VO Fresh

Wave breaking predictions for hot Jupiters

2026-05-06T08:59:36Z

Description: Tidal interactions shape the evolution of close-in giant planets, and internal-gravity-wave breaking offers an efficient pathway for dynamical-tide dissipation, though its population-wide impact remains poorly constrained. We aim to quantify wave-breaking tidal dissipation for 550 hot Jupiters, accounting for stellar-parameter uncertainties, and to identify the most promising systems for detecting orbital decay through transit timing. Stellar masses, radii, and ages were homogeneously redetermined from spectroscopic and photometric data using isochrone fitting. For each system, these parameters were propagated through a dedicated MESA model grid to calculate the tidal quality factor, wave-breaking probability, orbital decay rate, and transit- timing diagnostics. Long-term orbital evolution was modelled to predict planetary destruction timescales. Wave breaking is predicted to be largely inactive in pre-intermediate-age main sequence (IAMS) stars. For hosts with masses <1.2M_{sun}_, it becomes effective after the IAMS, while in more massive stars it begins between the IAMS and the terminal-age main sequence (TAMS). The tidal quality factor for systems undergoing wave breaking peaks between 10^6 and 10^7, consistent with population-level inferences. About 43 % of planets, mostly with periods <3.5d, are expected to inspiral on the main sequence, providing a physical explanation for the observed tendency of hot Jupiters to orbit younger stars. A further 41 % inspiral during post-main- sequence evolution within the stages considered. Roche-limit disruption dominates overall, with engulfment occurring mainly for planets with periods > 5-6d. Systems with periods <1d, that could in principle experience the strongest tidal forcing, are unlikely to trigger wave breaking, leaving planets on stable orbits. Conversely, the most rapidly inspiralling systems with high wave-breaking probability may display measurable orbital-period shortening only over multi-decade baselines, eluding immediate detection. By contrast, the demographic imprint of wave breaking on occurrence rates should emerge more readily, with the first signs already visible in current population statistics.
Author(s): Golonka J.; Maciejewski G.
IVOA id: ivo://cds.vizier/j/a+a/709/a60

Perseus cluster LOFAR sub-80MHz LBA images

2026-05-06T08:17:11Z

Description: The Perseus cluster is a nearby cool-core galaxy cluster that hosts an archetypal radio mini-halo. Recent Low Frequency Array (LOFAR) High Band Antenna (HBA) observations at 120-168MHz have revealed the presence of a giant radio halo within the cluster with a size of 1.1Mpc enveloping the mini-halo. By exploring the spectral properties of the radio emission at low frequencies, we can gain deeper insights into the nature of this emission and improve our understanding of its origin. Here we present LOFAR Low Band Antenna (LBA) images of the cluster between 30.0-57.7MHz, with a resolution of 19.2"x15.0" and a r.m.s. noise of 3.7mJy/beam . In our images, we detect both the mini-halo and giant radio halo. We measured the spectral indices between 44 and 144 MHz of the mini-halo and giant radio halo to be -1.34+/-0.10, and -1.01+/-0.11, respectively. An alternative and more direct measurement of the spectrum of the giant radio halo results in a spectral index of -1.28+/-0.15. The discrepancy between both values is caused by the poor ionospheric conditions. In addition, we study two X-ray 'ghost cavities' in the cluster. These cavities are thought to have been produced by an older outburst from the central AGN 3C 84. We measure a spectral index between 44 and 144MHz for the radio plasma in these cavities of -1.86+/-0.12 and -1.90+/-0.12 for the northwest and southern ghost cavities, respectively. Furthermore, by including VLA 352MHz data, we find that the spectrum steepens at higher frequencies. These results are consistent with the ghost cavities being filled with old and aged radio plasma. We also detect the tailed radio galaxies NGC 1265 and IC 310. In our analysis, these sources show signs of spectral steepening along their tails.
Author(s): Groeneveld C.; van Weeren R.J.; Gendron-Marsolais M.-L.; Osinga E.,Botteon A.; de Gasperin F.; Cianfaglione M.; di Gennaro G.; Brunetti G.,Cassano R.
IVOA id: ivo://cds.vizier/j/a+a/709/a64

0446+11 15GHz VLBA images in Stokes I, Q, U

2026-05-06T08:14:56Z

Description: The physical mechanisms driving neutrino and electromagnetic flares in blazars remain poorly understood. We investigate a prominent multimessenger flare in the quasar PKS 0446+11 to identify the processes responsible for its high-energy emission. We analyzed the IceCube-240105A high-energy neutrino event together with contemporaneous observations in the gamma-ray, X-ray, optical, and radio bands. We modeled the on- and off-flare spectral energy distributions (SEDs) within a single-zone leptohadronic framework. Multi-epoch VLBA observations from the MOJAVE program provide parsec-scale polarization data that complement the multiwavelength light curves. No significant time delay was detected between the neutrino arrival and the flares in different energy bands. This is consistent with an extremely small jet viewing angle below 1 deg, inferred from the parsec-scale polarization structure. The flare can be reproduced by the injection of a proton population and an increase in the Doppler factor from 18 to 24. We also detected an approximately 90 deg rotation of the EVPA in the parsec-scale core during the initial phase of the flare, indicating the emergence of a shock formed by the change in the bulk plasma speed. Our comprehensive multimessenger analysis demonstrates that the extreme beaming and subdegree viewing angle of this distant blazar can account for the observed neutrino and electromagnetic activity. These findings strengthen the case for blazars as efficient accelerators of hadrons and significant contributors to the observed high-energy neutrino flux.
Author(s): Kovalev Y.Y.; Aller M.F.; Erkenov A.K.; Gomez J.L.; Homan D.C.,Kivokurtseva P.I.; Kovalev Yu.A.; Lister M.L.; de la Parra P.V.,Plavin A.V.; Popkov A.V.; Pushkarev A.B.; Readhead A.C.S.,Shablovinskaia E.; Sotnikova Yu.V.; Spiridonova O.I.; Troitsky S.V.,Vlasyuk V.V.
IVOA id: ivo://cds.vizier/j/a+a/709/a50

3C 84 jet images

2026-05-06T08:11:05Z

Description: The location of gamma-ray creation and emission within extra-galactic jets is a matter of active debate. One particularly well-suited source to pinpoint the location is the nearby, bright radio galaxy 3C 84, harbouring a powerful jet. Here we investigate the origin of gamma-rays measured during a recent gamma-ray flare, by analysing the linear polarisation signal of close-in-time very long baseline interferometry (VLBI) observations at centimetre and millimetre wavelengths. While 3C 84 is overall almost unpolarised, we find that close-in-time to the gamma-ray flare peak regions at parsec-scale distances from the central engine shows a fractional linear polarisation increase. Under the physically well-motivated assumption of a causal relation between this polarisation enhancement and the gamma-ray flare, and combined with insights from concurrent X-ray polarisation measurements, the gamma-rays being created in this region is a physically motivated scenario, in a process consistent with synchrotron self-Compton.
Author(s): Paraschos G.F.; Liodakis I.; Jorstad S.; Kovalev Y.Y.; Chakraborty S.,Marin F.; Ehlert S.R.; Traianou E.; Debbrecht L.C.; Agudo I.; Barnouin T.,Casey J.J.; Di Gesu L.; Kaaret P.; Kim D.E.; Kislat F.; Ratheesh A.,Saade M.L.; Tombesi F.; Marscher A.; Gomez J.-L.; Pushkarev A.B.,Savolainen T.; Myserlis I.; Gurwell M.; Keating G.; Rao R.; Kang S.,Lee S.-S.; Kim S.; Yeon Cheong W.; Jeong H.-W.; Song C.; Li S.; Nam M.-S.,Alvarez-Ortega D.; Casadio C.; Chen C.-T.; Costa E.; Churazov E.,Ferrazzoli R.; Galanti G.; Khabibullin I.; O'Dell S.L.; Pacciani L.,Roncadelli M.; Roberts O.J.; Soffitta P.; Swartz D.A.; Tavecchio F.,Weisskopf M.C.; Zhuravleva I.
IVOA id: ivo://cds.vizier/j/a+a/709/a92

1782 Mira variables candidates with VVV survey

2026-05-06T00:00:00Z

Description: The properties of the Milky Way's nuclear stellar disc give crucial information on the epoch of bar formation. Mira variables are promising bright candidates to study the nuclear stellar disc, and through their period-age relation dissect its star formation history. We report on a sample of 1782 Mira variable candidates across the central 3*3 deg^2^ of the Galaxy using the multi-epoch infrared VISTA Variables in Via Lactea (VVV) survey. We describe the algorithms employed to select candidate variable stars and then model their light curves using periodogram and Gaussian process methods. By combining with WISE, 2MASS, and other archival photometry, we model the multiband light curves to refine the periods and inspect the amplitude variation between different photometric bands. The infrared brightness of the Mira variables means many are too bright and missed by VVV. However, our sample follows a well-defined selection function as expected from artificial star tests. The multiband photometry is modelled using stellar models with circumstellar dust that characterize the mass-loss rates. We demonstrate how ~>90 per cent of our sample is consistent with O-rich chemistry. Comparison to period-luminosity relations demonstrates that the bulk of the short period stars are situated at the Galactic Centre distance. Many of the longer period variables are very dusty, falling significantly under the O-rich Magellanic Cloud and solar neighbourhood period-luminosity relations and exhibit high mass-loss rates of ~2.5*10^-5^M_{sun}_yr^-1^. The period distribution appears consistent with the nuclear stellar disc forming ~> 8 Gyr ago, although it is not possible to disentangle the relative contributions of the nuclear stellar disc and the contaminating bulge.
Author(s): Sanders J.L.; Matsunaga N.; Kawata D.; Smith L.C.; Minniti D.; Lucas P.W.
IVOA id: ivo://cds.vizier/j/mnras/517/257

Extended cluster radio sources catalog

2026-05-06T00:00:00Z

Description: The radio jets of radio galaxies in galaxy clusters are often bent due to the ram pressure of the intracluster medium. Most studies of bent radio tails initially identified tailed sources and then attempted to characterise their environments. In this paper we take an alternative approach, by starting with a well-defined sample of galaxy clusters and subsequently identifying tailed radio sources in these known environments. Our sample consists of 81 galaxy clusters from the Planck ESZ cluster sample. We present a catalogue of 127 extended cluster radio sources, including brightest cluster galaxies, obtained by visually inspecting Karl G. Jansky Very Large Array (1-2 GHz) observations. We have determined the bending angle of 109 well-structured sources, and classified them accordingly: 84 narrow-angle tailed sources (NATs), 16 wide-angle tailed sources (WATs), and 9 non-bent radio sources (i.e. with bending angles of less than 15{deg}). We find a negative correlation between the bending angle and the distance to the cluster centre (impact radius), and we observe that NATs generally have smaller impact radii than the regular galaxy population and WATs. We present a phase-space diagram of tailed radio galaxy velocities and impact radii and find that NATs have a significant excess in the high-velocity and low-impact radius region of phase space, indicating they undergo the largest amount of ram pressure bending. We compared the results from our sample with those for jellyfish galaxies, and suggest that the mechanism responsible for bending the radio tails is similar to the stripping of gas in jellyfish galaxies, although tailed radio galaxies are more concentrated in the centre of the phase space. Finally, we find that NATs and WATs have the same occurrence ratio in merging and relaxed clusters. However, their distribution in the phase-space is significantly different. We report an excess of NATs in the high-velocity and low-impact-radius phase-space region in merging clusters, and an excess of NATs in relaxed clusters in the low-velocity and low-impact-radius region.
Author(s): van der Jagt S.; Osinga E.; van Weeren R.J.; Miley G.K.; Roberts I.D.,Botteon A.; Ignesti A.
IVOA id: ivo://cds.vizier/j/a+a/699/a66

Lithium study with GC NGC 6752

2026-05-06T00:00:00Z

Description: This paper presents a chemical abundance analysis of 217 stars in the metal-poor globular cluster NGC 6752, distributed from the turn-off to the lower red giant branch. Al and Li abundances were derived through spectral synthesis applied to spectra collected with FLAMES, in both GIRAFFE and UVES modes. The work aims to gain insight into the nature of the polluter(s) responsible for the abundance variations and the C-N, Na-O, Al-Mg anticorrelations associated with the multiple-population phenomenon. We found a plateau at A(Li) = 2.33 +/- 0.06 dex in unevolved stars, with the average Li content decreasing continuously down to ~1.25 dex at the bottom of the red giant branch. As expected in the classic anticorrelation scenario, we found stars low in Al and high in Li abundance, and stars high in Al and low in Li. However, in addition, we also found evidence of Al-rich, second-generation stars with high Li content. This finding suggests the need for Li production, known to happen in intermediate-mass (~4-8 M_{Sun}_) asymptotic giant branch stars through the Cameron-Fowler mechanism. It is worth noting that the Li abundance observed in Al-rich stars never exceeds that in Al- poor stars.
Author(s): Schiappacasse-Ulloa J.; Lucatello S.; Rain M.J.; Pietrinferni A.
IVOA id: ivo://cds.vizier/j/mnras/511/231

Polarization characteristics of FRB 20240114A

2026-05-05T16:39:22Z

Description: Fast radio bursts (FRBs) are transient radio bursts of extragalactic origin characterized by millisecond durations and high luminosities. We report on observations of FRB 20240114A conducted with the Robert C. Byrd Green Bank Telescope at frequencies ranging from 720 to 920MHz. A total of 437 bursts were detected, with a single observation recording 365 bursts over 1.38hr, corresponding to a burst rate of 264 bursts per hour. The average rotation measures (RMs) were 347.0+/-1.0rad/m2 on 2024-Feb-23, and 353.7+/-0.6rad/m2 on 2024-Mar-01. Of the 301 bursts with detected RMs, 81% have a linear polarization fraction greater than 90%, and 14% exhibit circular polarization with a signal-to-noise ratio >5. Our sample also displayed polarization angle swings. We compared the linear polarization fraction of FRB 20240114A with those of the repeating sources FRB 20201124A and FRB 20220912A. Our analysis reveals that all three exhibit similar distributions in both linear and circular polarization fractions. These results indicate that the three sources share the same radiation mechanism. We analyze the fluence and waiting-time distributions of FRB 20240114A, revealing a right-skewed fluence distribution and a bimodal waiting-time structure, suggesting intrinsic emission timescales and potential multiple burst populations. Additionally, we present a novel method to determine the frequency range of bursts based on their spectral characteristics. This algorithm is independent of spectral models and remains unaffected by the removal of interference-affected channels in the data, ensuring robust performance.
Author(s): Xie J.-T.; Feng Yi; Li Di; Zhang Y.-K.; Zhou D.-K.; Qu Y.; Cui X.-H.,Fang J.-H.; Xu J.-Y.; Miao C.-C.; Yuan M.; Tsai C.-W.; Wang P.; Niu C.-H.,Chen X.; Xue M.; Zhang J.
IVOA id: ivo://cds.vizier/j/apjs/278/49

KMTNet Synoptic Survey of Southern Sky (KS4) DR1

2026-05-05T13:51:08Z

Description: We present the first public data release (DR1) of the KMTNet Synoptic Survey of Southern Sky (KS4). This deep, wide-field imaging survey covers a southern footprint of -85{deg}<DEC<-28.8{deg} in the B, V, R, and I bands using a network of three 1.6-m telescopes. Although primarily designed to secure reference imaging for gravitational wave counterpart identification, DR1 delivers science-ready data for ~4000deg2 to enable a broad range of astrophysical research. The release includes deep co-added images reaching median 5{sigma} depths of 22.0-23.5 AB mag. It is accompanied by two source catalogs containing over 200 million sources with SNR>5: an I-band-selected forced-photometry catalog optimized for consistent colors, and a band-merged catalog offering enhanced completeness. Validation demonstrates robust data quality, characterized by mean astrometric offsets of +0.054+/-0.129arcsec in RA and -0.015+/-0.120arcsec in DEC relative to Gaia DR3. Photometric uniformity for point sources is maintained within +/-0.03mag relative to Gaia XP for 97.5-99.8% of the footprint across all four bands. A key advantage of KS4 is its uniform and contiguous spatial coverage. It extends to fainter magnitudes than other uniform surveys while filling irregular gaps in existing deep datasets.
Author(s): Chang S.-W.; Im M.; Jeong M.; Kim J.; Park B.; Lee J.; Buckley D.A.H.,Cooke J.; Jung S.; Kim D.-J.; Kim J.H.; Kim Y.; Lee C.-U.; Lee S.-K.,Paek G.S.H.; Shin J.
IVOA id: ivo://cds.vizier/ii/391

Rc-band polarimetric survey in Sgr spiral arm

2026-05-05T08:28:19Z

Description: The Galactic global magnetic field is thought to play a vital role in shaping Galactic structures such as spiral arms and giant molecular clouds. However, our knowledge of magnetic field structures in the Galactic plane at different distances is limited, as measurements used to map the magnetic field are the integrated effect along the line of sight. In this study, we present the first ever tomographic imaging of magnetic field structures in a Galactic spiral arm. Using optical stellar polarimetry over a 17'x10' field of view, we probe the Sagittarius spiral arm. Combining these data with stellar distances from the Gaia mission, we can isolate the contributions of five individual clouds along the line of sight by analyzing the polarimetry data as a function of distance. The observed clouds include a foreground cloud (d<200pc) and four clouds in the Sagittarius arm at 1.23, 1.47, 1.63, and 2.23kpc. The column densities of these clouds range from 0.5 to 2.8x10^21^cm^-2^. The magnetic fields associated with each cloud show smooth spatial distributions within their observed regions on scales smaller than 10pc and display distinct orientations. The position angles projected on the plane of the sky, measured from the Galactic north to the east, for the clouds in increasing order of distance are 135{deg}, 46{deg}, 58{deg}, 150{deg}, and 40{deg}, with uncertainties of a few degrees. Notably, these position angles deviate significantly from the direction parallel to the Galactic plane.
Author(s): Doi Y.; Nakamura K.; Kawabata K.S.; Matsumura M.; Akitaya H.; Coude S.,Rodrigues C.V.; Kwon J.; Tamura M.; Tahani M.; Magalhaes A.M.,Santos-Lima R.; Angarita Y.; Versteeg J.; Haverkorn M.; Hasegawa T.,Sadavoy S.; Arzoumanian D.; Bastien P.
IVOA id: ivo://cds.vizier/j/apj/961/13

VLBI images of the FRII radio galaxy 3C 452

2026-05-05T07:21:54Z

Description: We present a comprehensive multifrequency VLBI analysis of the FRII high-excitation radio galaxy 3C 452, aiming to resolve and analyse for the first time its twin-jet structure on sub-parsec scales. Our dataset comprises High Sensitivity Array (HSA) observations at 4.9, 8.4, 15.4, 23.6, and 43.2GHz. Using fitting methods applied in both the visibility and image planes, we traced the jet expansion from scales of a few thousand up to nearly 10^5^ Schwarzschild radii on both the approaching and receding jets. Our study provides the first detailed description of the twin-jet system in 3C 452 on VLBI scales. Both jet and counter-jet are resolved down to scales of a few thousand Schwarzschild radii, revealing a symmetric parabolic expansion with power-law indices k~0.66 for the jet and k~0.47 for the counter-jet. The jet-to-counter-jet intensity ratio remains nearly constant on larger scales but increases sharply within the inner 1-1.5mas. The brightness temperature analysis yields low Doppler factors indicating Doppler de-boosting due to the large viewing angle and/or a magnetically dominated jet base.
Author(s): Madika E.; Boccardi B.; Ricci L.; Grandi P.; Torresi E.; Giovannini G.,Kadler M.; Zensus J.A.
IVOA id: ivo://cds.vizier/j/a+a/709/a89

Star-galaxy classification in deep LSST data

2026-05-05T07:21:02Z

Description: The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will produce unprecedentedly deep and wide photometric catalogues, enabling transformative studies of faint stellar systems such as the research of ultra-faint dwarf (UFD) galaxies. A critical challenge for these studies is reliable star-galaxy separation at faint magnitudes, where compact background galaxies increasingly contaminate stellar samples. This work aims to assess the performance of supervised machine-learning techniques for star-galaxy separation in LSST-like data, to quantify the relative importance of morphological and photometric information, and to identify the most effective combinations of input features for minimizing galaxy contamination while preserving stellar completeness in the faint regime relevant for UFD searches. We applied a Random Forest classifier to observations of the Extended Chandra Deep Field South from LSST Data Preview 1 (DP1), the deepest field observed within the DP1. We constructed a curated sample of bona fide stars and galaxies using spectroscopic data, Gaia DR3, and multi-band photometric catalogues. We trained and validated the classifier using several configurations of LSST-based input features, including multi-band colours, the LSST morphological parameter refExtendedness, and photometric uncertainties. We find that LSST multi-band photometry alone delivers a good star-galaxy separation, significantly outperforming morphology-based classification at faint magnitudes. Colours involving the u band are essential to provide a robust star-galaxy separation. Furthermore, explicitly including photometric uncertainties as input features yields the best overall performance. Across all configurations that include all the six LSST filters, galaxy contamination remains negligible almost the whole magnitude range probed in this work (i.e. r<27.5mag). Our results demonstrate that supervised machine-learning methods, when combined with LSST multi-band photometry, can effectively suppress galaxy contamination in deep stellar catalogues, ensuring that searches for UFDs are not significantly compromised. Given that the DP1 data are shallower and have poorer seeing than the final LSST survey, our findings should be regarded as a conservative lower limit on the performance achievable with the full 10-year dataset. To facilitate further development, we will publicly release the curated star-galaxy sample used in this work.
Author(s): Gatto M.; Ripepi V.; Bellazzini M.; Tortora C.; Dall'Ora M.
IVOA id: ivo://cds.vizier/j/a+a/709/a79

TOI-4552 radial velocity time series

2026-05-05T07:19:29Z

Description: A particularly intriguing subclass of rocky exoplanets are the ultra- short period (USP) worlds that orbit their host stars in less than a day. These planets are particularly rare around M dwarf stars, with so far only ten that have a constrained mass and radius. We present the validation and characterisation of the ultra-short period (0.3 days), Earth-sized planet TOI-4552 b orbiting a nearby (27.26pc away) M4.5V dwarf. Complementing the TESS photometry, ground-based transit observations from LCO, ExTrA and SPECULOOS validated the planetary radius and cleared the field of any contaminants. Speckle imaging with Zorro (Gemini-S) rules out false positive scenarios caused by eclipsing binary sources. Spectroscopic observations with NIRPS and HARPS were used to obtain stellar abundances, constrain the planetary mass, and, in conjunction with the transit observations, estimate the orbital parameters. TOI-4552 is a quiet star exhibiting no short-term stellar variations seen in photometric or radial velocity data that can be associated to stellar rotation. Long-term photometric data from ASAS-SN also suggests a lack of activity signals. TOI-4552 b (Mp=1.83+/-0.47M_{Earth}_, Rp=1.11+/-0.04R_{Earth}_) lies between the Earth-like and iron-rich composition tracks on the Mass-Radius diagram. The exopie interior structure model, without constraints from refractory abundance ratio, yields a core mass fraction (CMF) of 0.54^+0.17^_-0.25_ and a bulk density of 7.74g/cm^3^. Since the CMF spans a wide range due to the large uncertainty on the mass, the definitive interior composition cannot be determined with the current dataset. TOI-4552 b hints as being marginally more iron- rich compared to the Earth but confirmation of its status requires additional, precise radial velocity measurements. Combined with its high emission spectroscopic metric (ESM=19.5), negligible stellar activity and short orbital period, TOI-4552 b emerges as a compelling target for atmospheric and surface composition studies with JWST.
Author(s): Srivastava A.; Doyon R.; Bouchy F.; Artigau E.; Cadieux C.; Gromek N.,Delgado-Mena E.; Messias Y.S.; Bonfils X.; de Lima Gomes R.; Barros S.C.C.,Benneke B.; Bryan M.; Cloutier R.; Cowan N.B.; Cristo E.; Delfosse X.,Dumusque X.; Ehrenreich D.; Gonzalez Hernandez J.I.; Lafreniere D.,de Castro Leao I.; Lovis C.; Suarez Mascareno A.; Canto Martins B.L.,De Medeiros J.R.; Mignon L.; Mordasini C.; Pepe F.; Rebolo R.; Rowe J.,Santos N.C.; Segransan D.; Udry S.; Valencia D.; Wade G.; Almenara J.M.,Collins K.A.; Conti D.M.; Dransfield G.; Ducrot E.; Essack Z.,Fontinele D.O.; Forveille T.; Jafariyazani M.; Lamontagne P.; L'Heureux A.,Al Moulla K.; Osborn A.; Parc L.; Rodriguez D.R.; Schwartz R.P.; Scott M.G.,Shporer A.; Stefanov A.K.; Timmermans M.; Triaud A.H.M.J.; Wardenier J.P.,Weisserman D.; Zuniga-Fernandez S.
IVOA id: ivo://cds.vizier/j/a+a/709/a73

GALAH DR4 halo substructures catalog

2026-05-05T07:16:59Z

Description: Recent studies have revealed that the Milky Way's stellar halo is a composite of stellar populations of different origins, including multiple accretion events. To better understand how the Milky Way and other spiral galaxies were formed, it is necessary to thoroughly characterize the chemical and kinematic properties of these structures. We search for kinematic structures of the stellar halo to find any substructures within them (when indeed present) and charac- terize the chemodynamical properties of the identified groups with the GALAH DR4 and Gaia surveys. We applied wavelet transforms in the space defined by a square root of radial action (Jr) and azimuthal action (Lz) to search for kinematic overdensities. Then, we selected stars in the detected structures and investigated their elemental abundances to determine their origin. Additionally, we checked for any contamination from other stellar populations within the detected groups with the unsupervised machine learning algorithm t-Distributed Stochastic Neighbor Embedding (t-SNE), for which we performed chemical tagging in a high-dimensional parameter space using 15 elemental abundances as input. We recovered five kinematic structures in the action space with the wavelet transform. These groups are the Galactic disk, Splash, Gaia-Sausage-Enceladus (GSE), Thamnos1, and Thamnos2. We found that GSE has two peaks with the wavelet transform. One of these peaks is located at SQRT(Jr)~=25kpc.km/s and is a result of contamination from disk stars. The other peak corresponds to the "cleanest" GSE population and is located above SQRT(Jr)~=40kpc.km/s. We also detected three peaks in Thamnos. We linked two of them to Thamnos1, while the peak with the stars on the most retrograde orbits was linked to Thamnos2. The t-SNE algorithm confirmed these findings. We also analyzed individual elemental abundances of each group and found that Thamnos2 has a higher [alpha/Fe] ratio than the other groups and that iron-peak elements are more abundant in the Splash than in the halo groups, while the halo structures retain a higher r-process signature than the splashed disk. A multiply peaked substructure we observe in action space in GSE and Thamnos suggests that the splashed disk extends beyond the borders of prograde orbits. Each of the four halo groups studied in this paper have unique chemodynamical properties that confirm their extra-galactic origin.
Author(s): Kushniruk I.; Youakim K.; Lind K.; Buder S.; Kos J.; Feuillet D.,Martell L.S.; de Grijs R.; Lewis F.G.; Bland-Hawthorn J.; Da Costa G.,Hayden M.; Zucker D.; Zwitter T.; Sharma S.
IVOA id: ivo://cds.vizier/j/a+a/709/a69

EVN Data Archive obs_radio Table

2026-05-04T10:05:20Z

Description

An IVOA-defined metadata table for radio measurements, with extra
metadata for interferometric measurements ("visibilities") as well as
single-dish observations. You will almost always want to join this
table to ivoa.obscore (do a natural join).

Author(s)

Mark Kettenis

IVOA id

ivo://jive.eu/__system__/obs-radio/obs_radio

Kilioparsec morphology OIII catalog

2026-05-04T08:13:21Z

Description: Active Galactic Nuclei (AGN) outflows can regulate host galaxy evolution via AGN feedback. Ionised gas outflows have been linked to enhanced radio emission. In the first paper of this series, AGN detected with the International LOFAR Telescope (ILT) at 6" were more likely to host an [OIII] 5007{AA} outflow than AGN not detected, although only high-powered jets were ruled out as the origin of radio emission. New wide-field, sub-arcsecond resolution imaging at 144 MHz with the ILT now enables a resolved morphological study of this sample. We present the first wide-field, sub-arcsecond images of the Bootes Deep Field at 144 MHz, detecting 4074 sources in the ~0.3" image with a central sensitivity of 33.8uJy/beam. For 47 AGN matched in AGN luminosity, we probe radio emission on kiloparsec-scales to investigate correlations with [OIII] outflows. This sample spans z<0.83, 10^40^<L[OIII]<10^43^erg/s, and 10^21^<L144MHz<10^24.5^W/Hz. We find that if we detect an AGN on both large-scales (6") and small-scales (0.3"), 90+/-7 per cent have an [O III] outflow, compared to 63+/-9 per cent of sources detected on large-scales, but undetected on small-scales. Furthermore, 17+/-6 per cent of sources without an [OIII] outflow are detected on kiloparsec-scales, compared to 51+/-12 per cent of sources with an [OIII] outflow. This implies a connection between [OIII] outflows and kiloparsec-scale radio emission, which is likely AGN-driven. In contrast, AGN without an [OIII] outflow are dominated by diffuse radio emission, likely to be associated with star formation.
Author(s): Escott E.L.; Morabito L.K.; Sweijen F.; Harrison C.M.; Petley J.,de Jong J.M.G.H.J.; van Weeren R.J.; Higginson T.S.; Prandoni I.; Miley G.,Roettgering H.J.A.
IVOA id: ivo://cds.vizier/j/mnras/547/g274

Predicted detections of exoplanets using CHES & HWO

2026-05-01T13:46:12Z

Description: The detection and characterization of habitable planets around nearby stars persist as some of the foremost objectives in contemporary astrophysics. This work investigates the synergistic integration of astrometric and direct imaging techniques by capitalizing on the complementary capabilities of the Closeby Habitable Exoplanet Survey (CHES) and Habitable Worlds Observatory (HWO). Planetary brightness and position vary over time due to phase effects and orbital architecture, information that can be precisely provided by CHES's astrometric measurements. By combining the precise orbital constraints from CHES with the imaging capabilities of HWO, we evaluate the improvements in detection efficiency, signal-to-noise ratio, and overall planet yield. Completeness is quantified as the fraction of injected planets that are successfully detected, while yields are estimated for various scenarios using terrestrial planet occurrence rates derived from the Kepler data set. Our results indicate that prior astrometric data significantly enhance detection efficiency. Under the adopted detection limit, our analysis indicates that prior CHES observations can increase completeness by approximately 10% and improve detection efficiency by factors ranging from 2 to 30. The findings underscore the importance of interdisciplinary approaches in the search for and characterization of habitable worlds.
Author(s): Bao C.; Ji J.; Tan D.; Chen G.; Huang X.; Wang Su; Dong Y.
IVOA id: ivo://cds.vizier/j/aj/170/26

Gaia DR3 dormant compact-object binaries

2026-05-01T11:05:02Z

Description: We present a rigorous identification of candidates for dormant black holes (BHs) and neutron stars (NSs) in binaries using summary statistics from Gaia Data Release 3 (DR3), rather than full orbital solutions. Although Gaia astrometric orbits have already revealed a small sample of compact object binaries, many systems remain undetected due to stringent quality cuts imposed on the published orbits. Using a forward-modelling framework that simulates Gaia observables, in particular the re-normalised unit weight error (ruwe) and radial velocity (RV) scatter, we infer posterior distributions for companion mass and orbital period via Markov chain Monte Carlo (MCMC) sampling, marginalising over nuisance orbital parameters. We validate our approach by comparing the predicted masses and periods against full orbit solutions from DR3, and by successfully recovering known compact object binaries as promising candidates. The method is best suited for systems with red giant primaries, which have more reliable Gaia RV scatter and a light centroid more likely dominated by one component, compared to main-sequence stars, and they are less likely to be triples with short-period inner binaries, which produce confounding signatures. We applied the method to three million giants and identify 389 systems with best-fit companion masses >~3M_{sun}_. Recovery simulations suggest our selection method is substantially more sensitive than the DR3 non-single-star catalogue, particularly for binaries with periods below 1 year and above ~6 years. These candidates represent promising targets for spectroscopic follow-up and Gaia DR4 analysis to confirm the presence of compact objects and build a more complete census of the Galactic BH and NS population. Candidate main-sequence stars with massive companions face a larger set of confounding effects. Therefore, we present an analogous catalogue of 279 additional main-sequence candidates only as an appendix.
Author(s): Mueller-Horn J.; Rix H.-W.; El-Badry K.; Pennell B.; Green M.; Li J.,Seeburger R.
IVOA id: ivo://cds.vizier/j/a+a/709/a62

Hot subdwarf stars physical parameter

2026-05-01T11:01:07Z

Description: The formation mechanisms of spectrally diverse hot subdwarfs remain unclear. While existing mass distribution analyses suggest additional channels beyond helium white dwarf (He-WD) mergers contribute to He-rich subdwarf formation, these conclusions are constrained by limited sample sizes of mass-measured He-rich objects. We developed a deep leaning model which combines a convolution neural network (CNN) together with a squeeze-and-excitation (SE) block to calculate synthetic spectral energy distributions (SEDs) for 1012 spectroscopically confirmed hot subdwarfs. Through directly comparison between synthetic SEDs and observed flux density, we derived stellar parameters (mass, radius, luminosity) for unprecedented number size of hot subdwarf stars, enabling more conclusive channel discrimination than prior studies. The mass distribution of sdB/sdOB stars confirmed the results from model predictions of binary populations synthesis (BPS). A primary and secondary peak (i.e., around 0.56 and 0.4 Msun) is obviously presented in the mass distribution of He-rich hot subdwarf stars. By comparing with the results from the predictions of recent BPS model, it proposed that the merger of two He-WDs could produce most of the observed He-rich hot subdwarf stars, but the mass transfer during the stable Roche lobe overflow (RLOF) phase in binary evolution should be partially conserved.
Author(s): Feng M.; Lei Z.; Kou B.; Dong Y.; Hu K.; Xiao H.; Zhao J.
IVOA id: ivo://cds.vizier/j/a+a/709/a52

FRB 20240114A dynamic spectra of bursts detections

2026-05-01T10:57:55Z

Description: FRB 20240114A is a hyperactive repeating fast radio burst (FRB) source discovered by the CHIME/FRB Collaboration in January 2024. The source has been followed up by numerous radio telescopes, including MeerKAT, uGMRT, and FAST, and has been localized to a dwarf star-forming galaxy at a redshift of z~0.13 with a confirmed persistent radio source. We report observations of FRB 20240114A with the Effelsberg 100-m radio telescope using the Ultra BroadBand (UBB) receiver, covering 1.3-6.0GHz. Over four epochs, we detected more than 700 bursts, providing an unprecedented broadband dataset for statistical analysis of this active repeater. We performed a comprehensive study of the bursts' morphologies, occurrence rates, spectral and temporal widths, and waiting-time distributions across six sub-bands spanning the UBB frequency range. The bursts exhibit four main spectral morphologies, including simple, complex, and frequency-drifting structures. No bursts were detected across the full 1.3-6GHz band, confirming band-limited emission. Burst widths show modest frequency evolution, while fractional bandwidths remain roughly constant at ~10%. Burst rates vary strongly with time and frequency, partly influenced by scintillation. The waiting-time distribution is bimodal, with largely independent bursts and short-timescale clustering on ~10ms, indicating a characteristic emission timescale. The source can switch emission frequencies by GHz on seconds and by ~700MHz on millisecond timescales, implying a highly agile emission mechanism.
Author(s): Limaye P.; Spitler L.G.; Manaswini N.; Benacek J.; Eppel F.; Kadler M.,Nicotera L.; Wongphechauxsorn J.
IVOA id: ivo://cds.vizier/j/a+a/709/a47

PAH across the Orion Bar

2026-05-01T10:41:40Z

Description: JWST observations of the Orion Bar have revealed rich and diverse Polycyclic Aromatic Hydrocarbon (PAH) emission. These observations allow for the first time a comprehensive characterisation of the charge state and size of the PAH population on morphologically resolved PDR scales, properties closely linked to physical conditions of their inhabiting environments. We investigate the evolution of the PAH population's charge state and size across key physical zones in the Orion Bar, which include the HII region, the atomic PDR (APDR), and three bright HI/H_2_ dissociation fronts (DF1, DF2, and DF3). We connect changes in PAH charge and size as probed by empirical emission proxies with the varying physical properties of their surrounding environments. Utilising the NASA Ames PAH Infrared Spectroscopic Database (PAHdb) and the pyPAHdb spectral modelling tool, we analysed the MIRI-MRS observations of the Orion Bar from the "PDRs4All" JWST Early Release Science Program. Decomposition and modelling was performed on the 5-15um spectrum across the entire JWST mosaic, as well as on the weighted average spectra of the five key physical zones. pyPAHdb modelling reveals the fractional contribution of the different PAH charge states and sizes to the total PAH emission across the Orion Bar. Cationic PAH emission peaks in the APDR region, where neutral PAHs have minimal contribution. Emission from neutral PAHs peaks in the HII region that consists of emission from a face-on PDR associated to the background OMC-1 molecular cloud, and in the molecular cloud regions past DF2. PAH anions are observed deep within the DF2 and DF3 zones. Small and medium sized PAHs make up ~70% of the PAH emission across the mosaic, with the peak of the small PAH emission found between the DF2 and DF3 zones. The average PAH size in the Orion Bar ranges between ~60-74N_C_ . The modelling reveals regions of top-down PAH formation at the ionisation front, and bottom-up PAH formation within the molecular cloud region. The PAH ionisation parameter gamma ranges between ~2-9x10^4^. Intensity ratios which are empirical tracers of PAH ionisation (I_6.2_ /I_11.2_, I_7.7_ /I_11.2_, I_8.6_ /I_11.2_) scale well with gamma in regions encompassing edge-on or face-on PDR emission, but their correlation weakens within the molecular cloud zone. Modelling of the 5-15um PAH spectrum with pyPAHdb achieves comprehensive characterization of the net contribution of neutral and cationic PAHs across different environments, whereas empirical PAH proxy intensity ratio tracers can be highly variable and unreliable outside regions dominated by PDR emission. The derived average PAH size in the different physical zones is consistent with a view of PAHs being more extensively subjected to ultraviolet processing closer to the ionisation front, and less affected within the molecular cloud.
Author(s): Maragkoudakis A.; Boersma C.; Peeters E.; Allamandola J.L.; Temi P.,Esposito J.V.; Bregman D.J.; Ricca A.; Alarcon F.; Berne O.; Buragohain M.,Cami J.; Canin A.; Chown R.; Dartois E.; Fuente F.; Goicoechea J.R.,Habart E.; Kannavou O.; Khan B.; Lai T.S.-Y.; Onaka T.; Van De Putte D.,Schroetter I.; Sidhu A.; Tielens A.G.G.M.; Trahin B.; Zhang Y.
IVOA id: ivo://cds.vizier/j/a+a/709/a38

BlazEr1. The eROSITA blazar catalog

2026-05-01T10:39:40Z

Description: eROSITA on board of the Spectrum Roentgen Gamma (SRG) spacecraft performed its first X-ray all-sky survey (eRASS1) between December 2019 and June 2020. It detected about 930000 sources, providing us with an unprecedented opportunity for a detailed blazar census. We present the properties of blazars and blazar candidates in eRASS1 and the compilation of the eROSITA blazar catalog. We compile a list of blazar and blazar candidates from the literature and match it with the eRASS1 catalog, creating the Blazars in eRASS1 (BlazEr1) catalog. For sources with more than 50 counts we obtain their X-ray spectral properties. We compile multiwavelength data from the radio to the gamma-ray regimes for all sources, including multiwavelength spectral indices and redshifts. The full catalog is available online. We present the BlazEr1 catalog, containing 5865 sources, of which 2106 are associated with confirmed blazars. For 2966 sources, eROSITA provides the first X-ray data. The contamination from non-blazar sources of the entire sample is less than 11%. Most candidates exhibit properties typical for blazars. We present properties of the entire X-ray detected blazar population, including the distributions of X-ray luminosities and photon indices, multiwavelength properties, and the blazar logN-logS distribution. Our catalog provides follow up targets, such as potential MeV and TeV blazars. The BlazEr1 catalog provides a compilation of X-ray detected blazars and blazar candidates. The catalog serves as a starting point for exploiting further eROSITA surveys using the same methodology, enabling us to study the X-ray variability and a large number of spectral energy distributions of blazars in the future.
Author(s): Haemmerich S.; Gokus A.; McBride F.; Weber P.; Marcotulli L.; Zainab A.,Collmar W.; Salvato M.; Wolf J.; Sbarrato T.; Belladitta S.; Buchner J.,Saeedi S.; Dauner L.; Lorenz M.; Koenig O.; Kirsch C.; Berger K.; Bahic S.,Tubin-Arenas D.; Krumpe M.; Homan D.; Markowitz A.; Benke P.; Roesch F.,Rajasekar Kavitha P.; Tambe H.; Kadler M.; Ros E.; Ohja R.; Wilms J.
IVOA id: ivo://cds.vizier/j/a+a/709/a37