Astronomy & Astrophysics最新文献

{"title":"Kolmogorov analysis of JWST deep survey galaxies","authors":"N. Galikyan, A. A. Kocharyan, V. G. Gurzadyan","doi":"10.1051/0004-6361/202554745","DOIUrl":"https://doi.org/10.1051/0004-6361/202554745","url":null,"abstract":"JWST galaxy deep spectral surveys provide a unique opportunity to trace a broad range of evolutionary features of galaxies and the intergalactic medium given the huge distance the photons are propagating. We have analyzed the spectral data of JWST galaxies up to a redshift of around 7 using the Kolmogorov technique, which is an efficient tool for testing the tiny comparative randomness properties of cumulative signals, that is, for distinguishing the contributions of regular and stochastic sub-signals. Our aim is to determine if certain identical spectral features of galaxies have undergone any distortions or systematic evolution across a broad range of redshifts. Our results indicate a change in the spectral properties of the sample galaxies at around <i>z<i/> ≃ 2.7 at over a 99% confidence level.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"66 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884734","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 dependence of periodic density structures’ amplitude and length scale on solar wind density within stream interaction regions","authors":"C. Katsavrias, S. Di Matteo, L. Kepko, N. M. Viall","doi":"10.1051/0004-6361/202554483","DOIUrl":"https://doi.org/10.1051/0004-6361/202554483","url":null,"abstract":"<i>Context.<i/> Periodic density structures (PDSs) are a type of solar wind mesoscale structure characterised by quasi-periodic variations in the density of the solar wind ranging from a few minutes to a few hours. They are trains of advected density structures with radial length scales of <i>L<i/><sub>R<sub/> ≈ 100 − 10 000 Mm. Analysis of case studies shows that PDSs can be compressed when embedded in a stream interaction region (SIR), leading to larger density variations and an increased impact on the magnetospheric and radiation belt dynamics.<i>Aims.<i/> We perform an extensive statistical study to identify PDSs embedded in SIRs as well as their corresponding frequency and radial length scale distributions.<i>Methods.<i/> We used an extensive list of 186 SIRs and 1217 embedded PDS events from the entire Wind dataset (1995−2022), spanning more than two solar cycles, to investigate the frequency and radial length scales of PDSs. With the use of wavelet methods, we classified these PDSs as coherent or incoherent, based on the shared periodic behaviour between proton density and the alpha-to-proton ratio, and we derived the corresponding occurrence distributions.<i>Results.<i/> We found that 130 out of 186 SIR events have embedded coherent PDSs, which exhibit an increasing probability of occurrence with increasing frequency (up to ≈3 mHz). Furthermore, the investigation of radial length scales of coherent PDSs in SIRs reveals significant compression compared to PDSs in the ambient solar wind, as the most probable <i>L<i/><sub>R<sub/> values are 120−130 Mm and 160−190 Mm for the slow and fast compressed solar wind, respectively. The coherent PDS <i>L<i/><sub>R<sub/> decreases with a rate of −0.74, while the corresponding amplitude increases with a rate of 0.74 with increasing solar wind proton density, both following a power law function.<i>Conclusions.<i/> Our results indicate that coherent PDSs occur more often than not in SIRs. This is consistent with a picture in which PDSs are formed at the Sun, advected by the solar wind, and enhanced by their interaction with SIRs, while both their radial length scale and amplitude are controlled by the level of compression in the interaction region.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"140 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880666","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":"Characterisation of magnetic activity of M dwarfs","authors":"R. V. Ibañez Bustos, A. P. Buccino, N. Nardetto, D. Mourard, M. Flores, P. J. D. Mauas","doi":"10.1051/0004-6361/202450348","DOIUrl":"https://doi.org/10.1051/0004-6361/202450348","url":null,"abstract":"<i>Context.<i/> M dwarfs are an ideal laboratory for hunting Earth-like planets, and the study of chromospheric activity is an important part of this task. On the one hand, according to the study of short-term activity their high levels of magnetic activity can affect habitability and make it difficult to detect exoplanets orbiting around them. On the other hand, however, long-term activity studies can show whether or not these stars exhibit cyclical behaviour in their activity, facilitating the detection of planets in periods of low magnetic activity.<i>Aims.<i/> The long-term cyclical behaviour of magnetic activity can be detected by studying several spectral lines and explained by different stellar dynamo models (such as <i>α<i/>Ω or <i>α<i/><sup>2<sup/> dynamos). In the present work, we studied the Mount Wilson <i>S<i/> index to search for evidence of long-term activity possibly driven by a solar-type dynamo.<i>Methods.<i/> We studied a sample of 35 M dwarfs with different levels of chromospheric activity and spectral classes ranging from dM0 to dM6. To do this, we used 2965 spectra in the optical range from different instruments installed in the southern and northern hemispheres to construct time series with extensions of up to 21 years. We analysed these time series with different time-domain techniques to detect cyclical patterns. In addition, using 2MASS-<i>K<sub>S<sub/><i/> and visible photometry we also studied the potential impact of chromospheric activity on surface brightness.<i>Results.<i/> Using the colour index (<i>V<i/> − <i>K<sub>S<sub/><i/>), we calculated the chromospheric emission levels and found that most of the stars in the sample have low emission levels, indicating that most of them are inactive or very inactive stars. For 31 stars of 35, we constructed time series using the <i>S<i/> indexes, and we detected 13 potential cycles of magnetic activity. These cycles have an approximate duration of between three and 19 years, with false alarm probabilities (FAPs) less than 0.1%. For stars that do not show cyclic behaviour, we found that the mean value of the <i>S<i/> index varies between 0.350 and 1.765, and its mean variability and chromospheric emission level are around 12% and −5.110 dex, respectively. We do not find any impact of chromospheric activity on the surface brightness in the domain of −5.6 < log <i>R<i/>′<sub><i>H K<i/><sub/> < −4.5.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880754","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":"From filament to clumps and cores","authors":"Han-Tsung Lee, Ya-Wen Tang, Patrick M. Koch, Jia-Wei Wang, Seamus Clarke, Gary A. Fuller, Nicolas Peretto, Won-Ju Kim, Hsi-Wei Yen","doi":"10.1051/0004-6361/202452974","DOIUrl":"https://doi.org/10.1051/0004-6361/202452974","url":null,"abstract":"<i>Aims.<i/> Fragmentation is a multiscale process forming structures with sizes that vary by several orders of magnitude. However, multiscale investigations of the magnetic field characterizing its properties across the physical scales relevant to the fragmentation process (filaments and clouds, clumps, and cores) are elusive. In this work, we present a multiscale study of the magnetic field using polarization continuum observations with various resolutions.<i>Methods.<i/> We made use of data from the JCMT and the SMA at 850 μm and 1.3 millimeter (mm) wavelengths to study the filamentary infrared dark cloud SDC18.624-0.070. Our observations cover filament (~ 10 pc), filament-embedded clump (~ 1 pc), isolated clump (~ 0.1 pc), and clump-embedded core (~ 0.01) scales, which are key to investigating the impact of the magnetic field on fragmentation.<i>Results.<i/> We found a magnetic field that is predominantly perpendicular to the major axes of all structures (filament, clumps, and cores). While its circular mean orientations are preserved within about 20°, a systematically increasing field dispersion toward smaller scales indicates the growing impact of gravity. Velocity gradients traced by N<sub>2<sub/>H<sup>+<sup/>, with a resolution similar to that of the polarization observations, also tend to be perpendicular to the filament’s major axis. All these features suggest that the magnetic field constrains the direction of accretion and initial contraction, as predicted by strong-field models.<i>Conclusions.<i/> We argue that the observed magnetic field and velocity gradient can result from a combination of converging flows, based on a detected SiO component along the filament, and rotation, based on the measured N<sub>2<sub/>H<sup>+<sup/> specific angular momentum profile. A multiscale energy analysis of gravity, magnetic field, and turbulence quantifying their relative importance shows that SDC18-S, despite displaying less fragmentation, has a larger field strength than SDC18-N, which harbors more fragments. A faster (SDC18-N) and slower evolution (SDC18-S) to a gravity-dominated regime has been found to explain the different fragmentation at clump-embedded core scale, with the stronger magnetic field in SDC18-S suppressing fragmentation to a greater extent.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"37 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880664","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":"Quantifying jet–interstellar medium interactions in Cyg X-1: Insights from dual-frequency bow shock detection with MeerKAT","authors":"P. Atri, S. E. Motta, J. van den Eijnden, J. H. Matthews, J. C. A. Miller-Jones, R. Fender, D. Williams-Baldwin, I. Heywood, P. Woudt","doi":"10.1051/0004-6361/202452837","DOIUrl":"https://doi.org/10.1051/0004-6361/202452837","url":null,"abstract":"<i>Context.<i/> Accretion and outflows are astrophysical phenomena observed across a wide range of objects, from white dwarfs to supermassive black holes. Developing a complete picture of these processes requires complementary studies across this full spectrum of jet-launching sources. Jet–interstellar medium (ISM) interaction sites near black hole X-ray binaries provide unique laboratories that provide insights into the energetics of the jets launched from stellar-mass black holes.<i>Aims.<i/> This work aims to detect and characterise the bow shock near one black hole X-ray binary, Cyg X-1, and then use this bow shock structure to parametrise the properties of the jet launched by Cyg X-1 over its lifetime.<i>Methods.<i/> We used the MeerKAT radio telescope to investigate the bow shock structure formed by the interaction between the jets of Cyg X-1 and the ISM. Using new <i>L<i/>- and <i>S<i/>-band detections of the bow shock, we constrained the density of the unshocked ISM and mapped the bow shock’s spectral index. These values were applied to self-similar models developed initially for FR II galaxies to estimate the energy transport rate and the age of Cyg X-1 jets.<i>Results.<i/> We successfully detect the bow shock north of Cyg X-1 in the <i>L<i/> and <i>S<i/> bands and report its size and brightness. We present the spectral index distribution across the bow shock, which is in the range −0.9 ≤ <i>α<i/> ≤ 0.4, with an error distribution (0.6 ≤ Δ<i>α<i/> ≤ 1.5) that peaks at unity. We determine that the unshocked ISM density is 6–7 cm<sup>−3<sup/> for a temperature range of 10<sup>4<sup/>–3 × 10<sup>6<sup/> K. This temperature range suggests that the velocity of the bow shock is 21 km s km s<sup>−1<sup/>. The age of the Cyg X-1 jet responsible for the bow shock is 0.04–0.3 Myr, and the power of the jet is constrained to 2 × 10<sup>31<sup/> ergs s ergs s<sup>−1<sup/> for the case of opening angles of 0.3°–2.0°. We also detect new morphological features of the bow shock in the <i>S<i/>-band image. The comparison of archival H<sub><i>α<i/><sub/> maps with the new radio observations hints at different regions of emission, different temperature ranges, and different ISM densities.<i>Conclusions.<i/> MeerKAT’s sensitivity and resolution effectively reveal low surface brightness features of the Cyg X-1 bow shock. The spectral index suggests a consistent emission origin across the structure. The ISM density around Cyg X-1 is on the higher end for Galactic environments, and our results indicate a lower jet energy transport rate than prior estimates. Further searches with MeerKAT will help build a statistically significant sample, advancing our understanding of black hole X-ray binary jets and their impact on their local environments.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"108 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880665","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":"Do accretion-powered stellar winds help spin down T Tauri stars?","authors":"Lukas Gehrig, Eric Gaidos, Laura Venuti, Ann Marie Cody, Neal J. Turner","doi":"10.1051/0004-6361/202553730","DOIUrl":"https://doi.org/10.1051/0004-6361/202553730","url":null,"abstract":"How T Tauri stars remain slowly rotating while still accreting material is a long-standing puzzle. Current models suggest that these stars may lose angular momentum through magnetospheric ejections (MEs) of disk material and accretion-powered stellar winds (APSWs). The individual contribution of each mechanism to the stellar spin evolution, however, is also unclear. We explore how these two scenarios could be distinguished by applying stellar spin models to near-term observations. We produced synthetic stellar populations of accreting Class II stars with spreads in the parameters governing the spin-down processes and find that an APSW strongly affects the ratio of the disk truncation radius to the co-rotation radius, ℛ = <i>R<i/><sub>t<sub/>/<i>R<i/><sub>co<sub/>. The ME and APSW scenarios are distinguished to a high degree of confidence when at least <i>N<i/><sub>crit<sub/> ≳ 250 stars have values measured for ℛ. Newly developed light curve analysis methods enable the measuring of ℛ for enough stars to distinguish the spin-down scenarios and will be important in the course of upcoming observing campaigns.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880669","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":"Revisiting inelastic Cu + H collisions and the non-LTE Galactic evolution of copper","authors":"S. Caliskan, A. M. Amarsi, M. Racca, I. Koutsouridou, P. S. Barklem, K. Lind, S. Salvadori","doi":"10.1051/0004-6361/202554251","DOIUrl":"https://doi.org/10.1051/0004-6361/202554251","url":null,"abstract":"The Galactic evolution of copper remains poorly understood, partly due to the strong departures from local thermodynamic equilibrium (LTE) affecting Cu I lines. A key source of uncertainty in non-LTE modelling is the treatment of inelastic Cu + H collisions. We present new rate coefficients based on a combined asymptotic LCAO (linear combination of atomic orbitals) and free electron model approach, which show significant differences from previous calculations. Applying these updated rates to non-LTE stellar modelling, we find reduced line-to-line scatter and improved consistency between metal-poor dwarfs and giants. Our non-LTE analysis reveals a strong upturn in the [Cu/Fe] trend towards lower [Fe/H] < −1.7. We show that this may reflect the interplay between external enrichment of Cu-rich material of the Milky Way halo at low metallicities, and metallicity-dependent Cu yields from rapidly rotating massive stars. This highlights the unique diagnostic potential of accurate Cu abundances for understanding both stellar and Galactic evolution.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"100 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880708","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":"Double progenitor origin of the S-star cluster","authors":"Sill Verberne, Elena Maria Rossi, Sergey E. Koposov, Zephyr Penoyre, Manuel Cavieres, Konrad Kuijken","doi":"10.1051/0004-6361/202554247","DOIUrl":"https://doi.org/10.1051/0004-6361/202554247","url":null,"abstract":"The origin of the cluster of S-stars located in the Galactic Centre is tied to the supermassive black hole Sagittarius A*, but exactly how is still debated. In this paper, we investigate whether the Hills mechanism can simultaneously reproduce both the S-star cluster’s properties and the observed number of hypervelocity stars. To do so, we forward-modelled the capture and disruption of binary stars originating from the nuclear star cluster (NSC) and the clockwise disc (CWD). We find that the ratio of evolved to main-sequence S-stars is highly sensitive to the origin of the binaries, and that neither the injection of binaries from the CWD nor from the NSC exclusively can reproduce all observations. However, when considering the injection of binaries from both locations, we are able to reproduce all the observations simultaneously, including the number of observed hypervelocity stars, the evolutionary stage of the S-stars, their luminosity function, and the distribution of their semi-major axes. The implications of our findings include that ∼90% of hypervelocity stars ejected over the past ∼10 Myr should originate from the CWD, that the main-sequence S-stars originated in the CWD, and that the evolved S-stars originated in an old stellar population such as the NSC.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"53 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880709","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":"Coupling particle-in-cell and magnetohydrodynamics methods for realistic solar flare models","authors":"M. Haahr, B. V. Gudiksen, Å. Nordlund","doi":"10.1051/0004-6361/202452117","DOIUrl":"https://doi.org/10.1051/0004-6361/202452117","url":null,"abstract":"<i>Context.<i/> Simulating solar flares requires capturing both large-scale magnetohydrodynamic (MHD) evolution and small-scale kinetic processes near reconnection sites. Bridging these scales has been a significant computational challenge.<i>Aims.<i/> This study introduces a Particle-In-Cell (PIC) solver integrated within the DISPATCH framework, facilitating seamless embedding within MHD simulations. This development aims to enable self-consistent multi-scale solar flare simulations.<i>Methods.<i/> Our PIC solver, inspired by the PhotonPlasma code, addresses the Vlasov-Maxwell equations in collisionless plasma. We validate its accuracy through fundamental plasma tests – including plasma oscillations, two-stream instability, and current sheet reconnection. To make kinetic simulations computationally feasible, we employ physical adjustment of constants (PAC), modifying the speed of light, elementary charge, and electron mass to shift plasma scales. Additionally, we implement and validate a coupling strategy that enables smooth transitions between kinetic and fluid regimes.<i>Results.<i/> The PIC solver successfully recovers expected plasma dynamics and electromagnetic field behaviour. Our analysis highlights the effects of PAC on reconnection dynamics, underscoring the importance of transparent and well-documented scaling choices. Test cases involving propagating waves across PIC-MHD interfaces confirm the robustness of our coupling approach.<i>Conclusions.<i/> The integration of the PIC solver into the DISPATCH framework makes it possible to run self-consistent, multiscale solar flare simulations. Our approach provides a computationally efficient foundation for investigating reconnection physics in large-scale astrophysical plasmas.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"17 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880715","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":"Asymmetric accretion through a streamer onto the pre-stellar core H-MM1","authors":"Spandan Choudhury, Jongsoo Kim, Paola Caselli, Chang Won Lee, Jaime E. Pineda","doi":"10.1051/0004-6361/202453281","DOIUrl":"https://doi.org/10.1051/0004-6361/202453281","url":null,"abstract":"<i>Context.<i/> Dense cores inside molecular clouds are hubs of star formation. Cores have been thought to be isolated from their surrounding cloud. However, this idea is challenged by recent observations of streamers that show evidence of mass flow from outside the core onto the embedded protostar. Multi-component analysis using molecular line observations has also revealed the existence of subsonic material outside the traditional coherent boundary of dense cores.<i>Aims.<i/> In this study, we aim to probe the extended subsonic region observed around the pre-stellar core H-MM1 in the L1688 molecular cloud in Ophiuchus using multi-component kinematical analysis of very high-sensitivity NH<sub>3<sub/> data.<i>Methods.<i/> We used observations of NH<sub>3<sub/> (1,1) and (2,2) inversion transitions using the Green Bank Telescope (GBT). We then fitted up to two components towards the core and its surrounding molecular cloud.<i>Results.<i/> We detect an extended region of subsonic turbulence in addition to the ambient cloud, which shows supersonic turbulence. This extended subsonic region is approximately 12 times the size of and more than two times as massive as the previously detected subsonic material. The subsonic region is further split into two well-separated, velocity-coherent components, one of which is kinematically and spatially connected to the dense core. The two subsonic components are red- and blue-shifted with respect to the cloud component. We also detect a flow of material onto the dense core from the extended subsonic region via a streamer of length ≈0.15 pc (≈30000 au).<i>Conclusions.<i/> We find that the extended subsonic component kinematically associated with the dense core contains ≈27% more mass than the core. This material could be further accreted by the core. The other subsonic component contains a mass similar to that of the core mass, and could be tracing material in the early stage of core formation. The H-MM1 streamer is kinematically similar to the ones observed towards protostellar systems, but is the first instance of such an accretion feature onto a core in its pre-stellar phase. This accretion of chemically fresh material by the pre-stellar core challenges our current understanding of a core evolving with a mass that is unchanged since the time of its formation.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"35 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880718","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}