Astronomy & Astrophysics最新文献

{"title":"Dancing on the grain: Variety of CO and its isotopologue fluxes as a result of surface chemistry and T Tauri disk properties","authors":"L. Zwicky, T. Molyarova, Á. Kóspál, P. Ábrahám","doi":"10.1051/0004-6361/202453529","DOIUrl":"https://doi.org/10.1051/0004-6361/202453529","url":null,"abstract":"<i>Context.<i/> One of the most important problems in the study of protoplanetary disks is the determination of their parameters, such as their size, age, stellar characteristics, and, most importantly, gas mass in the disk. At the moment, one of the main ways to infer the disk mass is to use a combination of CO isotopologue line observations. A number of theoretical studies have concluded that CO must be a reliable gas tracer, as its relative abundance only depends weakly on disk parameters. However, the observed line fluxes cannot always be easily used to infer the column density, much less the abundance of CO.<i>Aims.<i/> The aim of this work is to study the dependence of the CO isotopologue millimeter line fluxes on the astrochemical model parameters of a standard protoplanetary disk around a T Tauri star and to conclude whether they can be used individually or in combinations to reliably determine the disk parameters. Our case is set apart from earlier studies in the literature by the adoption of a comprehensive chemical network with grain-surface chemistry, together with line radiative transfer.<i>Methods.<i/> We used the astrochemical model ANDES together with the radiative transfer code RADMC-3D to simulate CO isotopologue line fluxes from a set of disks with varying key parameters (disk mass, disk radius, stellar mass, and inclination). We studied how these values change with one parameter varying and others fixed and approximated the dependences log-linearly.<i>Results.<i/> We described the dependences of CO isotopologue fluxes on all chosen disk parameters. Physical and chemical processes responsible for these dependences are analyzed and explained for each parameter. We show that using a combination of the <sup>13<sup/>CO and C<sup>18<sup/>O line fluxes, the mass can be estimated only within two orders of magnitude uncertainty and a characteristic radius with an uncertainty of one order of magnitude. We find that the inclusion of the grain-surface chemistry reduces <sup>13<sup/>CO and C<sup>18<sup/>O fluxes, which can help explain the underestimation of disk mass in the previous studies.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685153","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 effects of the orbital configurations of mergers on reshaping galaxy structures","authors":"Xinyi Wu, Ling Zhu, Jiang Chang, Guangquan Zeng, Yu Lei","doi":"10.1051/0004-6361/202554638","DOIUrl":"https://doi.org/10.1051/0004-6361/202554638","url":null,"abstract":"We performed a systematic analysis of how the orbital configuration of a merger can influence the structural formation of remnant galaxies using 531 merger pairs selected from IllustrisTNG-100. We comprehensively described the merger orbital configuration, considering the relative orbital motion of the merger pair and their disk orientations. We quantified the galaxy structures by dynamically defining four components: bulge, disk, warm component, and hot inner stellar halo. For mergers on spiral-in orbits, the disk planes of the two merging galaxies tend to be aligned with the orbital plane, leading to higher fractions for the disk and warm components, as well as lower fractions for the bulge and hot inner stellar halo components in the remnant galaxy. For mergers on direct collision orbits, the disk planes of the two galaxies tend to be perpendicular to the orbital plane, leading to lower fractions for disk and warm components, as well as higher fractions of the bulge and hot inner stellar halo in the remnant. Mergers can lead to either an increase or decrease in the disk and bulge mass fraction in the remnant compared to the progenitor galaxy, depending on the merger orbital configurations; however, in 93% of cases, mergers cause an increase in the hot inner stellar halo. As a result, the luminosity fraction of the hot inner stellar halo (but not the bulge) in galaxies at <i>z<i/> = 0 is highly correlated with its total ex situ stellar mass. In addition, we find that merger on spiral-in orbits is one of the possible reasons for the formation of recently discovered red but H I-rich (RR) galaxies.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"27 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685168","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":"Presenting 28 years of Sun-as-a-star extreme ultraviolet light curves from SOHO EIT","authors":"Emily Sandford, Frédéric Auchère, Annelies Mortier, Laura A. Hayes, Daniel Müller","doi":"10.1051/0004-6361/202554946","DOIUrl":"https://doi.org/10.1051/0004-6361/202554946","url":null,"abstract":"&lt;i&gt;Context.&lt;i/&gt; The Solar and Heliospheric Observatory (SOHO) Extreme-ultraviolet Imaging Telescope (EIT) has been taking images of the solar disk and corona in four narrow extreme ultraviolet (EUV) bandpasses (171 Å, 195 Å, 284 Å, and 304 Å) at a minimum cadence of once per day since early 1996. The time series of fully calibrated EIT images now spans approximately 28 years, from early 1996 to early 2024, covering solar cycles 23 and 24 in their entirety, as well as the beginning of cycle 25.&lt;i&gt;Aims.&lt;i/&gt; We aim to convert this extensive EIT image archive into a set of “Sun-as-a-star” light curves in EIT's four bandpasses, observing the Sun as if it were a distant point source viewed from a fixed perspective.&lt;i&gt;Methods.&lt;i/&gt; To construct the light curves, we summed the flux in each EIT image into one flux value, with an uncertainty accounting for both the background noise in the image and the potential spillover of flux beyond the bounds of the image (which is especially important for the bands with significant coronal emission). We corrected for long-term instrumental systematic trends in the light curves by comparing our 304 Å light curve to the ultraviolet light curve taken by SOHO's CELIAS/SEM solar wind monitoring experiment, which has a very similar bandpass to the EIT 304 Å channel. We corrected for SOHO's viewing angle by fitting a trend to the flux values with respect to SOHO's heliocentric latitude at the time of each observation.&lt;i&gt;Results.&lt;i/&gt; We produced two sets of Sun-as-a-star light curves with different uncertainty characteristics, available for download from Zenodo, either of which might be preferred for different types of future analyses. In version (1), we treated the EIT instrumental systematics consistently across the entire SOHO mission lifetime, producing a light curve with approximately homoscedastic uncertainties. In version (2), we only divided out the EIT instrumental systematics from November 12, 2008, onward; this is the point at which these systematics start to have a noticeable deleterious effect on the data. Therefore, version (2) has heteroscedastic uncertainties, but these uncertainties are much smaller than the version (1) uncertainties over the first half of the mission.&lt;i&gt;Conclusions.&lt;i/&gt; We find that our EUV light curves trace the Sun's ∼11-year solar activity cycle and ∼27-day rotation period much better than comparable optical observations. In particular, we can accurately recover the solar rotation period from our 284 Å light curve for 26 out of 28 calendar years of EIT observations (93% of the time), compared to only 3 out of 29 calendar years (10% of the time) for the VIRGO total solar irradiance time series, which is dominated by optical light. Our EIT light curves, in conjunction with Sun-as-a-star light curves at optical wavelengths, will be valuable to those interested in inferring the EUV/UV character of stars with long optical light curves, but no intensive UV observations, as well as to those inte","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"20 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685175","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":"Polar faculae and their relationship to the solar cycle","authors":"Antonio Reche, Adur Pastor Yabar, Ana Belén Griñón-Marín","doi":"10.1051/0004-6361/202554578","DOIUrl":"https://doi.org/10.1051/0004-6361/202554578","url":null,"abstract":"<i>Context.<i/> The study of magnetic activity in the Sun's polar regions is essential for understanding the solar cycle. However, measuring polar magnetic fields presents challenges due to projection effects and their intrinsically weak magnetic field strength. Faculae, bright regions on the visible solar surface associated with increased magnetic activity, offer a valuable proxy for measuring polar fields.<i>Aims.<i/> This research aims to analyze the magnetic activity of the Sun's polar regions through the use of polar faculae.<i>Methods.<i/> A neural network model (U-Net) was employed to detect polar faculae in images from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). The model was trained on synthetic data, eliminating the need for manual labeling, and was used to analyze 14 years of data from May 2010 to May 2024.<i>Results.<i/> The U-Net model demonstrates superior performance and efficiency over existing methods, enabling automated large-scale studies. We find that polar faculae numbers exhibit cyclical behavior with distinct minima and maxima, showing similar patterns between poles but with notable temporal delays (south pole: minimum early 2014, maximum late 2016; north pole: minimum late 2014, maximum mid-2019). Polar faculae magnetic fields remain consistent in magnitude (∼±75 G) across both poles and throughout the solar cycle. A strong linear correlation was found between the polar faculae count and the overall polar magnetic field strength. The spatio-temporal evolution reveals systematic migration of field polarity reversals from mid-latitudes toward the poles at rates of 3−8 m/s. During solar minimum, we observe a small relative increase in stronger-field faculae compared to solar maximum, suggesting either the coexistence of two magnetic distributions or subtle solar cycle dependence in faculae properties.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"212 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685150","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":"Inner disc and circumplanetary material in the PDS 70 system: Insights from multi-epoch, multi-frequency ALMA observations","authors":"D. Fasano, M. Benisty, P. Curone, S. Facchini, F. Zagaria, T. C. Yoshida, K. Doi, A. Sierra, S. Andrews, J. Bae, A. Isella, N. Kurtovic, L. M. Pérez, P. Pinilla, L. Rampinelli, R. Teague","doi":"10.1051/0004-6361/202554959","DOIUrl":"https://doi.org/10.1051/0004-6361/202554959","url":null,"abstract":"<i>Context<i/>. The two giant protoplanets directly detected in the dust-depleted cavity of PDS 70 offer a unique opportunity to study the processes of ongoing planet formation. The planets have been detected both in IR thermal light and in the H<i>α<i/> line, indicating that they are actively accreting material from their surroundings.<i>Aims<i/>. We calibrated and analysed archival Atacama Large Millimeter/subMillimeter Array (ALMA) band 6 and 7 observations of PDS 70 to detect circumplanetary material in independent datasets taken at different epochs in 2019, 2021, and 2023 and assess its possible motion.<i>Methods<i/>. We performed 2D visibility modelling of the high-resolution ALMA band 6 (∼0.11<sup>′′<sup/> × 0.08<sup>′′<sup/>) and band 7 (∼0.05<sup>′′<sup/> × 0.05<sup>′′<sup/>) dust continuum emission of the outer disc. After subtracting the model from the data, we imaged the dust continuum emission in the cavity of PDS 70 at multiple epochs.<i>Results<i/>. We re-detect the compact dust emission around PDS 70 c in all our datasets in band 6 and 7, with a more than 3.8<i>σ<i/> significance, and tentatively detect compact emission around PDS 70 b at ∼3<i>σ<i/> in the band 6 datasets, with a peak emission of 59 ± 17 μJy/beam and 46 ± 14 μJy/beam. We find the astrometric relative position of the compact emission around PDS 70 c to be consistent with the expected position of the planet in the 2019–2023 time range. We measure a peak flux difference of up to 64 ± 34 μJy/beam at a 1<i>σ<i/> confidence level for the continuum emission coming from the region around PDS 70 c and perform a Bayesian test on our measurements, finding that they are not consistent with significant variable emission. We find no evidence of flux variability in the inner disc. We measure the dust mass of the material co-located with PDS 70 c and the inner disc to be in the range of 0.008−0.063 <i>M<i/><sub>⊕<sub/> and 0.04−0.31 <i>M<i/><sub>⊕<sub/>, respectively, consistent with previous measurements. Additionally, we obtain band 6–7 spectral indices of 2.5 ± 1.2 and 3.2 ± 0.5 for the dust emission around PDS 70 c and in the inner disc, respectively, suggesting the inner disc emission is dominated by optically thin dust.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"113 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685172","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":"Dust removal timescale in galaxies across cosmic time","authors":"A. Leśniewska, J. Hjorth, C. Gall","doi":"10.1051/0004-6361/202555007","DOIUrl":"https://doi.org/10.1051/0004-6361/202555007","url":null,"abstract":"Understanding the evolution of dust in galaxies is crucial because it affects the dynamics and cooling of gas, star formation, and chemical evolution. Recent work on dust removal in galaxies indicates timescales of gigayears, with old stellar populations and active galactic nuclei the primary drivers of this process. However, most statistically significant studies have focused on low redshifts, <i>z<i/><0.4. Here we determine the dust removal timescale in galaxies over a wide range of redshifts, up to <i>z<i/>∼5. We used publicly available catalogue data of infrared-selected galaxies observed by <i>Herschel<i/>. Using the inferred dust masses, stellar masses, and stellar ages, we calculated the dust removal timescale in a sample of more than 120 000 galaxies. We find that, with increasing redshift, the dust removal timescale decreases from 1.8 Gyr at redshift <i>z<i/>∼0.05 to less than 450 Myr at <i>z<i/>>3. Galaxies at higher redshifts undergo more efficient dust removal than galaxies at lower redshifts, likely driven by active galactic nucleus activity, supernova shocks, and astration. These findings indicate that dust removal evolves over cosmic time, reflecting the changing mechanisms regulating the dust content of galaxies as the Universe evolves.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"710 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685165","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 HI-to-H2 transition in the Draco cloud","authors":"Nicola Schneider, Volker Ossenkopf-Okada, Markus Röllig, Daniel Seifried, Ralf S. Klessen, Alexei G. Kritsuk, Eduard Keilmann, Simon Dannhauer, Lars Bonne, Simon C. O. Glover","doi":"10.1051/0004-6361/202555308","DOIUrl":"https://doi.org/10.1051/0004-6361/202555308","url":null,"abstract":"In recent decades, significant attention has been dedicated to analytical and observational studies of the atomic hydrogen (H I) to molecular hydrogen (H<sub>2<sub/>) transition in the interstellar medium. We focussed on the Draco diffuse cloud to gain deeper insights into the physical properties of the transition from H I to H<sub>2<sub/>. We employed the total hydrogen column density probability distribution function (N-PDF) derived from <i>Herschel<i/> dust observations and the N<sub>HI<sub/>-PDF obtained from H I data collected by the Effelsberg H I survey. The N-PDF of the Draco cloud exhibits a double-log-normal distribution, whereas the N<sub>HI<sub/>-PDF follows a single log-normal distribution. The H I-to-H<sub>2<sub/> transition is identified as the point where the two log-normal components of the dust N-PDF contribute equally; it occurs at A<sub>V<sub/> ~ 0.33 (N ~ 6.2 × 10<sup>20<sup/> cm<sup>−2<sup/>). The low-column-density segment of the dust N-PDF corresponds to the cold neutral medium, which is characterized by a temperature of around 100 K. The higher-column-density part is predominantly associated with H<sub>2<sub/>. The shape of the Draco N-PDF is qualitatively reproduced by numerical simulations. In the absence of substantial stellar feedback, such as radiation or stellar winds, turbulence exerts a significant influence on the thermal stability of the gas and can regulate the condensation of gas into denser regions and its subsequent evaporation. Recent observations of the ionized carbon line at 158 μm in Draco support this scenario. Using the KOSMA-tau photodissociation model, we estimate a gas density of n ~50 cm<sup>−3<sup/> and a temperature of ~100 K at the location of the H I-to-H<sub>2<sub/> transition. Both the molecular and atomic gas components are characterized by supersonic turbulence and strong mixing, suggesting that simplified steady-state chemical models are not applicable under these conditions.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"113 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685167","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 PICS Project","authors":"Lucas M. Valenzuela, Marcelo M. Miller Bertolami, Rhea-Silvia Remus, Roberto H. Méndez","doi":"10.1051/0004-6361/202553974","DOIUrl":"https://doi.org/10.1051/0004-6361/202553974","url":null,"abstract":"<i>Context.<i/> Planetary nebulae (PNe) and their luminosity function (PNLF) in galaxies have been used as a cosmic distance indicator for decades, yet a fundamental understanding is still lacking to explain the universality of the PNLF among different galaxies. So far, models for the PNLF have generally assumed near-solar metallicities and employed simplified stellar populations.<i>Aims.<i/> In this work, we investigate how metallicity and helium abundances affect the resulting PNe and PNLF as well as the importance of the initial-to-final mass relation (IFMR) and circumnebular extinction in order to resolve the tension between PNLF observations and previous models.<i>Methods.<i/> We introduce PICS (PNe In Cosmological Simulations), a PN model framework that takes into account the stellar metal-licity and is applicable to realistic stellar populations obtained from both cosmological simulations and observations. The framework combines current stellar evolution models with post-AGB tracks and PN models to obtain the PNe from the parent stellar population.<i>Results.<i/> We find that metallicity plays an important role for the resulting PNe, as old metal-rich populations can harbor much brighter PNe than old metal-poor populations. In addition, we show that the helium abundance is a vital ingredient at high metallicities, and we explored the impact on the PNLF of a possible saturation of the helium content at higher metallicities. We present PNLF grids for different stellar ages and metallicities, where the observed PNLF bright end can be reached even for old stellar populations of 10 Gyr at high metallicities. Finally, we find that the PNLFs of old stellar populations are extremely sensitive to the IFMR, potentially allowing for the production of bright PNe.<i>Conclusions.<i/> With PICS, we have laid the groundwork for studying how models and assumptions relevant to PNe affect the PNe and PNLF. Two of the central ingredients for the PNe and PNLF are the metallicity and helium abundance. Future applications of PICS include self-consistent modeling of PNe in a cosmological framework to explain the origin of the universality of the PNLF bright-end cutoff and using it as a diagnostic tool for galaxy formation.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"115 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685157","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 EDGE-CALIFA Survey: An integral field unit-based integrated molecular gas database for galaxy evolution studies in the Local Universe","authors":"D. Colombo, V. Kalinova, Z. Bazzi, S. F. Sanchez, A. D. Bolatto, T. Wong, V. Villanueva, N. Mudivarthi, E. Rosolowsky, A. Weiß, K. D. French, A. Leroy, J. Barrera-Ballesteros, Y. Garay-Solis, F. Bigiel, A. Tripathi, B. Rodriguez","doi":"10.1051/0004-6361/202453179","DOIUrl":"https://doi.org/10.1051/0004-6361/202453179","url":null,"abstract":"Studying galaxy evolution requires knowledge not only of the stellar properties, but also of the interstellar medium (in particular the molecular phase) out of which stars form, using a statistically significant and unbiased sample of galaxies. To this end, we introduce here the integrated Extragalactic Database for Galaxy Evolution (iEDGE), a collection of integrated stellar and nebular emission lines, and molecular gas properties from 643 galaxies in the local Universe. These galaxies are drawn from the CALIFA datasets, and are followed up in CO lines by the APEX, CARMA, and ACA telescopes. As this database is assembled from data coming from a heterogeneous set of telescopes (including IFU optical data and single-dish and interferometric CO data), we adopted a series of techniques (tapering, spatial and spectral smoothing, and aperture correction) to homogenise the data. Due to the application of these techniques, the database contains measurements from the inner regions of the galaxies and for the full galaxy extent. We used the database to study the fundamental star formation relationships between star formation rate (SFR), stellar mass (<i>M<i/><sub>*<sub/>), and molecular gas mass (<i>M<i/><sub>mol<sub/>) across galaxies with different morphologies. We observed that the diagrams defined by these quantities are bi-modal, with early-type passive objects well separated from spiral star-forming galaxies. Additionally, while the molecular gas fraction (<i>f<i/><sub>mol<sub/> = <i>M<i/><sub>mol<sub/>/<i>M<i/><sub>*<sub/>) decreases homogeneously across these two types of galaxies, the star formation efficiency (SFE=SFR/<i>M<i/><sub>mol<sub/>) in the inner regions of passive galaxies is almost two orders of magnitude lower compared to the global values. This indicates that inside-out quenching requires not only low <i>f<i/><sub>mol<sub/>, but also strongly reduced SFE in the galactic centres.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"27 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685149","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":"HOLISMOKES","authors":"S. Schuldt, R. Cañameras, Y. Shu, I. T. Andika, S. Bag, C. Grillo, A. Melo, S. H. Suyu, S. Taubenberger","doi":"10.1051/0004-6361/202554425","DOIUrl":"https://doi.org/10.1051/0004-6361/202554425","url":null,"abstract":"We have carried out a systematic search for galaxy-scale lenses exploiting multiband imaging data from the third public data release of the Hyper Suprime-Cam (HSC) survey with the focus on false-positive removal, after applying deep learning classifiers to all ~110 million sources with an <i>i<i/>-Kron radius above 0<i>.\"<i/>8 . To improve the performance, we tested the combination of multiple networks from our previous lens search projects and found the best performance by averaging the scores from five of our networks. Although this ensemble network leads already to a false-positive rate of ~0.01% at a true-positive rate (TPR) of 75% on known real lenses, we have elaborated techniques to further clean the network candidate list before visual inspection. In detail, we tested the rejection using SExtractor and the modeling network from HOLISMOKES IX, which resulted together in a candidate rejection of 29% without lowering the TPR. After the initial visual inspection stage to remove obvious non-lenses, 3408 lens candidates of the ~110 million parent sample remained. We carried out a comprehensive multistage visual inspection involving eight individuals and identified finally 95 grade A (average grade <i>G<i/> ≥ 2.5) and 503 grade B (2.5> <i>G<i/> ≥ 1.5) lens candidates, including 92 discoveries showing clear lensing features that are reported for the first time. This inspection also incorporated a novel environmental characterization using histograms of photometric redshifts. We publicly release the average grades, mass model predictions, and environment characterization of all visually inspected candidates, while including references for previously discovered systems, which makes this catalog one of the largest compilation of known lenses. The results demonstrate that (1) the combination of multiple networks enhances the selection performance and (2) both automated masking tools as well as modeling networks, which can be easily applied to hundreds of thousands of network candidates expected in the near future of wide-field imaging surveys, help reduce the number of false positives, which has been the main limitation in lens searches to date.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"115 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685169","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}