A cosmic wall would leave parallel tracks in ancient mica
If one crossed Earth in the last half-billion years, existing mica data already bound its strength.
astro-ph
Astrophysics
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EXor outburst exposes a 3,000 K water disk around young star
A year-long accretion burst on V557 Mon briefly recreated the hot molecular inner disk typical of younger protostars
· “Hot water emission during an outburst on a classical T Tauri star”
36 ultra-faint dwarfs stopped forming stars ~12.5 Gyr ago
Uniform deep-imaging photometry dates their quenching to z≈4.6, with an 800-Myr delay hint for LMC and first-infall satellites.
A 6.23 × 10¹⁴ g primordial black hole hits its Page time now
The narrow mass window still evaporating today is the key target for testing whether black hole information is recovered.
· “Page Time of Primordial Black Holes in the Standard Model and Beyond”
Faint sources explain outer Galaxy's diffuse gamma-ray excess
A source-count extrapolation from the LHAASO catalog closes the outer-Galaxy gap but leaves the inner Galaxy needing extra components.
· “Contribution of Unresolved Sources to Diffuse Gamma-Ray Emission from the Galactic Plane”
Sun's odd composition is galactic
A 50-star spectral study finds refractory depletion tracks stellar metallicity; planet hosts differ by just 1.5 sigma.
· “The peculiar composition of the Sun is not related to giant planets”
Three-point clustering beats two-point for reionization morphology
If right, future LAE surveys can tell apart reionization histories that look identical in two-point clustering.
· “The Lyman-α emitter bispectrum as a probe of reionization morphology”
Found: 12 starless cores massive enough to birth high-mass stars
Their 50–240 kyr lifetimes run 10–30× the free-fall time, implying turbulence or fields stall collapse.
· “ALMA-IMF XVII -- Census and lifetime of high-mass prestellar cores in 14 massive protoclusters”
M31 distance plus luminosity predicts dwarf quenching to 1.8 Gyr
HST star-formation histories for 36 Andromeda satellites show halo mass and environment set the shutdown time
Einstein Probe transient is likely an active blazar
NICER X-ray variability plus Fermi, Gaia, and WISE data identify EP240709A with a Fermi source.
8 of 9 strong Ly-alpha emitters sit in galaxy overdensities
JWST map ties strong Ly-alpha to dense galaxy groups and hints at a large ionized sightline in EGS.
· “The Impact of Galaxy Overdensities and Ionized Bubbles on Lyα Emission at zsim7.0-8.5”
Dark matter makes quark stars more compact
A two-fluid model says dark matter fraction and quark anisotropy set the curves that X-ray and pulsar timing can test.
· “Exploring the Structural Properties of Anisotropic Dark Matter-Admixed Quark Stars”
Relativistic jet, not viewing angle, drives a Seyfert's line changes
Higher-resolution spectra reveal the jet dumping energy into gas 100-400 pc from the black hole.
· “Interaction of the relativistic jet and the narrow-line region of PMN J0948+0022”
Stars are born as binaries
Galactic-field binary statistics would then be set by embedded-cluster encounters, not by star formation itself.
· “Are binary-star populations regionally different? --in memory of Sverre Aarseth--”
Galaxy gas density rises as (1+z)^1.5 from z=2 to z=5
Deep NIRSpec spectra put low-ionization gas at 268-480 per cubic cm between z=2.3 and z=5.3, with interiors 30 times denser.
· “The AURORA Survey: The Evolution of Multi-phase Electron Densities at High Redshift”
A monotonic SFR–halo relation fits galaxy populations to z~2
DECODE shows halo quenching handles massive galaxies; the lowest-mass galaxies need extra quenching.
Star clusters explain Gaia black hole discoveries
Forward modeling predicts ~30 dormant black holes in DR4 and ~45 in DR5 if the cluster channel is right.
JWST rules out low-metallicity air on super-Earth TOI-776b
Two transits at 34 ppm precision rule out clear hydrogen air below 100 times solar metallicity.
· “JWST COMPASS: NIRSpec/G395H Transmission Observations of the Super-Earth TOI-776b”
Three quasars pass a UV test for binary black holes
HST spectra show Lyα and Hβ share the same velocity shift in three objects, boosting the case for close binaries.
Molecular clouds lose their turbulent support as metallicity drops
The finding rewrites the conditions under which stars form in dwarf galaxies and the early Universe.
· “Inadequate turbulent support in low-metallicity molecular clouds”
Dust gaps don't starve the inner disc of water
Ten discs show dust gaps fail to fully block icy delivery; water-rich and carbon-rich inner discs split cleanly.
· “MINDS. The influence of outer dust disc structure on the volatile delivery to the inner disc”
Starburst radiation yields fewer heavy cores and richer star clusters
Hydrodynamic simulations show high-radiation environments shift core and system mass functions to top-heavy shapes.
· “The fragmentation of molecular clouds in starburst environments”
GLEAM-X J0704-37's radio clock is its 2.9-hour binary orbit
Spectroscopy shows an M dwarf orbiting a massive white dwarf every 10,496 seconds; radio pulses arrive at the ascending node.
· “Spectroscopic Detection of a 2.9-hour Orbit in a Long Period Radio Transient”
Cold ices plus hydrogen atoms can make butane and likely hexane
A lab experiment shows saturated alkanes form on 10 K grain surfaces, linking dark clouds to comet 67P and Ryugu.
· “Production of linear alkanes via the solid-state hydrogenation of interstellar polyynes”
Sulfur abundances unified across 13 stars with new non-LTE model
Updated atomic model and correction grid cover A-K stars from 4000 to 10000 K, including IR H-band lines.
· “Influence of departures from LTE on determinations of the sulfur abundances in A-K type stars”
Hard X-ray tail of magnetar 1E 1841-045 is 70% polarized
First IXPE observation of a magnetar in outburst finds polarization rising from 15% to 70% across 2-8 keV.
Photodiode detector tags ions from Z=5 to 75 at 0.3 precision
The silicon monitor also covers charges 1 to 80 and runs quasi-real-time, unlike strip detectors needing complex corrections.
· “Development of a High-Resolution, High-Dynamic-Range Charge Detector for Ion Beam Monitoring”
Spectroastrometry measures extragalactic binary distances to 6 percent
Fitting spectroastrometry, velocities, and light curves yields calibration-free distances to test the Hubble tension.
· “Geometrical Distances of Extragalactic Binaries through Spectroastrometry”
TESS survey finds 29 EL CVn binaries
The 29 systems match the white-dwarf mass–period relation, pointing to stable mass transfer formation.
· “Discoveries and Properties of EL CVn-type Binaries in the TESS Survey”
New spectra split carbon stars by oxygen isotope ratio
Six dustless stars carry more oxygen-18 than oxygen-16; six dusty RCB stars carry far less.
883 core temperatures and 151 luminosities challenge accretion models
Data-based masses and luminosities for massive protostars favor a larger, replenished mass reservoir than the host core.
Kaon condensates reproduce two light neutron stars at once
One equation of state with $K^{-}$ and $\bar{K}^{0}$ condensates fits both XTE J1814-338 and HESS J1731-347 simultaneously.
Upgraded 90 GHz detectors halve noise
Four redesigned TES wafers push detector efficiency above 90 percent and widen the stable bias range across the CLASS focal plane.
· “High-Efficiency and Low-Noise Detectors for the Upgraded CLASS 90 GHz Focal Plane”
Two molecules in a dusty disk are colder than the gas around them
In the IRS 48 dust trap, methanol and formaldehyde are sub-thermally excited; only SO2 traces the midplane.
Accretion bursts slow from every 2,400 to 8,000 years
Fossil snowlines around 39 Perseus protostars show the earliest embedded phase is the most burst-active.
· “Chronology of Episodic Accretion in Protostars -- an ALMA survey of the CO and H₂O snowlines”
Kilonova mass pinned near 0.05 Suns by r-process heating
The week-long break in GW170817's light curve is a diffusion wave, and the ejecta mass is about 0.05 solar masses.
· “Radioactive heating rate of r-process elements and macronova light curve”
Recalibrating 11 surveys cuts a supernova dark-energy error 1.5x
An open, white-dwarf-anchored recalibration of 11 surveys tightens the Pantheon+ photometric systematic to 0.016.
· “A Reassessment of the Pantheon+ and DES 5YR Calibration Uncertainties: Dovekie”
Coronal dimmings predict flare energy and CME speed
In one active region, dimming area and growth rate track flare flux and CME speed; coronagraph-only speeds weaken it.
· “Coronal dimmings from active region 13664 during the May 2024 solar energetic events”
COSMOS-Web: 7.7-micron counts span five decades of flux
The largest JWST survey's MIRI catalog matches Spitzer and other JWST counts across a 0.2 deg2 field.
· “COSMOS-Web: MIRI Data Reduction and Number Counts at 7.7μm using JWST”
JWST spectrum nails WASP-80 b's metallicity and C/O
Four molecules detected at >7.5σ point to a hot-giant formation path around a low-mass star.
Highest-energy cosmic rays are heavy nuclei
A synthesis of six decades of data narrows the source list to relativistic jets and intergalactic shocks.
Balloon mission detects ~10 cosmic-ray air showers in 37 hours
A leak ended the flight early, but the Cherenkov telescope's two-spot trigger worked as planned.
· “The Extreme Universe Observatory on a Super-Pressure Balloon II: Mission, Payload, and Flight”
Coronal dimmings reveal which fields a CME tears open
New classification ties each dimming shape to a specific reconnection process, turning EUV dark regions into CME diagnostics.
· “Coronal dimmings and what they tell us about solar and stellar coronal mass ejections”
43,000 dwarf galaxy candidates found in the northern sky
A machine-learning catalog from the UNIONS survey flags faint galaxies by dwarf probability, ready for follow-up studies.
Habitable zones of the smallest stars likely strip rocky atmospheres
New models put every JWST Earth-sized target outside the atmosphere retention distance.
220 PeV neutrino should come with a detectable gamma-ray flash
Existing telescopes could spot the counterpart hours to days after the KM3NeT event, unless the intergalactic magnetic field is too strong.
· “Cascaded Gamma-ray Emission Associated with the KM3NeT Ultra-High-Energy Event KM3-230213A”
A better halo map erases the 'lensing is low' deficit
Stellar-to-halo masses fixed by PAC cross-correlations reproduce BOSS shear without baryon tweaks.
M 101's giant HII regions flatten below 100 MHz
The cores absorb about 30 percent of 100 MHz light, so low-frequency star-formation surveys need a correction.
· “The low-frequency flattening of the radio spectrum of giant HII regions in M 101”
No dark energy needed: structure formation alone eases H0 and fσ8
A stochastic backreaction model yields acceleration and eases the Hubble and growth-rate tensions.
First inner-disk detections of C18O16O and H13CN
JWST MIRI spectra of edge-on MY Lup open isotope ratios in the planet-forming zone to direct measurement.
· “Emission from multiple molecular isotopologues in a high-inclination protoplanetary disk”
Earth's pull can boost axion-wind signals by orders of magnitude
Quadratic dark-matter couplings create large field gradients near Earth, boosting gradient-based searches at low masses.
JWST adds 12 white dwarf debris disks
New spectra span the faintest to strongest debris disks, from 2000 K refractory dust to possible glassy silica
· “Subtle and Spectacular: Diverse White Dwarf Debris Disks Revealed by JWST”
UDG 32 was born from pre-enriched gas
MUSE data show the Hydra I object is about 8 Gyr and metal-rich, pointing to an origin in the cluster's south-east group.
Warped black hole disks fail the multicolor blackbody test
Low-energy X-ray slope shows the warp must lie beyond 50 Schwarzschild radii, contradicting GRMHD.
60% of Galactic molecular clouds match turbulent-cascade scaling
Relative velocity exponents match the supersonic-intermittency model, signaling external turbulence driving.
Synchrotron emission explains most GRB prompt high-energy spectra
Across 35 Fermi bursts, GeV data pin the electron index near p≈2.7 and expose a rare extra component.
· “Gamma-ray burst prompt emission spectra at high energies”
A galaxy at z=8.5 shut down star formation in under 30 million years
A steep UV slope plus a Balmer break points to a starburst that ended quickly and a high escape fraction.
Machine learning finds 44 z>3 quiescent galaxies with 5x smaller pool
UMAP on seven NIRCam colors cuts the pre-selection pool from ~10,500 to ~2,300 and catches young <300 Myr systems.
· “Searching for Quiescent Galaxies over 3 < z < 6 in JWST Surveys Using Manifold Learning”
Mkn 421 X-ray variability pivots at a fixed energy
Four years of AstroSat data give the same pivot energy under three spectral models, pointing to acceleration timescales.
GD 1400B shifts 81% of its starlight to the night side
Phase-resolved spectra show this brown dwarf's hemispheres are nearly identical, a miniature warm-Jupiter analog.
No efficiency boost needed for first galaxies
A constant star-formation efficiency plus ever-younger stars matches the UV and stellar-mass functions out to z=13.
· “No evidence (yet) for increased star-formation efficiency at early times”
40 jetted AGN show decade-long gamma-ray trends
First systematic sample with 32 linear and 8 quadratic flux trends found in 12 years of Fermi-LAT data.
· “Systematic Search for Long-Term Trends in Fermi-LAT Jetted Active Galactic Nuclei”
DD-ME2 deformation beats alternatives for A≈70 half-lives
Feeding DD-ME2's quadrupole deformation into pn-QRPA matches measured lifetimes across eight rp-process nuclei.
· “Reexamination of nuclear structure properties and shape coexistence of nuclei around A70”
F-star glitch fits need a term at twice the acoustic depth
Adding that harmonic moves the inferred convection-zone base from 0.850 to 0.422 in KIC6679371—matching models.
· “Glitches in solar-like oscillating F-type stars: Possible contribution of non-linear terms”
Diffuse interstellar silicates hold 11 oxygens per metal
JWST spectra of nine Milky Way sightlines tie the 10-micron dust band to Mg, Fe, and O abundances
Gravity's own radiation bath can dominate dark matter freeze-in
A third dark-matter source during reheating can set the relic density when dark matter is heavier than the reheating temperature.
· “Aspects of Gravitational Portals and Freeze-in during Reheating”
DESI–Planck cross-correlation keeps f_NL consistent with zero
The cross-correlation resists imaging systematics better than the autocorrelation, pointing to tighter future PNG bounds
Wobble data reveal an eccentric giant planet
Archival radial velocities plus Hipparcos-Gaia astrometry pin a true mass on a 5.7-AU orbit.
· “A multi-technique detection of an eccentric giant planet around accelerating star HD 57625”
Weak [OIII] galaxies are hiding efficient ionizers
At metallicities below 10% solar, [OIII] fades but Hα stays strong, so common selections miss the best ionizers.
Kilonova light found in 65-second gamma-ray burst
A compact merger, not a supernova, may explain the burst's late optical glow and its ~0.06 solar-mass ejecta.
· “The puzzling long GRB 191019A: Evidence for Kilonova Light”
Strong fields boost magnetar neutrino absorption tenfold
At fields above 10^16 gauss, quantum electron levels create density resonances and lift Pauli blocking in merger ejecta.
· “Effects of Landau quantization on neutrino emission and absorption”
Gaia and LAMOST expose 23 triple-star systems
Two systems get complete orbital fits, and the survey's sensitivity window is pinned to inner periods under 20 days.
· “Identifying Hierarchically Triple Star Systems with Gaia DR3 and LAMOST”
Dense environments quench star formation by 100x
Causal analysis of 18,629 simulated galaxies shows the effect flips: at z>1 dense environments boost star formation.
Primordial magnetic fields obey a k⁴ spectrum
Kibble-mechanism simulations set the slope; MHD decay gives 10⁻¹³ G on kpc scales, or 10⁻¹⁰ G on Mpc if helical.
· “Spectra of magnetic fields from electroweak symmetry breaking”
Disk-locking shapes stellar spin in young cluster NGC 2264
Slower rotators keep their disks longer, suggesting wide spin spreads are set at birth, not by later mergers.
· “Disk-Locking Regulates Stellar Rotation in Young Clusters: Insights from NGC 2264”
WASP-189b's dayside wind blows day-to-night at 4.4 km/s
A retrieval of CO and Fe emission lines finds the equatorial jet near zero on this ultra-hot Jupiter.
· “Retrieving wind properties from the ultra-hot dayside of WASP-189b with CRIRES^+”
WASP-43b shows water at 0.6% mixing ratio
Four high-resolution transits yield log10(H2O) = −2.24 and a C/O upper limit below 0.95.
Dark-sector Fermi balls can collapse into black holes
A quartic scalar self-coupling lets dark Fermi balls grow dense enough to cross their Schwarzschild radius.
Bayesian model finds expansion and rotation in nearby star clusters
Open-source Kalkayotl 2.0 recovers expansion ages and rotation signals from Gaia data for associations up to 1.5 kpc.
Carbon star's molecular bands reshaped in 18.6 years
JWST vs Spitzer spectra of an LMC Mira show 5 and 7.5 micron bands fading while an unknown 10 micron band strengthens.
· “Temporal Changes in the Infrared Spectra of Magellanic Carbon Stars”
