UchUchU

研究動向

宇宙工学・惑星科学・宇宙物理の最新プレプリント。

astro-ph.GAastro-ph.COgr-qc

Binary-lens amplification of starlight: from magnification flares to quasi-periodic tracking of orbital evolution

Hanxi Wang, Bence Kocsis, Miguel Zumalacárregui

Supermassive black hole binaries (SMBHB) are expected at the center of galaxies as a result of galaxy mergers. The dynamics and evolution of SMBHBs shed light on the evolution and formation of galaxies, the gravitational wave background and the nature of gravity. Many methods have been proposed to identify sub-parsec SMBHBs via the detection of gravitational waves or the modulation of the emission from the surrounding gaseous environment. In a previous study, we proposed a new method of identify…

詳細を見る →
astro-ph.IM

Refurbishment and Cryocooler Upgrade of the CPAPIR Wide-Field Near-Infrared Camera: Design, Integration, and Lessons Learned

Philippe Vallee, Jonathan St-Antoine, Lison Malo, Frederique Baron, Sylvie F Beaulieu, Rene Doyon, Etienne Artigau, Fidele Robichaud et al.

The CAmera PAnoramique Proche Infrarouge (CPAPIR) is a wide-field near-infrared imager that has been operating at the Observatoire du Mont-Mégantic (OMM) since 2004. After more than two decades of service, the instrument required a major refurbishment due to detector degradation, including the loss of one quadrant, as well as operational constraints associated with its liquid-nitrogen cooling system. To extend the instrument's lifetime and reduce maintenance requirements, the detector was replac…

詳細を見る →
astro-ph.SR

Dynamics of a switchback-like magnetic deflection induced by a propagating coronal jet

Jade Touresse, Etienne Pariat, Clara Froment, Peter F. Wyper

Parker Solar Probe (PSP) revealed the ubiquity of switchbacks (SBs), sharp, localised magnetic deflections in the nascent solar wind, renewing interest in their origin. One proposed mechanism involves solar jets: collimated, impulsive features driven by magnetic reconnection that launch Alfvénic torsional wavefronts into the heliosphere. We test whether realistic spacecraft sampling of a propagating solar jet produces in-situ signatures consistent with PSP observations. We also examine the 3D ma…

詳細を見る →
astro-ph.EPphysics.space-ph

Revealing the Spatial Distribution of Dust and Plasma Solitary Waves in Jupiter's Innermost Magnetosphere Using Juno Waves Observations

Wenyu Zhang, Hao Cao, William S. Kurth, Mitchell M. Shen, Darrelle Wilkinson, Donglai Ma, Martin Brennan, George Hospodarsky et al.

Jupiter's faint ring system contains micron- and submicron-sized dust whose dynamics are influenced by the planet's rapidly rotating magnetic field. Optical observations have established the morphology of the main ring and halo, but tenuous dust close to Jupiter remains difficult to characterize. We analyze nearly a decade of in-situ Juno Waves electric-field measurements using a two-stage convolutional neural network to identify and classify dust impacts, solitary waves, and other plasma waves.…

詳細を見る →
astro-ph.SRastro-ph.GA

A Parsec-scale Circumstellar Shell Around VX Sgr: Mass Loss and RSG/TŻO Nature

Julian Shapiro

A thin, arc-shaped shell is discovered surrounding VX Sagittarii (VX Sgr), the largest known CSM shell around an RSG at a scale $r\sim0.59\,\mathrm{pc}$. The nebula has an extinction-corrected H$α$ intensity $I_{\mathrm{H}α}\sim38\,\mathrm{R}$ and an ionized mass $\sim0.1\,\mathrm{M_\odot}$. The slow $12\,\mathrm{km\,s}^{-1}$ peculiar velocity of VX Sgr and the lack of far-infrared emission in the arc indicate that it is not produced by a bow shock, but is likely instead steady RSG wind or eject…

詳細を見る →
astro-ph.HEastro-ph.COastro-ph.GAhep-ph

Can bosenovae deplete the galactic dark matter?

Samuel Gómez Gómez, Joshua Eby

No: neither through the bosenovae of gravitational atoms formed around stars and compact objects, nor through those of boson stars formed in the galactic dark-matter halo. We assume that all the dark matter consists of ultralight bosons with attractive self-interactions, which can be captured in the gravitational potential of astrophysical objects or condense into self-gravitating configurations. When these systems collapse in a bosenova, part of their mass is turned into relativistic radiation…

詳細を見る →
astro-ph.SR

Modelling the 6.7 GHz Methanol Flaring in G358.93-0.03 Using the Maxwell-Bloch Framework

Ningyan Fang, Toktam Rashidi, Yoshinori Yonekura, Vahid Anari, Ross A. Burns, Martin Houde, Fereshteh Rajabi

We model selected 6.7 GHz methanol flare profiles in G358.93-0.03 using the one-dimensional Maxwell-Bloch framework. The 2019 non-periodic flare, associated with an accretion burst, produced complex single-dish light curves characterized by sharp rises, multiple peaks, secondary structure, and extended decays. For six representative velocity channels, we model each light curve as a sum of scaled intensity responses from effective emitting systems driven by phenomenological pump pulses of fixed w…

詳細を見る →
astro-ph.GAastro-ph.CO

A Step-Like Transition Underlying the Life and Death of Galaxies

Zhicheng He, Enci Wang, Luis C. Ho, Yingjie Peng, Huiyuan Wang, Yong Shi, Tao Wang, Yongquan Xue et al.

How galaxies stop forming stars is a complex and central problem in astrophysics. Numerous physical mechanisms have been proposed, yet a simple, unified framework connecting these mechanisms remains lacking. Here, we derive a step-function quenching response from the fundamental principle of gas mass conservation, governed by the competition between gas-supply and gas-depletion timescales. This response also enables the gas-supply timescale to be inferred from the observed quenched fraction. App…

詳細を見る →
astro-ph.HEastro-ph.GA

A Parsec-Scale Transient High-Frequency-Peaked Radio Source in the Very Large Array Sky Survey Brightening and Fading over a Decadal Timescale

Yuyang Chen, B. M. Gaensler, Maria R. Drout, Dillon Z. Dong, Emmanuel Momjian, Tracy Clarke, Wendy Peters, Emil Polisensky et al.

A subset of active galactic nuclei (AGN) manifests as compact radio sources with peaked radio spectra, commonly referred to as peaked-spectrum (PS) sources. Generally, PS sources are interpreted as young radio jets, but the early evolution of the jet is rarely observed and not fully understood. Here, we present VT J182357-234511 (VT J1823-2345), a radio transient in the Very Large Array Sky Survey (VLASS) that resembles a PS source. Notable properties of VT J1823-2345 include: (i) brightening by…

詳細を見る →
astro-ph.HE

LHAASO Constraints on New-Source Cosmic Rays:Abundance Scenarios and Injection Spectral Indices

Xu-Lin Dong, Pei-Pei Zhang, Qi-Ling Chen, Shu-Wang Cu, Yi-Qing Guo

Recent LHAASO observations indicate that microquasars and massive star clusters contribute to Galactic cosmic rays, and likely also to the pre-knee spectral hardening. Their markedly different astrophysical environments, compared with supernova remnants (SNRs), may imprint distinct cosmic-ray abundances. We investigate the spectra and composition of new-source cosmic rays under two abundance scenarios: Case-1, the SNR-like composition with enhanced heavy nuclei, and Case-2, the surface abundance…

詳細を見る →
astro-ph.GAastro-ph.EPastro-ph.IM

The contact frontier in Galactic civilization networks: radial structure and the Galactic habitable zone

Kohji Tsumura

The probability of interstellar contact depends not only on the abundance of technological civilizations but also on their spatial connectivity. Treating civilizations as nodes linked whenever their separation is smaller than the distance a signal travels within a communicative lifetime, we determine the radial structure of Galactic civilization networks. An exponential stellar disc replaces the uniform disc of earlier work, and the fraction of stars hosting civilizations may vary with radius as…

詳細を見る →
astro-ph.COastro-ph.IM

Joint Line Intensity Recovery from Multi-Tracer Cross-Correlations

Carlos E. Sierra, Kirit S. Karkare

Line intensity mapping (LIM) provides a unique window into the high-redshift universe, but the separation of signals from overlapping emission lines and bright continuum foregrounds remains a central analysis challenge. At millimeter wavelengths in particular, [CII], [CI] and numerous CO transitions overlap with comparable brightness, leading to significant spectral confusion. This work presents a joint likelihood framework that incorporates multi-tracer cross-correlations both between distinct…

詳細を見る →
astro-ph.IM

Updates to STIS NUV Dark Calibration

Jacqueline Brown, Sean Lockwood, TalaWanda Monroe, Amy Jones, Joleen Carlberg

We present new superdark calibration files (DARKFILEs) and a new dark correction table (TDCTAB) for use with data taken by the Space Telescope Imaging Spectrograph near-ultraviolet microchannel array (STIS NUV-MAMA) detector for HST Cycle 19 onward. These superdarks include 12 years of NUV dark exposures and make use of an updated temperature scaling equation developed in 2013 to more accurately characterize the dark rate. In tested datasets, the new superdarks provide an average 3% increase in…

詳細を見る →
astro-ph.HE

Rotochemical heating of neutron stars in 2D

Mikhail V. Beznogov, Jerome Novak, Dany Page, Adriana R. Raduta

The matter inside a spinning-down neutron star (NS) undergoes a slow compression that may drive it out of chemical equilibrium and, consequently, trigger non-equilibrium nuclear reactions that can heat up the star. This phenomenon is called rotochemical heating, and it is relatively well-investigated in the literature. Historically, it has been studied almost exclusively via 1D spherically symmetric models. However, rapidly rotating NSs are not spherically symmetric. We present pioneering simula…

詳細を見る →
astro-ph.EPastro-ph.SR

Probing Planet Formation within 10 au: Dust Substructures in Extremely Compact Protoplanetary Disks

Pietro Curone, Gijs D. Mulders, Nienke van der Marel, Laura M. Pérez

ALMA high-resolution surveys have so far focused mainly on large, bright protoplanetary disks, where substructures are routinely detected, leaving compact disks poorly characterized. Yet, the survival of millimeter emission in Class II sources implies that radial drift must have been halted by pressure traps, previously undetected due to limited angular resolution. We present ALMA Band 7 (0.9 mm) continuum observations of 11 of the smallest ($R_{68} < 10$ au) Class II disks in Lupus, reaching $0…

詳細を見る →
astro-ph.GA

IRAC-Excess Galaxies in the NIRSpec Wide Survey: physical properties of bright EELGs at $z\sim7$ and implications for Reionization

Katherine Ormerod, Renske Smit, Joris Witstok, Anna de Graaff, Michael V. Maseda, Andrew J. Bunker, Chris Willott

We present an analysis of 23 Spitzer/IRAC excess galaxies at $5.66 < z < 7.64$, observed as part of the NIRSpec Wide GTO survey. With NIRSpec PRISM spectroscopy, we measure a median rest-frame [OIII]$+\rm{H}β$ EW $=1583$~Å, consistent with predictions from the pre-JWST selection and we identify $17/23$ $(\sim74\%)$ of our sample as extreme emission line galaxies (EELGs), based on a selection of [OIII]$+\rm{H}β$ EW $\geq1000$~Å. The typical EELG is powered by star-formation rather than active gal…

詳細を見る →
astro-ph.IMastro-ph.CO

Geometrical and Optical Design of the GUEST Laser-Ranged Test Masses for the Detection of Gravitational Waves in the $μ$Hz range

Dario Vetrano, Giada Bargiacchi, Nicolò Burzillà, Roberto Campagnola, Francesco Del Ferraro Iacobelli, Luca Porcelli, Simone Dell'Agnello, Diego Blas et al.

The GUEST (Gravitational Universe Exploration with Satellite Tracking) mission aims at detecting gravitational waves in the yet almost unexplored $μ$Hz frequency range through high-precision orbital tracking. The unprecedented scientific objectives of this experiment demand equally advanced optical solutions: the highly eccentric orbit imposes dual measurement regimes; a low-velocity, long-range scenario at apogee and a high-velocity, short-range scenario at perigee. The substantial disparity be…

詳細を見る →
astro-ph.GA

The ringing Large Magellanic Cloud: evidence for a recent dwarf-dwarf collision

Slater J. Oden, Bethany Garver, Joshua Povick, David L. Nidever, Victor P. Debattista

Galaxy interactions are ubiquitous in the Universe and represent a primary pathway for galaxy growth. Close passages of dwarf galaxies can induce large-scale vertical oscillations in stellar disks, a phenomenon first identified in the Milky Way within the past decade. Here, we use recent red clump distance maps of the Large Magellanic Cloud (LMC) to show that its stellar periphery is vertically offset from the central disk plane by $\sim$1.2 kpc at radii of $\sim$8.5 kpc and exhibits an S-shaped…

詳細を見る →
astro-ph.SR

HD 120678: a classical Be star with a tilting heartbeat disk

Dietrich Baade, Jonathan Labadie-Bartz, Thomas Rivinius

Classical Oe/Be/Ae stars possess Keplerian circum-equatorial decretion disks which produce not just the eponymous emission lines but also the bewildering diversity of photometric variations on timescales above a few days. The variability is due to varying amounts and geometric distributions of the circumstellar gas. The ASAS-3 V-band light curve of HD 120678 between March 2005 and November 2008 resembled an inverse P Cygni profile, which may have been a one-off event. The peak-to-valley amplitud…

詳細を見る →
astro-ph.GA

Constrain the Size of Broad Line Region in NGC 1068 Using Sub-millimeter Excess

Qi Guo, Junzhi Wang, Lingrui Lin, Yuqiang Li, Zhi-yu Zhang, Fengyao Zhu

Constraining the size of broad-line region (BLR) close to the accretion disk in active galactic nuclei (AGNs) is key to understand the central engine and evolution of AGN. We propose a new method to constrain the BLR size, based on millimeter to sub-millimeter spectral energy distribution (SED), from which a sub-millimeter excess may be found. Such excess can be used to determine the solid angle of the free-free emission region from BLR, as a region with high electron density and optically thick…

詳細を見る →
astro-ph.GA

Constrain the Size of Broad Line Region in NGC 1068 Using Sub-millimeter Excess

Qi Guo, Junzhi Wang, Lingrui Lin, Yuqiang Li, Zhi-yu Zhang, Fengyao Zhu

Constraining the size of broad-line region (BLR) close to the accretion disk in active galactic nuclei (AGNs) is key to understand the central engine and evolution of AGN. We propose a new method to constrain the BLR size, based on millimeter to sub-millimeter spectral energy distribution (SED), from which a sub-millimeter excess may be found. Such excess can be used to determine the solid angle of the free-free emission region from BLR, as a region with high electron density and optically thick…

詳細を見る →
astro-ph.SR

Resolving the heart of the Wolf-Rayet binary Apep with ALMA

S. del Palacio, W. Vlemmings, M. Fernández-López, M. De Becker, P. Benaglia, V. Bosch-Ramon, B. Marcote, Luis A. Zapata et al.

The Wolf-Rayet (WR) phase is a critical stage in the evolution of massive stars. During this phase, the stars experience a large mass loss in the form of fast winds that are enriched with heavy elements. There are only a few WR binaries in the galaxy, with Apep being a truly exceptional system exhibiting a bright colliding-wind region at radio wavelengths and an impressive dust plume in the infrared. Although the angular separation between the two (WN and WC) components has been indirectly infer…

詳細を見る →
nucl-exastro-ph.SR

$^{16}$O(p,$γ$)$^{17}$F Reaction and the C and O Isotopic Ratios in Red Giant Branch Stars

D. Robb, P. McGlynn, M. Aliotta, C. Ananna, F. Barile, L. Barbieri, D. Bemmerer, A. Best et al.

The $^{16}$O/$^{17}$O isotopic ratio is a widely used tracer of nucleosynthesis and mixing processes in red giant stars. Its value depends on the rates of the proton-capture reactions responsible for the production and destruction of $^{16}$O and $^{17}$O among which the $^{16}$O(p,$γ$)$^{17}$F reaction plays a central role, as it involves both isotopes. This work reports on a new measurement of the $^{16}$O(p,$γ$)$^{17}$F cross section carried out at the Laboratory for Underground Nuclear Astro…

詳細を見る →
gr-qcastro-ph.HE

Biases in Ringdown Tests of General Relativity from Gravitational-Wave Microlensing

Sreelakshmi Mundakkal Dasan, Anuj Mishra, Apratim Ganguly

Gravitational-wave (GW) ringdown signals provide a powerful probe of the strong-field regime of general relativity (GR) through black hole spectroscopy and tests of the Kerr hypothesis. However, unmodeled propagation effects can bias the inference of remnant properties and the interpretation of ringdown features. We investigate the impact of gravitational lensing on ringdown inference and tests of GR using GW150914-like simulated signals spanning the long-wavelength, wave-optics, and geometric-o…

詳細を見る →
astro-ph.SRastro-ph.EPastro-ph.IM

Revisiting the Optical F-corona from the Artemis II Total Solar Eclipse with RAW Data: How Far Can Consumer JPEG Images Be Trusted for Astronomical Photometry?

Kohji Tsumura, Ko Arimatsu

We reanalyze the total solar eclipse images taken with a consumer camera during the Artemis II lunar flyby, using the RAW data as ground truth for our previous analysis of the released JPEG image. Calibrated with field stars, the RAW data show that the lens vignetting and the variation of the pixel solid angle reduce the signal of diffuse light by up to $\sim$70% at the edge of the field, and that the signal on the dark side of the Moon is most likely foreground light rather than an instrumental…

詳細を見る →
astro-ph.HE

Search for High-Energy Neutrinos from Infrared Flares

R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, J. M. Alameddine, S. Ali, N. M. Amin et al.

IceCube has detected a diffuse flux of high-energy astrophysical neutrinos. While its astrophysical origin is unknown, a significant neutrino emission has been observed from the gamma-ray blazar TXS 0506+056 and the Seyfert galaxy NGC 1068. This suggests accretion by supermassive black holes as one of the candidate mechanisms of the diffuse neutrino flux. Indeed, external studies that made use of IceCube data identified candidate sources, including AT2019dsg, likely a stellar tidal disruption ev…

詳細を見る →
astro-ph.IMphysics.ao-ph

R&D activity in INAF on light instrumentation for continuous optical turbulence monitoring

Camilo Weinberger, Elena Masciadri, Luca Carbonaro, Marlene de Sepibus, Fernando Pedichini, Ciro Del Vecchio, Christian Veillet, Sam Ragland et al.

Measurements of optical turbulence are essential in both ground-based astronomy and free-space optical communication systems contexts for multiple reasons including supporting and optimizing Adaptive Optics. Similarly, forecasting these parameters is highly valuable for planning observational campaigns; however, it requires at least two years of continuous data to generate a reliable training dataset. The most commonly used instruments to monitor continuously the optical turbulence include DIMM,…

詳細を見る →
astro-ph.GA

Uncovering the origin of complex velocity distributions in edge-on disc galaxies

Sophie Townson, Marie Martig, Robert J. J. Grand, Prashin Jethwa, Jesús Falcón-Barroso, Timothy A. Davis

Stellar line-of-sight velocity distributions are a powerful tool for studying galaxy kinematics and formation history, with multiple-peaked LOSVDs often indicating the presence of complex kinematic components. We extract stellar LOSVDs across the disc of a simulated spiral galaxy viewed edge-on, and study how often and why we see multiple-peaked LOSVDs. We find that the multiple-peaked LOSVDs are mainly found close to the midplane because they result from the presence of spiral arms. This is not…

詳細を見る →
astro-ph.HE

Optical constraints on intranight variability in TeV HBLs from a two-year Asiago Schmidt monitoring campaign

Domenico Impiombato, Giacomo Bonnoli, Elisa Prandini, Luca Zampieri, Irene Albanese

We present a two-year homogeneous optical monitoring campaign of three TeV-emitting high-synchrotron-peaked BL Lac objects, 1ES 1959+650, H 1426+428, and PG 1553+113, carried out with the Asiago Schmidt 67/92 cm telescope. TeV blazars are key targets in high-energy astrophysics, relevant for relativistic jet physics, particle acceleration, multiwavelength variability studies, and, in selected cases, multimessenger programmes. In this context, dense optical monitoring provides a low-energy synchr…

詳細を見る →
astro-ph.SRastro-ph.EP

HD 152384: A 5 Myr old debris disk system showing a gaseous ring of refractory elements at the dust sublimation radius

Mario van den Ancker, Daniela Iglesias, Olja Panić, Monika Petr-Gotzens, Miguel Vioque

Context: Circumstellar gas around young stars provides key insights into planet formation and disk evolution. HD 152384, a young (5 Myr) A0 V star in Sco-Cen, shows hybrid-disk traits: a modest infrared excess from small dust grains and atomic emission lines dominated by refractory elements, but its disk structure and origin remain unclear. Aims: We characterise the kinematics and excitation of the circumstellar gas around HD 152384 and constrain the physical properties of its emitting region. M…

詳細を見る →