Astronomy & Astrophysics最新文献

{"title":"IViS: Interferometric Visibility-domain inversion Software. A GPU-accelerated Python framework for joint deconvolution with ASKAP","authors":"A. Marchal,N. M. McClure-Griffiths,J. Dempsey,H. Nguyen,H. Dénes,J. Dickey,C. Lynn,Y. K. Ma,D. McConnell,M.-A. Miville-Deschênes,N. Pingel,J. Th. van Loon","doi":"10.1051/0004-6361/202661540","DOIUrl":"https://doi.org/10.1051/0004-6361/202661540","url":null,"abstract":"Wide-field spectral-line imaging with modern radio interferometers remains challenging when the emission is extended, multiscale, and distributed over many overlapping pointings. In this regime, accurate reconstruction requires a joint treatment of the calibrated visibilities, control of image-domain regularity, and, when necessary, recovery of missing short spacings from single-dish data. We present of Galactic foreground emission and LMC emission with reduced residual side-lobe structure and realistic multiscale morphology. A comparison with using multiscale CLEAN shows that, for this specific target and a single observing block, (Interferometric Visibility-domain Inversion Software), a GPU-accelerated Python framework for visibility-domain joint deconvolution, and assess its performance for wide-field ̋I imaging with the Australian Square Kilometre Array Pathfinder (ASKAP). The current model, reconstructs a nonparametric sky cube directly from calibrated visibilities by minimizing a regularized least-squares criterion. The forward model relies on a nonuniform fast Fourier transform (NUFFT), supports joint deconvolution across all mosaic pointings, and allows positivity constraints through bounded optimization. Short-spacing information can be incorporated through a fusion term that models single-dish data from the same sky estimate. We validate the method using synthetic point-source, noise-only, and multiscale diffuse-emission simulations, and apply it to ASKAP full-survey observations toward the Large Magellanic Cloud (LMC). The simulations show that recovers point-source flux accurately in the absence of regularization and that the regularization strength sets the trade-off between noise suppression and effective resolution. Relative to linear mosaicking of independently deconvolved pointings, joint deconvolution can recover more large-scale power. When single-dish information is included, the reconstructed power spectra closely reproduce the input sky statistics over a broad range of spatial frequencies. Applied to ASKAP data, yields 10,h mosaics with an effective resolution of 22 ASKAPSoft exhibits fewer residual side-lobes and recovers substantially more power at low spatial frequencies. provides a flexible visibility-domain framework for joint deconvolution of large spectral-line mosaics, and illustrates the potential of regularized inverse-problem approaches as an alternative to traditional CLEAN-based imaging for next-generation radio surveys.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"34 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209020","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":"A0538-66: A transient ultraluminous X-ray source with a relativistic outflow, 69,ms pulsations, and anomalous optical activity","authors":"Lorenzo Ducci,Sandro Mereghetti,Ciro Pinto,Matteo Bachetti,Motoki Nakajima,Rahul Sharma,Stefano Covino,Michela Rigoselli,Caterina Tresoldi,Tatehiro Mihara,Mutsumi Sugizaki","doi":"10.1051/0004-6361/202663088","DOIUrl":"https://doi.org/10.1051/0004-6361/202663088","url":null,"abstract":"A0538-66 is a peculiar Be/X-ray binary in the Large Magellanic Cloud, hosting the fastest spinning neutron star of its class (sim69,ms) and showing the brightest optical bursts of any system of this type. We report four observations obtained near periastron in 2025, together with MAXI and REM monitoring, and a reanalysis of archival RXTE data. On 30 September 2025 the source reached L_ ̊m X ≈ 1.5 ,erg,s-1 (0.2-10,keV), the highest level since 1980, and in February, May, and August 2026, MAXI detected similarly bright outbursts. During the =69.25878(2),ms and dot 10^ 39 observation taken on 30 September 2025, we detected the pulsations, measuring P_ ̊m spin P _ ̊m spin =6.58(9) ,s,s-1; the pulsed fraction was low ( ≈ 1.5 ,erg,s , and it makes >10^ -10 in 1$-10,keV), increased with energy, and the soft and hard pulse profiles were shifted by half a cycle. A new detection in RXTE data of 3 December 1998 gives a faster spin period of P=68.88813(28),ms. The spectra show emission lines from photoionised plasma at rest and blueshifted absorption lines that imply an outflow at ∼ 0.12c. This indicates a highly super-Eddington accretion rate and an intrinsic L_ ̊m X 10^ 39 -1 a transient ultra-luminous X-ray pulsar, a class of which only a few objects are known so far. Since 2023 the optical bursts observed by REM have become longer and brighter, resembling those of the 1980s, but most of them lack a luminous X-ray counterpart (L_ X 37 ,erg,s -1 ). We interpret these results in terms of a radiation pressure dominated accretion disc whose geometrically thick inner regions intermittently screen the innermost emitting regions.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209048","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":"Continuous mass ablation of planets engulfed in stellar envelopes","authors":"Mike Y. M. Lau,Robert Andrassy,Giovanni Leidi,Damien Gagnier,Javier Morán-Fraile,Friedrich K. Röpke,Ilya Mandel","doi":"10.1051/0004-6361/202660892","DOIUrl":"https://doi.org/10.1051/0004-6361/202660892","url":null,"abstract":"Most stars host short-period planets that are expected to be engulfed during post-main-sequence expansion. The dissolution of engulfed planets has been proposed as a possible mechanism for producing stars enriched in lithium and refractory elements. We performed three-dimensional hydrodynamical simulations of a Jupiter-like planet engulfed within a stellar envelope using the code. Unlike previous studies that represent the planet as a point mass or rigid sphere, we adopted a wind-tunnel setup that resolves the planet's gaseous structure. We find that a continuous mass-ablation process operates during planetary engulfment, contrary to the common assumption that destruction occurs at a specific depth due to ram pressure, tidal forces, or thermal evaporation. The ablation rate scales nearly linearly with the wind momentum flux and is largely insensitive to the Mach number, consistent with an analytical model based on Kelvin--Helmholtz instability developing at the planetary surface. Our study provides a framework for large parameter-space studies of planetary engulfment using parametrised drag and mass-loss models. We define efficiency coefficients for drag and ablation, finding pressure-drag coefficients of 0.44--0.56 and ablation efficiencies of 0.054--0.11. Applying these coefficients to a numerically integrated inspiral through a stellar profile, we find that continuous ablation could deposit a significant fraction of the planet's mass within the convective envelope, producing observable lithium enrichment at the stellar surface. This result suggests that chemical enrichment occurs over a broader range of stellar parameters than previously thought. Seven-League Hydro","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"37 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209113","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":"Isochrones in primordial magnetic field evolution","authors":"A. Brandenburg,M. Cielo,O. Iarygina,F. Vazza","doi":"10.1051/0004-6361/202661355","DOIUrl":"https://doi.org/10.1051/0004-6361/202661355","url":null,"abstract":"In the early Universe, a primordial magnetic field undergoes a turbulent decay while its length scale increases due to an inverse cascade. The size of the largest processed eddy scales with the Alfvén speed and grows with time. In a diagram of Alfvén speed versus length scale, all possible solutions must lie on a line through the origin, with a slope proportional to the inverse of the present time. In principle, however, such lines can also be defined for earlier times. The lines for earlier times form isochrones that might be observationally accessible, for example, through the magnetically driven stochastic gravitational wave background. However, the position and slope of these isochrones is sensitive to the zeropoint of the time. We show that for any initial magnetic field, a proper time can be determined such that the resulting isochrones at early times are nearly parallel to those at late times, that is, they have the same slope. We used two-dimensional numerical simulations of decaying magnetohydrodynamic turbulence and varied the initial position of the peak in the magnetic energy spectrum. In this case, the evolution is governed by the conservation of anastrophy. A fit to the Alfvén time yielded an accurate estimate of the factor by which the decay time is longer than the Alfvén time, while the offset in the fit provided an estimate of the proper time that needs to be added to the nominal time since the beginning of each simulation. We also found that an initial velocity field with a realistic strength produced a straighter track from the beginning. The magnetic field parameters lie on universal isochrones even for early times. They provide a testable framework for magnetic fields generated at times as early as the end of inflation, starting with the time of reheating.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210378","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":"Detecting seven new glitches in PSR J1341-6220 using six-year timing observations from the Parkes 64 m radio telescope","authors":"L. H. Shang,Y. L. Liang,Y. Z. Qiao,P. Liu,W. J. Xiao","doi":"10.1051/0004-6361/202661329","DOIUrl":"https://doi.org/10.1051/0004-6361/202661329","url":null,"abstract":"This paper aims to report seven newly detected glitches in pulsar (PSR) J1341-6220 from six-year timing observations of the Parkes 64 m radio telescope, and to conduct a detailed analysis of the post-glitch recovery processes via Bayesian methods and the vortex creep model. We used six-year (MJD 58222-60589) timing observations obtained from the Parkes 64 m radio telescope to search for glitches and study the rotational evolution of PSR J1341-6220. We measured the key parameters of the detected glitches and examined their temporal distribution and recovery behaviours. Bayesian analysis and the vortex creep model were used to quantitatively study glitches with sufficient post-glitch data and interpret the delayed spin-down rate increase as the response of inward-moving vortices transported by crustquake-driven platelet motion. We further evaluated the relative decrease in moment of inertia assuming starquake-driven glitches, and compared the result with standard neutron star structure models. We detected seven new glitches (G36-G42) for PSR J1341-6220. Reliable parameters are successfully measured for five of these glitches (G36 and G39-G42), with Deltaν/ν from 136.4 to 953.4 10^ -9 and Δ from 0.36 to 1.57 The intervals between successive glitches range from 149 to 579 days and show no significant periodicity. None of these glitches exhibits definite exponential or linear recovery behaviour, but instead show a pronounced non-linear recovery process. Unidentified small-amplitude glitches may exist between the two unconstrained glitches G37 and G38, and a possible overshoot is observed in the recovery of G41. We performed a Bayesian analysis of glitches G39-G42 with the vortex creep model. G36 was excluded from the vortex-creep modelling because of insufficient post-glitch data. The model reproduces the observations well and indicates that non-linear responses dominate the post-glitch recovery. For G40 and G41, inward vortex motion is invoked to explain the delayed spin-down rate increase after the glitches.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210359","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":"Radiation hydrodynamics of star–disc collisions: From system parameters to outflows and light curves","authors":"Taj Jankovič,Sergey Karpov,Michal Zajaček,Vladimír Karas,Marzena Śniegowska","doi":"10.1051/0004-6361/202661811","DOIUrl":"https://doi.org/10.1051/0004-6361/202661811","url":null,"abstract":"Quasi-periodic eruptions (QPEs) are nuclear transients that produce bright, repeating soft X-ray flares superimposed on quiescent emission. A promising interpretation is that they are powered by star-disc collisions, in which a star crosses an accretion disc around a supermassive black hole, drives shocks, and launches dense outflows from which radiation emerges. We present a systematic study of star-disc collisions, linking the physical parameters of the collision to the resulting outflows and emerging bolometric luminosities. We performed three-dimensional local radiation-hydrodynamic simulations, varying the disc surface density and vertical density profiles , stellar velocity and radius, and local collision angle . We focused on the regime in which the star remains unperturbed by the collision. Variations of the stellar velocity and the accretion-disc surface density leave the bow-shock and outflow morphology largely unchanged. However, faster stars produce brighter flares, while denser discs mainly increase the flare duration. Increasing the stellar radius increases the momentum of the forward outflow and produces brighter and longer flares. More centrally concentrated discs yield brighter and shorter flares because radiation escapes more efficiently through the outer low-density layers. More oblique crossings reduce the momentum and luminosity asymmetry of two outflows and lengthen the flares. We provide empirical scalings for the peak luminosity and flare duration with the individual system parameters and apply them to GSN 069. The best candidate solutions favour a star with a radius ∼ R_⊙ on a retrograde orbit that collides with a dense post-stellar tidal disruption event (TDE) disc with a vertically concentrated density profile. Our findings suggest that specific combinations of system parameters can reproduce the characteristic flare amplitudes, durations, duty cycles, and `strong-weak' flare patterns observed in QPE sources.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209117","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":"Beneath the surface: >85% of z>5.9 quasi-stellar objects in massive host galaxies are UV-faint","authors":"Rychard J. Bouwens,Eduardo Bañados,Roberto Decarli,Joseph Hennawi,Daming Yang,Hiddo Algera,Manuel Aravena,Emanuele Farina,Anniek Gloudemans,Jacqueline Hodge,Hanae Inami,Jorryt Matthee,Romain Meyer,Rohan P. Naidu,Pascal Oesch,Huub J.A. Röttgering,Sander Schouws,Renske Smit,Mauro Stefanon,Paul van der Werf,Bram Venemans,Fabian Walter,Yoshinobu Fudamoto","doi":"10.1051/0004-6361/202556183","DOIUrl":"https://doi.org/10.1051/0004-6361/202556183","url":null,"abstract":"We used C II _ 158μ m observations of a large quasi-stellar object (QSO) sample to segregate sources by host galaxy mass to identify those in the most massive hosts. The CII luminosity is a known tracer of molecular gas. It was taken as a proxy for the host mass and was used to rank 190 QSOs at z>5.9, spanning a UV luminosity range of 6 mag (-28<M_ UV,AB <-22). Atacama Large Millimeter Array (ALMA) data from a cycle-10 program were particularly valuable. They provide CII coverage for 46 UV-faint (M_ UV,AB >-24.5) and 25 especially UV-faint (M_ UV,AB >-23.5) QSOs. This improved the statistics by five and six times, respectively. Taking massive host galaxies to be those where L_ CII $>1.8 of UV-bright QSOs), we identified 63 QSOs, including 13 that are UV-faint and 7 that are especially UV-faint. Using these selections and recent QSO luminosity functions (LFs), we present the first characterization of UV luminosity distribution for QSOs in massive host galaxies and quantify L_⊙ (median L_ CII CII LFs for the UV-bright and UV-faint QSOs. While ∼3% of the massive-host QSOs are UV-bright (M_ UV,AB <-26), ≳85% are UV-faint (M_ UV,AB >-24.5). This wide dispersion in UV luminosities reflects variations in dust obscuration, accretion efficiency, and black hole mass. Even though spectroscopy is needed for definitive conclusions, the black hole mass appears to be the dominant factor driving variations in the UV luminosity, based on 34 CII -luminous (L_ CII >1.8 ∼-23, the median extrapolated $ (M_ L_⊙) QSOs distributed across a baseline of ∼3 mag in UV luminosity and with measured M_BH. At M_ UV,AB 10 BH /M_⊙)$ is 8.1 ^ consistent with the local relation. Supermassive black holes (SMBHs) in UV-bright QSOs thus appear to be ∼15_ -9 +25 times more massive than is typical for massive host galaxies at z∼6.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209119","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":"Disentangling chemical evolution histories with phylogenetic trees","authors":"R. Canales,P. Jofré,C. Aguilera-Gómez,P. Das,R. Yates,T. Signor,P. Tissera,X. Hua,R. Foley","doi":"10.1051/0004-6361/202661199","DOIUrl":"https://doi.org/10.1051/0004-6361/202661199","url":null,"abstract":"Chemical abundances encode the fossil record of galaxy evolution in a complex and diverse way that requires innovative approaches to reconstruct galactic histories. We investigate the power of using phylogenetic methods to disentangle different evolutionary pathways in analytical chemical evolution models. We ran 1024 one-zone chemical evolution models using . The resulting chemical abundances were then combined with those of two fiducial models, flexCE and These combined abundances were then used to determine which combinations produce two-branched phylogenetic trees and how purely these trees split the two input models. We used random forests and Shapley analysis to predict which model combinations return well-separated trees and explain which input parameters are most important for this. We also studied the abundance patterns as well as star formation rates, mass accumulation, and branch lengths. We find that η, the mass-loading outflow parameter in , had the largest impact in separating models into separate branches, due to its importance in driving the chemical enrichment rates and total abundances. Star formation rates and mass accumulation had some impact on η, but no direct relation between these quantities and the abundance planes was found. We also found that the branches in our trees connected through the most metal-rich tips, which is opposite to how phylogenetic trees connect in biological systems. This opens new avenues of phylogenetic research in different fields. flexCE Phylogenetic trees help reconstruct histories when there is information that is inherited between generations, which is the case of the chemical elements in galaxy evolution. Branch topologies can provide information about the rates of evolutionary change of the various populations, and the connection between branches also contains information about their shared history. This work brings us a step forward in understanding galaxy evolution through cross-disciplinary research.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209041","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":"Merger remnant in TXS 1033+026. I. Hα and 21 cm observations suggest counter-rotating gas","authors":"J. N. H. S. Aditya,Hyein Yoon,L. G. Dahmer-Hahn,Renzhi Su,Rajeshwari Dutta,Xiaolong Yang,Elaine Sadler,Matthew T. Whiting","doi":"10.1051/0004-6361/202661548","DOIUrl":"https://doi.org/10.1051/0004-6361/202661548","url":null,"abstract":"We conducted eMERLIN and Gemini integral field unit (IFU) observations towards TXS 1033+026, a post-merger ultraluminous infrared galaxy, to study the radio continuum and ̊m Hα and . We note that these are the first results to probe ̊m Hα and cold neutral hydrogen gas in TXS 1033+026 at sub-kiloparsec scales. 21 cm lines at sub-kiloparsec scales. We find a symmetric, two-sided core-jet structure in both L- (≈ 1.4 GHz) and C- (≈ 4.8 GHz) band continuum images. The active galactic nucleus likely has a double-double radio morphology, indicating possible multiple episodes of activity. The Gemini IFU observations provided sub-arcsecond resolution. Results from these observations suggest the presence of a kiloparsec-scale circumnuclear, warped ̊m Hα disc that rotates around the core. The 21 cm maps reveal a complex kinematic structure, with indications of two counter-rotating gas components orbiting the core-jet axis; one of these components counter-rotates relative to the kiloparsec-scale ̊m Hα disc. However, the true morphology of this structure may be more complex than our interpretation suggests. We estimate a 21 cm velocity-integrated optical depth of ̊m 90 ± 3 km s^ -1","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"60 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209110","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 bar-driven central complex of NGC 6946: A panchromatic and spatially resolved view of its star formation history and interstellar medium","authors":"Santiago Álvarez-Córdoba,Jacopo Fritz,M. A. Lara-López,Bernardo Cervantes Sodi,L. S. Pilyugin,Viviana Casasola,Sami Dib,Omar López-Cruz,L. E. Garduño,G. Valé,I. A. Zinchenko,M. E. De Rossi,M.M. Puebla,Vidhi Tailor,Gustavo Bruzual,J. Zaragoza-Cardiel,Margarita Rosado","doi":"10.1051/0004-6361/202660702","DOIUrl":"https://doi.org/10.1051/0004-6361/202660702","url":null,"abstract":"We present a detailed multi-wavelength analysis of the nearby spiral galaxy NGC 6946, combining optical integral field spectroscopy (GCMS), infrared ( ), and radio observations (THINGS and HERACLES). Herschel We aim to characterise both the integrated and spatially resolved properties of the stellar populations and interstellar medium (ISM), and to interpret them in the context of bar-driven galaxy evolution. We used the spectral energy distribution fitting code to derive stellar population properties (stellar mass, star formation history), and different prescriptions to derive ISM properties including atomic and molecular gas masses and the dust mass, dust temperature, and dust emissivity index, combining optical, infrared, and radio datasets. SINOPSIS 25 ) hosts sim40% of the stellar mass, as well as the bulk of the molecular gas and dust, and has sustained enhanced star formation over cosmic time. A major star formation episode occurred ∼ 0.6 Gyr ago. The spatially resolved Kennicutt--Schmidt relation shows that molecular gas alone explains only part of the current SFR variance, while alternative prescriptions incorporating stellar mass and dynamical equilibrium pressure yield only modest improvements. We also find radial enhancements in the effective oxygen yield, Y_ eff , and gas mass fraction, μ, relative to surrounding regions, consistent with sustained gas accumulation. Together with the molecular gas streaming motions previously detected in CO and Hα kinematic studies, our results are consistent with, and provide independent support for, the inward transport of gas driven by a system of nested bars. Our results are consistent with a scenario in which a recent episode of bar-driven gas inflow enhanced the central molecular gas reservoir and sustained elevated star formation, further supported by the elevated gas-to-dust ratio in the inner region, and the low global M_ HI /M_ H _2 ratio. These findings point to efficient HI-to-H_2 conversion, likely promoted by the combined effect of the secondary bar and the large dust content, ultimately regulating star formation. We also find indications consistent with a young stellar bar, given by the presence of a low-mass pseudo-bulge. The current decline in star formation despite large gas reservoirs suggests recent bar-driven quenching.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"63 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209111","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}