UchUchU

Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.SR

Population demographics of post-interaction WDMS binaries: From common envelope evolution to stable mass transfer

Natsuko Yamaguchi, Kareem El-Badry, Cheyanne Shariat

Close white dwarf (WD) + main-sequence (MS) binaries are end products of mass transfer (MT) that occurred when the WD progenitor was a giant, making their population demographics a powerful probe of binary evolution. Several recent works have constructed samples of WD+MS binaries with well-understood selection functions using data from wide-field surveys. These include (a) au-scale astrometric binaries from Gaia that can be shown to contain a WD on dynamical grounds, (b) au-scale astrometric bin…

Read →
astro-ph.GAastro-ph.HEastro-ph.SR

The JADES Transient Survey III: Linking Core-Collapse Supernova Rates to Cosmic Star Formation

Christian Vassallo, Seppo Mattila, Christa DeCoursey, Louis-Gregory Strolger, Erkki Kankare, Max M. Briel, Eiichi Egami, Iikka Mäntynen et al.

We investigate how core-collapse supernova (CCSN) rates trace the star-formation rate densities (SFRDs) over the redshift range $0 \le z \le 5$. For this we use new high-redshift results from the James Webb Space Telescope Advanced Deep Extragalactic Survey (JADES) Transient Survey (JTS, see the companion paper by DeCoursey et al. 2026), together with published CCSN rates. Using the observed CCSN rates to constrain the CCSN production efficiency relating SFRDs to CCSN rates, we examine how the i…

Read →
astro-ph.GAastro-ph.CO

Galaxy mergers drive enhancements in ionization states

A. Le Reste, K. B. Mantha

Recent studies have suggested that galaxy mergers may help drive the escape of ionizing photons from galaxies. However, the ionization properties of merging galaxies have not yet been systematically studied across the full merger sequence in a large, well-defined sample. Here, we investigate the impact of mergers on the line ratio $\rm{O}_{32}$ tracing the ionization state and study its evolution as a function of merger progression. We identify 7641 galaxy mergers with robust ($\rm{SNR}>3$) emis…

Read →
astro-ph.GAastro-ph.HE

The JADES Transient Survey II: Volumetric Supernova Rates out to z~5

Christa DeCoursey, Christian Vassallo, Louis-Gregory Strolger, Justin D. R. Pierel, Eiichi Egami, Seppo Mattila, Armin Rest, David A. Coulter et al.

The JADES Transient Survey (JTS) identified 83 supernova (SN) candidates in the JADES Deep Field, a $\sim$25 arcmin$^2$ region with deep ($\sim$30 mag) multi-band, multi-epoch JWST/NIRCam coverage. We use this sample to derive the first volumetric core-collapse (CC) SN and Type Ia (SN Ia) rates in the $z$$\sim$2-5 range. Many of these SNe are photometrically classified from single-epoch photometry (i.e., single spectral energy distributions (SEDs)), so we simulate and classify $\sim$23,000 CC SN…

Read →
astro-ph.GA

The onset of stellar bars at Cosmic Noon. Bar-driven quenching and AGN co-evolution in a mature disc galaxy

Luca Costantin, Lorenzo Morelli, Cristina Cabello, Virginia Cuomo, Michele Perna, J. Alfonso L. Aguerri, Mahmood Roshan, Edoardo Borsato et al.

Observations with the JWST revealed an unexpected abundance of barred galaxies at Cosmic Noon. However, the physical properties of these early bars are almost unconstrained, as it is their impact in the structural evolution of high-z disc galaxies. In this work, we derived the stellar populations of EGS-24154, a barred spiral galaxy at $z=1.17$. First, we investigated the role of the stellar bar in the early assembly history and structural evolution of the galaxy. Second, we studied the properti…

Read →
astro-ph.EPastro-ph.IM

Biosignature detectability on transiting habitable worlds with ELT/ANDES

E. Kurzawa-Ferrandez, A. Bello-Arufe, R. Hu

The search for life beyond the Solar System is at a turning point, transitioning from theoretical predictions to observations enabled by next-generation observatories. The Extremely Large Telescope (ELT) will host the ArmazoNes high Dispersion Echelle Spectrograph (ANDES), optimized for visible-to-near-infrared high-resolution spectroscopy. We present a simulation--detection pipeline and evaluate the detectability of CO$_2$, H$_2$O, and the biosignature gases O$_2$ and CH$_4$ in high-resolution…

Read →
astro-ph.EPastro-ph.GAastro-ph.SR

Probing the Innermost Region of the V883 Ori Disk Using ALMA Band 1 Methanol Line Observations

Yoshihide Yamato, Shota Notsu, Rui Zhuang, Yuri Aikawa, Nami Sakai

The snowlines of major volatiles in protoplanetary disks play a pivotal role in dust evolutions and volatile delivery to nascent planetary systems. In this paper, we report the Atacama Large Millimeter/submillimeter Array Band 1 ($\approx7.5\,\mathrm{mm}$) observations of methanol (CH$_3$OH) emission lines in the disk around the FU-Ori type star V883 Ori, where accretion outburst heats the disk and the majority of ices has sublimated. We detect three CH$_3$OH emission lines at an angular resolut…

Read →
math-phastro-ph.EP

Expansion of the planetary Hamiltonian for small eccentricities and inclinations: a vector formalism

Federico Mogavero

We revisit the classical expansion of the planetary Hamiltonian for small eccentricities and mutual inclinations of the orbits, presenting a derivation based entirely on vector formalism. We demonstrate that the secular part of the disturbing function, as well as any other Fourier harmonic, can be expressed in terms of scalar products of vectors lying in the system's invariant plane. Furthermore, we show how to express any such term using the angular momentum and eccentricity vectors of the orbi…

Read →
astro-ph.GAhep-ph

A Universal Distribution of Dark Matter in Milky Way-like galaxies and How to Infer It

Sam Cheng-Tse Huang, Matthew R. Buckley, Justin I. Read, David Shih

The phase-space density of dark matter within the Milky Way is a key quantity that encodes information about the nature of the dark sector. The local phase-space density is also required to properly interpret the results of dark matter direct detection experiments. However, there are at present few observational constraints. In this paper, we show that a simple coordinate transformation reveals a near-universal DM phase-space distribution function among three independent suites of cosmological s…

Read →
astro-ph.GAastro-ph.SRhep-ph

Evolution of Binaries Under Stochastic Perturbations

Andrea Caputo, Giovanni Maria Tomaselli, Chris Hamilton

We develop a general Fokker-Planck framework describing the dynamical evolution of Keplerian binaries subjected to stochastic perturbations. The formalism provides an algorithmic way to obtain the Fokker-Planck drift and diffusion coefficients of any set of orbital variables given the statistics of the perturbations. We apply the method to three physically distinct regimes: adiabatic tidal perturbations, white-noise tidal perturbations, and impulsive encounters with a third body of arbitrary den…

Read →
astro-ph.EP

Modeling the Evolution of Protoplanetary Disks: Two Pathways from Gravitational Instability to MHD Wind-Driven Accretion

Yang Ni, Wenrui Xu, Xue-Ning Bai

The global evolution of protoplanetary disks sets the initial conditions for planet formation. However, most models focus on individual evolutionary phases, with idealized initial conditions and oversimplified prescriptions for angular momentum transport and thermodynamics. We present a more realistic semi-two-dimensional ($1+1$D) model incorporating gravitational instability (GI), magnetohydrodynamic (MHD) winds, magneto-rotational instability (MRI), stellar irradiation, self-shadowing, and rad…

Read →
astro-ph.COastro-ph.HEhep-ph

Signatures of $10-10^4\,{\rm M}_{\odot}$ Dark Matter halos in LISA via Stochastic Diffraction

Han Gil Choi, Juan Urrutia, Miguel Zumalacárregui

Cold Dark Matter predicts a population of low-mass halos which are sensitive to its fundamental nature and the primordial power spectrum, yet remain undetected. Although elusive, their discovery may be possible thanks to wave-optics lensing of gravitational waves (GWs) by the superposition of many halos along the line of sight. We study the statistical properties of stochastic diffractive lensing, which imprints correlated fluctuations on the amplitude and phase of the original waveform. The sto…

Read →
astro-ph.SRphysics.plasm-phphysics.space-ph

Direct Measurement of Diffusion Coefficients: Evidence for Diffusive Stochastic Heating in Collisionless Plasmas

Tamar Ervin, Trevor A. Bowen, Alfred Mallet, Philip A. Isenberg, Kristopher G. Klein, Stuart D. Bale, Benjamin D. G. Chandran, Roberto Livi et al.

Open questions in collisionless plasma dissipation can be addressed using space-based observations in different astrophysical environments, with implications for both astrophysical and laboratory plasma systems. We study a low-$β$, highly imbalanced, sub-Alfvénic stream observed by Parker Solar Probe (PSP) to identify and distinguish between signatures of stochastic heating (SH) and resonant heating (RH) by parallel ion cyclotron waves (ICWs). Prior work studying this stream (Bowen et al., 2025)…

Read →
astro-ph.GA

Electron Density of Ionized Gas Outflows: Insights from the MaNGA Survey

Andrew Weldon, Casey Papovich, Justin Spilker, Robert C. Kennicutt

We investigate the properties of ionized gas outflows in nearby star-forming galaxies from the final Data Release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) Survey. Using spatially resolved spectroscopy, we search for signatures of ionized outflows within physically motivated outflow apertures. We find significant evidence for additional broad H$α$, [N II]$λλ$6550,6584, and [S II]$λλ$6718,6733 emission-line components in 115 galaxies, $\sim$3% of star-forming MaNGA galaxi…

Read →
astro-ph.IMastro-ph.GAastro-ph.HE

Ardua: Unveiling the Baryon Cycle from Stars to the Cosmic Web

Carlos J. Vargas, Caroline Kilbourne, Haeun Chung, Erika Hamden, Ralph Kraft, Joseph N. Burchett, Lauren Corlies, Claude-André Faucher-Giguère et al.

The circumgalactic medium (CGM) -- the multiphase gas reservoirs surrounding galaxies -- remains the least understood component of the baryon cycle governing galaxy growth, despite its central role in the Astro2020 Decadal Survey's priorities. Existing constraints come almost exclusively from pencil-beam absorption spectroscopy, leaving the spatial structure, kinematics, and phase interactions of CGM gas fundamentally unmapped. We present Ardua, a mission concept for NASA's ASTRA Initiative that…

Read →
astro-ph.COastro-ph.GAastro-ph.IMgr-qc

Reconstructing the kinematics of Laniakea using Type Ia Supernovae

Francesco Sorrenti, Erick Pastén, Leonardo Giani

We develop a kinematic framework that relates the monopole, dipole, and quadrupole of the luminosity distance to an ellipsoidal peculiar velocity field describing the dynamics of the Laniakea supercluster. By properly accounting for the transformations between the CMB and Laniakea reference frames and selecting Type Ia supernovae within the volume associated with the superstructure, we show that luminosity distance multipoles encode the expansion and shear of the local velocity field. This allow…

Read →
astro-ph.EP

Ice Deposition Fronts In Porous Bodies From Transient Heating Events In a Protoplanetary Disk

Stephen Li, Alice C. Quillen, Adam E. Rubinstein, Dominique Segura-Cox, Kevin Righter

Using a 1D mass and heat transport model, we numerically integrate heat flow and gas transport in a porous body exposed to a transient heating event while embedded in a protoplanetary disk. When small icy grains are heated, volatiles sublimate, enriching the disk with volatile gases. When a porous body enters this heated, volatile-rich environment, volatile gases diffuse throughout the cool, porous body and deposit ice where the partial pressure of a volatile exceeds its vapor pressure. We simul…

Read →
astro-ph.IM

WALOP-South: a four camera one shot imaging polarimeter for the PASIPHAE survey. Paper III -- PSF modelling

Indrajit Paul, Kishan Deka, Tuhin Ghosh, Siddharth Maharana, A. N. Ramaprakash, Ramya M. Anche, Artem Basyrov, Dmitry Blinov et al.

The two WALOP instruments, built for the PASIPHAE survey, will measure the linear polarization of large numbers of stars in the Galactic polar regions in the SDSS-$r$ band. They are designed with a wide field-of-view, enabling measurement of the Stokes parameters $I$, $q$, and $u$ for multiple stars simultaneously within a $35^\prime \times 35^\prime$ region of sky for WALOP-South and $30^\prime \times 30^\prime$ region for WALOP-North. In this paper, we present a polar shapelet-based PSF photom…

Read →
astro-ph.SR

Time-Resolved Connection between Starspots and Flares in Nearby Young Solar-type Stars Observed by TESS

Daijiro Hitotsuyanagi, Hiroto Yamada, Daisuke Yamashiki, Kazuma Ishihara, Yosuke Yamashiki, Kosuke Namekata

Superflares are energetic explosions on stellar surface with energies of 10^33-10^36 erg, significantly exceeding those of typical solar flares. While previous studies have suggested that these events are driven by magnetic energy stored in large starspots, the detailed time-resolved relationship between starspot area and flare activity on individual stars has remained unclear. In this paper, we investigate the time evolution of magnetic activity on three representative young solar-type stars (E…

Read →