Astronomy & Astrophysics最新文献

{"title":"The Galactic bulge exploration","authors":"Z. Prudil, A. Kunder, L. Beraldo e Silva, S. Gough-Kelly, M. Rejkuba, S. R. Anderson, V. P. Debattista, O. Gerhard, R. M. Rich, D. M. Nataf, A. J. Koch-Hansen, A. Savino, I. Dékány","doi":"10.1051/0004-6361/202450620","DOIUrl":"https://doi.org/10.1051/0004-6361/202450620","url":null,"abstract":"RR Lyrae stars toward the Galactic bulge are used to investigate whether this old stellar population traces the Galactic bar. Although the bar is known to dominate the mass in the inner Galaxy, there is no consensus on whether the RR Lyrae star population, which constitutes some of the most ancient stars in the bulge and thus traces the earliest epochs of star formation, contributes to the barred bulge. We create new reddening maps and derive new extinction laws from visual to near-infrared passbands using improved RR Lyrae period-absolute magnitude-metallicity relations, enabling distance estimates for individual bulge RR Lyrae variables. The extinction law is most uniform in and and the distances to individual RR Lyrae based on these colors are determined with an accuracy of 6 and 4%, respectively. Using only the near-infrared passbands for distance estimation, we infer the distance to the Galactic center equal to pc after geometrical correction. We show that variations in the extinction law toward the Galactic bulge can mimic a barred spatial distribution in the bulge RR Lyrae star population in visual passbands. This arises from a gradient in extinction differences along Galactic longitudes and latitudes, which can create the perception of the Galactic bar, particularly when using visual passband-based distances. A barred angle in the RR Lyrae spatial distribution disappears when near-infrared passband-based distances are used, as well as when reddening law variations are incorporated in visual passband-based distances. The prominence of the bar, traced by RR Lyrae stars, depends on their metallicity, with metal-poor RR Lyrae stars ([Fe/H] < −1.0 dex) showing little to no tilt with respect to the bar. Metal-rich ([Fe/H] > −1.0 dex) RR Lyrae stars do show a barred bulge signature in spatial properties derived using near-infrared distances, with an angle of <i>ι<i/> = 18 ± 5 deg, consistent with previous bar measurements from the literature. This also hints at a younger age for this RR Lyrae subgroup. The 5D kinematic analysis, primarily based on transverse velocities, indicates a rotational lag in RR Lyrae stars compared to red clump giants. Despite variations in the extinction law, our kinematic conclusions are robust across different distance estimation methods.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"6 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677590","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 EDIBLES survey","authors":"A. Ebenbichler, M. Ončák, N. Przybilla, H. R. Hrodmarsson, J. V. Smoker, R. Lallement, A. Farhang, C. Bhatt, J. Cami, M. Cordiner, P. Ehrenfreund, N. L. J. Cox, J. Th. van Loon, B. Foing","doi":"10.1051/0004-6361/202453259","DOIUrl":"https://doi.org/10.1051/0004-6361/202453259","url":null,"abstract":"<i>Context.<i/> Numerous studies of diffuse interstellar band (DIB) profiles have detected substructures, which in turn suggests that large molecules are acting as their carriers. However, some of the narrowest DIBs generally do not show such substructures, suggesting the possibility of very small carriers.<i>Aims.<i/> Based on the previously found tight correlation of the three narrow DIBs at 6196, 6440, and 6623 Å and the present detection of weaker side DIBs to each of them in the extensive dataset from the ESO Diffuse Interstellar Bands Large Exploration Survey, we investigated whether they may stem from small linear carrier molecules. This approach can lead to concrete DIB carrier suggestions, which can be tested in laboratory measurements in future studies.<i>Methods.<i/> We suggest that the DIBs we studied here represent individual rotational transitions of a small molecule. We determined the molecular constants from observations and compared them with data from a large set of quantum-chemical calculations to constrain possible carrier candidates. Furthermore, we determined the rotational temperatures by fitting line ratios using the fitted molecular models.<i>Results.<i/> We determined molecular constants for three DIB systems and the corresponding transition types. The fitted rotational temperatures lie within the range of known interstellar diatomic molecules. We identified several DIB carrier candidates, almost all of them molecular ions. Some of them are metastable species, indicating the possibility of collision complexes as DIB carriers.<i>Conclusions.<i/> If our hypothesis holds, this would be a major step towards the identification of a carrier molecule of the 6196 Å DIB, the strongest among the narrow DIBs.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"6 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the detection likelihood of faint peaks in interferometric data through jackknifing","authors":"Joshiwa van Marrewijk, Melanie Kaasinen, Gergö Popping, Luca Di Mascolo, Tony Mroczkowski, Leindert Boogaard, Francesco Valentino, Tom Bakx, Ilsang Yoon","doi":"10.1051/0004-6361/202451927","DOIUrl":"https://doi.org/10.1051/0004-6361/202451927","url":null,"abstract":"<i>Context<i/>. False-positive emission-line detections bias our understanding of astronomical sources; for example, falsely identifying <i>z<i/> ∼ 3–4 passive galaxies as <i>z<i/> > 10 galaxies leads to incorrect number counts and flawed tests of cosmology.<i>Aims<i/>. In this work, we provide a novel but simple tool to better quantify the detection of faint lines in interferometric data sets and properly characterize the underlying noise distribution. We demonstrate the method on three sets of archival observations of <i>z<i/> > 10 galaxy candidates, taken with the Atacama Large Millimeter/Submillimeter Array (ALMA).<i>Methods<i/>. By jackknifing the visibilities using our tool, jackknify, we create observation-specific noise realizations of the interferometric measurement set. We apply a line-finding algorithm to both the noise cubes and the real data and determine the likelihood that any given positive peak is a real signal by taking the ratio of the two sampled probability distributions.<i>Results<i/>. We show that the previously reported, tentative emission-line detections of these <i>z<i/> > 10 galaxy candidates are consistent with noise. We further expand upon the technique and demonstrate how to properly incorporate prior information on the redshift of the candidate from auxiliary data, such as from the James Webb Space Telescope.<i>Conclusions<i/>. Our work highlights the need to achieve a significance of ≳ 5<i>σ<i/> to confirm an emission line when searching in broad 30 GHz bandwidths. Using our publicly available method enables the quantification of false detection likelihoods, which are crucial for accurately interpreting line detections.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677464","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":"J-PLUS: Spectroscopic validation of Hα emission line maps in spatially resolved galaxies","authors":"P. T. Rahna, M. Akhlaghi, C. López-Sanjuan, R. Logroño-García, D. J. Muniesa, H. Domínguez-Sánchez, J. A. Fernández-Ontiveros, D. Sobral, A. Lumbreras-Calle, A. L. Chies-Santos, J. E. Rodríguez-Martín, S. Eskandarlou, A. Ederoclite, A. Alvarez-Candal, H. Vázquez Ramió, A. J. Cenarro, A. Marín-Franch, J. Alcaniz, R. E. Angulo, D. Cristóbal-Hornillos, R. A. Dupke, C. Hernández-Monteagudo, M. Moles, L. Sodré, J. Varela","doi":"10.1051/0004-6361/202453633","DOIUrl":"https://doi.org/10.1051/0004-6361/202453633","url":null,"abstract":"<i>Aims<i/>. We present a dedicated automated pipeline to construct spatially resolved emission H<i>α<i/>+[NII] maps and to derive the spectral energy distributions (SEDs) in 12 optical filters (five broad and seven narrow and medium) of H<i>α<i/> emission line regions in nearby galaxies (z < 0.0165) observed by the Javalambre Photometric Local Universe Survey (J-PLUS).<i>Methods<i/>. We used the <i>J<i/>0660 filter of 140 Å width centered at 6600 Å to trace H <i>α<i/> + [NII] emission, and <i>r<i/> and <i>i<i/> broad bands were used to estimate the stellar continuum. We created pure emission line images after the continnum subtraction, where the H<i>α<i/> emission line regions were detected. This method was also applied to integral field unit (IFU) spectroscopic data from PHANGS-MUSE, CALIFA, and MaNGA surveys by building synthetic narrow bands based on J-PLUS filters. The studied sample includes the cross-matched catalog of these IFU surveys with the J-PLUS third data release (DR3), amounting to two PHANGS-MUSE, 78 CALIFA, and 78 MaNGA galaxies at <i>z<i/> < 0.0165, respectively.<i>Results<i/>. We compared the H<i>α<i/>+[NII] radial profiles from J-PLUS and the IFU surveys, finding good agreement within the expected uncertainties. We also compared the SEDs from the emission line regions detected in J-PLUS images, reproducing the main spectral features present in the spectroscopic data. Finally, we compared the emission fluxes from the J-PLUS and IFU surveys accounting for scale differences, finding a difference of only 2% with a dispersion of 7% in the measurements.<i>Conclusions<i/>. The J-PLUS data provide reliable spatially resolved H<i>α<i/>+[NII] emission maps for nearby galaxies. We provide the J-PLUS DR3 catalog for the 158 galaxies with IFU data, including emission maps, SEDs of star-forming clumps, and radial profiles.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"59 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677466","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":"Erosion of a dense molecular core by a strong outflow from a massive protostar","authors":"J. A. López-Vázquez, M. Fernández-López, J. M. Girart, S. Curiel, R. Estalella, G. Busquet, L. A. Zapata, C.-F. Lee, R. Galván-Madrid","doi":"10.1051/0004-6361/202453196","DOIUrl":"https://doi.org/10.1051/0004-6361/202453196","url":null,"abstract":"<i>Context.<i/> Molecular outflows from massive protostars can impact the interstellar medium in different ways, adding turbulence on different spatial scales, dragging material at supersonic velocities, producing shocks and heating, and physically impinging onto dense structures that may be harboring other protostars.<i>Aims.<i/> We aim to quantify the impact of the outflow associated with the high-mass protostar GGD 27-MM2(E) on its parent envelope and how this outflow affects its environment.<i>Methods.<i/> We present Atacama Large Millimeter/submillimeter Array Band 3 observations of N<sub>2<sub/>H<sup>+<sup/> (1–0) and CH<sub>3<sub/>CN (5–4), as well as Band 7 observations of the H<sub>2<sub/>CO molecular line emissions from the protostellar system GGD 27-MM2(E). Through position–velocity diagrams along and across the outflow axis, we studied the kinematics and structure of the outflow. We also fit extracted spectra of the CH<sub>3<sub/>CN emission to obtain the physical conditions of the gas. We use the results to discuss the impact of the outflow on its surroundings.<i>Results.<i/> We find that N<sub>2<sub/>H<sup>+<sup/> emission traces a dense molecular cloud surrounding GGD 27-MM2(E). We estimate that the mass of this cloud is ~13.3–26.5 <i>M<i/><sub>⊙<sub/>. The molecular cloud contains an internal cavity aligned with the H<sub>2<sub/>CO-traced molecular outflow. The outflow, also traced by CH<sub>3<sub/>CN, shows evidence of a collision with a molecular core (MC), as indicated by the distinctive increases in the distinct physical properties of the gas such as the excitation temperature, column density, line width, and velocity. This collision results in an X-shaped structure in the northern part of the outflow around the position of the MC, which produces spray-shocked material downstream in the north of MC, as observed in position–velocity diagrams both along and across the outflow axis. The outflow has a mass of 1.7–2.1 <i>M<i/><sub>⊙<sub/>, a momentum of 7.8–10.1 <i>M<i/><sub>⊙<sub/> km s<sup>−1<sup/>, a kinetic energy of 5.0–6.6×10<sup>44<sup/> erg, and a mass-loss rate of 4.9–6.0×10<sup>−4<sup/> <i>M<i/><sub>⊙<sub/> yr<sup>−1<sup/>.<i>Conclusions.<i/> The molecular outflow from GGD 27-MM2(E) significantly perturbs and erodes its parent cloud, compressing the gas of sources such as the MC and ALMA 12. The feedback from this powerful protostellar outflow helps maintain the turbulence in the surrounding area.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"94 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677463","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":"T CrA has a companion","authors":"J. Varga, A. Matter, F. Millour, G. Weigelt, R. van Boekel, B. Lopez, F. Lykou, Á Kóspál, L. Chen, P. A. Boley, S. Wolf, M. Hogerheijde, A. Moór, P. Ábrahám, J.-C. Augereau, F. Cruz-Saenz de Miera, W.-C. Danchi, Th. Henning, T. Juhász, P. Priolet, M. Scheuck, J. Scigliuto, L. van Haastere, L. Zwicky","doi":"10.1051/0004-6361/202453443","DOIUrl":"https://doi.org/10.1051/0004-6361/202453443","url":null,"abstract":"T CrA is a Herbig Ae-type young star in a complex circumstellar environment; it includes a circumstellar disk, accretion streamers, jets, and outflows. It has long been suspected to be a binary. However, until now, there has been no direct detection of a companion. Here we present new VLTI/MATISSE <i>L<i/>- and <i>N<i/>-band observations of T CrA taken between 2023 May and 2024 August with the aim of testing the binary nature of the system. We modeled the data with a geometric model using the Python tool oimodeler. We detected a companion (T CrA B) with a projected separation of Δ<i>r<i/> = 153.2 ± 1.2 mas (≈23 au) toward the west direction at a position angle of 275.4 ± 0.1°, in 2024 May–August. Our results support that the companion has a nearly edge-on orbit that is highly misaligned with respect to the circumprimary disk. Such a configuration could cause warping and tearing of the disk around the primary, which has been proposed by recent studies. In the <i>L<i/> band the companion is extended, with a full width at half maximum (FWHM) size of ∼1 au, suggesting that the emission comes from a disk around the secondary star. The companion flux is 0.2–0.3 Jy in the <i>L<i/> band, and 0.2–0.7 Jy in the <i>N<i/> band, accounting for 4–20% of the total emission at those wavelengths. The SED of the companion is compatible with thermal radiation of warm dust (600–800 K).","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"12 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677770","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":"Search for new Galactic Wolf–Rayet stars using Gaia DR3","authors":"Lionel Mulato, Jaroslav Merc, Stéphane Charbonnel, Olivier Garde, Pascal Le Dȗ, Thomas Petit","doi":"10.1051/0004-6361/202453359","DOIUrl":"https://doi.org/10.1051/0004-6361/202453359","url":null,"abstract":"<i>Context. Gaia<i/> DR3, released in June 2022, included low-resolution XP spectra that have been used for the classification of various types of emission-line objects through machine-learning techniques. The <i>Gaia Extended Stellar Parametrizer for Emission-Line Stars<i/> (ESP-ELS) algorithm identified 565 sources as potential Wolf-Rayet (WR) stars. Over half of them were already known as WR stars in the Milky Way and Magellanic Clouds.<i>Aims.<i/> We utilized <i>Gaia<i/> DR3 data to identify new Galactic WR stars.<i>Methods.<i/> We extracted all sources from the <i>Gaia<i/> catalog classified as WC- or WN-type stars by the ESP-ELS algorithm. By applying judicious 2MASS color selection criteria, leveraging <i>Gaia<i/> H<i>α<i/> measurements, and filtering out objects already cataloged in various databases, we selected 37 bright candidates (<i>G<i/> ≤ 16 mag) and 22 faint candidates (<i>G ><i/> 16 mag). Spectroscopic follow-up observations of these candidates were conducted using the 2SPOT facilities in Chile and France, as well as the 1 m C2PU’s Epsilon telescope at the Calern Observatory.<i>Results.<i/> This paper focuses on the brighter sample. Among the 37 targets, we confirmed 17 and 16 new Galactic WC- and WN-type WR stars, respectively. Three of them were recently reported as new WR stars in an independent study.<i>Conclusions.<i/> The <i>Gaia<i/> mission provides a valuable resource for identifying WR stars missed in earlier surveys. While this work concentrated on a relatively small starting sample provided by the ESP-ELS algorithm, our findings highlight the potential for refining selection criteria to identify additional candidates not included in the outputs of the algorithm. Furthermore, the observation program underscores the utility of small telescopes in acquiring initial spectral data for sources with magnitudes up to <i>G ~<i/> 16 mag.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"35 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677460","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":"Broad absorption line outflows are common in low Eddington ratio active galactic nuclei","authors":"M. Vivek, Dominika Wylezalek","doi":"10.1051/0004-6361/202453352","DOIUrl":"https://doi.org/10.1051/0004-6361/202453352","url":null,"abstract":"<i>Context.<i/> Broad absorption line (BAL) quasars exhibit significant outflows, offering insights into active galactic nucleus (AGN) feedback. While typically associated with high Eddington ratios, BAL quasars also occur in low Eddington ratio regimes, which remain poorly understood. The aim of this study is to compare BAL properties and variability across these regimes.<i>Aims.<i/> We investigate the occurrence rates, absorption characteristics, and variability of BAL quasars at low and high Eddington ratios.<i>Methods.<i/> Using the SDSS DR16 quasar catalog, we selected a redshift-matched control sample to compare low and high Eddington ratio BAL quasar sources. We first examined the BAL fraction as a function of Eddington ratio. Key absorption parameters (equivalent width, absorption line width, velocity range, and depth) were analyzed, and a multi-epoch variability study was conducted using repeat spectra, followed by a comparison of parameter distributions between the two samples.<i>Results.<i/> For the first time, we report an increase in the BAL fraction toward low Eddington ratios, in addition to the previously known trend of high BAL fraction at high Eddington ratios. While high Eddington sources show extreme absorption features, overall distributions are statistically similar except for maximum outflow velocity. No significant variability differences were observed. The correlation between outflow velocity, Eddington ratio, and luminosity supports the role of radiation pressure in driving quasar outflows. For low Eddington ratios, additional mechanisms, such as softer SEDs, larger outflow distances, and thickened accretion disks from radiatively inefficient processes, likely drive outflow formation.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"57 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677764","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":"Flaires","authors":"J. Necker, E. Graikou, M. Kowalski, A. Franckowiak, J. Nordin, T. Pernice, S. van Velzen, P. M. Veres","doi":"10.1051/0004-6361/202451340","DOIUrl":"https://doi.org/10.1051/0004-6361/202451340","url":null,"abstract":"<i>Context.<i/> Observations of transient emission from extreme accretion events onto supermassive black holes can reveal conditions in the center of galaxies and the black hole itself. Most recently, it has been suggested these sources could be emitters of high-energy neutrinos. However, in most cases, it remains unclear whether this would be classified as the outcome of rejuvenated accretion or a tidal disruption event (TDE).<i>Aims.<i/> We expand on existing samples of infrared (IR) flares to compile the largest and most complete list available. A large sample size is necessary to provide high-enough statistics for distant and faint objects to estimate their rates. Our catalog is large enough to facilitate a preliminary study of the rate evolution with redshift for the first time.<i>Methods.<i/> We compiled a sample of 40 million galaxies. Using a custom, publicly available pipeline, we analyzed the WISE light curves for these 40 million objects using the Bayesian Blocks algorithm. We selected promising for dust echo candidates involved in transient accretion events and we inferred the luminosity, extension, and temperature of the hot dust by fitting a blackbody spectrum.<i>Results.<i/> We established a clean sample of 823 dust echo-like IR flares, dubbed the Flaires catalog. For 568 of them, we were able to estimate the dust properties. After removing 70 objects with possible contributions from synchrotron emission, the luminosity, extension, and temperature are consistent with dust echos. Estimating the dust extension from the light curve shape revealed that the duration of the incident flare is broadly compatible with the duration of TDEs. The resulting rate per galaxy is consistent with the latest measurements of IR-detected TDEs and appears to decline with increasing redshift.<i>Conclusions.<i/> Although systematic uncertainties may impact the calculation of the rate evolution, this catalog will enable further research of phenomena related to dust echos from TDEs and extreme accretion flares.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"28 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677771","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":"Multi-wavelength characterization of VVVX open clusters","authors":"C. O. Obasi, E. R. Garro, J. G. Fernández-Trincado, D. Minniti, M. Gómez, M. C. Parisi, M. Ortigoza-Urdaneta","doi":"10.1051/0004-6361/202453227","DOIUrl":"https://doi.org/10.1051/0004-6361/202453227","url":null,"abstract":"<i>Context.<i/> With the rise of large surveys across wavelengths, both supervised and unsupervised machine learning algorithms have increasingly aided in detecting large samples of old open clusters in high-extinction regions of the Milky Way bulge and disk.<i>Aims.<i/> Our primary goal is to confirm or discard automatically detected open clusters from poorly studied, heavily contaminated regions of the Milky Way. Cleaning these samples is critical for reconstructing the Galactic disk’s star formation history and understanding the thin and thick disk formation model.<i>Methods.<i/> We used data from the VVVX, 2MASS, and <i>Gaia<i/> DR3 surveys to confirm and characterize nine open cluster candidates: BH118, BH 144, Schuster-MWSC 1756, Saurer 3, FSR 1521, Saurer 2, Haffner 10-FSR 1231, Juchert 12, and Pismis 3. We constructed density maps and vector–proper motion diagrams to analyse the targets and performed photometric analysis to derive their main physical parameters.<i>Results.<i/> We examined cluster images from the 2MASS, WISE, and DECaPS surveys, identifying star clusters through an over-density of stars. This was confirmed with a VVVX photometry density map and validated using Gaussian kernel density estimation. Using <i>Gaia<i/> proper motion data, we refined cluster memberships and decontaminated the data to build the final cluster catalogue with objects with a high probability of being star cluster members. We derived the following parameters: extinction values (A<sub><i>Ks<i/><sub/>) ranging from 0.07±0.03 to 0.50±0.04; colour excess values (E(J-K<sub><i>s<i/><sub/>)) from 0.16±0.03 to 0.60±0.03; distances (D) from 2.19±0.06 kpc to 8.94±0.06 kpc; Galactocentric distances (R<sub><i>G<i/><sub/>) from 7.82 kpc to 15.08 kpc; vertical distance component values (Z) from −0.09 kpc to 0.34 kpc; and tangential velocities (V<sub><i>T<i/><sub/>) from 30.59 km/s to 245.42 km/s. We also computed ages and metallicities by fitting PARSEC isochrones, finding ages (t) ranging from 20 Myr to 5 Gyr and metallicities ([Fe/H]) from −0.5 to 0.5. Structural parameters include core radii (r<sub><i>c<i/><sub/>) from 0.71′ to 5.21′, tidal radii (r<sub><i>t<i/><sub/>) from 3.4′ to 12.0′, and concentration indices (c) from 0.36 to 0.83.<i>Conclusions.<i/> We photometrically confirm the open cluster nature for the nine targets in our compilation and updated their main physical parameters.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"46 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677533","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}