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Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.GA

Electron temperature and emission measure of HII regions in the central molecular zone (CMZ) from H40 αrecombination line and continuum emissions by ALMA CMZ Exploration Survey - ACES -

Yoshiaki Sofue, Steven N. Longmore, Daniel Walker, Adam Ginsburg, Jonathan D. Henshaw, John Bally, Ashley T. Barnes, Cara Battersby et al.

Star formation activity in the Central Molecular Zone (CMZ) directly manifests itself as radio continuum free-free emission (Bremsstrahlung) and radio recombination line emission from HII regions surrounding newly formed massive stars. We derive the overall distribution of the HII regions and their fundamental properties: electron temperature ($\Te$) and emission measure ($EM$), and hence electron density in the form of two dimensional distribution maps over the CMZ by analyzing the ACES (ALMA C…

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astro-ph.GA

Electron temperature and emission measure of HII regions in the central molecular zone (CMZ) from H40 αrecombination line and continuum emissions by ALMA CMZ Exploration Survey - ACES -

Yoshiaki Sofue, Steven N. Longmore, Daniel Walker, Adam Ginsburg, Jonathan D. Henshaw, John Bally, Ashley T. Barnes, Cara Battersby et al.

Star formation activity in the Central Molecular Zone (CMZ) directly manifests itself as radio continuum free-free emission (Bremsstrahlung) and radio recombination line emission from HII regions surrounding newly formed massive stars. We derive the overall distribution of the HII regions and their fundamental properties: electron temperature ($\Te$) and emission measure ($EM$), and hence electron density in the form of two dimensional distribution maps over the CMZ by analyzing the ACES (ALMA C…

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astro-ph.IMastro-ph.EP

The final design of GMagAO-X: high-contrast imaging at first-light of the GMT

Jared R. Males, Laird M. Close, Sebastiaan Y. Haffert, Victor Gasho, Adam Fletcher, Joseph Boales, Dhruv Lakhani, Maggie Y. Kautz et al.

GMagAO-X will be the first-light high-contrast imager on the 25 m Giant Magellan Telescope. The driving science case for GMagAO-X is characterization of the atmospheres of nearby rocky exoplanets such as Proxima Centauri b. The revolutionary increase in spatial resolution and sensitivity provided by GMagAO-X will enable detailed study of such planets for the first time. Additional science cases include: reflected light characterization of mature giant planets; measurement of young extrasolar gia…

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astro-ph.SR

Parametric Study of Torus Instability Threshold

Jun Chen, Bernhard Kliem, Tibor Török, Rui Liu

The torus instability of an arched current channel has been suggested to initiate and drive major solar and stellar eruptions. Its threshold, given by the critical decay index of the equilibrium external poloidal field (the so-called strapping field) at the position of the current channel, is insufficiently known. Here, we carry out a parametric numerical study of the threshold, employing the force-free Titov-Démoulin equilibrium of a line-tied partial toroidal current channel and flux rope. Thi…

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astro-ph.SR

Parametric Study of Torus Instability Threshold

Jun Chen, Bernhard Kliem, Tibor Török, Rui Liu

The torus instability of an arched current channel has been suggested to initiate and drive major solar and stellar eruptions. Its threshold, given by the critical decay index of the equilibrium external poloidal field (the so-called strapping field) at the position of the current channel, is insufficiently known. Here, we carry out a parametric numerical study of the threshold, employing the force-free Titov-Démoulin equilibrium of a line-tied partial toroidal current channel and flux rope. Thi…

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astro-ph.IM

Sensor fusion on MagAO-X: real time vibration control using accelerometers

Parker T. Johnson, Jared R. Males, Povilas Palunas, Olivier Guyon, Sebastiaan Haffert, Joseph Long, Vincent Deo, Julien Lozi et al.

Mechanical vibrations are a significant source of residual wavefront error (WFE) in adaptive optics (AO) systems, limiting the performance of high-contrast imaging instruments. We present the design and on-sky deployment of a low-cost, modular accelerometer telemetry system for the MagAO-X extreme AO instrument on the 6.5 m Magellan Clay Telescope, consisting of piezoelectric accelerometers and a Raspberry Pi-based acquisition system that streams synchronized data to the real-time control comput…

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astro-ph.IM

Wavelength Calibration Accuracy Across the STIS CCD: Pipeline Update and User Guidance

Matilde Mingozzi, Robert Jedrzejewski, Matthew Siebert, Daniel Welty, Sean Lockwood, Joleen Carlberg

We investigate the wavelength calibration accuracy of STIS CCD spectra as a function of detector position, focusing on the E1/E2 pseudo-apertures. Comparison between measured lamp line centroids and laboratory wavelengths shows that, while the standard calstis solution is stable at the detector center, significant offsets are present toward the CCD edges and increase with time. We used a test version of calstis in which the wavelength calibration step employs a row-selected cross-correlation, le…

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astro-ph.GA

The Rotation Curve of the Milky Way: State of the Art, the Keplerian Decline Debate, and Implications for Dark Matter

Alessandro Melchiorri, Ruchika

For four decades, the roughly flat rotation curve (RC) of the Milky Way (MW) stood as local evidence for an extended dark matter (DM) halo. \textit{Gaia} DR3 has changed the picture: several analyses now find a velocity decline beyond R \approx 15\kpc, and the most radical interpretation \citep{jiao2023} claims a nearly Keplerian fall-off (\vc \propto R^{-1/2}) that excludes a flat RC at 3σand implies a total dynamical mass of only \sim 2 \times 10^{11}\Msun---three to five times below pre-\text…

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astro-ph.GA

Constructing X-ray Spectral Models of Galaxies: Varying Contributions from X-ray Binary Populations with Host Galaxy Properties

Emerson Gehr, Bret D. Lehmer, Antara R. Basu-Zych, Konstantinos Kovlakas, Vianney Lebouteiller, Erik B. Monson, Izabela Pavel, Chris Richardson et al.

Recent work has shown that the emission from X-ray binary (XRB) populations in galaxies varies with stellar mass ($M_\star$), star formation rate (SFR), and metallicity ($Z$). Such scaling relations are widely used to predict the XRB contributions to galaxy-integrated X-ray luminosities including studies focused on dwarf active galactic nuclei (AGN) and the X-ray radiation field during the epoch of heating in the early ($z \geq 8$) universe. However, as galaxies approach low SFR and low $Z$, the…

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gr-qcastro-ph.HE

A parametrized test of general relativity for inspiralling eccentric binaries in LISA

Pankaj Saini, Sylvain Marsat, Lorenz Zwick, János Takátsy, Johan Samsing

The space-based detector Laser Interferometer Space Antenna (LISA) will observe inspiralling black hole binaries in the mHz band, many of which may retain orbital eccentricity. In contrast to quasicircular binaries, eccentric systems radiate through multiple orbital harmonics, while relativistic periastron precession introduces a secular phase structure in the waveform. We exploit this structure to develop a parametrized test of general relativity (GR) for eccentric bound orbits. We construct a…

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astro-ph.IM

CCD Rotation Rates From Regular Dispersion Solution Monitoring

Matilde Mingozzi, Matthew Siebert

It has been previously studied that the STIS CCD exhibits a slow rotation, evident from changes in spectral traces and flat-field evolution. In this Instrument Science Report, we present an independent spectroscopic analysis of the CCD rotation angle and a comparison with previous studies. We describe the methodology used to derive rotation angles and rates across different gratings and central wavelengths, and report the corresponding median rotation rates over time. The results are broadly con…

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astro-ph.GA

The Extended Mapping Obscuration to Reionization with ALMA (Ex-MORA) Survey: A Molecular Gas Line Search

V. Catán, J. González-López, M. Aravena, A. S. Long, C. M. Casey, D. L. Clements, E. da Cunha, M. Franco et al.

Current investigations of cold gas in the interstellar medium face selection biases, as optical/near-infrared surveys favor massive, low-obscuration galaxies and miss gas-rich passive or inefficient star-forming systems. Overcoming this requires large-volume line surveys selected by molecular gas rather than stellar luminosity. We present a molecular gas census across $0.5 10^{10}\,\text{M}_{\odot}$). Gas fraction ($μ_{\text{gas}}$) increases with redshift for active populations, though high-red…

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astro-ph.COastro-ph.GA

CORN -- Chronometers of Relic Nature I: The first estimate of the expansion rate of the Universe using compact relic galaxies

Krzysztof Lisiecki, Nicola Principi Cavaterra, Agnieszka Pollo, Chiara Spiniello, Laura Hunt, Charlie Rosen, Marek Biesiada, Darko Donevski et al.

Measuring the expansion rate of the Universe is a central challenge in cosmology, particularly due to the persistent statistically significant discrepancy between the measurements of the Hubble constant, H0, obtained using early- and late-time probes, commonly known as the Hubble tension. Independent and robust methods are therefore essential to validate existing measurements and assess potential systematic effects. We employ the cosmic chronometer (CC) approach, which uses the differential age…

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astro-ph.COastro-ph.GA

CORN -- Chronometers of Relic Nature I: The first estimate of the expansion rate of the Universe using compact relic galaxies

Krzysztof Lisiecki, Nicola Principi Cavaterra, Agnieszka Pollo, Chiara Spiniello, Laura Hunt, Charlie Rosen, Marek Biesiada, Darko Donevski et al.

Measuring the expansion rate of the Universe is a central challenge in cosmology. Independent and robust methods are essential to validate existing measurements and assess potential systematic effects. We employ the cosmic chronometer (CC) approach, which uses the differential age evolution of quiescent galaxies to measure the Hubble parameter H(z) without assuming an underlying cosmological model. In contrast to previous CC studies, we restrict our analysis to relics -- ultra compact massive ga…

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astro-ph.IM

The eXtreme Wavefront Control Toolkit: High-Contrast Imaging Instrument Control for Ground and Space-Based Coronagraphs

Jared R. Males, Joseph D. Long, Sebastiaan Y. Haffert, Kyle Van Gorkom, Parker Johnson, Rico Landman, Eden McEwen, Olivier Guyon et al.

We present the eXtreme Wavefront Control Toolkit (XWCTk) instrument control software system developed for the MagAO-X extreme adaptive optics (ExAO) instrument. The XWCTk is built on a foundation of the ImageStreamIO (ISIO) / MILK / CACAO low-latency image processing and high dimensional control tool chain. Instrument control is managed with the Instrument Neutral Distributed Interface (INDI). The application framework provides configuration, logging, and distributed IPC with INDI and low-latenc…

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astro-ph.IM

Freezing the speckles: focal plane wavefront sensing with the spatially-clipped self-coherent camera

Joshua Liberman, Sebastiaan Y. Haffert, Jared R. Males, Aditya Khandelwal, Stephanie Rinaldi, Joseph D. Long, Katie M. Twitchell, Jay K. Kueny et al.

The next generation of Extremely Large Telescopes (ELTs) and the Habitable Worlds Observatory (HWO) require active speckle suppression to directly image exo-Earths. Focal plane wavefront sensing and control allows us to detect and remove time-varying speckles through measurements of the electric field. Wavefront sensing approaches include pairwise probing (PWP) and the self-coherent camera (SCC). However, the PWP technique is time-consuming, requiring at least 4 images and reducing the speed at…

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astro-ph.SRastro-ph.EP

A Pre-Main Sequence Binary Viewed Through its Circumbinary Disk: A New Phase for KH 15D

Catrina M. Hamilton, Adi B. Chacko, George A. Carson, Aidan J. Pidgeon, C. Nicole Foley, Hillel Finder, Kyle Gimmy, Aleezah Ali et al.

The binary T Tauri system, KH 15D, is poised to provide unprecedented detail of gas and ices located between $\sim$3-5 AU of its circumbinary disk over the next few years. We analyze for the first time a complete set of ground-based time series photometry of the KH 15D system for which the 2022 October - 2025 April data have never been presented. By combining the latest $I$-band data with historical measurements, we show that the era of large amplitude photometric variability has ended. We defin…

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astro-ph.IMastro-ph.EPastro-ph.SR

The Carruthers Mission Concept and Performance

W. Craig, T. Immel, L. Waldrop, J. Troeltzsch, E. Taylor, J. McPhate, K. Rider, A. Butterworth et al.

The Carruthers Geocoronal Observatory (Carruthers), formerly GLIDE, is a NASA Heliophysics Science Mission of Opportunity implemented through the Solar Terrestrial Probes (STP) Program and launched as a rideshare in September 2025. Carruthers is the first spaceflight mission edicated to continuous global imaging of Earth's hydrogen exosphere through observations of geocoronal Lyman-$α$ emission at 121.6 nm. The observatory operates at distances of 1.3-1.7 million km in a halo orbit about the Sun…

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astro-ph.GA

Does IRS13 require an intermediate-mass black hole?

Václav Pavlík, Vladimír Karas, Florian Peißker, Bhavana Bhat, Andreas Eckart

We investigate whether the Galactic-centre association IRS13 requires an intermediate-mass black hole (IMBH) to remain bound. Using high-precision $N$-body calculations of IRS13-like systems orbiting the Milky Way supermassive black hole (SMBH), as well as simulations of more massive infalling clusters, we find that an IRS13-sized cluster dissolves on a very short timescale even when an IMBH of $4\times10^4\,M_\odot$ is present. The observed velocity dispersion can arise naturally from the tidal…

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astro-ph.COastro-ph.IMhep-exhep-phphysics.ins-det

Reconstructing Dark Matter Mass and Discriminating Standard and Non-Standard WIMP-Nucleus Interactions with Paleo-Detectors

Dionysios P. Theodosopoulos, Katherine Freese, Chris Kelso, Patrick Stengel

Paleo-detectors record and retain crystal damage in ancient minerals from nuclear recoils induced by dark matter scattering over geological timescales. Previous studies have shown that paleo-detectors can provide sensitivity to a variety of dark matter (DM) scenarios which is complementary to conventional direct-detection experiments. In this paper, we complete the first detailed study of how well paleo-detectors can reconstruct DM parameters or distinguish between different types of DM interact…

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astro-ph.HEgr-qc

3D Binary Neutron Star Merger Ejecta Evolution up to Seconds Timescale: Dynamics, Element Distribution, and Light Curves

Luis Felipe Longo Micchi, Fabio Magistrelli, Maximilian Jacobi, Sebastiano Bernuzzi

We present long-term, three-dimensional simulations of ejecta from four binary neutron star mergers to second-long time-scales. Numerical-relativity data serve as boundary conditions for a general-relativistic hydrodynamics evolution incorporating an equation of state valid outside nuclear statistical equilibrium and an effective nuclear-heating prescription based on reaction-network calculations. We investigate the ejecta's dynamical and geometrical properties, the impact of nuclear heating, th…

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astro-ph.GA

From Cluster Core to Splashback: Linking Dynamical Structure to Multidimensional Galaxy Evolution in the Coma Cluster

Mohamed H. Abdullah, S. W. El-Sogheir, Gillian Wilson, Magdy Y. Amin, A. Ahmed

We investigate galaxy evolution across the full dynamical structure of the Coma cluster using the GalWCat19 spectroscopic cluster catalog combined with SDSS-based value-added galaxy properties. We measure a splashback radius of $R_{sp} = 2.94 \pm 0.16~h^{-1}\, Mpc$. Using specific star formation rate (sSFR), color offset from the red sequence ($Δ(g-r)_{RS}$), and bulge-to-total ratio ($B/T$) as independent diagnostics, we find a coherent environmental transition from quiescent, red, bulge-domina…

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astro-ph.GA

Spiral Morphology and Radial Migration: Kinematically heating, cooling, and cold

Kathryne J. Daniel, M. E. Wisz, Karen L. Masters, Rosemary F. G. Wyse, Amy Smock, Lipika Chatur

Transient spiral arms are known to drive radial redistribution of stars and thus could play a central role in shaping disk galaxies, including modifying, over time, the age, chemical, and kinematic (chrono-chemo-dynamic) distributions in the Milky Way. However, the physical factors governing the efficiency of such processes remain poorly understood. This paper investigates how the morphology of spiral arms -- the number, pitch angle, lifetime, and radial dependence of the pattern speed -- influe…

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astro-ph.EPastro-ph.GAastro-ph.SR

SMA Observations Reveal Abundant HNC Chemistry in Transition Disks

Kyle Gresko, Charles J. Law, Deryl E. Long, L. Ilsedore Cleeves, Feng Long, Yuri Aikawa, Jennifer B. Bergner, Romane Le Gal et al.

The physical and chemical conditions of protoplanetary disks shape the properties of nascent planetary systems. The line ratios and relative abundances of the HCN-HNC isomer pair are well-suited for tracing these gas conditions, since isomer chemistry is linked to the underlying temperature, elemental abundances, and irradiation environment of the emitting gas. While HCN emits bright lines regularly observed in disks, the fainter HNC lines are targeted significantly less often, precluding our ab…

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astro-ph.EPastro-ph.IM

Technology and Science Advancing Observations with Roman Coronagraph Informed by Ground-Based High-Contrast Imaging

Mona El Morsy, Thayne Currie, Brianna Lacy, Danielle Bovie, Erica Dykes, Jie Li, Olivier Guyon, Julien Lozi et al.

The Roman Coronagraph technology demonstration focuses on achieving $<$ 10$^{-7}$ contrasts within the instrument's dark hole and our ability to detect and characterize properties of faint companions around bright stars. Here, we describe results from a study of potential Roman Coronagraph technology demonstration phase observations focused on these goals, informed by the ongoing OASIS survey at the Subaru Telescope and precursor survey work. OASIS provides at least three compelling targets for…

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astro-ph.GA

An X-ray Absorption-Line Survey of the Circumgalactic Medium of M31 with XMM-Newton

Kaile Wang, Zheng Zhou, Taotao Fang, Fabrizio Nicastro

X-ray absorption line spectroscopy provides a powerful method for probing the extended hot circumgalactic medium (CGM) of individual galaxies. In this study, we present the first survey of \osv and \oeit absorption lines toward the hot halo of M\,31, using $15$ and $18$ background active galactic nuclei, with impact parameters ranging from $R_{\rm imp}\sim300$--$730$~kpc and $\sim190$--$730$~kpc, respectively. We find a marginal excess absorption above the expected Milky Way (MW) foreground towa…

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hep-phastro-ph.HEhep-ex

A $U(1)_{(B-L)_3}$ model for dark matter and the $B^+\to K^+ν\barν$ excess reported by Belle II

MohammadAli Abri, Yasaman Farzan

We explore the $U(1)_{(B-L)_3}$ gauge symmetry under which only third generation fermions are charged. The cancelation of the $[U(1)_{(B-L)_3}]^3$ anomaly requires a chiral fermion, $χ_L$, singlet under the gauge group but charged under $U(1)_{(B-L)_3}$. This chiral fermion can play the role of thermal dark matter with a relic abundance set via the freeze-out scenario through the annihilation to pairs of the third generation fermions. In the quark mass basis, the new gauge boson will have off-di…

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quant-phastro-ph.IM

Eliminating photon transport in long-baseline optical interferometry using quantum memories

Yousef K. Chahine, Chaohan Cui, William DeRocco, Daniel Gottesman, Saikat Guha, Emil T. Khabiboulline, Zhenning Liu, Brittany McClinton et al.

In this paper, we describe the fundamental operating mechanisms of optical interferometry using quantum memory and entanglement. We show how these remove the optical delay line bottleneck. Quantum memory is not without its own set of challenges, some of which include very small bandwidths as well as limitations in storage time. We examine the influence of timing artifacts on memory photon capture probability and interferometric complex visibility. We highlight keystone areas of technology that r…

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astro-ph.SRastro-ph.GA

Filling the Gap: Calibrating Gyrochronology at 1.3 Gyr with the Benchmark Cluster NGC-752

Andrew W. Boyle, Andrew W. Mann

Empirical gyrochronology relies on co-eval stellar associations to map stellar rotation as a function of mass and age. The accuracy of its age predictions is therefore limited by the number and quality of benchmark rotation sequences. The well-characterized clusters NGC-6811 (t ~ 1 Gyr) and NGC-6819 (t ~ 2.5 Gyr) bracket an intermediate-age interval in which stellar spin-down remains poorly constrained due to lack of available rotation data. At t ~ 1.3 Gyr, NGC-752 provides a critical benchmark…

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astro-ph.GAastro-ph.COgr-qc

Flat Galactic Rotation Curves Interpreted as Evidence for the Mach's Principle

Andres Escala

We explore the possibility of a Machian interpretation for the phenomena associated with asymptotically flat rotation curves in disk galaxies, providing an alternative to both the Lambda-Cold Dark Matter ($Λ$CDM) paradigm and MOdified Newtonian Dynamics (MOND). We argue that the MOND acceleration scale $a_0$ is likely not a new fundamental constant, but rather a manifestation of the cosmological scales of the observable Universe ($a_0 \sim c^2/R_u \sim c^4/GM_u \sim c/t_u$). We rewrite the Baryo…

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