Astronomy & Astrophysics最新文献

{"title":"Fundamental relation in isolated galaxies, pairs, and triplets in the local Universe","authors":"M. Argudo-Fernández, S. Duarte Puertas, S. Verley","doi":"10.1051/0004-6361/202348724","DOIUrl":"https://doi.org/10.1051/0004-6361/202348724","url":null,"abstract":"<i>Context.<i/> The correlations between star formation rate (SFR), stellar mass (M<sub>⋆<sub/>), and gas-phase metallicity for star-forming (SF) galaxies, known as global scaling relations or fundamental relations, have been studied during the past decades to understand the evolution of galaxies. However, the origin of these correlations and their scatter, which may also be related to their morphology or environment, is still a subject of debate.<i>Aims.<i/> In this work, we establish fundamental relations, for the first time, in isolated systems in the local Universe (with 0.005 ≤ <i>z<i/> ≤ 0.080), which can give insight into the underlying physics of star formation. We used a sample of isolated galaxies to explore whether star formation is regulated by smooth secular processes. In addition, galaxies in physically bound isolated pairs and isolated triplets may also interact with each other, where interaction itself may enhance or regulate star formation and the distribution of gas and metals within galaxies.<i>Methods.<i/> We made use of published emission line flux information from the Sloan Digital Sky Survey (SDSS) to identify SF galaxies in the SDSS-based catalogue of isolated galaxies (SIGs), isolated pairs (SIPs), and isolated triplets (SITs). We also used these data to derive their aperture-corrected SFR (considering two different methods) and oxygen abundance, 12 + log(O/H), using bright line calibrations. Stellar masses for SIG, SIP, and SIT galaxies were estimated by fitting their spectral energy distribution on the five SDSS bands.<i>Results.<i/> The SFR results found using both methods seem to be consistent. We compared our results with a sample of SF galaxies in the SDSS. We found that, on average, at a fixed stellar mass, the SIG SF galaxies have lower SFR values than Main Sequence (MS) SF galaxies in the SDSS and central galaxies in the SIP and SIT. On average, SIG galaxies have higher 12 + log(O/H) values than galaxies in the SIP, SIT, and comparison sample. When distinguishing between central and satellite galaxies in the SIP and SIT, centrals and SIG galaxies present similar values (∼8.55), while satellites have values close to M33 (∼8.4). Using the <i>D<i/><sub><i>n<i/><sub/>(4000) parameter as a proxy of the age of the stellar populations, we found that, on average, SIG and central galaxies have higher <i>D<i/><sub><i>n<i/><sub/>(4000) values than satellites and comparison galaxies.<i>Conclusions.<i/> In general SIG galaxies do not present stellar starbursts produced by interactions with other galaxies, and therefore their gas is consumed more slowly and at a regular pace. On the contrary, SIP and SIT galaxies present higher SFR values at fixed mass (both in central and satellite galaxies). Therefore, the effect of adding one or two companion galaxies is noticeable and produces a similar effect as the typical average environment around galaxies in the local Universe. The successive interactions between the galaxies that for","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143712934","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 influence of stellar activity on detecting Earth-like planets via nulling interferometry","authors":"Rui-Si Zhou, Hui-Gen Liu, Li-Yong Zhou","doi":"10.1051/0004-6361/202452725","DOIUrl":"https://doi.org/10.1051/0004-6361/202452725","url":null,"abstract":"<i>Context.<i/> To investigate the influence of stellar activities on the detection of Earth-like planets via the nulling interferometer, we aim to estimate the signal-to-noise ratio (S/N) values of Earth-like planets around typical dwarf stars G and M, with different stellar activities. We also study the fitted accuracy of the planetary locations with different S/N values, which is crucial to evaluating the possibility of a planet in the habitable zone (HZ).<i>Aims.<i/> The direct imaging of Earth-like planets in solar neighbors is challenging. Both transit and radial velocity (RV) methods suffer from noise due to stellar activity. Here, we focus on the differential nulling interferometer with an X configuration and examine whether stellar activities are likely to influence the detection of planets in the HZ and the location accuracy. We aim to provide a basis for selecting target stars according to their specific activity levels for future interferometer observatories in space.<i>Methods.<i/> By choosing a typical configuration of an X array interferometer, we used theoretical formulas to calculate the intrinsic Poisson noise and the noise of stellar activities. Assuming a fixed array with no rotation and ignoring other systematic and astrophysical noises, we considered a single active region on a stellar disk, including both spots and flares with different parameters, for instance, the position, size, and temperature of the active regions. Then we simulated the S/N of Earth-like planets in HZ around G dwarf stars (solar-like) and M dwarfs (Proxima-like), with different stellar activities in the mid-infrared (MIR) band (7–12 µm). Furthermore, we used analytic and numerical ways to investigate the influence on the determination of the planet’s location, based on the deduced S/N caused by the stellar activity.<i>Results.<i/> The noise attributed to stellar activity has much less of an influence than the TV and RV when attempting to detect Earthlike planets around both G and M dwarfs. Stellar activity may hardly influence the detection of Earth-like planets around G dwarf stars, with a S/N exceeding 10 for both flares and spots even when the active region reaches three times Jupiter’s radius. However, detecting Earth-like planets around M dwarfs, which are usually more active, can be significantly hindered. If the stellar activity is violent enough, the S/N can drop below 5 for both flares and spots when the active region is as large as three times Jupiter’s radius. We also analyzed the uncertainty of the planet’s location due to the deduced S/N. Consequently, we have determined the possibility of mistaking a planet in the HZ as being outside the HZ based on an erroneous S/N measurement.<i>Conclusions.<i/> Since the nulling interferometer largely suppresses the stellar signal, the impact of stellar activities, such as spots and flares, on the detection of Earth-like planets is significantly reduced. However, for some extremely active M stars, such","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"57 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143712932","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":"COMetary dust TAIL Simulator (COMTAILS): A computer code to generate comet dust tail brightness images","authors":"Fernando Moreno","doi":"10.1051/0004-6361/202453458","DOIUrl":"https://doi.org/10.1051/0004-6361/202453458","url":null,"abstract":"<i>Context.<i/> We present the COMetary dust TAIL Simulator (COMTAILS), a numerical Monte Carlo code to generate images of dust tail brightness from comets and active asteroids in the Solar System.<i>Aims.<i/> We describe a numerical code, available to interested users, capable of generating simulated images of dust tail brightness for comparison with observations, to retrieve key dust parameters including size distribution, ejection velocities, and dust loss rates. An optional stellar field can be included in the background allowing for the assessment of stellar extinction by the tail, which can be compared with observational data.<i>Methods.<i/> A Monte Carlo procedure was used to obtain the simulated images. The orbital parameters of the targets and their heliocentric positions and velocities were obtained from the JPL Horizons on-line ephemeris system.<i>Results.<i/> Earlier versions of this code have been used to characterize the dust environment of various targets. In this study we present recent examples that demonstrate its ability to fit observed images of the long-period comets C/2014 N3 (NEOWISE) and C/2023 A3 (Tsuchinshan-ATLAS). The code is readily applicable to future targets that may be identified for the upcoming European Space Agency Comet Interceptor mission.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"10 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713006","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":"Temperature profiles of accretion disks in luminous active galactic nuclei derived from ultraviolet spectroscopic variability","authors":"Suyeon Son, Minjin Kim, Luis C. Ho","doi":"10.1051/0004-6361/202452467","DOIUrl":"https://doi.org/10.1051/0004-6361/202452467","url":null,"abstract":"The characteristic timescale (<i>τ<i/>) of the continuum variability of the accretion disk in active galactic nuclei (AGNs) is known to be related to the thermal timescale, which is predicted to scale with AGN luminosity (<i>L<i/>) and the rest-frame wavelength (<i>λ<i/><sub>RF<sub/>) as <i>t<i/><sub>th<sub/> ∝ <i>L<i/><sup>0.5<sup/><i>λ<i/><sub>RF<sub/><sup>2<sup/> in the standard disk model. Using multi-epoch spectroscopic data from the Sloan Digital Sky Survey Reverberation Mapping project, we constructed ultraviolet ensemble structure functions of luminous AGNs as a function of their luminosity and wavelength. Assuming that AGNs exhibit a single universal structure function when Δ<i>t<i/> is normalized by <i>τ<i/>, wherein τ ∝ <i>L<i/> <sup>a<sup/>λ<sup>b<sup/><sub>RF<sub/>, we find <i>a<i/> = 0.50 ± 0.03 and <i>b<i/> = 1.42 ± 0.09. While the value of <i>a<i/> aligns with the prediction from the standard disk model, <i>b<i/> is significantly smaller than expected, suggesting that the radial temperature (color) profile of the accretion disk is significantly steeper (shallower) than the standard disk model. Notably, this discrepancy with theory has been observed in previous studies based on spectroscopic reverberation mapping and gravitational microlensing. Although no current model of accretion disks fully matches our results, our findings provide valuable constraints for testing future physical models.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713011","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":"Energetic proton bursts downstream of an interplanetary shock","authors":"L. Yang, X.-Y. Li, V. Heidrich-Meisner, R. F. Wimmer-Schweingruber, L. Wang, A. Kollhoff, X. Zhu, G. Nicolaou, Z. Ding, L. Berger, H. Liu, J. Rodríguez-Pacheco, G. M. Mason, G. C. Ho","doi":"10.1051/0004-6361/202453103","DOIUrl":"https://doi.org/10.1051/0004-6361/202453103","url":null,"abstract":"<i>Context.<i/> The Energetic Particle Detector (EPD) suite on board Solar Orbiter provides unprecedented high-resolution measurements of suprathermal and energetic particles in interplanetary space. These data can resolve particle dynamics near interplanetary shocks, offering new insights into particle acceleration and transport processes.<i>Aims.<i/> We present observations of energetic proton bursts downstream of an interplanetary shock and discuss possible acceleration and formation processes.<i>Methods.<i/> We combined data from two sensors of EPD, the SupraThermal Electron Proton (STEP) sensor and the Electron-Proton Telescope (EPT), to investigate the proton bursts across the full energy range. We examined the dynamic energy spectra, temporal flux profiles, pitch-angle distributions, and spectral features of these proton bursts.<i>Results.<i/> We find that these proton bursts travel anti-parallel to the interplanetary magnetic field (IMF) in a region where the IMF is pointing southward, substantially out of the ecliptic plane. These bursts typically last for ∼10−20 s and span a wide energy range from ∼20 to ∼1000 keV. Their energy spectra typically show an evident bump in the ∼20−100 keV range, characterized by a valley at ∼20−30 keV, a peak at ∼40−50 keV, a full width at half maximum of ∼30 keV, and a positive spectral slope of ∼1 between the valley and peak. These proton bursts exhibit no velocity dispersion feature and their occurrences do not coincide with significant changes in the IMF direction or with enhancements in the 0.1−4 Hz magnetic field fluctuations.<i>Conclusions.<i/> These results suggest that the proton bursts could originate from a source below the ecliptic plane, probably the part of the shock situated there. These protons could be accelerated through shock-drift acceleration or shock-surfing acceleration, with spatially varying efficiencies in the source region. The observed spectral bumps likely arise from the relatively low intensities of the low-energy ∼10−50 keV protons.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"183 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713012","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":"Gaia-ESO survey: Massive stars in the Carina Nebula","authors":"S. R. Berlanas, L. Mahy, A. Herrero, J. Maíz Apellániz, R. Blomme, F. Comerón, I. Negueruela, J. A. Molina Lera, M. Pantaleoni González, S. Daflon, W. Santos, V. M. Kalari","doi":"10.1051/0004-6361/202453269","DOIUrl":"https://doi.org/10.1051/0004-6361/202453269","url":null,"abstract":"&lt;i&gt;Context.&lt;i/&gt; The new census of massive stars in the Carina Nebula reveals the presence of 54 apparently single O-type stars in the Car OB1 association, an extremely active star-forming region that hosts some of the most luminous stars of the Milky Way. A detailed spectroscopic analysis of the current most complete sample of O-type stars in the association can be used to inspect the main physical properties of cluster members and test evolutionary and stellar atmosphere models.&lt;i&gt;Aims.&lt;i/&gt; Our aim is to carry out a spectroscopic characterization of the census of the apparently single (actual single or SB1) O-type stars in Car OB1, obtaining a reliable distribution of rotational velocities and stellar parameters from high-resolution spectra from the &lt;i&gt;Gaia&lt;i/&gt;-ESO survey (GES) and the LiLiMaRlin library database, which is itself fed by spectroscopic surveys such as the high-resolution spectroscopic monitoring survey of Southern Galactic O- and WN-type stars (OWN), the high-resolution, multi-epoch project of Galactic OB stars (IACOB), the northern massive dim stars survey (NoMaDS), and the Calar Alto fiber-fed echelle – binary evolution Andalusian northern survey (CAFÉ-BEANS).&lt;i&gt;Methods.&lt;i/&gt; To derive rotational velocities, we used the semi-automatized tool for the line-broadening characterization of OB stars (iacob-broad) which is based on a combined Fourier transform and the goodness-of-fit methodology. To derive the stellar parameters, we used the iacob-gbat tool, FASTWIND stellar models, and astrometry provided by the &lt;i&gt;Gaia&lt;i/&gt; third data release. The BONNSAI tool was used to compute evolutionary masses and ages.&lt;i&gt;Results.&lt;i/&gt; We performed quantitative spectroscopic analysis for the most complete sample of apparently single O-type stars in Car OB1 with available spectroscopic data. From the high-resolution GES and OWN spectra, we obtain a reliable distribution of rotational velocities for a sample of 37 O-type stars. It shows a bimodal structure with a low velocity peak at 60 km s&lt;sup&gt;−1&lt;sup/&gt; and a short tail of fast rotators reaching 320 km s&lt;sup&gt;−1&lt;sup/&gt;. We also performed a quantitative spectroscopic analysis and derived effective temperature, surface gravity, and He abundance for a sample of 47 O-type stars, now including further stars from the GOSSS database. Radii, luminosities, and spectroscopic masses were also determined using &lt;i&gt;Gaia&lt;i/&gt; astrometry. We created the Hertzsprung-Russell diagram to inspect the evolutionary status of the region and confirm the lack of stars close to the zero-age main sequence (ZAMS) from ∼35–55 M&lt;sub&gt;⊙&lt;sub/&gt;. We confirm a very young population with an age distribution peaking at 1 Myr, with some stars close to or even on the ZAMS, and a secondary peak at 4–5 Myr in the age distribution. We confirm the youth of Trumpler 14, which is also the only cluster not showing the secondary peak. We also find a clear trend of evolutionary masses higher than derived spectroscopic masses for stars with an evoluti","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"20 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143712937","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":"Can circumstellar interaction explain the strange light-curve features of Type Ib/c supernovae?","authors":"Andrea P. Nagy, Zsófia R. Bodola","doi":"10.1051/0004-6361/202348689","DOIUrl":"https://doi.org/10.1051/0004-6361/202348689","url":null,"abstract":"<i>Context.<i/> The evolution and surrounding of the progenitors of stripped-envelope supernovae are still debated: some studies suggest single-star progenitors, but others prefer massive binary progenitors. Moreover, the basic physical properties of the exploding star and its interaction with circumstellar matter could significantly modify the overall light-curve features of these objects. To better understand the effect of stellar evolution and circumstellar interaction, systematic hydrodynamic calculations are needed.<i>Aims.<i/> We test the hypothesis that circumstellar matter generated by an extreme episodic <i>η<i/> Carinae-like eruption that occurs days or weeks before the supernova explosion may explain the differences related to the general light-curve features of stripped-envelope supernovae.<i>Methods.<i/> We present our bolometric light-curve calculations of single-star and binary progenitors generated by hydrodynamic simulations via MESA and SNEC. We also studied the effect of an interaction with close low-mass circumstellar matter assumed to be created just a few days or weeks before the explosion. In addition to generating a model light-curve grid, we compared our results with some observational data.<i>Results.<i/> We found that the shape of the supernova light curve alone can indicate that the cataclysmic death of the massive star occurred in a binary system or was related to the explosion of a single star. Moreover, our study also shows that confined dense circumstellar matter may cause the strange light-curve features (bumps, rebrightening, or steeper tail) of some Type Ib/c supernovae.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"17 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143712938","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":"Low-Eddington ratio, changing-look active galactic nuclei: The case of NGC 4614","authors":"Elisabeta Lusso, Lapo Casetti, Marco Romoli, Lara Fossi, Emanuele Nardini, Emanuele Arra, Benedetta Barsi, Clarissa Calamai, Francesca Campani, Riccardo Capogrosso, Francesco Chiti Tegli, Riccardo Ciantini, Eirini Demertzi, Marina A. Gaitani, Asia Giudice, Alessia Gori, Lorenzo Graziani, Laura Macchiarini, Marianna Michelagnoli, Chiara Niccolai, Irene Parenti, Simone Pistolesi, Martina Rago, Ofelia Romani, Leonardo Sani, Jacopo Sartini, Matilde Scianni, Alba Triggianese, Gloria Andreuzzi, Filippo Ambrosino","doi":"10.1051/0004-6361/202453147","DOIUrl":"https://doi.org/10.1051/0004-6361/202453147","url":null,"abstract":"Active galactic nuclei (AGNs) are known to be variable sources across the entire electromagnetic spectrum, in particular at optical/ultraviolet and X-ray energies. Over the past few decades, a growing number of AGNs have been observed to change type, from type 1 to type 2 or vice versa, within a few years or even months. These galaxies have been commonly referred to as changing-look AGNs (CLAGNs). Here we report on a newly discovered CLAGN, NGC 4614, which transitioned from a type 1.9 to a type 2 state. NGC 4614 is a nearly face-on barred galaxy at redshift <i>z<i/> = 0.016 and is classified as a low-luminosity AGN. Its central black hole has a mass of about 1.6 × 10<sup>7<sup/> <i>M<i/><sub>⊙<sub/> and an Eddington ratio of around 1 percent. We recently acquired optical spectra of NGC 4614 at the Telescopio Nazionale <i>Galileo<i/>, and the data clearly suggest that the broad H<i>α<i/> component has strongly dimmed, if not disappeared. A very recent <i>Swift<i/> observation confirmed our current optical data, with the AGN weakened by almost a factor of 10 with respect to previous X-ray observations. NGC 4614 had also been observed by <i>Swift<i/>/XRT six times in 2011, and the source was clearly detected in all those observations. By fitting the stack of the 2011 <i>Swift<i/> observations, we obtain a photon index of Γ = 1.3 ± 0.3 and an equivalent hydrogen column density of <i>N<i/><sub>H<sub/> = 1.2 ± 0.3 × 10<sup>22<sup/> cm<sup>−2<sup/>, indicating that NGC 4614 can be moderately absorbed in X-rays. Although a significant change in the foreground gas absorption that may have obscured the broad-line region cannot be entirely ruled out, the most likely explanation is that NGC 4614 is experiencing a change in its accretion state that reduces the radiative efficiency of the X-ray corona.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143702930","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":"Shedding light on the star formation rate-halo accretion rate connection and halo quenching mechanism via DECODE, the Discrete statistical sEmi-empiriCal mODEl","authors":"Hao Fu, Lumen Boco, Francesco Shankar, Andrea Lapi, Mohammadreza Ayromlou, Daniel Roberts, Yingjie Peng, Aldo Rodríguez-Puebla, Feng Yuan, Cressida Cleland, Simona Mei, Nicola Menci","doi":"10.1051/0004-6361/202453218","DOIUrl":"https://doi.org/10.1051/0004-6361/202453218","url":null,"abstract":"<i>Aims.<i/> The relative roles of the physical mechanisms involved in quenching galaxy star formation are still unclear. We tackle this fundamental problem with our cosmological semi-empirical model DECODE (Discrete statistical sEmi-empiriCal mODEl), designed to predict galaxy stellar mass assembly histories, from minimal input assumptions.<i>Methods.<i/> Specifically, in this work the star formation history of each galaxy is calculated along its progenitor dark matter halo by assigning at each redshift a star formation rate extracted from a monotonic star formation rate-halo accretion rate (SFR-HAR) relation derived from abundance matching between the (observed) SFR function and the (numerically predicted) HAR function, a relation that is also predicted by the TNG100 simulation. SFRs are integrated across cosmic time to build up the mass of galaxies, which may halt their star formation following input physical quenching recipes.<i>Results.<i/> In this work we test the popular halo quenching scenario and we find that (1) the assumption of a monotonic relation between the SFR and HAR allows us to reproduce the number densities of the bulk of star-forming galaxies in the local Universe; (2) the halo quenching is sufficient to reproduce the statistics of the quenched galaxies and flat (steep) high-mass end of the stellar mass-halo mass relation (or SMF); and (3) to align with the observed steep (flat) low-mass end of the stellar mass-halo mass (or SMF) additional quenching processes in the least massive haloes are needed.<i>Conclusions.<i/> DECODE is an invaluable tool and will pave the way to investigate the origin of newly observed high-redshift objects from the latest ongoing facilities such as JWST and Euclid.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143702987","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":"YOLO-CL cluster detection in the Rubin/LSST DC2 simulations","authors":"Kirill Grishin, Simona Mei, Stephane Ilic, Michel Aguena, Dominique Boutigny, Marie Paturel","doi":"10.1051/0004-6361/202452119","DOIUrl":"https://doi.org/10.1051/0004-6361/202452119","url":null,"abstract":"The next generation large ground-based telescopes like the Vera Rubin Telescope Legacy Survey of Space and Time (LSST) and space missions like Euclid and the Nancy Roman Space Telescope will deliver wide area imaging surveys at unprecedented depth. In particular, LSST will provide galaxy cluster catalogs up to &lt;i&gt;z&lt;i/&gt; ∼ 1 that can be used to constrain cosmological models once their selection function is well-understood. Machine learning based cluster detection algorithms can be applied directly on images to circumvent systematics due to models and photometric and photometric redshift catalogs. In this work, we have applied the deep convolutional network YOLO for CLuster detection (YOLO-CL) to LSST simulations from the Dark Energy Science Collaboration Data Challenge 2 (DC2), and characterized the LSST YOLO-CL cluster selection function. We have trained and validated the network on images from a hybrid sample of (1) clusters observed in the Sloan Digital Sky Survey and detected with the red-sequence Matched-filter Probabilistic Percolation, and (2) dark matter halos with masses &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;200&lt;i&gt;c&lt;i/&gt;&lt;sub/&gt; &gt; 10&lt;sup&gt;14&lt;sup/&gt; &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;⊙&lt;sub/&gt; from the DC2 simulation, resampled to the SDSS resolution. We quantify the completeness and purity of the YOLO-CL cluster catalog with respect to DC2 halos with &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;200&lt;i&gt;c&lt;i/&gt;&lt;sub/&gt; &gt; 10&lt;sup&gt;14&lt;sup/&gt; &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;⊙&lt;sub/&gt;. The YOLO-CL cluster catalog is 100% and 94% complete for halo mass &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;200&lt;i&gt;c&lt;i/&gt;&lt;sub/&gt; &gt; 10&lt;sup&gt;14.6&lt;sup/&gt; &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;⊙&lt;sub/&gt; at 0.2 &lt; &lt;i&gt;z&lt;i/&gt; &lt; 0.8, and &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;200&lt;i&gt;c&lt;i/&gt;&lt;sub/&gt; &gt; 10&lt;sup&gt;14&lt;sup/&gt; &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;⊙&lt;sub/&gt; and redshift &lt;i&gt;z&lt;i/&gt; ≲ 1, respectively, with only 6% false positive detections. We find that all the false positive detections are dark matter halos with 10&lt;sup&gt;13.4&lt;sup/&gt; &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;⊙&lt;sub/&gt; ≲ &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;200&lt;i&gt;c&lt;i/&gt;&lt;sub/&gt; ≲ 10&lt;sup&gt;14&lt;sup/&gt; &lt;i&gt;M&lt;i/&gt;&lt;sub&gt;⊙&lt;sub/&gt;, which corresponds to galaxy groups. We also found that the YOLO-CL selection function is almost flat with respect to the halo mass at 0.2 ≲ &lt;i&gt;z&lt;i/&gt; ≲ 0.9. The overall performance of YOLO-CL is comparable or better than other cluster detection methods used for current and future optical and infrared surveys. YOLO-CL shows better completeness for low mass clusters when compared to current detections based on Matched Filter cluster finding algorithms applied to Stage 3 surveys using the Sunyaev Zel’dovich effect, such as SPT-3G, and detects clusters at higher redshifts than X-ray-based catalogs. Future complementary cluster catalogs detected with the Sunyaev Zel’dovich effect will reach similar mass depth and will be directly comparable with optical cluster detections in LSST, providing cluster catalogs with unprecedented coverage in area, redshift and cluster properties. The strong advantage of YOLO-CL over traditional galaxy cluster detection techniques is that it works directly on images and does not require photometric and photometric redshift catalogs, nor does it need to mask s","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"61 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703053","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}