VO Fresh

Reconstructed TSI series

2026-09-11T06:57:31Z

Description: Constraining long-term variations in total solar irradiance (TSI) is important for assessing the solar influence on Earth's climate. Most current irradiance reconstructions suggest only a modest secular increase in TSI between the 1700 and 1986 activity minima (<1Wm-2), while two models suggest substantially larger changes of 2.1-5.9W/m^2^. These are the Code for the High spectral ResolutiOn recoNstructiOn of Solar irradiance (CHRONOS) and the model by Penza et al. (2024ApJ...976...11P; PEA24, hereafter). Although the two models differ substantially in their architecture, both use cosmogenic isotope records combined with neutron monitor data to describe the long-term irradiance variability. However, cross-calibrating modulation potential reconstructions from cosmogenic isotopes against neutron monitor data remains highly uncertain. We reassess the origin and the magnitude of the large secular trends in the CHRONOS and PEA24 models. We update the CHRONOS and PEA24 models using recent heliospheric modulation potential and open solar flux reconstructions based on geomagnetic data and neutron monitor measurements, which provide a more reliable connection between cosmogenic isotope and neutron monitor records. We further apply a more robust smoothing methodology for the long-term series. These allow the secular component of the reconstructions to be extended consistently to the satellite era and compare the resulting TSI reconstructions with direct TSI measurements. We find that the original CHRONOS and PEA24 reconstructions substantially overestimated the secular variability in irradiance. When constrained by direct TSI measurements, CHRONOS yields a TSI increase of about 0.1+/-0.17W/m^2^ between the 1700 and 1986 minima, while PEA24 returns about 0.2-0.25 W/m^2^. Our analysis indicates that the previously inferred large secular trends arose primarily from improper linking cosmogenic isotope and neutron monitor records, together with issues in the adopted smoothing approach. The updated reconstructions presented here point toward a relatively modest secular increase in TSI since the Maunder Minimum, likely below 1 Wm-2, consistent with the majority of current irradiance models.
Author(s): Chatzistergos T.; Krivova N.A.; Owens M.; Egorova T.
IVOA id: ivo://cds.vizier/j/a+a/713/a135

Spectroscopic constants of SO+

2026-09-11T06:54:31Z

Description: Potential energy curves (PECs), transition dipole moments (TDS), spectroscopic constants, and spin-orbit coupling (SOC) matrix elements for eight doublet and two quartet states of the sulfur monoxide cation were calculated using the multireference configuration interaction (MRCI) method. Furthermore, the PECs of the Furthermore, the PECs of the The X2Pi and A2Pi potential energy curves were refined by fitting to the experimentally measured vibrational energy levels. Based on these data, the absorption cross sections arising from the A2Pi-X2Pi transition within the 30000-50000cm^-1^ range were simulated, and a comprehensive spectral analysis was performed. Moreover, the absorption cross sections for a total of six transitions were computed to simulate the absorption spectra of SO+ in cosmic atmospheres. It is expected that the spectroscopic data presented in this work will facilitate the characterization of exoplanet atmospheres in future observational missions. higher-lying electronic states.
Author(s): Gu R.; Liu D.; Wei Q.; Wang T.; An S.; Minaev B.F.; Agren H.; Yan B.
IVOA id: ivo://cds.vizier/j/a+a/713/a107

AMS-02 All Particle Rates Catalog

2026-09-11T00:00:00Z

Description: The AMS02RATES database table records the incident rates for all particle species obtained with the Alpha Magnetic Spectrometer (AMS-02) experiment on the International Space Station (ISS), a cosmic ray particle detector installed in May 2011. The experiment consists of several components, which collectively measure particle species, energy, geomagnetic rigidity, or veto off-axis particles and high-energy photons. The experiment covers the energy range of ~0.1 GeV - ~2 TeV. AMS-02 is the result of a collaboration between MIT, the University of Hawaii, CERN, NASA, the U.S. Department of Energy, and ESA. It was launched on the Space Shuttle Endeavor (STS-134) on May 16, 2011 and was installed three days later at which time science operations commenced. Operations were interrupted by in-flight servicing of the cooling pumps for the silicon tracker: servicing took place between November 2019 and January 2020, after which science operations were restored. It is anticipated to continue operations for as long as the ISS itself remains functional. The rate at which all particle species are observed within a one-second time integration period is recorded for each interval, corrected for the livetime fraction. Each integration period contains the livetime value, observed rate, and the position of the AMS-02 instrument in latitude, longitude, and radius from the Earth's center in the Earth Centered Earth Fixed (ECEF) frame of reference. This database table was first ingested by the HEASARC in July 2026. The AMS-02 team in collaboration with the HEASARC developed the FITS file structure for these data which were created by the HEASARC from daily particle rate data provided by the AMS collaboration. The data and the database table are updated periodically to reflect additional data as they become available. This is a service provided by NASA HEASARC .
Author(s): HEASARC
IVOA id: ivo://nasa.heasarc/ams02rates

AMS-02 Spectral Results Catalog

2026-09-11T00:00:00Z

Description: The AMS02SPEC database table records the spectral results obtained with the Alpha Magnetic Spectrometer (AMS-02) experiment on the International Space Station (ISS), a cosmic ray particle detector installed in May 2011. The experiment consists of several components, which collectively measure particle species, energy, geomagnetic rigidity, or veto off-axis particles and high-energy photons. The experiment covers the energy range of ~0.1 GeV - ~2 TeV. AMS-02 is the result of a collaboration between MIT, the University of Hawaii, CERN, NASA, the U.S. Department of Energy, and ESA. It was launched on the Space Shuttle Endeavor (STS-134) on May 16, 2011 and was installed three days later at which time science operations commenced. Operations were interrupted by in-flight servicing of the cooling pumps for the silicon tracker: servicing took place between November 2019 and January 2020, after which science operations were restored. It is anticipated to continue operations for as long as the ISS itself remains functional. This database table was first ingested by the HEASARC in June 2026. The AMS-02 team in collaboration with the HEASARC developed the FITS file structure for these data. The data have been published in a series of papers (see bibliographic references) and archived in FITS format at the HEASARC. The data and the database table are updated periodically to reflect additional data as they becomes available. This is a service provided by NASA HEASARC .
Author(s): HEASARC
IVOA id: ivo://nasa.heasarc/ams02spec

Chandra Source Catalog Stacked Observation Detections, v2.1.1

2026-09-11T00:00:00Z

Description: The Chandra Source Catalog's Stacked Observation Detections Table (CSCSTACK) includes 493,236 detections (855,402 total entries consisting of detections plus photometric upper limits) based on 10,034 stacks of X-ray observations. Exploiting the unique resolution and very low background of Chandra data, the limiting sensitivity of the catalog is enhanced significantly by stacking (co-adding) multiple observations of the same field prior to source detection. To minimize the impact of the variation in the Chandra point spread function (PSF) with off-axis angles, source detection is constrained to run on stacks of observations that have telescope pointings that are co-located within 60 arcseconds and that were obtained using the same instrument (ACIS or HRC-I). Formally, the observations are matched using a tree clustering algorithm with complete linkage. This means that the pointing direction of every observation in the stack is co-aligned with the pointing direction of every other observation in the stack within 60 arcseconds. The stacked-observation level allows composite properties to be reported from the co-added observations for detections that would otherwise not be visible or have poor S/N in individual observations, while for higher S/N detections the per-observation properties facilitate analysis of variable sources. CSCSTACK is related to the <a href="/W3Browse/chandra/csc.html">Chandra Source Catalog (CSC)</a> catalog, which is the definitive catalog of X-ray sources detected by the Chandra X-ray Observatory. The CSC contains 407,806 unique compact and extended X-ray sources. By combining Chandra's sub-arcsecond on-axis spatial resolution and low instrumental background with consistent data processing, the CSC delivers a wide variety of uniformly calibrated properties and science ready data products for detected sources over four decades of flux. Each identified distinct X-ray source on the sky is represented in the catalog by one or more "stack detection" entries -- one for each stack in which the source has been detected -- and a single "master source" entry. The individual stack entries record all of the properties about a detection extracted from a single stack, as well as associated file-based data products, which are stack-specific. If a source is detected in one or more stacked-observations, photometric upper limits that are useful for temporal variability analyses are calculated for any overlapping stacked- and individual-observations in which the source is not detected. This database table was ingested by the HEASARC in July 2026 and is based on a download of the online version of the "Stacked Observation Detections" Table v. 2.1.1, at the CXC using the CLI. Refer to <a href="https://cxc.harvard.edu/csc/cli/">https://cxc.harvard.edu/csc/cli/</a> for details. This is a service provided by NASA HEASARC .
Author(s): Evans, Civano
IVOA id: ivo://nasa.heasarc/cscstack

Swift-XRT Living Point Source Catalog (LSXPS)

2026-09-11T00:00:00Z

Description: This is the Live Swift X-ray Point Source (LSXPS) catalog of detections by the Swift X-ray Telescope (XRT) used in Photon Counting (PC) mode in the 0.3-10 keV energy range. Swift is a NASA mission with international participation dedicated to studying gamma-ray bursts. It carries three instruments. The BAT is the large field-of-view instrument and operates in the 10-300 keV energy band; and two narrow field instruments, XRT and UVOT, that operate in the X-ray and UV/optical regime, respectively. This catalog is similar to the <a href="swift2sxps.html">2SXPS</a> catalog (Evans, P. A., et al. 2020, ApJS, 247, 54) and uses an almost identical source detection process. The primary change is that this is a living catalog: it is updated in near-real time and transient searches are carried out on each dataset as it is received. The improved statistics (below) compared to 2SXPS for source detections, unique and variables sources, uncatalogued sources, and temporal and total sky area coverage are a function of its ongoing live nature, compared to the static 2SXPS which was current up to 2018-08-01. On average, LSXPS grows by 49 new sources and the unique sky coverage increases 0.94 square degrees per day. This table was added to the HEASARC database in June 2026 and is based on the contents of its dedicated website at <a href="https://www.swift.ac.uk/LSXPS">https://www.swift.ac.uk/LSXPS</a>. The version available from the HEASARC corresponds to the catalog designated as "Sources" on the Leicester website and will typically be updated at the HEASARC within a day or so of a new version appearing on the Leicester website. This is a service provided by NASA HEASARC .
Author(s): Evans et al.
IVOA id: ivo://nasa.heasarc/swiftlsxps

CL-AGNs with repeated sp. of SDSS-V first year

2026-09-10T08:44:59Z

Description: "Changing-look" active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-year Sloan Digital Sky Survey V (SDSS-V) repeated spectroscopy of nearly 29,000 previously known active galactic nuclei (AGNs), combined with dedicated follow-up spectroscopy, and publicly available optical light curves, we have identified 116 CL-AGNs where (at least) one broad emission line has essentially (dis-)appeared, as well as 88 other extremely variable systems. Our CL-AGN sample, with 107 newly identified cases, is the largest reported to date, and includes ~0.4% of the AGNs reobserved in first-year SDSS-V operations. Among our CL-AGNs, 67% exhibit dimming while 33% exhibit brightening. Our sample probes extreme AGN spectral variability on months to decades timescales, including some cases of recurring transitions on surprisingly short timescales (<~2 months in the rest frame). We find that CL events are preferentially found in lower-Eddington-ratio (fEdd) systems: Our CL-AGNs have a fEdd distribution that significantly differs from that of a carefully constructed, redshift- and luminosity-matched control sample (Anderson-Darling test yielding p_AD_~6x10^-5^; median fEdd~0.025 versus 0.043). This preference for low fEdd strengthens previous findings of higher CL-AGN incidence at lower fEdd, found in smaller samples. Finally, we show that the broad MgII emission line in our CL-AGN sample tends to vary significantly less than the broad H{beta} emission line. Our large CL-AGN sample demonstrates the advantages and challenges in using multi-epoch spectroscopy from large surveys to study extreme AGN variability and physics.
Author(s): Zeltyn G.; Trakhtenbrot B.; Eracleous M.; Yang Q.; Green P.,Anderson S.F.; LaMassa S.; Runnoe J.; Assef R.J.; Bauer F.E.; Brandt W.N.,Davis M.C.; Frederick S.E.; Fries L.B.; Graham M.J.; Grogin N.A.,Guolo M.; Hernandez-Garcia L.; Koekemoer A.M.; Krumpe M.; Liu X.,Martinez-Aldama M.L.; Ricci C.; Schneider D.P.; Shen Y.; Sniegowska M.,Temple M.J.; Trump J.R.; Xue Y.; Brownstein J.R.; Dwelly T.; Morrison S.,Bizyaev D.; Pan K.; Kollmeier J.A.
IVOA id: ivo://cds.vizier/j/apj/966/85

Halpha, g- and r- ZTF light curves of AGNs

2026-09-10T08:16:19Z

Description: In our previous work on broadband photometric reverberation mapping (PRM), we proposed the interpolated cross-correlation function (ICCF)-Cut process to obtain the time lags of the H{alpha} emission line from two broadband lightcurves via subtracting the continuum emission from the line band. Extending the work, we enlarge our sample to the Zwicky Transient Facility (ZTF) database. We adopt two criteria to select 123 type 1 active galactic nuclei (AGNs) with sufficient variability and smooth light curves from 3537 AGNs at z<0.09 with more than 100 epoch observations in the g and r bands from the ZTF database. We calculate the H{alpha} time lags for 23 of them that have previous spectroscopic reverberation mapping (SRM) results using the ICCF-Cut, Just Another Vehicle for Estimating Lags In Nuclei (JAVELIN), and {chi}2 methods. Our obtained H{alpha} time lags are slightly larger than the H{beta} time lags, which is consistent with the previous SRM results and the theoretical model of the AGN broad-line region. The comparisons between the SRM and PRM lag distributions and between the subtracted emission line light curves indicate that after selecting AGNs with the two criteria, combining the ICCF-Cut, JAVELIN, and {chi}2 methods provides an efficient way to get the reliable H{alpha} lags from the broadband PRM. Such techniques can be used to estimate the black hole masses of a large sample of AGNs in large multiepoch photometric sky surveys such as the Legacy Survey of Space and Time and the survey from the Wide Field Survey Telescope in the near future.
Author(s): Ma Q.; Wen Y.; Wu X.-B.; Gu H.; Fu Y.
IVOA id: ivo://cds.vizier/j/apj/966/5

WDs in open clusters and tidal tails

2026-09-10T07:09:29Z

Description: Recent Gaia studies have identified numerous open clusters (OCs) and tidal tail catalogues, enabling systematic searches for white dwarfs (WDs) associated with clusters and their extended structures. We compile a literature-based sample of OC-WD pairs to validate WD membership in cluster cores and tidal tails, investigate the initial-final mass relation (IFMR), identify WDs formed through non-canonical evolution, and interpret the observed WD populations using a grid of N-body simulations. We combine Gaia DR3 cluster and tidal tail catalogues with ultraviolet-to- infrared photometry to analyse the OC-WD pairs. WD masses, cooling ages, radii, effective temperatures, and luminosities are estimated using colour- magnitude diagrams and spectral energy distributions. These observations are interpreted in the context of N-body simulations. We identify 235 OC-WD pairs in 80 clusters, including 99 WDs in tidal tails. More than 28% of the pairs are likely spurious, with contamination substantially higher in the tails (>48%) than in the cluster cores (>13%), indicating significant field-star contamination in current Gaia-based catalogues. The Pleiades tidal tails also show severe contamination by old WDs. Simulations predict that the fraction of core WDs increases with cluster age, reaching >10%, whereas the observed fractions remain systematically lower, consistent with the WD deficit problem. Despite the high contamination rate, most tail WDs (~83%) are consistent with having been born inside the tidal radius. We additionally identify 63 candidate binary-origin WDs and 47 new IFMR candidates. WDs provide a powerful probe of contamination in cluster and tidal tail catalogues and place important constraints on cluster detection methods and N-body simulations. Resolving the WD deficit and improving membership validation will require improved observations, membership methods, WD physics, and spectroscopic follow-up, ultimately enabling stronger constraints on dynamical cluster evolution and the WD IFMR.
Author(s): Jadhav V.V.; Kroupa P.; Miller D.R.; Sahu S.; Frantisek D.; Subr L.
IVOA id: ivo://cds.vizier/j/a+a/713/a93

M-subdwarf research. II. Catalog of ~3000 subdwarfs

2026-09-09T11:44:59Z

Description: We applied the revised M subdwarf classification criteria discussed in Zhang+ 2019, J/ApJS/240/31 (Paper I) to Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR7 and combined the result with the M subdwarf sample from Savcheva+ 2014ApJ...794..145S to construct a new M subdwarf sample for further study. The atmospheric parameters for each object were derived from fitting to the PHOENIX grid, and the sources with available astrometry and photometry from Gaia DR2 were combined for further analysis. The relationship between the gravity and metallicity was explored according to the locus both in the color-absolute magnitude diagram and the reduced proper motion diagram. Objects that have both the largest gravity and the lowest metallicity are located away from the main-sequence cloud and may be considered as the intrinsic M subdwarfs, which can be classified as luminosity class VI. Another group of objects whose spectra show typical M subdwarf characteristics have lower gravity and relatively moderate metal deficiency and occupy part of the ordinary M dwarf region in both diagrams. The Galactic U, V, W space velocity components and their dispersion show that the local Galactic halo population sampled in the solar neighborhood is represented by objects of high gravity and an inconspicuous bimodal metallicity distribution, with a fraction of prograde orbits. The other M subdwarfs seem to belong in part to the thick disk component, with a significant fraction of thin disk, moderately metal-poor objects intricately mixed with them. However, selection effects, especially the favored anticenter direction of investigation in the LAMOST subsample, as well as contamination by multiplicity and parameter coupling, could play important roles and need to be investigated further.
Author(s): Zhang S.; Luo A.-L.; Comte G.; Wang R.; Li Y.-B.; Du B.; Hou W.; Qin Li,Gizis J.; Chen J.-J.; Chen X.-L.; Lu Y.; Song Y.-H.; Zhang H.-W.; Zuo F.
IVOA id: ivo://cds.vizier/j/apj/908/131

Mass estimates of 1783 asteroids

2026-09-09T11:22:03Z

Description: Mutual perturbations between asteroids during close encounters allow the estimation of their masses using precise astrometric observations. We use all astrometry reported to the Minor Planet Center, high-precision astrometry from ESA's Gaia Focused Product Release, and radar delay-Doppler data when available. A search for close encounters between all known asteroids and a preliminary list of the largest asteroids leads to approximately 975,000 asteroids that may have been perturbed in a measurable way. We find about 86,000 asteroids with signal in their astrometry for one or more asteroid masses. The multidimensional, weighted combination of all estimates yields 77 asteroid masses with signal-to-noise ratio SNR>10, and 232 asteroid masses with SNR>3, all in the main belt or outer main belt. We did not find any signal for individual masses of Trojans, Centaurs, or Trans-Neptunian Objects. From the estimated asteroid masses, we derive updated density estimates for asteroids with well-determined diameters. The updated total main belt mass estimate (sum-of-all-a<4.6AU, H<18) is (13.11+/-0.06)x10^-10^M_{sun}_.
Author(s): Fuentes-Munoz O.; Farnocchia D.; Giorgini J.D.; Park R.S.
IVOA id: ivo://cds.vizier/j/aj/170/353

PN Tc 1 MUSE imaging spectroscopy

2026-09-09T06:16:18Z

Description: The planetary nebula Tc 1 (PN G345.2-08.8), one of the rare group of Galactic PNe showing fullerene emission in the infrared, is spatially extended with high a surface brightness. Optical imaging spectroscopy enables the line and continuum structure and diagnostics to be examined, and permits a search for any correlations to the presence of fullerene dust. Tc 1 was observed with MUSE wide field mode with adaptive optics, wavelength range 4700-9300{AA}, at three exposure levels to ensure unsaturated emission lines. Extinction, electron temperature (T_e_), and density (N_e_) diagnostic images are presented from collisionally excited and recombination line ratios. The nebula has a high surface brightness core, with a diameter 12'', an elliptical ring of major axis 2.8'' around the central star and some low ionization knots, and an extended halo of 55'' in diameter; between the core and halo is an annulus with intermediate properties, including a higher T_e_ and a lower N_e than in the core. The spectrum of the central star was extracted and fitted by a 31000K model atmosphere and is of type O7.5I(f). The image of optical extinction from H Balmer line ratios is highly structured, and shows an annulus, which is adjacent to the core, of low extinction, with values lower than the line-of-sight interstellar extinction. Instrumental effects to account for this anomalously low extinction area were investigated and intrinsic effects from the scattering properties of the nebular dust; neither can entirely explain the low-extinction region and the most likely cause is a local non-standard dust reddening law. This low extinction region additionally shows an anomalously high HeI 7281/6678{AA} line ratio, possibly caused by a contaminating line, but none have been conclusively identified; its origin remains unresolved. Spectra over extended regions were also analysed and distinct enhancement of the continuum above the expected nebular continuum (as also seen in some other PNe observed with MUSE) was found. The annulus of low extinction occurs outside the region of strongest fullerene emission, in the zone where N_e_ declines and T_e_ rises. A change in dust properties linked to conditions in this transition region between the higher density core nebula and lower density halo is deduced.
Author(s): Walsh J.R.; Barlow M.J.; Monreal-Ibero A.; Cami J.; Peeters E.; Wesson R.,Bernard-Salas J.; Cox N.L.J.; Watt G.F.J.
IVOA id: ivo://cds.vizier/j/a+a/713/a103

LMC field surrounding NGC 1846 JWST phot.

2026-09-09T06:12:08Z

Description: Nearby galaxies such as the Large Magellanic Cloud (LMC) offer an ideal laboratory to test the initial mass function under different physical conditions, but previous works have been limited by photometric depth and have therefore poorly constrained the low-mass regime. Here, we analyze ultra-deep James Webb Space Telescope observations of a field in the LMC outskirts, near the intermediate-age and massive star cluster NGC 1846. Using the m_F322W2_ versus m_F115W_-m_F322W2_ color-magnitude diagram, we derive the mass function (MF) down to unprecedentedly low masses (M=0.17M_{Sun}_), explicitly accounting for the contribution of unresolved binaries, whose fraction is constrained directly from the data. For systems with mass ratios q>0.6, we measure a binary fraction of f_bin_^q^>0.6=0.15+/-0.01, implying a total binary fraction of f_bin_^TOT^=0.34+/-0.02 for a flat mass-ratio distribution. This is consistent with values in the Small Magellanic Cloud (SMC) and in the Milky Way field, suggesting similar binary formation efficiency across low-density environments. We also derive the MF over the mass interval 0.17-0.82M_{Sun}_ and fit it with a power law, obtaining a slope of alpha=-1.49+/-0.16. This slope is shallower than the canonical Salpeter value (alpha=-2.35) and slightly shallower than that measured in the SMC field, while remaining consistent with determinations for Galactic open clusters and for several clusters in the Magellanic Clouds and the Milky Way. Together, these results support a scenario in which both binary formation efficiency and the shape of the low-mass MF depend only weakly on the environment.
Author(s): Legnardi M.V.; Muratore F.; Milone A.P.; Cordoni G.; Dondoglio E.,Gorza L.N.; Bellini A.; Calura F.; Jang S.; Jerjen H.; Karakas A.,Lagioia E.P.; Li C.; Mastrobuono-Battisti A.; Tailo M.; Vesperini E.,Bortolan E.; Marino A. F.; Di Stefano S.
IVOA id: ivo://cds.vizier/j/a+a/713/a99

New redshift 1.6
2026-09-09T00:00:00Z

Description

The QUBRICS (QUasars as BRIght beacons for Cosmology in the Southern hemisphere) survey aims at constructing a sample of the brightest quasars with z~>2.5, observable with facilities in the Southern Hemisphere. QUBRICS makes use of the available optical and IR wide-field surveys in the South and of Machine Learning techniques to produce thousands of bright quasar candidates of which only a few hundred have been confirmed with follow-up spectroscopy. Taking advantage of the recent Gaia Data Release 3, which contains 220 million low-resolution spectra, and of a newly developed spectral energy distribution fitting technique, designed to combine the photometric information with the Gaia spectroscopy, it has been possible to measure 1672 new secure redshifts of QUBRICS candidates, with a typical uncertainty of {sigma}z = 0.02. This significant progress of QUBRICS brings it closer to (one of) its primary goals: providing a sample of bright quasars at redshift 2.5 < z < 5 to perform the Sandage test of the cosmological redshift drift. A Golden Sample of seven quasars is presented that makes it possible to carry out this experiment in about 1500 h of observation in 25 yr, using the ANDES spectrograph at the 39m ELT, a significant improvement with respect to previous estimates.

Author(s)

Cristiani S.; Porru M.; Guarneri F.; Calderone G.; Boutsia K.; Grazian A.,Cupani G.; D'Odorico V.; Fontanot F.; Martins C.J.A.P.; Marques C.M.J.,Maitra S.; Trost A.

IVOA id

ivo://cds.vizier/j/mnras/522/2019

MaNGA galaxies DynPop I JAM dynamical properties

2026-09-09T00:00:00Z

Description: This is the first paper in our series on the combined analysis of the Dynamics and stellar Population (DynPop) for the MaNGA survey in the final SDSS Data Release 17 (DR17). Here, we present a catalogue of dynamically determined quantities for over 10000 nearby galaxies based on integral-field stellar kinematics from the MaNGA survey. The dynamical properties are extracted using the axisymmetric Jeans Anisotropic Modelling (JAM) method, which was previously shown to be the most accurate for this kind of study. We assess systematic uncertainties using eight dynamical models with different assumptions. We use two orientations of the velocity ellipsoid: either cylindrically aligned JAMcyl or spherically aligned JAMsph. We also make four assumptions for the models' dark versus luminous matter distributions: (1) mass-follows-light, (2) free NFW dark halo, (3) cosmologically constrained NFW halo, (4) generalized NFW dark halo, i.e. with free inner slope. In this catalogue, we provide the quantities related to the mass distributions (e.g. the density slopes and enclosed mass within a sphere of a given radius for total mass, stellar mass, and dark matter mass components). We also provide the complete models which can be used to compute the full luminous and mass distribution of each galaxy. Additionally, we visually assess the qualities of the models to help with model selections. We estimate the observed scatter in the measured quantities which decreases as expected with improvements in quality. For the best data quality, we find a remarkable consistency of measured quantities between different models, highlighting the robustness of the results.
Author(s): Zhu K.; Lu S.; Cappellari M.; Li R.; Mao S.; Gao L.
IVOA id: ivo://cds.vizier/j/mnras/522/6326

AGNs Optical/MIR time series analysis properties

2026-09-09T00:00:00Z

Description: We compile optical and mid-infrared light curves from the time-domain surveys (i.e. CRTS, PTF, ZTF, and ASAS-SN) and Wide-field Infrared Survey Explorer (WISE) archive for a selected sample of active galactic nuclei (AGNs) with H{beta} reverberation mapping (RM) measurements. We measure the time lags (and thus torus sizes) of W1 (~3.4 {mu}m) and W2 (~4.6 {mu}m) band light curves relative to the optical one using the MICA method. Through H{beta} RM, the sample has well-measured AGN properties, therefore allowing us to reliably constrain the relations between torus sizes and AGN properties. We perform linear regressions for the relations between torus sizes and 5100 {AA} luminosities (R {prop.to} L^{beta}^_5100_) in two cases: {beta} = 0.5 and {beta} set free. The latter case yields {beta} =~ 0.37 +/- 0.028 for both W1 and W2 bands, shallower than the expected value of 0.5, possibly due to the dependence of torus size on accretion rate. For {beta} = 0.5, by combining with the previous K band RM measurements, we obtain the characteristic broad-line region (BLR) and tours sizes following R_BLR_ : R_K_ : R_W1_ : R_W2_ = 1.0 : 6.2 : 9.2 : 11.2. We investigate the deviations of the W1 and W2 band observed torus sizes from the corresponding best-fitting relations (with {beta} = 0.5) and find that they both are correlated with accretion rate. As the accretion rate increases, the torus sizes tend to be shortened compared to the anticipated sizes from the best-fitting relations, similar to the behaviour found in BLRs. Such behaviours can be explained by the self-shadowing effect of slim discs. This is further supported by ratios of the W1 and W2 band torus sizes to BLR sizes, which do not show significant correlations with AGN properties.
Author(s): Chen Y.-J.; Liu J.-R.; Zhai S.; Yao Z.-H.; Li Y.-R.; Du P.; Hu C.,Guo W.-J.; Xiao M.; Songsheng Y.-Y.; Wang J.-M.
IVOA id: ivo://cds.vizier/j/mnras/522/3439

Spectroscopic multiple-star syst. from LAMOST DR10

2026-09-08T13:02:36Z

Description: We employed the Gaussian decomposition package Gausspy+ (Riener+ 2019A&A...628A..78R) to autonomously identify multipeak features in the cross-correlation functions (CCFs) of spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Medium-Resolution Survey (MRS), enabling the detection of single-lined spectroscopic binaries (SB1s), double-lined spectroscopic binaries (SB2s), and spectroscopic triples (STs). By providing Gausspy+ with training spectra exhibiting single-, double-, and triple-peak CCFs, we derived optimal fitting parameters suited to the dataset. To ensure the reliability of the fits, we established selection criteria for exposures showing double- or triple-peak CCFs based on statistical analysis of the test sample. Combining visual screening with our testing sets, the accuracy for SB2 identification reached 95.7%, while the accuracy for ST identification reached 98.6%. Applying this method to nearly 450,000 LAMOST DR10 targets, we identified 15,887 SB 2 candidates and 8771 ST candidates. In addition, we analyzed 903 targets that exhibit significant radial velocity (RV) variations but whose CCFs only show a single peak. For these objects, we performed orbital parameter inference using The Joker, and identified 294 SB1 candidates with periodic RV variations. Notably, among the identified candidates, 65.3% of SB2s, 93.9% of STs, and 93.9% of SB1s are newly discovered systems, substantially expanding the census of spectroscopic multiple systems in the LAMOST MRS dataset. Furthermore, we also provide orbital solutions for 334 SB2 systems. For ST systems, we identified 46 hierarchical triple systems and obtained their orbital solutions. These results further enrich the characterization of multiple star systems in the LAMOST MRS dataset.
Author(s): Han Y.; Li K.; Gao X.
IVOA id: ivo://cds.vizier/j/apjs/284/5

Multiwavelength observations of the Be/XRB SXP 182

2026-09-08T09:36:41Z

Description: We report on the discovery of Swift J010902.6-723710, a rare eclipsing Be/X-ray Binary system by the Swift SMC Survey (S-CUBED). Swift J010902.6-723710 was discovered via weekly S-CUBED monitoring observations when it was observed to enter a state of X-ray outburst on 2023 October 10. X-ray emission was found to be modulated by a 182s period. Optical spectroscopy is used to confirm the presence of a highly inclined circumstellar disk surrounding a B0-0.5Ve optical companion. Historical UV and IR photometry is then used to identify strong eclipse-like features reoccurring in both light curves with a 60.623 day period, which is adopted as the orbital period of the system. Eclipsing behavior is found to be the result of a large accretion disk surrounding the neutron star. Eclipses are produced when the disk passes in front of the OBe companion, blocking light from both the stellar surface and circumstellar disk. This is only the third Be/X-ray binary to have confirmed eclipses. We note that this rare behavior provides an important opportunity to constrain the physical parameters of a Be/X-ray binary with greater accuracy than is possible in noneclipsing systems.
Author(s): Gaudin T.M.; Kennea J.A.; Coe M.J.; Monageng I.M.; Udalski A.,Townsend L.J.; Buckley D.A.H.; Evans P.A.
IVOA id: ivo://cds.vizier/j/apj/965/l10

Abell 2244 multi-component radio emission

2026-09-08T07:12:17Z

Description: In recent years, clusters have been observed that host multi-component haloes, both in non-merging and merging systems. The existence of these multi-component haloes suggests that there is no clear distinction between the single components. Abell 2244 is an intermediate-mass cluster that hosts a double component diffuse radio emission. The aim of this paper is to carry out an in-depth study of the diffuse radio emission to constrain its origin and characterize its main radio properties. In this work we present LOFAR HBA, MeerKAT UHF, and L-band observations of the cluster Abell 2244. We investigated the nature of the diffuse radio emission, combining high sensitivity radio data with XMM-Newton deep X-ray observations. We also used mock LOFAR observations to investigate contamination of the emission from faint radio sources. We find an integrated spectral index of alpha^1279^_144_=0.9+/-0.1 for both components, where only the radio halo shows spectral steepening at higher frequencies. These values are comparable with the spectral indices observed in disturbed massive clusters. The outer component does not follow the same radio X-ray correlation as the radio halo, which suggests a different physical origin. By analysing the physical and morphological properties of the diffuse emission, we find that the characteristics of the outer component of the emission are intermediate between those of radio haloes and of known megahaloes. Hence, we speculate that the source is either a morphologically disturbed radio halo, caused by a minor merger interaction, or a megahalo but we cannot reach a final classification. From the mock observations, we find that it is unlikely that the emission is caused by faint sources at low resolutions.
Author(s): Cianfaglione M.; De Gasperin F.; Cuciti V.; Balboni M.; van Weeren R.J.,Groeneveld C.; Boxelaar J.M.; Della Chiesa M.; Bonafede A.; Di Gennaro G.,Gastaldello F.; Brunetti G.
IVOA id: ivo://cds.vizier/j/a+a/713/a91

Milky Way open cluster age determination

2026-09-08T07:11:11Z

Description: Open Clusters are excellent tracers for the Galactic thin disk, providing insights into its formation and evolution. Precise cluster age determination is essential for studying cluster evolution, as well as the evolution of the disk as a whole. With this work, we aim to produce an updated catalog of cluster parameters (age, extinction, distance) by constraining the age determination via newly available spectroscopic measurements of metallicity, improving upon the precision of existing catalogs. Using high-quality astrometry from Gaia DR3, we derive new cluster memberships via a Machine Learning-based clustering algorithm (AstroLink). We compile metallicity measurements from multiple ground-based spectroscopic surveys (Gaia-ESO, GALAH DR3, APOGEE-OCCAM) and Gaia GSP-Spec into a uniform scale. The ages of 320 clusters are determined using a Machine Learning-accelerated approximate Bayesian isochrone-fitting code (based on ASteCA), adopting a multiband approach that incorporates Gaia XP and synthetic photometry. This work results in a robust sample of open clusters with precisely determined parameters and uncertainties. Additionally, this catalog may provide a foundation for Machine Learning models to infer parameters for a larger sample of objects without spectroscopic data, which is to be explored in future work.
Author(s): Kallimanis I.N.; Vallenari A.; Bossini D.; Bragaglia A.; Pasquato M.,Carrera R.; Boeche C.; Hatzidimitriou D.
IVOA id: ivo://cds.vizier/j/a+a/713/a82

Small close-in planets when cold Jupiters

2026-09-08T07:07:23Z

Description: The architecture of our Solar System, with small inner planets (ISPs) and outer giants, may or may not be common. Understanding whether a correlation exists between ISPs and outer cold giants is key to evaluating how common systems with a similar architecture to our own are. This study aims to build a large, homogeneous sample of systems hosting cold Jupiters (CJs, aperi>1au, msini>0.1MJ) detected via radial velocities (RVs), and to assess the presence of additional ISPs (P<400d, 3<=msini<=31.7M_{Earth}.), studying the correlation between these two types of objects. We selected 137 stars known to host a CJ, including 23 which also harbor a hot Jupiter and were treated separately. Data from various instruments were compiled, including unpublished data gathered with the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) within the Global Architectures of Planetary Systems (GAPS) program, and consistently fitted using PyORBIT. We derived RV detection maps and calculated occurrence rates for ISPs, cross-validating results with two independent codes. The sample was divided into subgroups to evaluate how system parameters influence planet occurrence. Results. We confirmed the 213 already known planets in the 137 systems and also identified six new candidates. We divided them, based on mass and period, into Neptunes (10<msini<31.7M_{Earth}_) and Super-Earths (3<msini<=10M_{Earth}_), and into hot (1<=P<=10d), warm (10<P<=100d), and cool (100<P<=400d). We found occurrences of ~5%, ~13%, and ~12% for hot, warm, and cool Neptunes, respectively, and ~11% and ~16% for hot and warm Super-Earths, respectively. Systems with dynamically stable inner regions show higher rates of small planets. These findings are consistent with previous studies showing no strong correlation between ISPs and CJs at average stellar metallicity and mass, and suggest that hot Jupiters may be more commonly associated with external giants.
Author(s): Ruggieri A.; Desidera S.; Pinamonti M.; Barbato D.; Sozzetti A.,Bonomo A.S.; Naponiello L.; Damasso M.; Benatti S.; Carleo I.; Gratton R.,Biazzo K.; Lanza A.F.; Piccinini; G.; Nari N.; Mantovan G.; Maldonado J.,Nardiello D.; Fiorenzano A.; Ghedina A.; Bignamini A.
IVOA id: ivo://cds.vizier/j/a+a/713/a78

[Y/Mg] chemical clock from asteroseismic ages

2026-09-08T06:54:07Z

Description: Building on our previous study, which demonstrated the necessity of accounting for departures from the local thermodynamic equilibrium while determining elemental abundances, and the importance of asteroseismic ages, we aim to characterise the spatial variations of the empirical [Y/Mg]-age relation across the Galactic disc with a significantly larger sample of stars. We observed high-resolution stellar spectra and determined Mg and Y abundances via spectral synthesis of multiple spectral features, rigorously accounting for non-local thermodynamic equilibrium (NLTE) effects. To anchor the time scale, we determined asteroseismic ages for stars showing solar-type pulsations, while employing cross-checked isochrone-based methods for the remaining stars. We determined the main atmospheric parameters and abundances of Mg and Y for a sample of 528 Galactic field stars, as well as asteroseismic ages for 307 stars and cross-checked isochronal ages for 221 stars. We identified two new triple-lined and nine double-lined spectroscopic stellar systems. Based on a total sample of 736 stars, with data from this and our previous study, we have explored the [Y/Mg] versus age relations across the Galactic disc. The [Y/Mg] versus age relations exhibit systematic variations across the Galactic discs, reflecting differences in star formation and enrichment histories. There is a tendency for [Y/Mg] to increase with increasing metallicity across the age range. However, at the supersolar metallicity this tendency may not hold, and the relations become flatter compared to solar metallicity stars, having lower [Y/Mg] values at young ages and higher at old ages.
Author(s): Mikolaitis S.; Tautvaisiene G.; Pakstiene E.; Drazdauskas A.; Bagdonas V.,Viscasillas Vazquez C.; Ambrosch M.; Chorniy Y.; Minkeviciute R.,Stonkute E.; Bale B.; Curjuric B.; Sharma A.; Diktanaite K.
IVOA id: ivo://cds.vizier/j/a+a/713/a48

MEGARA obs. of Ha & FeI during HD 189733b transit

2026-09-07T15:05:29Z

Description: Transmission spectroscopy allows us to detect molecules in planetary atmospheres, but is subject to contamination from inhomogeneities on the stellar surface. Quantifying the extent of this contamination is essential for accurate measurements of atmospheric composition, as stellar activity can manifest as false atmospheric signals in planetary transmission spectra. We present a study of hot Jupiter HD 189733b, which has over 50hr of JWST observations scheduled or taken, to measure the activity level of the host star at the current epoch. We utilize high-resolution spectra of the H{alpha} line from the MEGARA spectrograph on the 10m GTC to examine the activity level of HD 189733 during a transit. We measure H{alpha} becoming shallower midtransit by an H{alpha} index of {delta}=0.00156+/-0.00026, which suggests that HD 189733b crosses an active region as it transits. We posit this deviation is likely caused by a spot along the transit chord with an approximate radius of R_spot_=3.47+/-0.30R_{Earth}_ becoming occulted during transit. Including an approximation for unocculted spots, we estimate that this spot could result in transit depth variations of ~17ppm at the 4.3um CO2 feature. Since this is comparable to JWST NIRCam Grism mode's noise floor of ~20ppm, it could bias atmospheric studies by altering the inferred depths of the planet's features. Thus, we suggest ground-based high-resolution monitoring of activity indicator species concurrently taken with JWST data when feasible to disentangle stellar activity signals from planetary atmospheric signals during transit.
Author(s): Ehrich K.E.; Dittmann J.A.; Halverson S.P.; Camazon-Pinilla A.
IVOA id: ivo://cds.vizier/j/aj/170/346

SPORES-HWO. II. 35yr of RV for 141 stars

2026-09-07T13:21:59Z

Description: A goal of the future Habitable Worlds Observatory (HWO) is to directly image and spectroscopically characterize true Earth-analogs. However, if a large fraction of HWO target stars host unknown dynamically disruptive giant planets in their habitable zones (HZs), then additional targets that are farther away will need to be surveyed, potentially requiring a larger-aperture telescope and a coronagraph with a smaller inner working angle. Therefore, the sooner we constrain the presence of massive planets orbiting potential HWO target stars, the easier and less costly it will be to adjust key aspects of HWO's architecture. In this work, we uniformly analyze over 153,000 public radial velocity (RV) observations of 120 potential HWO target stars to derive mass limits on planetary companions. The RVs were measured by 23 spectrographs located at 15 observatories around the world, with the first observations going back to 1987. Based on empirical search completeness tests, we determine that undetected Jupiter-mass (Saturn-mass) planets may be hiding in up to 38% (53%) of the HZs of targets in the ExEP Mission Star List. The median mass sensitivity limit in the middle of the conservative HZ is approximately 48M_{Earth}_. We also provide updated parameters for 53 known companions, and we detect at least 26 additional RV signals corresponding to stellar activity and 4 signals that are planet candidates. We note that 44 of the ExEP stars lack substantial RV monitoring history, and we advocate for community-coordinated observing campaigns of these stars using moderate-precision RV facilities.
Author(s): Harada C.K.; Dressing C.D.; Turtelboom E.V.; Kane S.R.; Blunt S.,Dietrich J.; Hinkel N.R.; Li Z.; Mamajek E.; Rice M.; Tuchow N.W.,Wittenmyer R.A.; Chin C.; Fernandez A.; Kulkarni S.; Lin E.; Liu N.,Liu R.; Nathan A.; Zbriger A.
IVOA id: ivo://cds.vizier/j/aj/170/343

Linelist used for the analysis of BH3

2026-09-07T07:45:41Z

Description: The Gaia BH3 system hosts the most massive known stellar-origin black hole and a low-mass metal-poor companion whose chemical composition may constrain early explosive nucleosynthesis processes. We investigate the chemical abundances of the companion in order to constrain the formation of this remarkable system. We perform a detailed analysis of high-resolution ESO-UVES spectra of the companion. 51 elements from lithium to uranium were investigated through spectral synthesis, including 15 treated in NLTE. We compare the resulting pattern to r-process enriched stars, to nucleosynthesis models and to stars of the ED-2 stream, from which BH3 is thought to originate. The abundance pattern of the BH3 companion is consistent with that of r-I stars and is well reproduced by a combination of core-collapse supernova yields and an r-process component. The chemical patterns of four ED-2 stars closely match that of the companion, particularly after accounting for different levels of mixing of the enriched material with the ambient gas. The present analysis provides the most detailed chemical characterisation of a metal-poor star associated with a stellar-mass black hole. The chemical similarity with ED-2 stars argue against local pollution across the binary system. The abundances instead reflect early spatially inhomogeneous enrichment of the progenitor cluster.
Author(s): Vanden Broeck G.; Merle T.; Mai N.T.; Van Eck S.; Goriely S.; Siess L.,Jorissen A.; Hoai D.T.
IVOA id: ivo://cds.vizier/j/a+a/713/l9

High radial velocity stars abundances

2026-09-07T07:44:42Z

Description: Old, metal-poor stars are perfect tracers of the formation of the Milky Way. The combination of chemical and kinematic investigations into them provides an insight into accretion episodes in the past history of our Galaxy. We present here a detailed chemical abundance analysis of 16 metal-poor stars, selected from the RAVE survey, which are characterised by a high radial velocity. We derived stellar parameters from Gaia photometry and parallaxes. Using high-resolution spectra obtained with UVES at the ESO-VLT, we determined elemental abundances for alpha-, iron-peak, and neutron-capture elements using the MYGISFOS pipeline. Departures from local thermodynamic equilibrium, where available, were investigated. We used the SPInS bayesian inference pipeline to derive ages for all the stars. Actions and other dynamical quantities were computed using the galpy pipeline applying the Galactic potential MWPotential2014, in order to classify the stars kinematically. The stars span a wide metallicity range (-1.2<~[Fe/H]<~-2.9) and exhibit kinematic properties consistent with the outer halo population. Star C0213360-505024, [Fe/H]=-1.4, appears to have an age of 1.3Gyr and a mass of 1.6M_{sun}_. Based also on its kinematics and line broadening, which we attribute to stellar rotation, we argue that this star is young and not an evolved blue straggler. The available evidence points towards an accreted origin for this star and we speculate about its possible progenitor. The other 15 stars have ages compatible with an old population.
Author(s): Alazzawi J.M.K.; Caffau E.; Bonifacio P.; Caliskan S.; Monaco L.,Sbordone L.; Lombardo L.
IVOA id: ivo://cds.vizier/j/a+a/713/a60

FUV flux inferred distribution in Orion stars

2026-09-07T07:39:41Z

Description: Orion is the closest region hosting active star formation and young OBA stars. Accurately determining the far-ultraviolet (FUV) flux at its stellar population is essential to connect stellar and protoplanetary disc properties to the environment. We (1) accurately estimated the FUV flux and its distribution at a numerous stellar population of Orion by statistically accounting for the uncertainty in parallax measurements, and (2) investigated the relation between stellar accretion and external FUV radiation field by comparing observations and disc evolution models. We selected a large stellar population in Orion (within a 6 deg radius of the Orion Nebula Cluster core), assigned sub-cluster memberships, and used the two-dimensional sub-cluster geometry to infer three-dimensional separations from OBA stars and compute the FUV flux (and its uncertainty) at each stellar position. We studied the accretion luminosities (Lacc) inferred from Halpha emission in Gaia XP spectra of Orion sources and determined their detection fraction as a function of age and FUV flux. We compared the results with population synthesis models of viscous discs experiencing external photoevaporation. We provided a publicly available table of FUV fluxes at ~8600 stars in Orion. Most of this stellar population is weakly FUV-irradiated, <10^2^ G0, ~35% is intermediately irradiated, 10^2^-10^4^ G0, and only ~5% has FUV fluxes >10^4^ G0. Gaia-based Lacc decreases with age, and Halpha detection fraction declines more rapidly in regions with strong FUV fluxes (>10^2^ G0) than in regions exposed to weaker FUV fluxes (<10^2^ G0), broadly consistent with the model. This result may suggest that external photoevaporation efficiently depletes strongly FUV-irradiated accretion discs, but it is not sufficient to reliably confirm this conclusion. The tools we provided for accurately computing FUV fluxes at the Orion stellar population will be essential for targeting sources in future observations aimed at assessing the role of external photoevaporation on protoplanetary disc. Our study highlights the need for additional measurements of stellar and disc properties across the Orion population, covering the FUV flux range 1-10^5^ G0.
Author(s): Anania R.; Winter A.J.; Vioque M.; Rosotti G.P.; Beccari G.; Lodato G.,Malanga L.A.; Piscarreta L.; Somigliana A.; Testi L.; Toci C.
IVOA id: ivo://cds.vizier/j/a+a/713/a57

Images from VLT observations of nearby AGB stars

2026-09-07T07:32:35Z

Description: We present the largest catalogue of asymptotic giant branch (AGB) stars, 45 targets in total, observed in polarized light at high angular resolution (~20 milliarcsec). The main goal of the study is to detect and characterize dust shells in the close environment of nearby AGB stars. This work also aims to systematically classify the AGB star circumstellar morphologies obtained with the SPHERE instrument installed at the Very Large Telescope (VLT), thanks to its Zurich Imaging Polarimeter (ZIMPOL). We extracted and analyzed polarized intensity maps for 45 AGB stars, constructed from polarimetric observation data obtained with the SPHERE/ZIMPOL instrument. An ellipse fitting method was applied to characterize the circumstellar envelopes. Stellar parameters (luminosity, effective temperature, surface gravity, extinction, metallicity) were compiled and recalculated when necessary from spectral energy distribution (SED) fitting using the Python SED fitting tool (PySSED) software. These data were then used to train a random forest machine learning model to determine the most discriminating variables for a resolved envelope around a given star. We constructed polarization maps for all stars in the sample, revealing a wide diversity of circumstellar morphologies. We detected 16 dusty circumstellar envelopes, including three never observed before. They display a wide range of morphologies, all of them showing a clear departure from spherical symmetry, indicating interaction with a companion or asymmetric mass ejections. The random forest model identified optimal thresholds for several physical parameters, thus providing robust criteria to anticipate SPHERE's ability to resolve dust envelopes around AGB stars. These results facilitate the selection of targets for future observations and contribute to a better understanding of the evolution mechanisms of circumstellar envelopes.
Author(s): Badolo N.A.; Lagadec E.; N'Diaye M.; Kam S.Z.; McDonald I.; Matter A.,Koulidiati J.; Abe L.; Carbillet M.; Fusco T.
IVOA id: ivo://cds.vizier/j/a+a/713/a56

HST survey of Magellanic Cloud star clusters

2026-09-07T07:30:45Z

Description: Binary stars are key tracers of the dynamical evolution of star clusters and provide important constraints on stellar populations and mass functions. The Magellanic Clouds host clusters with a wide range of ages and masses, offering an ideal laboratory to investigate these properties in regimes poorly sampled in the Milky Way. We aim to characterize the binary populations, mass functions (MFs), blue straggler (BS) content, and structural parameters of intermediate-age Magellanic Cloud clusters, and to explore their dependence on global cluster properties. We analyzed high-precision Hubble Space Telescope photometry for 16 clusters obtained with ACS/WFC and WFC3/UVIS. Structural parameters were derived from stellar density profiles. Binary fractions were measured using the binary map technique, focusing on systems with mass ratios q>0.7. We derived MFs accounting for unresolved binaries and identified candidate BS populations from color-magnitude diagrams. The fraction of binaries with q>0.7 ranges from 5% in NGC 2121 up to 13% in NGC 2173, with a mass-ratio distribution that is consistent with being flat on average. By combining our results with literature data, we confirm a clear anticorrelation between the core binary fraction and cluster mass, while no significant dependence on cluster age is found. The clusters follow the established relation between age and core radius, although with substantial scatter at fixed age. Within the narrow age range explored here, clusters exhibiting steeper MFs are found to have smaller core radii. We find no evidence of a correlation between the fractions of binaries and BS fractions. These findings are consistent with a scenario in which dynamical evolution plays a primary role in the formation of binary populations. The connection between MF slope and structural parameters provides new constraints on cluster evolution and suggests a link between MF slope and structural evolution.
Author(s): Muratore F.; Legnardi M.V.; Milone A.P.; Cordoni G.,Mastrobuono-Battisti A.; Marino A.F.; Ziliotto T.; Dondoglio E.,Bortolan E.; Lagioia E.P.
IVOA id: ivo://cds.vizier/j/a+a/713/a24