, yet the large magnification allows the detailed characterization of structures on sub-galactic scales (down to a few parsecs). Prominent optical H<i>α<i/>, H<i>β<i/>, and [OIII]<i>λλ<i/>4959, 5007 lines are spatially resolved with the high-spectral-resolution grating (G395H, R 2700), with large equivalent widths, EW(H<i>β<i/>+O III) ≳ 1000 Å, and elevated ionizing photon production efficiencies, log(<i>ξ<i/><sub>ion<sub/>/erg<sup>−1<sup/>Hz) = 25.2–25.7. NIRCam deep imaging reveals the presence of compact rest-UV-bright regions along with individual star clusters of <i>R<i/><sub>eff<sub/> = 3 − 8 pc in size and <i>M<i/> ∼ 2 ⋅ 10<sup>5<sup/> − 5 ⋅ 10<sup>6<sup/> M<sub>⊙<sub/> in mass. These clusters are characterized by steep UV slopes, <i>β<i/><sub>UV<sub/> ≲ −2.5, which in some cases are associated with a dearth of line emission, indicating possible leaking of the ionizing radiation, as also supported by a Lyman-<i>α<i/> emission peaking at ∼100 km s<sup>−1<sup/> from the systemic redshift. While the entire system is characterized by low metallicity, ∼0.1 Z<sub>⊙<sub/>, the NIRSpec-IFU map also reveals the presence of a low-luminosity, metal-poor region with <i>Z<i/> ≲ 2% Z<sub>⊙<sub/>, which is barely detected in NIRCam imaging; this region is displaced by > 200 pc from one of the brightest structures of the system in UV, and would have been too faint to detect if not for the large magnification of the system.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"38 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077605","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":"Structure formation in O-type stars and Wolf–Rayet stars","authors":"C. Van der Sijpt, J. O. Sundqvist, D. Debnath, F. A. Driessen, N. Moens","doi":"10.1051/0004-6361/202452385","DOIUrl":"https://doi.org/10.1051/0004-6361/202452385","url":null,"abstract":"<i>Context<i/>. Turbulent small-scale structures in the envelopes and winds of massive stars have long been suggested as the cause for excessive line broadening in the spectra of these stars that could not be explained by other mechanisms such as thermal broadening. However, while these structures are also seen in recent radiation-hydrodynamical simulations, their origin, particularly in the envelope, has not been extensively studied.<i>Aims<i/>. We study the origin of structures seen in 2D radiation-hydrodynamical unified stellar atmosphere and wind simulations of O stars and Wolf–Rayet stars. Particularly, we study whether the structure growth in the simulations is consistent with sub-surface convection, as is commonly assumed to be the origin of this turbulence.<i>Methods<i/>. Using a linear stability analysis of the optically thick, radiation-pressure dominated envelopes of massive stars, we identified multiple instabilities that could be driving structure growth. We quantified the structure growth in the non-linear simulations of O stars and Wolf–Rayet stars by computing density power spectra and tracking their temporal evolution. Then, we compared these results to the analytical results from the stability analysis to distinguish between the different instabilities.<i>Results<i/>. The stability analysis leads to two possible instabilities: the convective instability and an acoustic instability that is a local variant of so-called strange modes. Analytic expressions for the growth rates of these different instabilities are found. In particular, strong radiative diffusion damps the growth rate <i>ω<i/> of the convective instability in this regime leading to a distinct <i>ω<i/> ∼ 1/<i>k<i/><sup>2<sup/> dependence on wavenumber <i>k<i/>. From our power spectra analysis of the simulations, however, we find that structure growth rather increases with <i>k<i/> – tentatively as <i>ω<i/> ~ √<i>k<i/>.<i>Conclusions<i/>. Our results suggest that, contrary to what is commonly assumed, structures in luminous O and Wolf–Rayet star envelopes do not primarily develop from the sub-surface convective instability. Rather the growth seems compatible with either the acoustic instability in the radiation-dominated regime or with Rayleigh-Taylor type instabilities, although the exact origin remains inconclusive for now.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"130 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077608","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":"Monte Carlo post-processing for radiation hydro simulations of accreting planets in protoplanetary disks","authors":"Anton Krieger, Hubert Klahr, Julio David Melon Fuksman, Sebastian Wolf","doi":"10.1051/0004-6361/202451780","DOIUrl":"https://doi.org/10.1051/0004-6361/202451780","url":null,"abstract":"This paper is part of a series investigating the observational appearance of planets accreting from their nascent protoplanetary disk (PPD). We evaluate the differences between gas temperature distributions determined in our radiation hydrodynamical (RHD) simulations and those recalculated via post-processing with a Monte Carlo (MC) radiative transport (RT) scheme. Our MCRT simulations were performed for global PPD models, each composed of a local 3D high-resolution RHD model embedded in an axisymmetric global disk simulation. We report the level of agreement between the two approaches and point out several caveats that prevent a perfect match between the temperature distributions with our respective methods of choice. Overall, the level of agreement is high, with a typical discrepancy between the RHD and MCRT temperatures of the high-resolution region of only about 10 percent. The largest differences were found close to the disk photosphere, at the transition layer between optically dense and thin regions, as well as in the far-out regions of the PPD, occasionally exceeding values of 40 percent. We identify several reasons for these discrepancies, which are mostly related to general features of typical radiative transfer solvers used in hydrodynamical simulations (angle- and frequency-averaging and ignored scattering) and MCRT methods (ignored internal energy advection and compression and expansion work). This provides a clear pathway to reduce systematic temperature inaccuracies in future works. Based on MCRT simulations, we finally determined the expected error in flux estimates, both for the entire PPD and for planets accreting gas from their ambient disk, independently of the amount of gas piling up in the Hill sphere and the used model resolution.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"77 2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077607","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":"Probing the low-energy particle content of blazar jets through MeV observations","authors":"F. Tavecchio, L. Nava, A. Sciaccaluga, P. Coppi","doi":"10.1051/0004-6361/202453411","DOIUrl":"https://doi.org/10.1051/0004-6361/202453411","url":null,"abstract":"Many of the blazars observed by <i>Fermi<i/> actually have the peak of their time-averaged gamma-ray emission outside the ∼GeV <i>Fermi<i/> energy range, at ∼MeV energies. The detailed shape of the emission spectrum around the ∼MeV peak places important constraints on acceleration and radiation mechanisms in the blazar jet and may not be the simple broken power law obtained by extrapolating from the observed X-ray and GeV gamma-ray spectra. In particular, state-of-the-art simulations of particle acceleration by shocks show that a significant fraction (possibly up to ≈90%) of the available energy may go into bulk quasi-thermal heating of the plasma crossing the shock rather than producing a nonthermal power-law tail. Other gentler but possibly more pervasive acceleration mechanisms, such as shear acceleration at the jet boundary, may result in a further build-up of the low-energy (<i>γ<i/> ≲ 10<sup>2<sup/>) particle population in the jet. As already discussed for the case of gamma-ray bursts, the presence of a low-energy Maxwellian-like bump in the jet particle energy distribution can strongly affect the spectrum of the emitted radiation, for example producing an excess over the emission expected from a power-law extrapolation of a blazar’s GeV-TeV spectrum. We explore the potential detectability of the spectral component ascribable to a hot quasi-thermal population of electrons in the high-energy emission of flat-spectrum radio quasars (FSRQs). We show that for the typical physical parameters of FSRQs, the expected spectral signature is located at ∼MeV energies. For the brightest <i>Fermi<i/> FSRQ sources, the presence of such a component will be constrained by the upcoming MeV Compton Spectrometer and Imager (COSI) satellite.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"128 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072122","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":"Messier 90 galactic halo rotation in the microwaves","authors":"F. De Paolis, V. G. Gurzadyan, A. L. Kashin, G. Yegoryan, A. Qadir, N. Tahir, Ph. Jetzer","doi":"10.1051/0004-6361/202453170","DOIUrl":"https://doi.org/10.1051/0004-6361/202453170","url":null,"abstract":"We used <i>Planck<i/> data to study the Virgo Cluster’s galaxy M 90 and its surroundings. We find, as in the case of certain galaxies of the Local Group and its vicinity, a substantial temperature asymmetry that probably arises from the rotation of the M 90 halo and extends up to about one degree from its centre. This temperature asymmetry is particularly remarkable as M 90 is a rare blueshifted galaxy of the Virgo Cluster, and it thus has possible implications for the cluster internal dynamics versus the galactic halo’s formation and structure. Possible explanations for the observed effect are discussed.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"13 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072123","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":"Thermal environment and erosion of comet 67P/Churyumov-Gerasimenko","authors":"O. Groussin, L. Jorda, N. Attree, S. P. D. Birch, J. Bürger, P. Gutiérrez, A. S. Jindal, H. U. Keller, T. Kramer, R. Lasagni Manghi, M. Läuter, J. Markkanen, R. Marschall, C. Schuckart","doi":"10.1051/0004-6361/202452260","DOIUrl":"https://doi.org/10.1051/0004-6361/202452260","url":null,"abstract":"<i>Aims<i/>. This paper focuses on how insolation affects the nucleus of comet 67P/Churyumov-Gerasimenko over its current orbit. We aim to better understand the thermal environment of the nucleus, in particular its surface temperature variations, erosion, relationship with topography, and how insolation affects the interior temperature for the location of volatile species (H<sub>2<sub/>O and CO<sub>2<sub/>).<i>Methods<i/>. We have developed two thermal models to calculate the surface and subsurface temperatures of 67P over its 6.45-year orbit. The first model, with high resolution (300 000 facets), calculates surface temperatures, taking shadows and self-heating into account but ignoring thermal conductivity. The second model, with lower resolution (10 000 facets), includes thermal conductivity to estimate temperatures down to ~3 m below the surface.<i>Results<i/>. The thermal environment of 67P is strongly influenced by its large obliquity (52°), which causes significant seasonal effects and polar nights. The northern hemisphere is the coldest region, with temperatures of 210–300 K. H<sub>2<sub/>O is found in the first few centimetres, while CO<sub>2<sub/> is found deeper (~2 m) except during polar night around perihelion, when CO<sub>2<sub/> accumulates near the surface. Cliffs erode 3–5 times faster than plains, forming terraces. The equatorial region receives maximum solar energy (8.5×10<sup>9<sup/> J m<sup>−2<sup/> per orbit), with maximum surface temperatures of 300–350 K. On the plains, H<sub>2<sub/>O is found in the first few centimetres, while CO<sub>2<sub/> is found deeper (~2 m) and never accumulates near the surface. In the southern hemisphere, a brief intense perihelion heating raises temperatures to 350–400 K, which is followed by a 5-year polar night when surface temperatures drop to 55 K. Here H<sub>2<sub/>O remains in the first few centimetres, while CO<sub>2<sub/> accumulates shallowly during polar night, enriching the region. Erosion is maximal in the southern hemisphere and concentrated on the plains, which explains the observed overall flatness of this hemisphere compared to the northern one. Over one orbit, the total energy from self-heating is 17% of the total energy budget, and 34% for thermal conduction. Our study contributes to a better understanding of the surface changes observed on 67P.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"37 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072159","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":"Dynamical evolution of the open clusters with different star formation efficiencies and orbital parameters","authors":"M. Ishchenko, V. Masliukh, M. Hradov, P. Berczik, B. Shukirgaliyev, C. Omarov","doi":"10.1051/0004-6361/202452336","DOIUrl":"https://doi.org/10.1051/0004-6361/202452336","url":null,"abstract":"<i>Context<i/>. Open star clusters are dynamic systems whose evolution is critically influenced by initial conditions such as star formation efficiency and orbital parameters. Understanding their dissolution mechanisms provides insight into stellar population dynamical mixing in the Milky Way.<i>Aims<i/>. We aim to investigate the dynamical evolution and dissolution of initially non-virialised open clusters by examining how different global star formation efficiencies and orbital characteristics impact the cluster longevity and structural changes. We followed the evolution of the clusters up to their dissolution time on the basis of our calculations. Finally, we also compare our open cluster dynamical evolutionary models with the observed open clusters in our Galaxy’s solar vicinity.<i>Methods<i/>. Using high-order direct <i>N<i/> -body simulations, we modelled cluster evolution across different Galactic orbits, systematically varying initial star formation efficiencies to comprehensively explore dissolution mechanisms.<i>Results<i/>. Our simulations reveal that open clusters typically survive approximately ten orbital periods, with cluster lifetime being strongly dependent on global star formation efficiency and only marginally influenced by orbital eccentricity. We estimate gas expulsion timescales of ∼0.9 Myr, with initial supernova explosions efficiently removing gaseous components from the cluster. The expected lifetime of the cluster (in units of orbital periods) strongly depends on the cluster global star-formation efficiency and only slightly on the orbital eccentricities of the cluster.<i>Conclusions<i/>. The theoretical models demonstrate a remarkable agreement of the Roche-lobe filling parameter with the recent observed Gaia DR3 cluster catalogues in the solar vicinity. By incorporating a mixed sample of clusters with varying star formation efficiencies, we provide a more nuanced understanding of open cluster evolution in the Galactic disc.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"24 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072121","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}