VO Fresh

MESA Grid: Binary Evolution (M1=6.0, M2=4.0, Z=0.02)

2026-04-21T09:29:42Z

Description

Grid of Close-Binary Evolution Models

This dataset contains a grid of close-binary evolution models computed with the 
**MESA** (Modules for Experiments in Stellar Astrophysics) code, version `r24.08.1`. 
The primary objective is to investigate the dependence of binary interaction on 
the initial orbital period.

**Model Configuration:**

* **Donor Star (M1):** Fixed initial mass of 6.0 M_sun. The evolution is 
	followed self-consistently.
* **Companion (M2):** Represented as a point mass of 4.0 M_sun.
* **Orbit:** Initially circular; the grid is constructed by varying the initial 
	orbital period.

**Physics and Assumptions:**

* **Mass Transfer:** Implemented via the *Ritter prescription* for Roche-lobe 
	overflow (RLOF).
* **Efficiency:** Fully conservative mass transfer is assumed.
* **Angular Momentum:** Includes losses due to gravitational radiation, 
	magnetic braking, and systemic mass loss.
* **Tides:** Tidal synchronization of the donor star is accounted for.
* **Exclusions:** Wind mass transfer and irradiation effects are not included.

**Termination Criteria:**

Calculations are terminated if:

1. Roche-lobe overflow occurs at the very first timestep.
2. The system undergoes overflow through the outer Lagrangian point (L2).

The setup is designed to isolate the role of the initial orbital period in 
determining the onset of mass transfer and the subsequent evolutionary regime.

Author(s)

Vaidman, N. L.; Izmailova, I.

IVOA id

ivo://fai.kz/mesa_bin_6_4_0.02/q/q

TESS & KPF: TOI-2364 light & radial velocity curves

2026-04-17T13:21:11Z

Description: We measure the true obliquity of TOI-2364, a K dwarf with a sub-Saturn-mass (M_p_=0.18M_J_) transiting planet on the upper edge of the hot-Neptune desert. We used new Rossiter-McLaughlin observations gathered with the Keck Planet Finder to measure the sky-projected obliquity {lambda}=7{deg}+10{deg}-11{deg}. Combined with a stellar rotation period of 23.47+/-0.29days measured with photometry from the Tierras Observatory, this yields a stellar inclination of 90{deg}+/-13{deg} and a true obliquity {psi}=15:6+7:7-7:3, indicating that the planet's orbit is well aligned with the rotation axis of its host star. The determination of {psi} is important for investigating a potential bimodality in the orbits of short-period sub-Saturns around cool stars, which tend to be either aligned with or perpendicular to their host stars' spin axes.
Author(s): Tamburo P.; Yee S.W.; Garcia-mejia J.; Stefansson G.; Charbonneau D.,Bieryla A.; Howard A.W.; Isaacson H.; Fulton B.J.; Householder A.
IVOA id: ivo://cds.vizier/j/aj/170/34

TI-DYE. III. TOI-2076 light curves & comoving stars

2026-04-17T12:23:33Z

Description: Young (<500Myr) multiplanet transiting systems are valuable environments for understanding planet evolution by offering an opportunity to make direct comparisons between planets from the same formation conditions. TOI 2076 is known to harbor three 2.5-4R_{Earth}_ planets on 10-35days orbits. All three are JWST cycle 3 targets (for transmission spectroscopy). Here, we present the detection of TOI 2076 e; a smaller (1.35R_{Earth}_) inner (3.02days) planet in the system. We update the age of the system by analyzing the rotation periods, lithium equivalent widths, color-magnitude diagram, and variability of likely comoving stars, finding that TOI 2076 and comoving planetary system TOI 1807 are 210+/-20Myr. The discovery of TOI 2076 e is motivation to revisit known transiting systems in search of additional planets that are now detectable with new TESS data and updated search methods.
Author(s): Barber M.G.; Mann A.W.; Vanderburg A.; Boyle A.W.; Lopez Murillo A.I.
IVOA id: ivo://cds.vizier/j/aj/170/32

TI-DYE. IV. TOI-6448 comoving star candidates

2026-04-17T11:49:31Z

Description: The discovery of infant (<50Myr), close-in (<30-day-period) planets is vital in understanding the formation mechanisms that lead to the distribution of mature transiting planets as discovered by Kepler. Despite several discoveries in this age bin, the sample is still too small for a robust statistical comparison to older planets. Here we report the validation of TOI-6448b, an 8.8+/-0.8R_{Earth}_ planet on a 14.8-day orbit. TOI-6448 was previously identified to be a likely member of Vela Population IV. We confirm the star's membership and rederive the age of the cluster using isochrones, variability, and gyrochronology. We find the star, and thus planet, to be 34+/-3Myr. Like other young planets, TOI-6448 b lands in a region of parameter space with few older planets. While just one data point, this fits with prior findings of an excess of 5-11R_{Earth}_ planets around young stars far beyond what can be explained by reduced sensitivity at young ages. Our ongoing searches of Vela, Taurus-Auriga, Sco-Cen, and Orion are expected to reveal dozens more <50Myr transiting planets.
Author(s): Barber M.G.; Mann A.W.; Vanderburg A.; Barkaoui K.; Collins K.A.,Carrazco-Gaxiola S.; Evans P.; Fields M.J.; Gillon M.; Henry T.J.,Hesse K.M.; Jao W.-C.; Jehin E.; Jenkins S.; Johns T.; Rodriguez D.R.,Schwarz R.P.; Storch W.C.; Watkins C.N.; Wilkin F.P.
IVOA id: ivo://cds.vizier/j/aj/171/20

TI-DYE. II. HIP 67522 light curves & transit data

2026-04-17T11:48:10Z

Description: The youngest (<50Myr) planets are vital to understand planet formation and early evolution. The 17 Myr system HIP 67522 is already known to host a giant (~10R_{Earth}_) planet on a tight orbit. In their discovery paper, Rizzuto et al. reported a tentative single-transit detection of an additional planet in the system using TESS. Here, we report the discovery of HIP 67522c, a 7.9R_{Earth}_ planet that matches with that single-transit event. We confirm the signal with ground-based multiwavelength photometry from Sinistro and MuSCAT4. At a period of 14.33days, planet c is close to a 2:1 mean-motion resonance with b (6.96days or 2.06:1). The light curve shows distortions during many of the transits, which are consistent with spot-crossing events and/or flares. Fewer stellar activity events are seen in the transits of planet b, suggesting that planet c is crossing a more active latitude. Such distortions, combined with systematics in the TESS light-curve extraction, likely explain why planet c was previously missed.
Author(s): Barber M.G.; Thao Pa C.; Mann A.W.; Vanderburg A.; Mori M.,Livingston J.H.; Fukui A.; Narita N.; Kraus A.L.; Tofflemire B.M.,Newton E.R.; Winn J.N.; Jenkins J.M.; Seager S.; Collins K.A.,Twicken J.D.
IVOA id: ivo://cds.vizier/j/apj/973/l30

SN 2020lao light curves

2026-04-17T09:09:29Z

Description: We present infant-phase observations of the broad-lined Type Ic supernova (SN) 2020lao, including optical spectroscopy beginning within about 48 hours of the inferred explosion epoch and extending to nearly 100 days. The explosion time is constrained by power- law fits to the rising TESS and ZTF light curves, with the first ZTF detection occurring only ~27 hours after explosion. The optical light curves show a rapid rise of ~=8.8 days and a peak luminosity typical of SNe Ic-BL (i.e., Mr~=-18.5mag). Unlike some engine- driven SNe Ic-BL events, the early light curve of SN 2020lao shows no evidence of an optical afterglow or excess emission, and the absence of any detectable shock-cooling component in the TESS/ZTF data constrains the progenitor to a compact Wolf-Rayet like star with R* <~ few R_{sun}_ , ruling out any extended envelope. The spectra resemble those of the X-ray flash associated SN 2006aj but with systematically higher expansion velocities. From Arnett-type fits to the bolometric light curve and measured FeII {lambda}5169 line velocities, we infer a ^56^Ni mass of 0.23+/-0.03 M_{sun}_, an ejecta mass (M_ej_) of 3.2+/-0.8M_{sun}_ , and a kinetic energy of E_K_~(23.1+/-12.4)x10^516erg, corresponding to a specific kinetic energy of E_K_/M_ej_~=(7.2+/-3.5)x10^51^erg/M_{sun}_. Spectral synthesis modeling broadly reproduces the photospheric-phase spectra of SN 2020lao and suggest E_K_/M_ej_~=4.9x10^51^erg/M_{sun}_. SN 2020lao and SN 2006aj synthesized comparable amounts of ^56^Ni, yet SN 2020lao exhibits E_K_/M_ej_ values on the order of 5-10 times larger. Published VLA and Swift/XRT non-detections reveal no afterglow emission, imposing stringent limits on relativistic ejecta and dense circumstellar material. Given that SN 2020lao reaches a specific kinetic energy typical of engine-driven SNe Ic-BL, lack of an early optical excess together with the non-detections in the radio and X-ray bands suggest that if a relativistic jet was launched, the explosion must have been viewed far off axis or the jet was choked before breakout. Otherwise, SN 2020lao represents an extreme non-relativistic SN Ic-BL. This underscores the importance of continued infant-phase, multi-wavelength monitoring of these explosions.
Author(s): Stritzinger M.D.; Moriya T.J.; Bose S.; Mazzali P.A.; Lundqvist P.,Karamehmetoglu E.; Arndt L.S.; Ashall C.; Galbany L.; Hoogendam W.B.,Baron E.; DerKacy J.M.; Elias-Rosa N.; Hsiao E.Y.; Hoeflich P.; Pian E.,Jensen E.A.M.; Moran S.; Pastorello A.; Shahbandeh M.; Valerin G.
IVOA id: ivo://cds.vizier/j/a+a/708/a305

HD 140283 and BPS CS 29502-0092 equivalent widths

2026-04-17T09:05:09Z

Description: The aim of this study is to evaluate the reliability of spectroscopic and photometric approaches for deriving stellar parameters in metal-poor stars, focusing on a carbon-enhanced metal-poor (CEMP) star with a well-studied very metal-poor star as reference. The determination of stellar parameters is first based on spectroscopy, where parameters are derived from Fe line equivalent widths using the 1D local thermodynamical equilibrium (LTE) synthesis code pyMOOGi. The second approach is based on photometry, employing colour-Teff relations, Gaia parallaxes, and bolometric corrections. Analyses of the two stars reveal systematic discrepancies: photometric Teff, log(g), and [Fe/H] are higher than spectroscopic values. Offsets exceed uncertainties, mainly due to the limited Fe II line set and non-LTE effects in spectroscopy. Photometric based parameters prove more consistent and reliable, particularly when using (V-K) or (BP-K) colours. These findings confirm previous results and demonstrate that photometric methods yield more reliable stellar parameters, especially for CEMP stars than 1D LTE spectroscopic methods.
Author(s): Heil S.; Hansen C.J.
IVOA id: ivo://cds.vizier/j/a+a/708/l17

Characterization of type Ibn SNe

2026-04-15T17:56:12Z

Description: Type Ibn supernovae (SNe) are characterized by narrow helium (He i) lines from photons produced by the unshocked circumstellar material (CSM). About 80 SNe Ibn have been discovered to date, and only a handful have extensive observational records. Thus, many open questions regarding the progenitor system and the origin of the CSM remain. Here we investigate potential correlations between the spectral features of the prominent HeI {lambda}5876{AA} line and the optical and X-ray light curve properties of SNe Ibn. We compile the largest sample of 61 SNe Ibn to date, of which 24 SNe have photometric and spectroscopic data from the Young Supernova Experiment and 37 SNe have archival data sets. We fit 24 SNe Ibn with sufficient photometric coverage (B to z bands) using semi-analytical models from MOSFiT. We demonstrate that the light curves of SNe Ibn are more diverse than previous analyses suggest, with absolute r-band peak magnitudes (rmax) of -19.4+/-0.6mag and rise (from ~10 days to peak, {gamma}_-10_) and decay-rates (from peak to +10 days; {gamma}_+10_) of -0.08+/-0.06 and 0.08+/-0.03mag/day, respectively. We find that the majority of SNe Ibn in the sub-sample are consistent with a low-energy explosion (<10^51^erg) of a star with a compact envelope surrounded by ~0.1M_{sun}_ of helium-rich CSM. The inferred ejecta masses are small (M_ej_~1M_{sun}_) and expand with a velocity of ~5000km/s. Our spectroscopic analysis shows that the mean velocity of the narrow component of the HeI lines, associated to the CSM, peaks at ~1100km/s. The mean CSM and ejecta masses inferred for a sub-sample of SNe Ibn indicate that their progenitors are not massive (~10M_{sun}_), single stars at the moment of explosion, but are likely binary systems. This agrees with the detection of potential companion stars of SNe Ibn progenitors, and the inferred CSM properties from stellar evolution models.
Author(s): Farias D.; Gall C.; Villar V.A.; Auchettl K.; de Soto K.M.; Gagliano A.,Hoogendam W.B.; Narayan G.; Sedgewick A.; Yadavalli S.K.; Zenati Y.,Angus C.R.; Davis K.W.; Hjorth J.; Jacobson-Galan W.V.; Jones D.O.,Kilpatrick C.D.; Bustamante Rosell M.J.; Coulter D.A.; Dimitriadis G.,Foley R.J.; Gangopadhyay A.; Gao H.; Huber M.E.; Izzo L.; Johnson J.L.,Piro A.L.; Rest A.; Rojas-Bravo C.; Siebert M.R.; Taggart K.; Tinyanont S.
IVOA id: ivo://cds.vizier/j/a+a/708/a270

JWST/NIRCam data of CEERS galaxies at 4
2026-04-14T15:14:18Z

Description

We analyze 347 galaxies at redshift 4<z<9.5 using JWST observations from the Cosmic Evolution Early Release Science (CEERS) program by simultaneously fitting a two-dimensional parametric model to the seven-filter Near Infrared Camera images to measure the overall structural parameters and quantify the global properties of the galaxies in the rest-frame optical band. Particular attention is devoted to deriving robust uncertainties that include, among other factors, the influence of cosmological surface brightness dimming and resolution effects. Using the global Sersic index (n<1.5) and observed axial ratio (q<0.6) as a guide, we place a conservative lower limit of ~45% on the incidence of galactic disks. Galaxies follow a relation between the rest-frame optical luminosity and effective radius in the redshift range 4<z<9.5, as well as separately over the intervals 4<z<5 and 5<=z<9.5, with a very similar slope but a marginally lower zero-point in the higher-redshift bin (Re=0.69{\pm}0.05kpc) compared to the lower-redshift bin (Re=0.91{\pm}0.04kpc). Within the limitations of the current sample size, we find no significant redshift evolution of n or Re at these early epochs.

Author(s)

Sun W.; Ho L.C.; Zhuang M.-Y.; Ma C.; Chen C.; Li R.

IVOA id

ivo://cds.vizier/j/apj/960/104

ZTF light curves of 29 BTS supernovae

2026-04-14T15:02:07Z

Description: The direct detection of core-collapse supernova (SN) progenitor stars is a powerful way of probing the last stages of stellar evolution. However, detections in archival Hubble Space Telescope images are limited to about one detection per year. Here, we explore whether we can increase the detection rate by using data from ground-based wide-field surveys. Due to crowding and atmospheric blurring, progenitor stars can typically not be identified in preexplosion images alone. Instead, we combine many pre-SN and late-time images to search for the disappearance of the progenitor star. As a proof of concept, we implement our search of ZTF data. For a few hundred images, we achieve limiting magnitudes of ~23mag in the g and r bands. However, no progenitor stars or long-lived outbursts are detected for 29 SNe within z<=0.01, and the ZTF limits are typically several magnitudes less constraining than detected progenitors in the literature. Next, we estimate progenitor detection rates for the Legacy Survey of Space and Time (LSST) with the Vera C. Rubin telescope by simulating a population of nearby SNe. The background from bright host galaxies reduces the nominal LSST sensitivity by, on average, 0.4 mag. Over the 10 yr survey, we expect the detection of ~50 red supergiant progenitors and several yellow and blue supergiants. The progenitors of Type Ib and Ic SNe will be detectable if they are brighter than -4.7 or -4.0 mag in the LSST i band, respectively. In addition, we expect the detection of hundreds of pre-SN outbursts depending on their brightness and duration.
Author(s): Strotjohann N.L.; Ofek E.O.; Gal-Yam A.; Sollerman J.; Chen P.; Yaron O.,Zackay B.; Rehemtulla N.; Gris P.; Masci F.J.; Rusholme B.; Purdum J.
IVOA id: ivo://cds.vizier/j/apj/960/72

Ground-based & JWST obs. of SN 2022pul. I.

2026-04-14T13:35:35Z

Description: Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground- and space-based follow-up campaign to characterize SN 2022pul, a super-Chandrasekhar mass SN Ia (alternatively "03fg-like" SN), from before peak brightness to well into the nebular phase across optical to mid-infrared (MIR) wavelengths. The early rise of the light curve is atypical, exhibiting two distinct components, consistent with SN Ia ejecta interacting with dense carbon-oxygen (C/O)-rich circumstellar material (CSM). In the optical, SN 2022pul is most similar to SN2012dn, having a low estimated peak luminosity (M_B_=-18.9mag) and high photospheric velocity relative to other 03fg-like SNe. In the nebular phase, SN 2022pul adds to the increasing diversity of the 03fg-like subclass. From 168 to 336 days after peak B-band brightness, SN 2022pul exhibits asymmetric and narrow emission from [OI]{lambda}{lambda}6300,6364 (FWHM~2000km/s), strong, broad emission from [CaII]{lambda}{lambda}7291,7323 (FWHM~7300km/s), and a rapid FeIII to FeII ionization change. Finally, we present the first ever optical-to-MIR nebular spectrum of an 03fg-like SN Ia using data from JWST. In the MIR, strong lines of neon and argon, weak emission from stable nickel, and strong thermal dust emission (with T~500K), combined with prominent [OI] in the optical, suggest that SN 2022pul was produced by a white dwarf merger within C/O-rich CSM.
Author(s): Siebert M.R.; Kwok L.A.; Johansson J.; Jha S.W.; Blondin S.; Dessart L.,Foley R.J.; Hillier D.J.; Larison C.; Pakmor R.; Temim T.; Andrews J.E.,Auchettl K.; Badenes C.; Barna B.; Bostroem K.A.; Brenner Newman M.J.,Brink T.G.; Bustamante-Rosell M.J.; Camacho-Neves Y.; Clocchiatti A.,Coulter D.A.; Davis K.W.; Deckers M.; Dimitriadis G.; Dong Y.; Farah J.,Filippenko A.V.; Flors A.; Fox O.D.; Garnavich P.; Padilla Gonzalez E.,Graur Or; Hambsch F.-J.; Hosseinzadeh G.; Howell D.A.; Hughes J.P.,Kerzendorf W.E.; Le Saux X.K.; Maeda K.; Maguire K.; McCully C.,Mihalenko C.; Newsome M.; O'Brien J.T.; Pearson J.; Pellegrino C.,Pierel J.D.R.; Polin A.; Rest A.; Rojas-Bravo C.; Sand D.J.; Schwab M.,Shahbandeh M.; Shrestha M.; Smith N.; Strolger L.-G.; Szalai T.,Taggart K.; Terreran G.; Terwel J.H.; Tinyanont S.; Valenti S.; Vinko J.,Wheeler J.C.; Yang Yi; Zheng W.; Ashall C.; DerKacy J.M.; Galbany L.,Hoeflich P.; Hsiao E.; de Jaeger T.; Lu J.; Maund J.; Medler K.,Morrell N.; Shappee B.J.; Stritzinger M.; Suntzeff N.; Tucker M.; Wang L.
IVOA id: ivo://cds.vizier/j/apj/960/88

M-type T Tauri stars with LAMOST DR8, Gaia & WISEA

2026-04-14T12:23:41Z

Description: The full disk, full of gas and dust, determines the upper limit of planet masses, and its lifetime is critical for planet formation, especially for giant planets. In this work, we studied the evolutionary timescales of the full disks of T Tauri stars (TTSs) and their relations to accretion. Combined with Gaia EDR3, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer data, 1077 disk-bearing TTS candidates were found in LAMOST DR8, and stellar parameters were obtained. Among them, 783 are newly classified by spectra as classical T Tauri stars (CTTSs; 169) or weak-lined T Tauri stars (WTTSs). Based on EW and FWHM of H{alpha}, 157 TTSs in accretion were identified, with ~82% also having full disks. For TTSs with M<0.35M_{sun}_, about 80% seem to already lose their full disks at ~0.1Myr, which may explain their lower mass, while the remaining 20% with full disks evolve at similar rates of non-full disks within 5Myr, allowing enough time and material to form giant planets. The fraction of accreting TTSs to disk-bearing TTSs is stable at ~10% and can last ~5-10Myr, suggesting that full disks and accretion evolve with similar rates as non-full disks. For TTSs with M>0.35M_{sun}_, almost all full disks can survive more than 0.1Myr, most for 1 Myr and some even for 20Myr. For TTSs with M>0.35M_{sun}_, almost all full disks can survive more than 0.1Myr, most for 1Myr, and some even for 20Myr, which implies planets are more likely to be formed in their disks than those of M<0.35M_{sun}_, and thus M dwarfs with M>0.35M_{sun}_ can have more planets. The fraction of full-disk TTSs to disk-bearing TTSs decreases with age following the relation f{propto}t^-0.35^, and similar relations existed in the fraction of accreting TTSs and the fraction of full-disk CTTSs, suggesting faster full disks and accretion evolution than non-full disks. For full-disk stars, the ratio of accretion of lower-mass stars is systematically lower than that of higher-mass stars, confirming the dependence of accretion on stellar mass, which may be reflective of an observational bias in the detection of accretion levels, with the lower-mass stars crossing below the detection threshold earlier than higher-mass stars.
Author(s): Haerken H.; Li G.-W.; Li M.; Duan F.; Zhao Y.
IVOA id: ivo://cds.vizier/j/apj/960/58

Quasars from DESI SV data in the COSMOS/HSC fields

2026-04-14T11:47:20Z

Description: We present the first result in exploring the gaseous halo and galaxy correlation using the Dark Energy Spectroscopic Instrument survey validation data in the Cosmic Evolution Survey (COSMOS) and Hyper Suprime-Cam field. We obtain multiphase gaseous halo properties in the circumgalactic medium by using 115 quasar spectra (signal-to-noise ratio > 3). We detect MgII absorption at redshift 0.6<z<2.5, CIV absorption at 1.6<z<3.6, and HI absorption associated with the MgII and CIV. By crossmatching the COSMOS2020 catalog, we identify the MgII and CIV host galaxies in 10 quasar fields at 0.9<z<3.1. We find that within the impact parameter of 250kpc, a tight correlation is seen between the strong MgII equivalent width and the host galaxy star formation rate. The covering fraction fc of the strong MgII selected galaxies, which is the ratio of the absorbing galaxy in a certain galaxy population, shows significant evolution in the main-sequence galaxies and marginal evolution in all the galaxy populations within 250kpc at 0.9<z<2.2. The fc increase in the main-sequence galaxies likely suggests the coevolution of strong MgII absorbing gas and the main-sequence galaxies at the cosmic noon. Furthermore, MgII and CIV absorbing gas is detected out of the galaxy virial radius, tentatively indicating the feedback produced by the star formation and/or the environmental effects.
Author(s): Zou S.; Jiang L.; Cai Z.; Moustakas J.; Sun Z.; Pan Z.; Ding J.,Forero-Romero J.E.; Zou Hu; Ting Y.-S.; Pieri M.; Ahlen S.; Alexander D.,Brooks D.; Dey A.; Font-Ribera A.; Gontcho Gontcho S. A; Honscheid K.,Landriau M.; de la Macorra A.; Vargas Magana M.; Meisner A.; Miquel R.,Schubnell M.; Tarle G.; Zhou Z.
IVOA id: ivo://cds.vizier/j/apj/960/34

LEGA-C stellar population scaling relations. II

2026-04-14T09:09:09Z

Description: We analysed a sample of 552 galaxies from the LEGA-C spectroscopic survey (0.6<z<0.77), for which we estimated the stellar population parameters by a Bayesian analysis of the stellar absorption features and photometry. We investigated the effect of the current star formation activity on light-weighted mean stellar ages and metallicities and their median trends with stellar mass or velocity dispersion. The bimodality in the global age-mass relation stems from the different age distributions in the quiescent and star-forming populations. No bimodality is observed in the stellar metallicity-mass relation, although quiescent and star-forming galaxies have different distributions in this parameter space. We identified a high-metallicity sequence populated by quiescent and weakly star-forming galaxies. At masses lower than 10^10.8^M_{sun}_, the median stellar metallicity-mass relation of star-forming galaxies steepens as a consequence of the increasing scatter towards lower stellar metallicities for galaxies with an increasing specific star formation rate at fixed mass. Relying on a consistent analysis of SDSS DR7 spectra and accounting for aperture corrections, we quantified the evolution of the volume-weighted stellar age and stellar metallicity scaling relations between z=0.7 and the present. We found negligible evolution in the stellar metallicity-mass relation of quiescent galaxies and for M*>10^11^M_{sun}_ galaxies in general. Lower-mass star-forming galaxies instead have typically lower metallicities than their local counterparts, indicating significant enrichment since z~0.7 in the low-mass regime. Notably, the median of the stellar ages of the general population and of quiescent galaxies has changed by only 2Gyr between z=0.7 and z=0.1, which is less than expected from cosmic ageing. Some quiescent galaxies must evolve passively to reach the old boundary of the local population. In order to explain the evolution of the median trends, however, both individual evolution through rejuvenation and/or minor merging that affects the outer galaxy regions and population evolution through quenching of massive metal-rich star-forming galaxies are required.
Author(s): Gallazzi A.R.; Zibetti S.; van der Wel A.; Nersesian A.; Kaushal Y.,Bezanson R.; Mattolini D.; Bell E.F.; Scholz-Diaz L.; Leja J.; D'Eugenio F.,Wu P.-F.; Pacifici C.; Maseda M.
IVOA id: ivo://cds.vizier/j/a+a/708/a290

LEGA-C stellar population scaling relation. I.

2026-04-14T09:05:33Z

Description: We analysed the stellar population properties of a well-defined sample of 552 galaxies at redshift 0.6<z<0.77 drawn from the LEGA-C spectroscopic survey. This paper is the first of a series, and it is aimed at i) presenting the catalogue of revised absorption indices for LEGA-C DR3 and of the inferred physical parameter estimates while describing their systematic uncertainties and at ii) deriving benchmark scaling relations for the general massive galaxy population at intermediate redshift. We estimated light-weighted mean ages and stellar metallicities through careful analysis of key absorption features in the stellar continuum spectra of the galaxies coupled with photometry. The observables were interpreted in a Bayesian framework with a comprehensive library of model spectra based on stochastic star formation histories, chemical enrichment histories, and dust attenuations. We discuss various sources of systematic uncertainties within our method as well as systematic differences with results from other spectral fitting approaches. We derived volume-weighted scaling relations connecting light-weighted mean ages and stellar metallicities with galaxy stellar mass for the general galaxy population at <z>=0.7 and masses >10^10^M_{sun}_. We find the downsizing trends observed in the local Universe to be already in place 6Gyr ago. We also observe a bimodal distribution of light-weighted ages as a function of mass, transitioning around 10^11^M_{sun}_. Such a bimodality is not observed in the stellar metallicity-mass relation, which changes from a steep to a flat regime across Mstar~10^10.8^M_{sun}_. Similar trends in age and metallicity also emerge as a function of velocity dispersion, but with a sharper transition from young to old around log(sigma_star_)=2.3. Differences with respect to the trends as a function of stellar mass suggest that age is primarily dependent on velocity dispersion below and above the transition regime, while both the stellar mass and the depth of the total gravitational potential well (as traced by the velocity dispersion) contribute to stellar metallicity. We release the catalogues of revised absorption index measurements for LEGA-C DR3 used in this work and of the inferred stellar population physical parameters to public repositories.
Author(s): Gallazzi A.R.; Zibetti S.; van der Wel A.; Nersesian A.; Kaushal Y.,Bezanson R.; D'Eugenio F.; Bell E.F.; Leja J.; Scholz-Diaz L.; Wu P.-F.,Pacifici C.; Maseda M.; Mattolini D.
IVOA id: ivo://cds.vizier/j/a+a/708/a289

Gaia DR3 magnetic white dwarfs in LAMOST DR10

2026-04-14T08:59:44Z

Description: Magnetic white dwarfs (MWDs) are key to understanding the origin and evolution of magnetic fields in compact stars. While large spectroscopic surveys such as SDSS have greatly expanded the known sample, the potential of LAMOST has not yet been fully explored. Our aim is to identify and characterize isolated MWDs in the LAMOST data release ten (DR10). We crossmatched LAMOST DR10 spectra with white dwarf candidates from Gaia early data release three (EDR3) and with recent SDSS-based catalogs of MWDs. Zeeman splitting in Balmer and helium absorption lines was used as the primary diagnostic to identify magnetic fields and to estimate their strengths. Reference objects from the SDSS catalogs were used to test the detectability of MWDs in LAMOST low-resolution spectra. We identified 63 isolated MWDs in LAMOST DR10, 32 of which are new discoveries. Surface magnetic field strengths were measured from Zeeman splitting, covering a range from a few megagauss up to several tens. For previously known SDSS MWDs, our LAMOST-based field measurements mostly show agreement with published values. This work demonstrates the capability of LAMOST low-resolution spectroscopy to identify and characterize isolated MWDs. The newly discovered objects expand the known population and provide valuable targets for future high-resolution spectroscopic and polarimetric follow-up studies. Our results highlight the potential of combining LAMOST with Gaia and other large surveys to build a more complete census of MWDs.
Author(s): Yu S.-C.; Ren J.-J.; Neustroev V.V.; Hackman T.; Zhang H.-T.; Dong Y.-Q.,Bai Z.-R.; Yuan H.-L.; Wang M.; Zhou M.
IVOA id: ivo://cds.vizier/j/a+a/708/a275

THU SESNe spectra

2026-04-14T08:56:48Z

Description: The extent of envelope stripping in the progenitor stars is directly reflected in the diversity of spectral features observed in stripped-envelope supernovae (SESNe). Through extensive spectral observation and analysis, we aim to clarify the statistical differences between the subclasses of SESNe. The Tsinghua Supernova group obtained 249 optical spectra of 62 SESNe during the years from 2010 to 2020, covering phases from -16 to over 190 days relative to maximum light. Most spectra were obtained during the photospheric phases after the supernova explosion. For each spectrum, the pseudo-equivalent widths (pEWs) and blueshift velocities of principal lines were measured. We further investigated the common spectral features by analysing their velocity and strength correlations across all subtypes. We identify the feature near 6200{AA} in SNe Ib as H{alpha} through comparison with SNe IIb and Ic, which resolves inconsistent literature interpretations. Our finding reveals prevalent residual hydrogen in SNe Ib, further supporting a continuous stripping sequence from SNe IIb to Ib. We observe a trend in increasing velocity among different subtypes of stripped-envelope SNe, with SNe IIb exhibiting the lowest line velocities, followed by Ib, Ic, and Ic-BL. Typically, the O~I lines in SNe Ic/Ic-BL are stronger than those seen in SNe IIb/Ib. In nebular phases, the [CaII] emission dominates over [OI] in SNe IIb/Ib while [OI] is stronger in SNe Ic, including the He-rich SN 2016coi. This spectral dichotomy implies that progenitors of SNe Ic (BL) have more massive CO cores and hence higher initial masses.
Author(s): Xiang D.; Wang X.; Zhang J.; Yan S.; Lin H.; Rui L.; Mo J.; Zhang X.,Sai H.; Miao C.; Xi G.; Chen Z.; Guo F.; Ma X.; Li G.; Zhang T.; Chen L.,Liu J.; Li W.; Zhao X.; Huang F.; Cai Y.; Lin W.; Lin J.; Wu C.; Hu M.,Song C.; Zhang J.; Xia Q.; Li Z.; Li L.; Zhang K.; Zhai Q.; Chen J.,Fan Z.; Fu J.; Qian S.; Wu H.; Wu X.-B.; Yan J.; Zhang H.; Zhang J.,Zhang L.; Zheng J.
IVOA id: ivo://cds.vizier/j/a+a/708/a267

4 MW satellites stars APOGEE abundances

2026-04-14T08:55:24Z

Description: During its evolution, the Milky Way (MW) incorporated numerous dwarf galaxies, particularly low-mass systems. The surviving dwarf galaxies orbiting the MW serve as exceptional laboratories for studying the unique properties of these systems. Their metalpoor environments and shallow gravitational potentials likely drive significant differences in star formation and star cluster properties compared to those in the MW. Using high-quality near-infrared spectra from the APOGEE survey, we determined abundances of Fe, C, N, O, Mg, Al, Si, Ca, Ti, Cr, Mn, Ni, and Ce for 74 stars in four MW satellite dwarf galaxies: Fornax, Sextans, Draco, and Carina. Our analysis reveals that the distribution of {alpha] elements (e.g., [Si/Fe]) strongly correlates with galaxy luminosity (and hence mass), underscoring the critical role of galaxy mass in shaping chemical evolution. These dwarf galaxies exhibit [Al/Fe]~ -0.5, which is comparable to those of the metal-poor stars in the MW. Additionally, we identified nitrogen-rich field stars in the Fornax dwarf galaxy, which display distinct metallicities compared to its known globular clusters (GCs). If these stars originated in GCs and subsequently escaped, their presence suggests we are observing relics of destroyed GCs, offering possible evidence of cluster disruption.
Author(s): Xu C.; Qiao Y.; Tang B.T.; Fernandez-Trincado J.G.; Yan Z.Q.; Huang R.Y.,Geisler D.
IVOA id: ivo://cds.vizier/j/a+a/708/a259

Stellar half-mass radii for 3DHST+CANDELS gal.

2026-04-14T07:24:00Z

Description: We use CEERS JWST/NIRCam imaging to measure rest-frame near-IR light profiles of 435 M*>10^10^M_{sun}_ galaxies in the redshift range of 0.5<z<2.3. We compare the resulting rest-frame 1.5-2{mu}m half-light radii (RNIR) with stellar half-mass radii (R_M*_) derived with multicolor light profiles from CANDELS Hubble Space Telescope imaging. In general agreement with previous work, we find that RNIR and R_M*_ are up to 40% smaller than the rest-frame optical half-light radius Ropt. The agreement between RNIR and R_M*_ is excellent, with a negligible systematic offset (<0.03dex) up to z=2 for quiescent galaxies and up to z=1.5 for star-forming galaxies. We also deproject the profiles to estimate R_M*,3D_, the radius of a sphere containing 50% of the stellar mass. We present the R-M* distribution of galaxies at 0.5<z<1.5, comparing Ropt, R_M*_, and R_M*,3D_. The slope is significantly flatter for R_M*_ and R_M*,3D_ compared to Ropt, mostly due to downward shifts in size for massive star-forming galaxies, while R_M*_ and R_M*,3D_ do not show markedly different trends. Finally, we show rapid evolution of the size (R{propto}(1+z)^-1.7+/-0.1^) of massive (M*>10^11^M_{sun}_) quiescent galaxies between z=0.5 and z=2.3, again comparing Ropt, R_M*_, and R_M*,3D_. We conclude that the main tenets of the evolution of the size narrative established over the past 20yr, based on rest-frame optical light profile analysis, still hold in the era of JWST/NIRCam observations in the rest-frame near-IR.
Author(s): van der Wel A.; Martorano M.; Haussler B.; Nedkova K.V.; Miller T.B.,Brammer G.B.; van de Ven G.; Leja J.; Bezanson R.S.; Muzzin A.,Marchesini D.; de Graaff A.; Nelson E.J.; Kriek M.; Bell E.F.; Franx M.
IVOA id: ivo://cds.vizier/j/apj/960/53

HST survey of the young stellar cluster NGC2024

2026-04-14T07:13:47Z

Description: We performed an HST/WFC3-IR imaging survey of the young stellar cluster NGC 2024 in three filters probing the 1.4{mu}m H2O absorption feature, characteristic of the population of low-mass and substellar-mass objects down to a few Jupiter masses. We detect 812 point sources, 550 of them in all three filters with signal-to-noise ratio greater than 5. Using a distance-independent two-color diagram, we determine extinction values as high as A_V_~40. We also find that the change of effective wavelengths in our filters results in higher AV values as the reddening increases. Reconstructing a dereddened color-magnitude diagram, we derive a luminosity histogram both for the full sample of candidate cluster members and for an extinction-limited subsample containing the 50% of sources with A_V_<~15. Assuming a standard extinction law like Cardelli+ 1989ApJ...345..245C with a nominal R_V_=3.1, we produce a luminosity function in good agreement with the one resulting from a Salpeter-like initial mass function for a 1 Myr isochrone. There is some evidence of an excess of luminous stars in the most embedded region. We posit that the correlation may be due to those sources being younger, and therefore overluminous, than the more evolved and less extincted cluster's stars. We compare our classification scheme based on the depth of the 1.4{mu}m photometric feature with the results from the spectroscopic survey of Levine+ 2006, J/ApJ/646/1215, and we report a few peculiar sources and morphological features typical of the rich phenomenology commonly encountered in young star-forming regions.
Author(s): Robberto M.; Gennaro M.; Da Rio N.; Strampelli G.M.; Ubeda L.; Sabbi E.,Koeppe D.; Tan J.C.; Soderblom D.R.
IVOA id: ivo://cds.vizier/j/apj/960/49