Astrophysics of Galaxies
Phenomena pertaining to galaxies or the Milky Way. Star clusters, HII regions and planetary nebulae, the interstellar medium, atomic and molecular clouds, dust. Stellar populations. Galactic structure, formation, dynamics. Galactic nuclei, bulges, disks, halo. Active Galactic Nuclei, supermassive black holes, quasars. Gravitational lens systems. The Milky Way and its contents
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The radial acceleration relation in 79 star-forming galaxies at 0.33<z<1.44 shows a characteristic scale that increases linearly with look
· “MUSE-DARK III: The evolution of the radial acceleration relation at intermediate redshifts”
Candidate DESI-HVS1 shows hypervelocity stars include ancient metal-poor members flung 13 million years ago
· “An Old, Low-mass, Metal-poor Hypervelocity Star Candidate Consistent with a Galactic Center Origin”
Average profiles from many early-type galaxies show non-zero core radii near 10^11 solar masses, requiring stronger feedback than typical in
JWST imaging reveals a 4.5 kpc stellar bar and spiral arms in a massive disk galaxy only 1.2 billion years after the Big Bang.
· “A massive barred spiral galaxy at z = 5.102 discovered by JWST”
Detection of ~0.05 km/s ion-neutral velocity drift in L1544 interpreted as the first observational signature of ambipolar diffusion in a…
SDSS photometry locates cluster edges and produces abundances matching simulations at high masses.
· “The Splashback Mass Function of Galaxy Clusters from Photometric Data”
Column density ratios in RX J1713.7-3946 match typical star-forming regions, indicating recent exposure or magnetic shielding.
A discrete ledger argument pins α≈0.191 with no free knobs; SPARC rotation curves give median χ²/N≈3.06.
Radial rotation curve plus Gaia vertical spirals show no modified gravity model fits both fields, while dark matter halos do.
· “Milky Way Dynamics Favor Dark Matter over Modified Gravity Models”
New distribution functions replace the pseudo-isothermal form and change how disc masses are inferred from tracer stars
· “Non-isothermal vertical distribution functions for the Milky Way”
Low-mass clusters die within ~500 Myr either way; intermediate-mass survival drops sharply when GMC tides are included.
N-body models put the odds of dissolving into a stable triple at 25–35 percent, a new path to triple stars.
· “Exploring the survivability of higher-order multiple protostellar systems -- The case of VLA1623”
Flickering HI absorption toward B1929+10 sits ~215 pc out, more than 100 pc past the bubble wall.
A photoionisation-model method that skips correction factors finds higher sulphur-to-hydrogen ratios in active galaxies.
If true, it explains how some dwarf galaxies ended up with black holes weighing 10% of their total mass.
The 37-burst trend traces gas within 100 pc of each source, not galaxy-scale halos.
· “The Local Origin of a Host Dispersion Measure-Stellar Mass Relation in Fast Radio Bursts”
JWST data on 703 galaxies show low-ionization gas stops getting denser after z~4, reshaping how ISM evolves.
· “The Evolution of Low-Ionization Electron Densities in Galaxies Across Cosmic Epochs”
Most disk-hosting intermediate-mass stars remain undiscovered; surviving heavy disks peak where giant planets form.
· “An analysis of the Herbig star population and their protoplanetary disks within 1 kpc”
Carbon-chain gases rose relative to CN, moving the comet from strongly to moderately depleted in about a month.
· “The Highly Unusual Behavior and Chemical Composition of Interstellar Comet 2I/Borisov”
A 716-galaxy MgII survey finds green-valley galaxies sit between star-forming and quiescent in cool-gas content.
· “Cool CGM MgII Absorption Across the Star-Forming, Green Valley, and Quiescent Transition”
The fast inspiral erases the milli-Hz signal and leaves a deci-Hz fingerprint for next-generation detectors.
· “Signatures of Compact Object Mergers Inside Stars in AGN Disks”
Unreliable lags inflate the AGN radius–luminosity scatter; fixing that halves high-redshift black-hole mass estimates.
· “A simulation-based quality-control framework for the broad-line region radius-luminosity relation”
A 30-orbit BHEX campaign beats the 0.1 spin-precision target even with large systematic errors.
· “Spin inference with the Black Hole Explorer. I. Fisher information matrix forecast”
Young star-forming companions within 2 kpc are 2.4 times more common, hinting at synchronized black hole seed formation.
Descendants of z>10 galaxies are broad, group-scale populations, not ancestors of one local type.
· “The descendants of z gtrsim 10 JWST galaxies in the COLIBRE simulations”
Ten outflow-hosting protoclusters show clustering rising with centimetre luminosity per clump mass, tying star birth to cluster assembly.
Gas supply decides whether a seed stays faint, turns Little Red Dot, or is erased into a normal galaxy.
· “The Road to Normalcy: Environment-Driven Evolutionary Pathways for Primordial Black Holes”
A torque balance between gravity and accretion locks low-mass companions on the inner side, then flips them during capture.
· “Fragmentation and tidal locking in young quadruple systems”
It reaches radio sources 40 times fainter than earlier surveys and ties gas absorption to host galaxies.
· “FASHI DR2: A Catalog of 132 Low-Redshift HI 21 cm Absorption Systems”
New low-frequency radio images show the starburst's cosmic-ray electrons ride an accelerating outflow into the halo.
· “An improved view of cosmic-ray transport and the galactic outflow in NGC 253”
With N equal-mass components, halo density ripples drop by 1/N, yet the central core still heats stars.
· “Dynamics of Wave Structures in Multifield Fuzzy Dark Matter Halos”
If true, the galaxy's lopsidedness comes entirely from the intragroup wind acting on gas, leaving its old stars untouched.
A 399-kpc double shell around a quiet elliptical is the nearest, brightest odd radio circle known, ideal for follow-up.
· “ASKAP discovery of a pair of large radio bubbles: on the origin of odd radio circles”
Dust-poor primordial disks around 2 solar-mass stars can match the CO, weak atomic carbon, and absent HCO+ seen in gas-rich debris disks…
· “Thermochemical constraints on a primordial-origin of gas-rich debris disks”
Satellite orbital planes appear preferentially aligned with cosmic filaments, with a distance-dependent flip, reported as a 12.8 sigma…
A mass-size surface gains only 2.6% over mass alone and loses to a quality flag.
· “The Mass-Size Plane Does Not Resolve the Identifiability Limit of the Radial Acceleration Relation”
At the Galactic poles, subtracting dust, stars, and galaxies still leaves an unexplained ultraviolet glow.
In merger simulations, about half of [CII] comes from molecular gas; atomic and ionized gas contribute 30-40%.
· “[CII] as a global cold gas tracer in novel hydrodynamical simulations”
A machine-learning model matches expensive quantum chemistry within 378 K, with no per-site calculations.
Shocks a dozen parsecs out accelerate electrons to petaelectronvolt energies and carve the radio bow-tie.
Outflow detections push the onset of high-mass star formation earlier than the 70 micron dark phase.
· “MIAO-ALMA: Shocks and Protostellar Outflows in 70 μm-dark clumps with L/M < 1 L_(odot)/M_(odot)”
Independent torus and disk angle fits point to a rim-penetrating view, with thick clumps shielding carbon dust.
Population-synthesis codes disagree on nearly every merging black hole binary, even for identical starting stars.
High- and normal-velocity Type Ia supernovae share similar host galaxies; earlier differences trace to targeted surveys.
· “Supernovae Ia ejecta velocities and host galaxy environments: the role of survey-selection effects”
New JWST spectra suggest the red and blue compact AGN differ in gas column density, not just viewing angle.
Even though it sees less deeply, the metal-sensitive u band recovers the most faint dwarf galaxies.
Chemical-evolution fits show C/O and N/O in these galaxies demand pre-enriched inflow, not just in-situ stars.
Fitting the 408 MHz synchrotron sky favors a 1-kpc-tall disk, no thick halo or spiral arms.
A 33,817-galaxy sample links low-luminosity AGN to harder ionizing continua, echoing stellar black-hole accretion states.
Isolated and non-isolated discs in TNG100 have matching stellar angular momentum; atomic gas fraction does the separating
· “Angular momentum in isolated disc galaxies: Insights from TNG100”
A chemical network without C+HCO+ destruction predicts extreme HCO+ in hot, shocked gas; the reaction's true rate is still unknown.
· “The curious case of HCO^+: Extreme abundances under extreme conditions”
Just 0.36% of African-affiliated astronomy papers appear in Africa-based journals; the rest are validated elsewhere.
· “From Timbuktu to SKA: Who owns the Astronomy knowledge Africa produces?”
A 155-sightline absorption survey maps where cold gas turns into molecules and fuels star formation.
The quasi-periodic clumps host 73% of known star birth sites, hinting at pressure-driven fragmentation.
· “The superclumps of the local Milky Way. Supercloud fragmentation and the sites of star formation”
At moderate extinction, starlight knocks methanol off grain mantles before UV in the gas can destroy it.
· “Gas-phase and Surface Chemistry in the Massive Star-Forming Region RCW\,120”
Ten-times-deeper GTC images cap its stellar mass under 16,000 Suns, backing the dark-galaxy case.
· “Ultra-Deep imaging of the starless galaxy candidate Cloud-9”
A DESI-HST-trained cGAN keeps galaxy shape measures within about 5 percent; code and a 63,202-image catalog are public.
· “Amplifying the imaging power of digital sky surveys with space telescopes data and generative AI”
A six-parameter absorption model reconciles absorber counts with galaxy masses, probing below JWST limits.
Fisher analysis shows any good-fitting profile agrees on the enclosed mass at this radius, set by arc pixel geometry.
· “On what scales does strong lensing robustly constrain the mass profile of low-mass perturbers?”
High electron densities suppress [OIII], inflating apparent metal poverty by up to 1.1 dex.
· “An Optical Illusion: High Electron Densities Create Extremely Metal-Poor Galaxy Impostors”
Star-cluster orbits date and locate the explosions that carved the Sun's local bubbles and shells.
· “The Nearby Star Formation and Supernova Histories Reconstructed from Young Star Clusters”
A self-consistent calibration of 3.5 million regions erases the secondary SFR trend in the mass-metallicity relation.
A 56-clump survey finds infall, shocks, and masers coexisting with cold deuterated gas, implying early feedback.
· “ALOHA IRDCs Molecular Line Follow-up: I. Gas properties and kinematics”
Integrated [OIII] ratios in SBS0335-052E and Haro11 require dense plus diffuse gas; one-zone analyses yield only effective densities.
· “Diversity of Ionized Gas Structures in Nearby Metal-poor Dwarf Galaxies”
Homogenised 15-year light curves enable star formation history and dust-return studies in M33's centre.
Varying only feedback physics, with identical initial conditions, moves galaxies from discs to spheroids through two mass-dependent routes.
· “The VariableTNG project: mass-dependent regulation of galaxy morphology by baryonic feedback”
Ideal and non-ideal MHD yield similar protostellar disks; only the surrounding gas envelope shrinks.
111 are new, and most white-dwarf-locus variability may come from rotating single stars.
· “A Systematic Gaia--ZTF Search for Short-Period Blue Compact-Binary Candidates”
Matched MUSE and JWST maps show Lyα reaching ~33 kpc along the [C II] outflow while Hα stays in the disk.
· “Tracing Lyman alpha escape in the CRISTAL-02 galaxy at z~5.3”
The updated roger code classifies galaxy orbits in groups down to 10^13.5 solar masses, not just clusters.
Trained on one TESS sector, it also screens OGLE, KMTNet, and MOA light curves and estimates event durations.
A cheap stellar-mode model predicts less distortion and later mass return for close black-hole encounters.
Systematic visibility modeling shows substructures emerge late and disk size grows steeply with stellar mass.
A 27.9 mag arcsec−2 dwarf matching Andromeda's faintest satellites hints at a hidden cluster population.
· “Serendipitous discovery of an almost-dark galaxy in the Virgo Cluster”
Forecast ranks 14 Milky Way streams; Jet tops the list with 5.15 expected detectable subhalo kicks at 95 percent confidence.
Strong Lyα is rarer around galaxy overdensities, flipping an inside-out reionization expectation
Simulations show young stars cluster where the stellar mass stays smooth, reshaping how to read JWST clumps.
Cloud-scale maps show stripped-envelope supernovae sit in gas that turns into stars eight times faster than hydrogen-rich sites.
· “The efficient star-forming regions of stripped-envelope supernovae”
Rest-frame UV plus optical sizes reveal which physical channel shapes galaxy structure.
One quasar shows a strongly beamed, 3.5% polarized core; the other's case hinges on a disputed redshift.
