Astronomy & Astrophysics最新文献

{"title":"UNIONS and Euclid: Calibrating point source--galaxy separation for ground-based surveys","authors":"G. Thomas,S. E. T. Smith,S. Gwyn,A. W. McConnachie,J.-C. Cuillandre,M. Gatto,E. Balbinot,G. Battaglia,T. de Boer,V. Dornan,C. M. Gutierrez,A. Lançon,N. F. Martin,G. E. Medina,J. F. Navarro,D. Scott,M. Urbano,G. Zamorani,B. Altieri,S. Andreon,N. Auricchio,C. Baccigalupi,M. Baldi,S. Bardelli,P. Battaglia,A. Biviano,M. Bolzonella,E. Branchini,M. Brescia,S. Camera,V. Capobianco,C. Carbone,V. F. Cardone,J. Carretero,M. Castellano,G. Castignani,S. Cavuoti,K. C. Chambers,A. Cimatti,C. Colodro-Conde,G. Congedo,C. J. Conselice,L. Conversi,Y. Copin,F. Courbin,H. M. Courtois,M. Cropper,H. Degaudenzi,G. De Lucia,H. Dole,F. Dubath,X. Dupac,M. Fabricius,M. Farina,R. Farinelli,S. Farrens,S. Ferriol,F. Finelli,S. Fotopoulou,N. Fourmanoit,M. Frailis,E. Franceschi,M. Fumana,S. Galeotta,K. George,B. Gillis,C. Giocoli,J. Gracia-Carpio,A. Grazian,F. Grupp,S. V. H. Haugan,W. Holmes,I. M. Hook,F. Hormuth,A. Hornstrup,K. Jahnke,M. Jhabvala,B. Joachimi,S. Kermiche,A. Kiessling,M. Kilbinger,B. Kubik,M. Kümmel,M. Kunz,H. Kurki-Suonio,A. M. C. Le Brun,S. Ligori,P. B. Lilje,V. Lindholm,I. Lloro,G. Mainetti,O. Mansutti,O. Marggraf,M. Martinelli,N. Martinet,F. Marulli,R. J. Massey,E. Medinaceli,S. Mei,M. Meneghetti,E. Merlin,G. Meylan,A. Mora,M. Moresco,L. Moscardini,R. Nakajima,C. Neissner,S.-M. Niemi,C. Padilla,S. Paltani,F. Pasian,V. Pettorino,A. Pezzotta,S. Pires,G. Polenta,M. Poncet,L. A. Popa,F. Raison,A. Renzi,J. Rhodes,G. Riccio,F. Rizzo,E. Romelli,M. Roncarelli,C. Rosset,B. Rusholme,R. Saglia,Z. Sakr,A. G. Sánchez,D. Sapone,B. Sartoris,P. Schneider,T. Schrabback,A. Secroun,E. Sihvola,P. Simon,C. Sirignano,G. Sirri,L. Stanco,P. Tallada-Crespí,A. N. Taylor,H. I. Teplitz,I. Tereno,S. Toft,R. Toledo-Moreo,F. Torradeflot,I. Tutusaus,J. Valiviita,T. Vassallo,Y. Wang,J. Weller,E. Zucca,A. Montoro,M. Sereno","doi":"10.1051/0004-6361/202661856","DOIUrl":"https://doi.org/10.1051/0004-6361/202661856","url":null,"abstract":"An efficient and accurate separation of unresolved point sources from extended objects, usually referred to as star–galaxy separation, is essential for the scientific exploitation of deep wide-field imaging surveys, particularly at faint magnitudes where morphological differences become subtle. This paper presents a detailed assessment of two morphology-based classification methods applied to single-band, ground-based imaging from the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS), using observations as a high-fidelity reference to assess their performance, and to train one of the methods. Euclid We analysed 8 deg2$ of overlapping UNIONS r-band and Euclid data, comprising more than 7 data enable robust morphological labelling down to sources. The Euclid 26, which we used to train and validate two classification approaches applied to UNIONS alone; i.e. a curve-of-growth method and a supervised neural-network classifier, both of which are based on aperture photometry and image-quality information. The curve-of-growth method yields an almost perfectly complete point-source sample ($>95%$), but its purity decreases rapidly at magnitudes fainter than r ≃ 22.5. The neural-network approach significantly improves the purity at the faint end, maintaining ≥ 80% purity down to r ≃ 24, while the completeness decreases to almost $50% at similar depths. In both cases, the classification performance strongly depends on the image quality of the ground-based data. This work demonstrates how data can be used to develop, calibrate, and validate star–galaxy separation methods for ground-based surveys, which are particularly useful in regions not covered by . Both methods have already been applied to UNIONS data and are readily applicable to future surveys such as LSST, providing flexible solutions depending on whether completeness or purity is prioritised. Euclid Euclid","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"3 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149149911","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 JWST Proto-PAH project: Aromatic backbones with extensive aliphatic substitution account for both the aromatic and aliphatic emission","authors":"N. Clark,E. Peeters,J. Cami,G. C. Sloan,K. Volk,K. E. Kraemer,H. L. Dinerstein,M. A. Gόmez-Muñoz,G. M. Wahlgren,N. C. Sterling,A. Ricca,A. A. Zijlstra,J. Li,M. Matsuura,D. A. García-Hernández,R. Sahai,B. Aringer,C. Bhatt,J. Bernard-Salas,D. Das,A. Manchado","doi":"10.1051/0004-6361/202662644","DOIUrl":"https://doi.org/10.1051/0004-6361/202662644","url":null,"abstract":"We find that the aromatic and aliphatic emission bands in four carbon-rich post-asymptotic giant branch stars with class D emission arise from a single carrier population: extensive aliphatic decoration of an aromatic skeleton, i.e. molecules with a coherent aromatic backbone and an unusually high aliphatic content. This conclusion is based on JWST NIRSpec and MIRI/MRS spectroscopy, covering 2.88--28.7 The aliphatic 3.4 feature is stronger than the aromatic 3.3 feature, reversing the ratio seen in sources with typical polycyclic aromatic hydrocarbon (PAH) emission. If the aromatic emission arose from nominal PAHs, the 3.3 feature -- unavailable in previous observations -- together with the mid-infrared aromatic features, would constrain them to be large (≳200 carbon atoms), compact, and at least partially ionized. These properties predict a strong 8.6 feature. However, the 8.6 feature is weak or absent in all four sources, ruling out PAHs as the source of the aromatic emission. Instead, the emission must arise from the same carriers as the aliphatic emission. The position of the 6.9 feature and the broadened 11–14 out-of-plane emission independently support this. The and feature strengths vary across the sample, with the class D2 sources showing higher content. These carriers are far more aliphatic than the PAHs of planetary nebulae and the interstellar medium. However, they retain the aromatic skeleton that produces their aromatic features.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150154","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 potential contribution of radiative supernova remnants to the local cosmic ray spectrum","authors":"P. Cristofari,V. H. M. Phan,S. Recchia,S. Gabici","doi":"10.1051/0004-6361/202662838","DOIUrl":"https://doi.org/10.1051/0004-6361/202662838","url":null,"abstract":"Recent observations of very high-energy (VHE) gamma rays from massive stellar clusters and microquasars have demonstrated that these systems can efficiently accelerate particles to very high energies, renewing the debate on the dominant sources of Galactic cosmic rays (CRs) and casting further doubt on the role of supernova remnants (SNRs), long considered the prime candidates. In these astrophysical environments, particle acceleration is generally thought to be driven by diffusive shock acceleration (DSA). The question of the duration of the phase in which DSA can take place efficiently is therefore essential to clarify the contribution of the various candidate CR sources. We aim to clarify the contribution of SNRs to the Galactic CR spectrum and the expected efficiency of DSA, especially accounting for possible particle acceleration during part of the radiative phase. We compute the total CR proton content in typical SNRs from DSA and reaccelerated preexisting CRs, and discuss the importance of these two mechanisms throughout the adiabatic and early radiative phases. We find that if DSA and reacceleration occur during a fraction of the radiative phase, the total content of particles energized at SNRs can quickly overcome the typical budget required to account for the bulk of CRs. This suggests that the typical instantaneous efficiency, often defined as the fraction of fluid ram pressure converted into CRs, would need to remain below łesssim 1% for most of the SNR evolution. Moreover, the radiative phase can contribute to shaping the spectra injected from typical SNRs. We illustrate that the difference between SNRs from thermonuclear and core-collapse supernovae (SNe) could help account for the measured difference in the helium and proton of the local interstellar spectrum.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150157","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":"[CII] as a global cold gas tracer in novel hydrodynamical simulations","authors":"Valentina P. Miranda,Patricia B. Tissera,Jorge González-López,Emanuel Sillero","doi":"10.1051/0004-6361/202661156","DOIUrl":"https://doi.org/10.1051/0004-6361/202661156","url":null,"abstract":"̧ii emission is a powerful probe of the gas content in galaxies, especially at early stages of evolution. Given its low excitation potential, the ̧ii 158 μm line is the main coolant of neutral gas in photodissociation regions and giant molecular clouds, and hence a tracer of all phases of the interstellar medium. However, there is no consensus on the nature of the gas traced by this emission. We aim to provide insights into the physics of the ̧ii emission and predictions for future observations. We used four pre-prepared simulations performed with a version of which includes the ̨rome chemistry package. We implemented a post-processing semi-analytical model to simulate the ̧ii emission. We analysed an isolated Milky Way-mass-size galaxy, and three merger configurations: a co-rotating, counter-rotating, and perpendicular major merger of two Milky Way-mass-size galaxies. We reproduce fundamental relations such as the ̧ii luminosity and the star formation rate, łcii-SFR relation, in which mergers show an extra component for the ̧ii emission not traced by the star formation alone. During quiescent or starburst stages, galaxies deviate from the łcii-SFR relation. We find that in our simulations ̧ii is a robust tracer of molecular gas, as well as atomic gas in both cold and warm phases on a global scale. Our results indicate that around 50 percent of the total ̧ii emission is traced by molecular gas, while 30 to 40 percent is traced by atomic and ionised hydrogen regardless of the initial configuration of the merger simulation. Our findings suggest that the nature of the ̧ii emission depends strongly on the merger history of galaxies, in which mergers and starbursts can act as more efficient drivers of ̧ii emission through collisions with molecular hydrogen.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2017 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150158","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":"Orbital and stellar parameter determination of eclipsing β Cep pulsators","authors":"C. I. Eze,G. Handler,F. Kahraman Ali̧cavus,T. Pawar,P. De Cat","doi":"10.1051/0004-6361/202658934","DOIUrl":"https://doi.org/10.1051/0004-6361/202658934","url":null,"abstract":"Eclipsing binaries are veritable laboratories for the study of stellar structure and evolution. The dynamical properties (e.g. mass and radius) inferred from eclipsing binary modelling coupled with asteroseismic masses offer a unique opportunity to probe stellar evolution models. Spectroscopy characterises the stellar envelope and plays a key role in estimating more accurate dynamical parameters, as it provides invaluable priors for eclipsing light curve modelling. In this study, thirteen eclipsing binaries with massive primary components were spectroscopically and photometrically analysed to derive the orbital and stellar parameters and infer their possible evolutionary status. The systems were spectroscopically observed using SALT HRS, HERMES, CHIRON, and a spectrograph at Skalnate Pleso Observatory, as well as photometrically observed using TESS. Radial velocities and atmospheric parameters were determined; binary systems were modelled; and their absolute parameters were derived using appropriate modelling tools. The rotational properties, circularisation, and synchronisation of the systems were also investigated, and the general properties of the sample are discussed in this paper. The sample shows one slow rotator, two circularised and synchronised fast rotating systems, as well as five circular and five eccentric systems with asynchronous fast rotation. The systems are predominantly either single- or double-lined spectroscopic binaries with faint companions, resulting in dynamical mass estimates at 5 -- 12% precision and radius estimates at 1.5 -- 3.9% precision. The secondary components appear to cut across a wide mass spectrum ranging from low- to intermediate-mass systems. The eccentricity of the systems exhibits certain trends with the projected rotational velocity (v i), although no universal correlation exists between them. Also, there could be circularisation without co-rotation or synchronisation even for circularised short-period close binary systems.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"38 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150159","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":"How much gas and dust is in the z=5.7 Lyman-break galaxy HZ10? ALMA Bands 10 to 4 and JWST/NIRSpec study of its interstellar medium","authors":"H. S. B. Algera,R. Herrera-Camus,M. Aravena,R. J. Assef,T. L. J. C. Bakx,A. Bolatto,K. Cescon,C.-C. Chen,E. da Cunha,P. Dayal,I. De Looze,T. Diaz-Santos,A. Faisst,A. Ferrara,N. Förster Schreiber,N. Hathi,R. Ikeda,H. Inami,G. C. Jones,A. Koekemoer,D. Lutz,M. Relaño,M. Romano,L. Rowland,L. Sommovigo,L. Vallini,A. Vijayan,V. Villanueva,P. van der Werf","doi":"10.1051/0004-6361/202558319","DOIUrl":"https://doi.org/10.1051/0004-6361/202558319","url":null,"abstract":"A complete overview of the stellar, gas and dust contents of galaxies is key to understanding their assembly at early times. However, an estimation of molecular and atomic gas reservoirs at high redshift relies on various indirect tracers, while robust dust mass measurements require multiband far-infrared continuum observations. We present a census of the full baryonic content of the main sequence star-forming galaxy HZ10 at z=5.65, a unique case study where all the necessary tracers are available. We used new ALMA Band 10 (λ_ ̊m rest m ) and Band 4 ( observations toward HZ10, combined with data previously taken in ALMA Bands 6 through 9 (approx70 - 200,μ ) to constrain its dust properties. We complete the baryonic picture using archival high-resolution observations that provide both a dynamical mass and molecular and atomic gas mass estimates, a JVLA CO(2-1)-based molecular gas mass, and JWST metallicity and stellar mass measurements. m We detected continuum emission from HZ10 in Bands 10 and 4 at the 3.4-4.0σ level. We measured a dust temperature of T_ = 37_ dust -5 ^ +6 ,K and dust mass of łog(M_ /M_⊙) = 8.0 ± 0.1. By leveraging the dynamical constraints, we were able to infer its total gas budget. We find that commonly used -to-H_2 and -to-HI conversions might overpredict the gas mass relative to the dynamical mass. For this reason, we derived a -to-total-ISM mass (atomic + molecular) conversion factor. For HZ10, this corresponds to α_ dust ̊m CII ^ ̊m ISM = 38^ +28 _ -26 M_⊙ L_⊙^ -1 . We also found that HZ10 falls below the local scaling relation between the dust-to-gas ratio and metallicity, suggesting inefficient ISM dust growth. These results demonstrate a powerful synergy between ALMA and JWST in disentangling the baryonic components of early galaxies, paving the way for future studies of larger samples to dynamically calibrate -to-gas mass conversion factors and further unravel the pathways of early dust buildup.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"80 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149149910","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":"Novel geometrical test of cosmological expansion from photometric data","authors":"David Touzeau,Francis Bernardeau,Karim Benabed,Sandrine Codis","doi":"10.1051/0004-6361/202660556","DOIUrl":"https://doi.org/10.1051/0004-6361/202660556","url":null,"abstract":"In tomographic cosmic-shear observations, the Bernardeau, Nishimichi, Taruya (BNT) transform allows us to build weak lensing transformed maps for which the contribution from low-redshift lenses is nulled. As this transformation depends specifically on the expansion rate of the Universe and is independent of the matter distribution properties, it can be leveraged to extract information from large-scale structure probes at arbitrary non-linear scales. Thus, it provides constraints on cosmological background evolution. We demonstrate the applicability of the BNT transform as a probe by designing a null test and evaluating its performance for Stage IV weak lensing projects. Using a Fisher matrix analysis combined with parameter sampling, we show that this approach can significantly enhance constraints on the dark energy equation of state. In such surveys, apart from photometric redshifts uncertainties, performance is expected to be limited primarily by shape noise, rather than cosmic variance, making substantial improvements possible thanks to better designed surveys in the future.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"22 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150160","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":"Water abundance and the ortho-para ratio in the S140 photon -dominated region","authors":"Dariusz C. Lis,Sofia Lawsky,Emeric Bron,Franck Le Petit,Javier R. Goicoechea","doi":"10.1051/0004-6361/202660898","DOIUrl":"https://doi.org/10.1051/0004-6361/202660898","url":null,"abstract":"We analyzed archival far-infrared to submillimeter Herschel PACS, SPIRE, and HIFI spectroscopic observations of the S140 photon-dominated region (PDR) to constrain the water vapor abundance and the ortho-para ratio in this region. Toward the high-mass protostar IRS1, 52 spectral lines, including 15 water lines, are detected with the PACS and SPIRE instruments. The PDR modeling suggests a UV radiation field G_0 ≃ 1 in this region. The models strongly underestimate the intensities of the high-J CO lines, which might indicate the presence of hot shocked gas associated with outflows along the line of sight, in addition to the UV irradiated gas. The spectral resolution of the PACS and SPIRE spectrometers is insufficient to separate the PDR and shock contributions. The PDR models further suggest that optically thick ground-state water lines primarily trace the surface layers of the PDR. The gas temperature in this region is predicted to be ∼ 800 K, and the water abundance with respect to hydrogen nuclei reaches ∼ 10^ 10^3 Habing units and a thermal gas pressure of 5 10^8 K,cm -3 -5 . However, the bulk of the gas-phase water is located in a more shielded region, deeper inside the PDR, with a gas temperature of ∼ 24 K and a gas-phase H_2O abundance of ∼ 10^ -7 . A comparison of the observed water line fluxes toward IRS1 with PDR model predictions shows no evidence of departures from the local thermal equilibrium ortho-para ratio at the local gas temperature that is assumed in the models. The sensitivity of the Herschel instruments was insufficient to measure the water ortho-para ratio toward the externally illuminated edge-on PDR at the surface of the S140 molecular cloud. Such observations will be possible with the next generation far-infrared spectroscopic space missions currently in development.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"466 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149149950","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":"UX Men: Detached eclipsing binary as a benchmark candidate","authors":"G. N. Pawar,K. G. Hełminiak,N. J. Miller,F. Marcadon,A. Moharana,T. B. Pawar,A. Kalsi,M. Konacki","doi":"10.1051/0004-6361/202659300","DOIUrl":"https://doi.org/10.1051/0004-6361/202659300","url":null,"abstract":"Detached eclipsing binaries (DEBs) provide model‑independent measurements of stellar masses and radii, which are essential for testing stellar‑evolution models and calibrating space‑based photometric missions. We aim to deliver ultra-precise fundamental parameters for the DEB UX Men and to assess its suitability as a benchmark for upcoming missions such as . We evaluate the temporal stability of the photometric solutions and the way intrinsic stellar variability and instrumental systematics affect the derived parameters. PLATO We analysed 31 TESS sectors ( 882 d) with the lightkurve package, and detrended spot‑induced variability. Light‑curve modelling was performed independently with jktebop and allesfitter . Radial velocities from HARPS (HAM/EGGS), FEROS, CORALIE, and UCLES were extracted via todcor and fitted with a Keplerian orbit. Spectral disentangling (5350–5800 Å) yielded individual component spectra, which were processed with ispec to determine , mathrm M/H , and micro‑ and macroturbulence. Eclipse‑timing variations were examined through O-C diagrams. We also used multi-band photometry to determine the fluxes, flux ratios, and ultimately, to measure the photometric . We obtained masses of M_̊m A = 1.2300 M_⊙, M_̊m B = 1.1946 _ 0.0012 M_⊙ and radii of R_̊m A = 1.3605 = 0.02 $ dex and $ R_⊙, R_̊m B = 1.2801 _ R_⊙, with a sub-percent precision. Uncertainties were found to be dominated by systematic effects coming from (weak) stellar activity. The metallicity estimates are $ M/H ̊m A 0.13 M/H ̊m B = 0.07 $ dex. An isochrone fitting yielded a consistent age of τ = 2.75 0.10 Gyr. The system exhibits a 673-day periodicity in eclipse‑timing variations, likely due to stellar activity, with no evidence of a third body. UX Men is a high‑precision benchmark binary, providing stringent tests of stellar models and a robust calibration source for PLATO ’s determination of stellar and exoplanet properties. We found no dependence between the results and the specific code that was employed. However, without a proper treatment of systematics caused by activity, the uncertainties would end up underestimated. Expanding the sample of similarly well‑characterised DEBs will further strengthen the empirical foundation for stellar physics and improve the calibration of future photometric missions.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"26 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149149908","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":"Wolf-Rayet formation through L/M-dependent superwinds","authors":"Aisling McKeown,Ciarán Furey,Gautham N. Sabhahit,Jorick S. Vink","doi":"10.1051/0004-6361/202661554","DOIUrl":"https://doi.org/10.1051/0004-6361/202661554","url":null,"abstract":"̊m M _⊙ - 40, ̊m M _⊙, using the RSG L/M recipe and traditional mass-loss prescriptions. Independent of the treatment of the stellar envelope, we find for a 25$, VS23 ̊m M _⊙$ star that the L/M recipe reaches an order of magnitude higher mass-loss rate than traditional recipes due to its inverse mass dependence. As the RSG luminosity is set by the core mass and becomes largely insensitive to the current stellar mass, this creates a positive feedback loop driving runaway envelope stripping. Consequently, stars with an initial mass M_ ̊m init ∼ ,20, ̊m M _⊙ are able to strip their hydrogen envelope and form classical Wolf-Rayet (WR) stars. We draw this conclusion not solely on the basis of their HRD location, but also on their predicted emission-line spectrum that we compute with the PoWR stellar atmosphere code. Stars with M_ ̊m init <20, ̊m M _⊙ do not fully strip, meaning they expand after core helium burning. In Appendix A we present a generic analytical model showing that the tendency for runaway stripping increases rapidly with the strength of the inverse mass-loss scaling with mass. Our models demonstrate a viable single-star pathway into the yellow supergiant and WR regimes. The amounts of full and partial stripping have a direct effect on supernova (SN) progenitors, including partially stripped type IIb SNe.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"66 2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149149913","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}