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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。

astro-ph.IM

A dual-polarization whitened-template trigger for real-time radio detection of extensive air showers

Qader Dorosti, Alperen Aksoy, Ilja Bekman, Markus Cristinziani, Eric-Teunis de Boone, Vesselin Dimitrov, Chimezie Eguzo, Stefan Heidbrink et al.

Autonomous radio stations require a first-stage trigger that rejects measured background while preserving weak extensive-air-shower pulses under tight hardware constraints. We present a dual-polarization trigger based on a 16-sample whitened pulse template evaluated continuously on the orthogonal north-south and east-west channels of an Auger Engineering Radio Array station. The template is derived from detector-folded air-shower pulses and whitened using the covariance of measured background. R…

astro-ph.EP

Quasi-diurnal Kelvin Wave Observed in the Atmosphere of Mars by the Pressure Sensor on the InSight Lander

Anzu Asumi, Jorge Hernández-Bernal, Kaoru Sato, Aymeric Spiga

During the initiation phase of Martian dust storms, a spectral signature of a zonal wavenumber 1 normal mode Kelvin wave (K1) has been observed in several surface pressure records. However, the K1 signal has not been extracted directly since its eigenfrequency is close to that of the diurnal tide, making their separation difficult. We apply singular spectrum analysis to more than one Martian year of InSight surface pressure observations, including the MY34 C dust storm (C34). This analysis enabl…

astro-ph.HEastro-ph.GA

Quasi-periodic Eruptions from Recurrent Satellite Black Hole Transits through Magnetized Galactic Nucleus Accretion Disks

Na Wang, Jing-Tong Xing, Tong Liu, Ya-Ping Li, Shuang-Liang Li

Quasi-periodic eruptions (QPEs) are recurrent soft X-ray flares from galactic nuclei, but their origin remains uncertain. The delayed ultraviolet (UV) counterpart detected in Ansky provides a new constraint on viable models. We present a two-channel model in which a satellite black hole (sBH) repeatedly crosses a nuclear accretion disk threaded by a large-scale magnetic field. Gravitational focusing and dynamical drag generate hot, optically thick ejecta whose expansion and photon diffusion powe…

astro-ph.EP

Origin of nucleosynthetic isotope variability in the NC reservoir: Evidence from Ti, Cr, and Mo isotopes

Elias Wölfer, Christoph Burkhardt, Gerrit Budde, Christian A. Jansen, Jonas Pape, Thorsten Kleine

Nucleosynthetic isotope anomalies allow distinguishing between non-carbonaceous (NC) and carbonaceous (CC) type meteorites, and have revealed correlated isotope variations especially among NC bodies. Understanding the origin of this NC trend is important for identifying the processes that produced the NC isotope heterogeneity, and for using these isotope anomalies to reconstruct the early evolution of the solar protoplanetary disk. We report mass-independent Ti, Cr, and Mo isotope compositions f…

astro-ph.COastro-ph.GA

Cluster finding with outskirt stellar masses and percolation

Pablo Avalos, Conghao Zhou, Tesla Jeltema, Katya Leidig, Shuo Xu, Benedikt Diemer, Song Huang, Alexie Leauthaud et al.

The abundance of galaxy clusters is a powerful cosmological probe, but optical cluster cosmology is limited by selection systematics, in particular the projection effects that affect cluster finders based on galaxy populations such as the red sequence. The outer stellar mass ($M_\mathrm{out}$) of cluster central galaxies -- e.g., the stellar mass in a 50-100 kpc annulus -- offers an alternative selection that relies only on the central galaxy and is therefore largely free from projection effects…

astro-ph.IMastro-ph.EP

A Multi-instrument Generalized Lomb-Scargle Periodogram Implementation

Giulia Martos, Néstor Espinoza, Jorge Meléndez

We present an implementation of the well-known and broadly used Generalized Lomb-Scargle Periodogram (GLS) which simultaneously takes into account individual offsets introduced in the data by different instruments: a "multi-instrument" GLS periodogram. While the algorithm itself is not new, the simple closed form implementation we provide, to our knowledge, is. We showcase an application of our multi-instrument GLS on radial-velocity data of the hot Jupiter TOI-481 b, whose period is recovered w…

astro-ph.EP

Asymmetric Aerosol Distribution on the Terminators of the Warm Saturn WASP-69 b Revealed by JWST NIRISS/SOSS

Le-Chris Wang, Sagnick Mukherjee, Stephen P. Schmidt, Kevin B. Stevenson, Mei Ting Mak, Patrick McCreery, Harry Baskett, Carlos Gascón et al.

How aerosols form, are transported, and cycle between condensation and evaporation across exoplanet temperature regimes remains poorly understood. Recent models and observations suggest that warm giant planets near $800$--$1000$ K may span a transition between homogeneous and longitudinally heterogeneous aerosol distributions. We present a robust detection of aerosol asymmetry in a giant planet with $T_{\rm eq}\lesssim1000$ K, using the $0.86$--$2.82~μ$m JWST NIRISS/SOSS transmission spectrum of…

astro-ph.HE

Multi-scale Memory and Regime Shift in the Hyperactive Repeating FRB 20240114A

We-Long Zhang, Sheng-Lun Xie, Jun-Jie Wei, Di Xiao, Long-Xuan Zhang, Shuang-Xi Yi, Fa-Yin Wang, Xue-Feng Wu et al.

We present a statistical analysis of FRB~20240114A, a hyperactive repeating fast radio burst, based on 11,553 bursts detected by FAST over 214 days. Our main findings are fourfold. (1) On the most active day (MJD~60381, 3,197 bursts in 4.38 hr), event-rate coherence analysis reveals persistent correlated activity extending up to 3600~s, the longest reported for any repeating FRB, showing memory persists even in intense bursting epochs. (2) The waiting-time distribution on this day is well descri…

astro-ph.HE

Multi-scale Memory and Regime Shift in the Hyperactive Repeating FRB 20240114A

Wen-Long Zhang, Sheng-Lun Xie, Jun-Jie Wei, Di Xiao, Long-Xuan Zhang, Shuang-Xi Yi, Fa-Yin Wang, Xue-Feng Wu et al.

We present a statistical analysis of FRB~20240114A, a hyperactive repeating fast radio burst, based on 11,553 bursts detected by FAST over 214 days. Our main findings are fourfold. (1) On the most active day (MJD~60381, 3,197 bursts in 4.38 hr), event-rate coherence analysis reveals persistent correlated activity extending up to 3600~s, the longest reported for any repeating FRB, showing memory persists even in intense bursting epochs. (2) The waiting-time distribution on this day is well descri…

astro-ph.SRastro-ph.GAastro-ph.HE

The Kick Velocities of Neutron Stars in Binary Systems

Paul Disberg, Ilya Mandel, Ryosuke Hirai

Neutron stars (NSs) receive natal kicks on their formation in supernovae (SNe). We consider constraints placed on the natal kick magnitudes by NSs in different kinds of binary systems. We compare observed systems to predictions from the COMPAS rapid population synthesis code, where we apply kick models with varied natal kick prescriptions. Specifically, we compare binary orbits (i.e., periods and eccentricities) and systemic kick estimates of (1) Gaia observations of NS-harboring binaries (Gaia…

astro-ph.SRastro-ph.GAastro-ph.HE

The Kick Velocities of Neutron Stars in Binary Systems

Paul Disberg, Ilya Mandel, Ryosuke Hirai

Neutron stars (NSs) receive natal kicks on their formation in supernovae (SNe). We consider constraints placed on the natal kick magnitudes by NSs in different classes of binary systems. We compare observed systems to predictions from the COMPAS rapid population synthesis code, where we apply kick models with varied natal kick prescriptions. Specifically, we compare binary orbits (i.e., periods and eccentricities) and systemic kick estimates of (1) Gaia observations of NS-harboring binaries (Gai…

astro-ph.GA

OutThere Survey: Addressing $\mathrm{ξ_{ion}}$ and $\mathrm{f_{esc}}$ with a population of average galaxies at z$\sim$2

Ravi Jaiswar, Anshu Gupta, Elisabete da Cunha, Cathryn M. Trott, Andrew Battisti, Isabel Perez, Karl Glazebrook, Lalitwadee Kawinwanichakij et al.

Constraining the major contributors to the ionisation of the early universe is an ongoing endeavour of high-redshift galaxy research. We measure the ionising photon production efficiency and Lyman Continuum escape fraction for a sample of 230 intermediate redshift ($1.3 $5. This control sample allows us to verify the correlations between ionising and spectral/physical properties suggested by previous studies. We find no significant correlations between the ionising photon production efficiency (…

astro-ph.IMastro-ph.CO

Towards independent event horizon imaging of the supermassive black holes in M87 and the Milky Way

Nithyanandan Thyagarajan, Samuel Lai, Ivy Wong, Foivos Diakogiannis

The Event Horizon Telescope (EHT) Collaboration's images of the supermassive black holes in M87 and the Milky Way have provided the first event-horizon-scale views of these objects, opening new avenues for studies of gravitation, accretion physics, and black hole astrophysics. Achieving these results, however, requires imaging under some of the most challenging conditions in radio astronomy, including low signal-to-noise ratios, severe calibration uncertainties, and sparse aperture coverage. Wit…

astro-ph.GAastro-ph.CO

Diversity of Ionized Gas Structures in Nearby Metal-poor Dwarf Galaxies

Yuki Takagishi, Takuya Hashimoto, Kazuya Matsubayashi, Matthew Hayes, Aida Wofford, Masato Hagimoto, Akio K. Inoue, Ken Mawatari et al.

We investigate whether optical and far-infrared [O III] emission from nearby metal-poor dwarf galaxies can be represented by a homogeneous one-zone ionized-gas model with a single electron temperature and density. Our sample comprises five galaxies from the Herschel Dwarf Galaxy Survey: HS1222+3741, SBS0335-052E, POX186, Haro11, and IZw18. We combine galaxy-integrated or nearly galaxy-integrated [O III] 4363 and 5007 measurements from Seimei/KOOLS-IFU observations and published or archival spect…

astro-ph.GA

The UKIRT M33 Monitoring Project: A 15-Year Near-Infrared Variable Star Catalogue for the Central Kiloparsec, and Prospects for Star Formation History and Dust Return

Mina Alizadeh, Fatemeh Nikzat, Atefeh Javadi, Yousefali Abedini, Jacco Th. van Loon, Hedieh Abdollahi

We present results from the UKIRT M33 Monitoring Project, a near-infrared survey of variable red giants in the Local Group spiral galaxy M33. Combining four independent photometric datasets spanning UIST (2003), UFTI (2005), WFCAM (2005-2007), and a new UKIRT Hemisphere Survey epoch (2018), we construct a homogenised 15.11-year $K$-band light-curve catalogue for 847 stars in the central kiloparsec, of which 771 (91 per cent) are variable. Cross-matching with archival Spitzer photometry identifie…

astro-ph.EPastro-ph.IM

Diffractive-Sail Single-Impulse Reachable Set for Interplanetary Transfer Design

Shuyue Fu, Jinkai Zhang, Di Wu, Peng Shi, Shengping Gong

Interest in planetary exploration has renewed, and the design of interplanetary transfers has attracted remarkable attention. This paper considers the interplanetary transfer design using a diffractive sail. Considering a nonzero departure hyperbolic excess velocity, the interplanetary transfer problem is transformed into the problem of computing single-impulse reachable sets. Then, based on previous work, a complementary computational method for reachable sets under arbitrary dynamics is propos…

physics.plasm-phastro-ph.HE

Revisiting the Growth Rate of the Relativistic Tearing Instability: The Role of the Non-ideal MHD Structure

Kaoru Sugimoto, Kunihito Ioka, Masaru Shibata

Magnetic reconnection in magnetically dominated pair plasmas is a key process in high-energy astrophysical systems. We revisit the relativistic tearing instability in a Harris current sheet and derive an improved analytical expression for its linear growth rate and the most unstable wavenumber. The key modification is the treatment of the vector potential perturbation in the non-ideal magnetohydrodynamic (MHD) region. Instead of the conventional constant-A approximation, we use an extrapolated-A…

physics.hist-phastro-ph.EP

The comets discovered from New Zealand, and the astronomers who found them

John Drummond, Wayne Orchiston, Carolyn Brown, Jonathan Horner

Eleven comets were discovered by six New Zealanders from New Zealand shores. New Zealand's important geographical position south of the Equator is highlighted. This location allows observers to discover and observe comets that would be difficult to see from the Northern Hemisphere. The lives of these comet discoverers are explored, as well as the discovery circumstances and an analysis of the morphological changes of their comets. We find that numerous New Zealand observers made many observation…

astro-ph.HE

First Observational Evidence for QPO-like Coevolution between Characteristic Damping Timescales and X-ray Time Lags among AGNs

Haoyang Zhang, Li Zhang

Quasi-periodic oscillations (QPOs) and stochastic variability provide complementary probes of the inner accretion flow around supermassive black holes in active galactic nuclei (AGNs). Previous multi-epoch studies of narrow-line Seyfert 1 galaxy RE~J1034+396 revealed a coevolution between the QPO frequency and the X-ray time lag, but whether the stochastic variability participates in the same structural evolution has remained unclear. We analyze the multi-epoch XMM-Newton observations of RE~J103…

physics.plasm-phastro-ph.HE

Characterizing the temporal evolution of Biermann-battery-driven magnetic reconnection in laser-ablated plasmas

T. Morita, Y. Muramoto, S. Isayama, M. Edamoto, M. Hanano, R. Ishikawa, Y. Kanesada, K. Koba et al.

This paper presents an experimental investigation of magnetic reconnection between two laser-produced expanding plasmas, focusing on the quantitative evaluation of the reconnection rate and energy conversion under varying initial conditions. By changing the separation distance between the drive laser focal spots (1 mm and 2 mm), we systematically controlled the inflow parameters. The reconnection region was probed using a two-directional laser Thomson scattering (LTS) system, which simultaneousl…

astro-ph.HEastro-ph.SRnucl-th

Discovery of Three Glitches in the previously quiet pulsar PSR J1637$-$4642

Zhaoyi Wang, Chuwen Zheng, Yuhong Zhuang, Hanyu Zhang, Peng Liu, Zhonghao Tu, Ang Li

We present the discovery and analysis of three rotational glitches in the young pulsar PSR J1637$-$4642. The timing observations span from 19 February 2009 to 6 October 2024 (MJD 54881$-$60589) from the Murriyang radio telescope of the Parkes Observatory. The first and strongest glitch occurred around MJD 58352 with a fractional frequency change of $Δν/ν\sim 2.7 \times 10^{-6}$, while two additional smaller glitches were detected at MJD 59443 and MJD 60445 with fractional changes of $2.2 \times…

astro-ph.GA

The VariableTNG project: mass-dependent regulation of galaxy morphology by baryonic feedback

Yikai Liu, Hong Guo, Volker Springel, Kexin Liu, Luis C. Ho, BoCheng Zhu

Galaxy morphology is shaped by both assembly history and baryonic processes, but their relative roles remain uncertain. We use the VariableTNG (VTNG) simulation suite to investigate how variations in baryonic feedback regulate galaxy morphology while keeping the initial conditions fixed. VTNG consists of cosmological magnetohydrodynamic simulations performed with the moving-mesh code {\sc AREPO}, varying eight parameters governing stellar and AGN feedback. At $z=1$, we characterize morphology us…

astro-ph.SRastro-ph.GA

Non-ideal MHD and protostellar feedback effects on disc formation and evolution in numerical simulations of star cluster formation

Nina Filippova, Stella S. R. Offner, Michael Y. Grudic, Philip F. Hopkins

While recent surveys have resolved hundreds of nearby protostellar discs, numerical simulations assuming ideal magnetohydrodynamics (MHD) have historically struggled to achieve disc formation due to efficient angular momentum removal by magnetic torques. Non-ideal MHD effects, relevant at the low ionization fractions typical of molecular clouds, have been shown to reduce the effectiveness of magnetic braking and promote disc formation. In this work, we present the results from a suite of calcula…

astro-ph.HE

Outflows in steep density gradients: diversity of behavior and implications for tidal disruption events and luminous fast blue optical transients

Benjamin Amend, Michael Camilo, Eric R. Coughlin, Anna Y. Q. Ho, Jonathan Zrake

Powerful explosions may undergo sustained energy injection as a central engine launches a wind into the surrounding gas, generating a forward and a reverse shock separated by a contact discontinuity. During the adiabatic phase, the dynamics depend strongly on the wind-to-ambient density ratio $f \equiv ρ_{\rm w} / ρ_{\rm a}$. For $f 2$, initially underdense outflows produce accelerating forward shocks whose radii evolve as $R_{\rm s} \propto t^{3/(5-n)}$. Because $ρ_{\rm w} \propto r^{-2}$, f in…

astro-ph.SRastro-ph.GA

A Systematic Gaia--ZTF Search for Short-Period Blue Compact-Binary Candidates

Jiamao Lin, Liangliang Ren, Yilong Li, Bo Ma, Di-Chang Chen, Zi-Heng Yu, Sen Yang, Shun-Jia Huang et al.

We present a catalog of 147 short-period (10.34--106.46~min) blue compact-binary candidates, identified by combining Gaia DR3 astrometry and photometry with ZTF DR23 light curves via a Gaia selection, period searches, and machine-learning morphology ranking. Of these, 111 lack prior compact-binary classifications. Multiwavelength data (DESI DR1, GALEX, AllWISE) reveal a heterogeneous sample: on the Gaia colour--magnitude diagram, 52 sources lie on the white-dwarf locus, 69 in the hot-subdwarf re…

astro-ph.SR

Correlations with Magnetic Activity in the Solar Near-Surface Shear Layer. II. Radial Shear

M. Cristina Rabello Soares, Sarbani Basu, Richard S. Bogart, Charles S. Baldner

Using Helioseismic and Magnetic Imager ring-diagram measurements and building on the rotation-rate $Ω$ inferences presented in Paper I for depths of 1-17 Mm, we examine the properties of the dimensionless radial shear $\partial\lnΩ/\partial\ln r$. In the radial range overlapping global-mode analyses, the inferred shear agrees with previous results. The near-surface shear layer exhibits a three-region shear structure with an enhanced-shear middle layer, and the largest residual variations occur i…

astro-ph.IM

Fast Control for LIGO Interferometer Lock Acquisition

Masaya Ono, Nathan A. Holand, Radhika Bhatt, Peter G. Carney, Francisco Salces Càrcoba, Koji Arai, Rana X. Adhikari

Gravitational wave observatories are large scale laser interferometers which are held on resonance to facilitate the detection of gravitational waves. Achieving this resonant condition is a time consuming process, and in the LIGO gravitational-wave observatories this procedure has a relatively low success rate. This limitation leads to a loss of observation time thereby reducing the number of observable astrophysical events. The primary cause of this problem is the coupling among the longitudina…

astro-ph.EPastro-ph.IM

Finding Habitable Exoplanets with Binary Relative Astrometry: Planet Detection and Characterization with the Microarcsecond Astrometric Retrieval Algorithm (MARA)

William Roberson, Eric L. Nielsen, Jessie L. Christiansen, Gautam Vasisht, Eduardo Bendek, Alex Davis, Eric E. Mamajek, Catherine A. Clark et al.

Binary relative astrometry is a technique to search for rocky planets in the habitable zone of nearby binary stars using 1D relative astrometry at the microarcsecond level. This unprecedented precision would allow a custom-designed space telescope to directly measure the occurrence rate of these planets. The success of such a mission depends on our ability to recover and characterize planets from the unique format of extreme precision binary relative astrometry data. We present MARA, the Microar…

astro-ph.GA

Tracing Lyman alpha escape in the CRISTAL-02 galaxy at z~5.3

Arshi Ali, Lucia Guaita, Manuel Aravena, Rebecca L. Davies, Jorge Gonzalez, Vicente Villanueva, Diego Oyarzun, Rodrigo Herrera-Camus et al.

Aim. We investigate the mechanisms regulating Lyman-alpha (Ly-a) escape in the star-forming galaxy CRISTAL-02 at z~5.3. The galaxy hosts five distinct clumps, with Clumps A and B suggested as potential active galactic nuclei (AGN) candidates. We study how AGN or star formation activity influences the spatial distribution and escape of Ly-a emission. Methods. Using VLT/MUSE Ly-a and JWST/NIRSpec IFU H-a and H-b observations, complemented by NIRCam UV imaging, we constructed spatially matched emis…

astro-ph.GA

Tracing Lyman alpha escape in the CRISTAL-02 galaxy at z~5.3

Arshi Ali, Lucia Guaita, Manuel Aravena, Rebecca L. Davies, Jorge Gonzalez, Vicente Villanueva, Diego Oyarzun, Rodrigo Herrera-Camus et al.

We investigate the mechanisms regulating Lyman-alpha (Ly$α$) escape in the star-forming galaxy CRISTAL-02 at z~5.3. The galaxy has clumpy morphology, suggestive that it may be interacting with other system(s). Two clumps (A and B, hereafter) are suggested as a site for intense star-formation or potential AGN candidates. We investigate how the local gas, dust, and feedback shape the escape of Ly$α$ photons around these clumps. Using VLT/MUSE and JWST/NIRSpec IFU observations, complemented by NIRC…