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宇宙工学・惑星科学・宇宙物理の最新プレプリント。

hep-phastro-ph.GA

Simulation-Informed High-Velocity Dark Matter in the Effective Theory of Direct Detection

Xiuyuan Zhang, Gonzalo Herrera, Andreas Thoyas, Lina Necib

The interpretation and reach of direct detection (DD) experiments depend sensitively on the local dark matter (DM) velocity distribution, particularly its high-velocity tail. This tail is crucial for elastic scattering at low DM masses or large momentum transfers, and for inelastic upscattering, where additional kinetic energy is needed to overcome the mass splitting. In practice, however, phenomenological studies typically rely either on the Standard Halo Model (SHM) or, when an enhanced high-v…

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gr-qcastro-ph.IM

Noisy Pipelines I: An end-to-end pipeline to perform multivariate noise inference for LISA

Ollie Burke, Joseph Bayley, Charlie Hoy, Laura Nuttall

Instrumental data from the Laser Interferometer Space Antenna (LISA) must be post-processed prior to any global-fit based analysis. For example, it is critical to filter, downsample, segment and window the data in order to perform inference of both the signal and noise parameters in the frequency domain. Each step alters the noise process, requiring a correction to the noise covariance matrix that describes the underlying data stream. We present $\texttt{lisa-noise}$, a JAX-based noise inference…

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astro-ph.GAastro-ph.IM

Arepo-CD: Coupling Collisional $N$-Body Dynamics with Moving-Mesh Magnetohydrodynamics

Chuizheng Kong, Hui Li, Long Wang, Yunwei Deng, Elizabeth Moreno-Hilario

Star formation is a hierarchical, clustered process in turbulent giant molecular clouds (GMCs), where close stellar encounters can strongly affect cluster evolution and feedback. However, gravitational softening in many hydrodynamic simulations of GMCs limits the treatment of these encounters. We present Arepo-CD (Collisional Dynamics), a framework that couples star-by-star collisional $N$-body dynamics to the moving-mesh magnetohydrodynamics (MHD) code Arepo. Star-star interactions use unsoften…

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astro-ph.HEastro-ph.SR

Exploring the origin of slow-rotating pulsars: Emission from STARS simulated white dwarfs

Zenia Zuraiq, Banibrata Mukhopadhyay

An increasing number of slow-rotating pulsars and long-period transients have been observed in recent years. The periods of these sources can be significantly longer than typical pulsar sources, ranging from ~ 100 - 1000 s, or even longer. The observed periods and period derivatives predict high magnetic fields, higher than the Schwinger field, when we consider conventional pulsar models of dipole-driven emission from neutron stars. Interestingly, the periods of these sources are consistent with…

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astro-ph.GA

Chemical abundance patterns at z=1-7: Carbon, Nitrogen, Neon, Sulphur, and Argon abundances from JWST spectroscopy

E. Cataldi, F. Belfiore, M. Curti, B. Moreschini, A. Marconi, F. Mannucci, G. Cresci, A. Feltre et al.

The relative abundances of chemical elements in the interstellar medium (ISM) trace the history of star formation and chemical enrichment in galaxies. We investigate the abundance patterns of carbon (C), nitrogen (N), neon (Ne), sulfur (S), and argon (Ar) in star-forming galaxies at z=1-7, combining ultra-deep JWST/NIRSpec observations from the MARTA survey with archival spectroscopy. We assemble 244 galaxies with [OIII]4363 detections and derive direct Te-based abundances. New empirical strong-…

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astro-ph.GA

The Balmer Absorber Strength Problem of Little Red Dots

Hanpu Liu, Eliot Quataert, Bingjie Wang, Jenny E. Greene, Yan-Fei Jiang

Little Red Dots (LRDs) commonly show Balmer absorption features. Some observed LRD spectra have weaker absorption in H$α$ than in H$β$, in apparent contradiction to atomic physics according to standard attenuation models. This tension is naturally resolved when one considers emission from the absorbing medium itself, which is ignored in the standard model: when the Balmer absorption is optically thick, a non-negligible source function could fill in the H$α$ absorption trough and reduce its obser…

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astro-ph.HE

Constraints on Millimeter-wave Extragalactic Transient Populations from 4 Years of SPT-3G data

S. Guns, C. Tandoi, D. Anbajagane, E. Anderes, A. J. Anderson, B. Ansarinejad, M. Archipley, L. Balkenhol et al.

Wide-field cosmic microwave background (CMB) instruments have reached sufficient sensitivity and cadence to conduct untargeted millimeter-wave searches for astronomical transients. To date, such searches have primarily discovered stellar flares, while extragalactic detections remain limited to a few flaring blazars and active galactic nuclei. In contrast, recent simulations suggest that current and future CMB experiments should detect a few to dozens of extragalactic transients per year from sou…

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astro-ph.HEgr-qc

Dynamical stability of Magnetic Supramassive Neutron Stars

Jorge L. Rodríguez-Monteverde, Sebastiano Bernuzzi, William Cook, Maximilian Jacobi, Brynmor Haskell

We investigate the dynamical stability of strongly magnetized supramassive neutron stars close to the mass-shedding limit using fully general-relativistic magnetohydrodynamic simulations in three spatial dimensions. Equilibrium configurations are constructed using a microphysical equation of state and considering poloidal magnetic fields up to maximum strengths ${\sim} 10^{17}\,\mathrm{G}$. The initially unstable magnetic fields reorganize into mixed poloidal--toroidal configurations on Alfvén t…

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astro-ph.IM

Community Lessons from builders of infrared multi-object spectrographs

Solange V. Ramirez, Maren Cosens, Nicholas P. Konidaris, Francisco Garzón, Brian McLeod, Suzanne Ramsay, Leon Aslan, Robert Barkhouser et al.

We present a summary of lessons learned from our community on the design and construction of infrared multi-object spectrographs. As members of the Magellan Infrared Multi-Object Spectrograph (MIRMOS) development team, we were motivated to learn about the most common troubles faced by our colleagues and incorporate measures in our design and assembly plan to address known issues. The lessons are compiled as a result of interviews we carried out with members of the instrument development teams fo…

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astro-ph.SRastro-ph.EPphysics.space-ph

Automated optimization of solar energetic particle acceleration and transport parameters against five-spacecraft observations of the 9 October 2021 event

Hiroyuki Tako Ishikawa, Naho Fujita, Yuta Kato, Miki Kurihara, Takashi Minoshima, Daikou Shiota, Kazumasa Iwai, Marco Pinto et al.

Solar energetic particle (SEP) events threaten space infrastructure, yet physics-based prediction models depend on numerous poorly constrained free parameters. We introduce the Fujitsu Solar Energetic particle Intelligent Tuning and Evaluation Network (SEITEN), which couples the SUSANOO MHD model of CME propagation to SEPIF, a diffusive shock acceleration and focused transport model, through the shock conditions SUSANOO supplies, and automatically optimizes the free parameters of the particle mo…

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astro-ph.GA

Resolving the extended interstellar medium of infrared galaxies I. Polycyclic aromatic hydrocarbon emission

C. M. Lofaro, T. Diaz-Santos, L. Armus, V. Charmandaris, T. Lai, M. Pereira-Santaella, J. McKinney, R. Fernandez-Aranda et al.

We investigate spatial variations in polycyclic aromatic hydrocarbon (PAH) properties and photoelectric heating efficiency in 67 nearby luminous infrared galaxies from the Great Observatories All-sky LIRG Survey (GOALS). Using mid-infrared spectroscopy from Spitzer and far-infrared cooling-line maps from Herschel, we extract spectra in concentric annuli and matched aperture grids out to about 14 kpc. PAH features are measured with the CAFE spectral decomposition tool. We trace photoelectric heat…

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astro-ph.GA

Resolving the extended interstellar medium of infrared galaxies II. Fine-structure line emission

C. M. Lofaro, T. Diaz-Santos, L. Armus, V. Charmandaris, T. Lai, M. Pereira-Santaella, J. McKinney, R. Fernandez-Aranda et al.

We investigate how star formation and active galactic nuclei (AGNs) shape the ionized and neutral interstellar medium in 67 nearby luminous and ultraluminous infrared galaxies from the Great Observatories All-sky LIRG Survey (GOALS). Combining mid-infrared (MIR) spectral mapping from the Spitzer Infrared Spectrograph with far-infrared (FIR) spectroscopy from the Herschel Photodetector Array Camera and Spectrometer, we measure fine-structure emission lines in aperture grids extending to projected…

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astro-ph.GA

Large fluctuations and cusp-core transformation in dwarf galaxies

Mahmoud Hashim, Amr El-Zant, Francoise Combes

Dwarf galaxies are abundant and dark matter dominated, rendering them particularly relevant for testing a cosmological model dominated by a dark sector. Whether their density profiles agree with $Λ$CDM expectations has long been a point of contention, dubbed the cusp/core problem. While numerical simulations have suggested that the erasure of central dark matter cusps may arise from potential fluctuations in feedback-driven gas, whether the required fluctuation levels are achieved in actual gala…

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astro-ph.EPastro-ph.SR

A sub-Earth-sized TESS planet candidate in the nearby M-dwarf binary GJ 774, most likely orbiting GJ 774 A (TIC 351339274)

Jaden Tripp

Small planets transiting the nearest M dwarfs are the terrestrial planets most accessible to detailed characterisation. We report a sub-Earth-sized transiting planet candidate in the wide (17.6") M-dwarf binary GJ 774 at 12.86 pc, most likely orbiting the M2.5 primary GJ 774 A (TIC 351339274). The signal was a SPOC multi-sector threshold-crossing event (MES = 7.95) and is not a TESS Object of Interest. In eight TESS sectors (2019-2026) a 1.28-h transit recurs every 4.225138 +/- 0.000010 d with a…

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astro-ph.EPastro-ph.SR

A sub-Earth-sized TESS planet candidate in the nearby M-dwarf binary GJ 774, most likely orbiting GJ 774 A (TIC 351339274)

Jaden Tripp

Small planets transiting the nearest M dwarfs are the terrestrial planets most accessible to detailed characterisation. We report a sub-Earth-sized transiting planet candidate in the wide (17.6") M-dwarf binary GJ 774 at 12.86 pc, most likely orbiting the M2.5 primary GJ 774 A (TIC 351339274). The signal was a SPOC multi-sector threshold-crossing event (MES = 7.95) and is not a TESS Object of Interest. In eight TESS sectors (2019-2026) a 1.28-h transit recurs every 4.225138 +/- 0.000010 d with a…

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astro-ph.EP

TOI-3686: A Hot Jupiter and Sub-Neptune In A 2:1 Mean-Motion Resonance

Samuel W. Yee, Tarisai Dziire, Karen A. Collins, Luke G. Bouma, Daniel Tamayo, Erik A. Petigura, Allyson Bieryla, David W. Latham et al.

Hot Jupiters are typically thought to be "lonely", but a small and growing subset of them have been found to have nearby planets in the same system. We present the discovery of a new member of this class of systems, TOI-3686. TOI-3686 c is a hot Jupiter with $P_\mathrm{orb} = 5.078$ days detected by NASA's TESS mission that shows peak-to-peak transit timing variations (TTVs) of 40 minutes, amongst the largest ever observed for a hot Jupiter. A subsequent search of the TESS data revealed the tran…

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astro-ph.EP

Two Validated Planets and 179 Candidates From a TESS Faint Star Transit Search in the ULTRASAT Fields

Matthew Lastovka, Thomas Barclay, Robert F. Wilson, Emily A. Gilbert

The TESS mission is designed to survey the entire sky to find planets most amenable to follow-up observations, and transit searches have therefore focused specifically on bright targets. Faint stars ($T_{mag}>13.5$) have not been systematically searched for planets, despite TESS having the sensitivity necessary to do so, therefore representing a promising avenue for increasing TESS's scientific yield. We utilized TESS's sensitivity for faint stars in particular to find more planets for joint opt…

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astro-ph.GA

The clumpy fraction of galaxies at $z=1-9$ with JADES: evidence for a mass-dependent transition in clump origin

Dávid Puskás, Sandro Tacchella, Phoebe Chapman, Floor van Donkelaar, Andrew J. Bunker, Courtney Carreira, A. Lola Danhaive, Francesco D'Eugenio et al.

We measure the fraction of clumpy galaxies ($f_{\rm clumpy}$) over the redshift range $z=1-9$ and stellar masses $\log_{10}(M_\star/{\rm M_\odot}) \geq 8$ using JWST/NIRCam imaging from JADES. We define clumps as compact off-centre surface-brightness peaks with characteristic sizes of a few hundred parsecs, and develop a dendrogram-based clump-finding method with astrodendro to identify them directly in rest-frame UV, blue, and optical images. Clump-detection completeness is quantified through i…

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astro-ph.SR

Resonant three-mode coupling in asteroseismology I: Bifurcations, chaos, and DAV white-dwarf outbursts

Zhao Guo, Gordon I. Ogilvie

Resonant three-mode coupling is a fundamental nonlinear process in stellar oscillations and other wave systems. We investigate the global dynamics of a linearly overstable parent mode coupled to two damped daughter modes. The principal control parameters are frequency detuning $Δ$ and daughter damping rate $Γ$, normalized by the parent growth rate. We combine high-resolution maps of the largest Lyapunov exponent in the $(Γ,Δ)$ plane with linear stability analysis, Floquet calculations, and numer…

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astro-ph.IMastro-ph.EPastro-ph.SRphysics.optics

A Solar Optical Clock

Connor Fredrick, Ryan K. Cole, Ryan Terrien, Suvrath Mahadevan, Scott A. Diddams

Precision spectroscopy underpins quantum sensing, atomic timekeeping, and the search for terrestrial-mass exoplanets. Finding an Earth-Sun analog requires fractional splitting of spectral features that rivals the precision of the best laboratory spectroscopy. This corresponds to resolution of a few parts in $10^5$ of a typical stellar spectral line, or a Doppler velocity precision of less than 10 cm s$^{-1}$. Only a few astrophysical spectrometers reach this regime, and only by dispersing starli…

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astro-ph.IMastro-ph.EPastro-ph.SRphysics.optics

A Solar Optical Clock

Connor Fredrick, Ryan K. Cole, Ryan Terrien, Suvrath Mahadevan, Scott A. Diddams

Precision spectroscopy underpins quantum sensing, atomic timekeeping, and the search for terrestrial-mass exoplanets. Finding an Earth-Sun analog requires fractional splitting of spectral features that rivals the precision of the best laboratory spectroscopy. This corresponds to resolution of a few parts in $10^5$ of a typical stellar spectral line, or a Doppler velocity precision of less than 10 cm s$^{-1}$. Only a few astrophysical spectrometers reach this regime, and only by dispersing starli…

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astro-ph.IMastro-ph.CO

The "Rubin 2036: Opportunities for Discovery" Workshop: A Community Roadmap for the Future of the Vera C. Rubin Observatory After the LSST

Andrés Alejandro Plazas Malagón, Steve Allen, Shreya Anand, Muhammad Awais, Simon Birrer, Lindsey Bleem, Robert Blum, Adam S. Bolton et al.

The NSF-DOE Vera C. Rubin Observatory will complete its ten-year Legacy Survey of Space and Time (LSST) in the mid-2030s. Its 8.4 m aperture and 9.6 square degree field of view give it an étendue unmatched by any facility planned for that era. The Rubin 2036: Opportunities for Discovery workshop (KIPAC/SLAC, 3-5 August 2026) brought together approximately 100 participants to discuss Rubin's future after LSST. This paper summarizes the workshop's structure and discussions across five working grou…

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astro-ph.SR

Tight asteroseismic upper limits on hot subdwarf magnetism

Nicholas Z. Rui, Linhao Ma

The apparent absence of magnetism in subdwarf B stars (sdBs) has emerged as an outstanding observational puzzle, especially in light of their likely origin in binary interactions. Gravity-mode pulsations in some sdBs offer a unique opportunity to extend recent successes in asteroseismic magnetic field detection in red giants. In the presence of strong magnetic fields, gravity modes are expected to be significantly damped, suppressing their observed amplitudes. We place stringent upper limits on…

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astro-ph.HE

Identifying a jet-shaped point-symmetric morphology in the supernova remnant HB9

Noam Soker

I identify a point-symmetric morphology in the supernova remnant HB9 (G160.9+2.6), supposedly a core-collapse supernova (CCSN) remnant (CCSNR), and attribute this structure to two or more pairs of jets that exploded the star within the jittering-jets explosion mechanism (JJEM). The pairs of jets that shape the point-symmetric morphology of HB9 are part of a larger number of pairs that exploded the star. The point-symmetric structure is composed of a pair of ears, a pair of ears/nozzles, a pair o…

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physics.flu-dynastro-ph.SRphysics.plasm-phphysics.space-ph

Exponential Growth of Turbulent Cross Helicity in Shear-Flow-Driven Turbulence

B. Tripathi, A. E. Fraser, P. W. Terry, E. G. Zweibel, M. J. Pueschel, A. M. Beloborodov

Cross helicity, the velocity--magnetic-field correlation, is an ideal invariant of incompressible magnetohydrodynamics and constrains energy cascades and magnetic-field generation. Although cross helicity typically decays via visco-resistive effects, we analytically demonstrate that it grows exponentially in sheared inhomogeneous turbulence. This cross-helical shear instability is confirmed using three-dimensional numerical simulations. Growth requires a nonzero gradient of the Reynolds--Maxwell…

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nucl-thastro-ph.HEgr-qchep-ph

Hybrid Stars with Different Amount of Quark Matter

Milena Albino, Tuhin Malik, Márcio Ferreira, Constança Providência

In a previous work, we explored the possibility of neutron stars with large quark cores. Through Bayesian inference, we obtained large sets of equations of state imposing constraints regarding the properties of nuclear matter, mass-radius data from NICER, the GW170817 data from Virgo-LIGO collaboration, perturbative QCD and causality. We also imposed that the maximum mass neutron star (NS$\text{max}$) must have a large quark core. In this work, we obtain a new set of equations of state (SmallQ s…

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astro-ph.GA

KMOS Spectroscopic Follow-up of 16 Star Cluster Candidates of the Sagittarius Dwarf Galaxy

C. O. Obasi, J. G. Fernández-Trincado, D. Minniti, M. Gómez, E. R. Garro, R. K. Saito, J. Alonso-García, V. D. Ivanov et al.

The Sagittarius (Sgr) dwarf spheroidal galaxy hosts several known globular clusters and numerous additional cluster candidates identified toward its crowded central regions. Establishing the nature of these candidates is difficult because apparent spatial and astrometric structure can arise from the underlying Sgr population. We investigate sixteen Minni stellar-cluster candidates with KMOS spectroscopy to determine whether the observed stars are compatible with Sgr and whether any candidate fie…

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astro-ph.SR

Photometric variability of blue supergiants: Constraints on stellar masses and evolutionary stages

A. Alberici Adam, L. S. Cidale, M. Kourniotis, W. Glatzel, J. P. Sánchez Arias, M. Ruíz Díaz, A. Christen

Blue supergiants (BSGs) are crucial to understanding the evolution of massive stars. Although distinguishing between pre- and post-red supergiant (RSG) phases is challenging, stellar pulsations provide valuable constraints on their masses and evolutionary status. This study analyzes TESS light curves of six BSGs with high L/M to identify periodicities. We performed theoretical modeling of the radial unstable modes to characterize the strange modes. We aim to estimate asteroseismic masses, compar…

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astro-ph.IM

Revisiting the Unknown Unknowns in Transient Astrophysics with the SKA Telescopes

A. Andersson, M. Caleb, J. Callingham, A. Deller, D. Dobie, N. Hurley-Walker, B. Marcote, K. Rajwade et al.

It was already recognised in the 2004 and 2014 SKA Science Case Chapters: "The Exploration of the Unknown" and "The SKA and the Unknown Unknowns", respectively, that the exploration of the unknown is an extremely important concept in realising the potential of any new instrument. This is especially true in an era of limited budgets but expanding analysis algorithms and capabilities. While this Chapter considers transients and environments, the ethos of these previous Chapters should be considere…

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astro-ph.SRastro-ph.EP

Data-Driven Ages from Asteroseismology for FGK Dwarfs

Christopher Lam, Aida Behmard, Sarah Ballard, Andrew R. Casey, Jamie N. Tayar, Jared A. Goldberg

Age is the one of the most difficult stellar properties to constrain. However, upcoming surveys such as PLATO are about to revolutionize our ability to measure FGK dwarf ages with asteroseismology. Here, we use The Cannon to construct a data-driven model for inferring asteroseismic-quality age measurements from large spectroscopic survey observations and demonstrate that forthcoming asteroseismology datasets from future surveys can be leveraged, together with our model, to obtain stellar age sam…

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