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Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.GA

Determining Total Infrared Luminosities from Submm Measurements of High Redshift Galaxies

Maria Emilia De Rossi, George H. Rieke, Christina C. Williams, Volker Bromm, Jianwei Lyu, Meredith A. Stone, Yang Sun, Christopher N. A. Willmer et al.

Determining total infrared luminosities for very high redshift galaxies is important to estimate the rate of star formation in heavily dust-embedded environments. It is also challenging because the most sensitive far infrared observatory, Herschel, was limited in sensitivity and its deepest measurements are subject to confusion noise. Thus, these determinations largely depend on ALMA, observing in the mm- and/or submm-wavelengths, which sample only the long-wavelength part of the spectral energy…

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astro-ph.SR

Quasi-Keplerian Be-Star Disks with Mimicking Viscosity

Michel Cure, Ignacio Araya, Rodrigo Meneses, Matias Montesinos, Roberto O. J. Venero, Catalina Arcos, Abigali Rodriguez, Lydia S. Cidale et al.

Classical Be stars are fast-rotating B-type stars with gaseous quasi-Keplerian disks formed by equatorial ejection of material. While the viscous decretion disk (VDD) model reproduces many observed properties, the role of radiative line driving in shaping these disks remains unclear. We investigated the combined influence of viscosity and radiative acceleration on the hydrodynamic structure of Be star disks by coupling the m-CAK theory of line-driven winds with a mimicking viscous prescription g…

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astro-ph.HEhep-ph

Energy-dependent Optical/Near-infrared and X-ray Correlations in Swift J1727.8-1613

Ruican Ma, Federico Vincentelli, Diego Altamirano, Alexandra Veledina, Poshak Gandhi, Piergiorgio Casella, Tariq Shahbaz, Sian Woahene-Demehin et al.

We present a timing analysis of the black hole transient Swift J1727.8-1613 during its intermediate state. We use coordinated broadband X-ray observations from Insight-HXMT (2-150 keV), together with optical data from ULTRACAM (g_s and i_s bands) and near-infrared data from HAWK-I (K_s band), obtained on 2023 September 9. As shown by previous studies, the Fourier power spectrum shows a strong quasi-periodic oscillation (QPO) in the K_s, i_s and X-ray bands. Cross-correlation analysis reveals a c…

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astro-ph.EPastro-ph.IM

Optical and acoustic ground effects simulations from terminal defense asteroid disruption via the PI method

Brin Bailey, Alexander N. Cohen, Philip Lubin, Darrel K. Robertson, Mark Boslough, Sasha Egan, Elizabeth A. Silber, Dharv Patel et al.

Our simulations suggest that PI ("Pulverize It"), a NASA Phase II NIAC study, is an effective multi-modal approach for planetary defense that can operate in extremely short interdiction modes (with intercepts as short as hours prior to atmospheric entry) as well as long interdiction time scales with months to years of warning. The basic process is complete disruption of the threat via fragmentation. In scenarios with sufficiently long warning time, the fragment cloud spreads enough to miss Earth…

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astro-ph.GAastro-ph.SR

EWOCS-VIII: Internal kinematics and expansion of Westerlund 1 from VVVX proper motions

C. Ordenes-Huanca, A. Bayo, M. Guarcello, M. Zoccali, A. Rojas-Arriagada, Nicholas J. Wright, S. Sciortino, F. Damiani et al.

Westerlund 1 (Wd1) is the most massive young star cluster known in the Milky Way and a key laboratory for studying the early dynamical evolution of massive clusters. Owing to its high extinction, the internal kinematics of its intermediate-mass stellar population remain largely unexplored. We aim to characterize the internal kinematic properties of Wd1 using a homogeneous census of near-infrared (NIR) selected cluster members and their proper motions (PMs). We considered PMs from the VIRAC2 cata…

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astro-ph.IM

LUVCam: A high-performance, low-cost, UV/optical camera for the future of astronomy in space

Aaron Tohuvavohu, Suresh Sivanandam, Jean-Christophe Fronteddu, Patrick Nkwaria, Gavin Hay, Shaojie Chen, Sarik Jeram, Albert Lau et al.

Astronomy-grade cameras with robust performance and heritage in the space environment have long been costly, substantially limiting capacity for space-based astronomy and creating a resource barrier to access. Additionally, ultraviolet observations have historically been limited by the low quantum efficiency of most sensors in this wavelength range. The LUVCam program is designed to address both issues by providing a high-performance, low-cost, UV/optical camera system sufficiently capable to su…

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hep-phastro-ph.HE

Molecular clouds constraints on sub-GeV DM and asteroid-mass PBHs

Asier Salces Pérez, Pedro de la Torre Luque

We show that the ionization of molecular clouds provides a novel probe of dark matter scenarios producing low-energy $e^+e^-$ pairs through annihilation, decay, or Hawking evaporation of primordial black holes. We derive constraints on MeV-scale dark matter with masses between $\sim1$ and $100$ MeV, as well as on primordial black holes in the mass range $10^{14}$--$10^{17},$g. By modeling the propagation of electrons and positrons inside molecular clouds, we show that uncertainties in charged-pa…

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astro-ph.IM

Multi-sensor fusion for fine-guidance and milliarcsecond-level attitude estimation of balloon-borne telescope

Philippe Voyer, Maya Amit, Steven J. Benton, Benjamin E. Boyd, Anthony M. Brown, Giulia Cerini, Paul Clark, Matthew Craigie et al.

Balloon-borne telescopes rely on fine-guidance systems to achieve milliarcsecond image stability despite residual disturbances from the balloon environment. In these systems, the Fast Steering Mirror (FSM) stabilizes the image in two focal-plane axes, but leaves systematic, field-dependent residual motion induced by boresight roll. This effect, referred to as roll leakage, becomes more important for wider fields of view. In this work, roll leakage is characterized using data from the 2023 Superp…

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astro-ph.GA

SDSS-V Local Volume Mapper (LVM): The Integrated Light and Internal Rotation of Omega Centauri

Maximilian Häberle, Dmitry Bizyaev, Alina Boecker, Callie Clontz, Bruno Dias, Antoine Dumont, Evgeniya Egorova, Anja Feldmeier-Krause et al.

The SDSS-V Local Volume Mapper (LVM) is a wide-field integral field spectroscopic survey of the Southern Milky Way plane, the Magellanic Clouds, and nearby Local Group galaxies. We use Early Science observations of the whole body of the nearest nuclear cluster, Omega Centauri, to extend the LVM beyond its primary interstellar-medium science case. The wide LVM field allows us to precisely map $ω$ Cen's line-of-sight rotation out to $\sim 3r_{HL}$ or $15^\prime$, reaching a maximum value of $(8.4…

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astro-ph.SRphysics.space-ph

Averaging Effects on the Solar Wind Alfven Mach Number: Implications for Switchbacks and Alfven Transition

Joshua Goodwill, Subash Adhikari, Francesco Pecora, Rayta Pradata, Jiaming Wang, Sujan Prasad Gautam, Manuel E. Cuesta, Orlando Romeo et al.

Averaging techniques in solar wind measurements have been a longstanding subject of debate. Using Parker Solar Probe (PSP) observations from encounters 1 to 19, we investigate how averaging timescales influence the characterization of turbulent properties across the Alfvenic transition. We compute the rolling mean Alfven Mach number over various averaging intervals, which are then analyzed against switchbacks, magnetic fluctuation energy, and correlation time. We find that the distribution of su…

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astro-ph.GA

Fishing for Jellyfish Galaxies: Exploring ram-pressure stripping with crowd science

C. Bellhouse, Y. L. Jaffé, J. P. Crossett, S. L. McGee, Ignacio Quiroz, C. Dulcien, R. Smith, B. M. Poggianti et al.

Aims: We present the first results of Fishing for Jellyfish Galaxies, a pilot citizen-science project using Zooniverse to identify galaxies undergoing ram-pressure stripping (RPS). Methods: Volunteers visually inspected colour images of late-type galaxies from the Dark Energy Camera Legacy Survey, from a sample of 49,703 galaxies selected within $4 \times R_{500}$ of clusters and groups, restricted to galaxies brighter than 19th magnitude in the g and r bands, and with a minimum half-light radiu…

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

Cataclysmic variables from Gaia XP spectra: The Gaia emission-line magnitude (GEM) diagram

Ilkham Galiullin, Vladislav Dodon, Antonio C. Rodriguez, Askar Sibgatullin

Gaia DR3 opens a new window for the census of Galactic stellar populations in all-sky surveys, specifically for identifying cataclysmic variables (CVs). While the majority of CVs are distributed below the main sequence on the Gaia HR diagram, identifying them among dominant background stellar populations remains a significant challenge. Here, we present the Gaia Emission-line Magnitude (GEM) diagram - a tool designed to isolate CV candidates from background stars located below the main sequence.…

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astro-ph.GAphysics.data-an

Changing-Look AGNs from DESI. VI. Host Galaxies

Shengxiu Sun, Linhua Jiang, Wei-Jian Guo, Sarah E. I. Bosman, Zhiwei Pan

Changing-look (CL) AGNs trace rapid changes in nuclear activity, but their connection to host galaxy properties remains unclear. We present a study of the host galaxies of 105 CL AGNs previously selected by comparing DESI and SDSS data. We apply a two-epoch spectrophotometric decomposition to the DESI and SDSS spectra of the 105 objects. Meanwhile, HSC images are used to constrain their varying AGN components and non-varying stellar population components. We find that 79 of the 105 (75.2%) CL AG…

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astro-ph.GAastro-ph.IM

Quiescent Host Galaxies of Extended Quasars Revealed by Spectrophotometric Decomposition

Shengxiu Sun, Linhua Jiang, Zhiwei Pan, Małgorzata Siudek, Mar Mezcua, Gaocheng Yin, Swayamtrupta Panda, Wei-Jian Guo et al.

Previous works of low-redshift quasar host galaxies have focused on compact quasars and found that their host galaxies are mainly star-forming galaxies. Here we present a study of host galaxies for quasars with extended morphologies in ground-based optical images. We select a sample of more than 1000 type 1 quasars at redshift $0.1<z<1$ that are classified as extended objects by DESI. Combining high-resolution spectra from DESI and high-quality images from Subaru HSC, we develop a spectrophotome…

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astro-ph.SRastro-ph.GA

The s-process at Subsolar Metallicity: Insights from High-Resolution Infrared Spectroscopy of Magellanic Cloud Planetary Nebulae

N. C. Sterling, M. G. Stephenson, Harriet L. Dinerstein, A. Yagüe-López, Kyle F. Kaplan, J. Beaumont, Maria Lugaro, Amanda I. Karakas et al.

We present observations of 12 Magellanic Cloud planetary nebulae (PNe) obtained with the high-resolution near-infrared spectrometer IGRINS on Gemini South. In 10 targets we detect multiple neutron(n)-capture elements that can be synthesized by the s-process during the preceding asymptotic giant branch (AGB) phase, including the widely-observed species Se and Kr, and first detections of Rb, Cd, and Te in extragalactic PNe. The derived abundances significantly expand the inventory of trans-iron el…

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astro-ph.IM

End-to-end differentiable retrieval of molecular spectra using hydrodynamics, chemistry, and radiative transfer

T. Grassi, G. Vermariën, J. E. Pineda, S. Spezzano, S. Bovino, P. Caselli

We aim to reproduce observed molecular line emission using a pipeline that couples hydrodynamics, chemistry, and radiative transfer, capable of simultaneously optimizing all relevant physical and chemical parameters. We developed an end-to-end differentiable Jax pipeline consisting of a custom hydrodynamical code, a modified version of the differentiable chemical code Carbox, and a custom radiative transfer code. We tested the framework using controlled synthetic data. We demonstrate that the fr…

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astro-ph.SR

A New Sirius-like System at Only 21 Parsecs: An Elusive White Dwarf Companion to the Nearby K-dwarf HD 38230

Alexander Venner, Logan A. Pearce, Qier An, Clémence Fontanive, Elisabeth C. Matthews, Kyle Franson, Justin R. Crepp, Hai Fu et al.

White dwarfs are among the rarest and faintest stars found in the solar neighbourhood and are therefore persistently challenging to detect. Whereas the \textit{Gaia} mission has vastly expanded our knowledge of isolated white dwarfs, limited contrast sensitivity means that white dwarfs companions to much brighter solar-type stars are easily missed, leaving a subset of white dwarfs in "Sirius-like systems" that can only be discovered via high-contrast imaging. Here we report the discovery of a wh…

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astro-ph.HE

Deep Learning-Based Classification and Analysis of Pulsar Candidates in Fermi-LAT Unassociated Sources

C. Pozo González, R. López-Coto, J. Méndez-Gallego, E. de Oña Wilhelm

The Large Area Telescope (LAT) has revolutionized our understanding of the high-energy sky, yet approximately one-third of the sources in the Fourth Fermi-LAT Source Catalog (4FGL) remain unassociated. Conventional machine learning, such as Decision Trees, often treat spectral features as independent tabular entries, neglecting the sequential topological information inherent in the Spectral Energy Distribution (SED). We aim to classify unassociated Fermi-LAT sources by exploiting the intrinsic s…

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astro-ph.EPastro-ph.SR

Atmospheric Signatures of Common Envelope Evolution in White Dwarf Planets

Sydney Jenkins, Andrew Vanderburg, James Mang, Juliette Becker, Caroline V. Morley, Melinda Soares-Furtado, Ricardo Yarza

The majority of confirmed exoplanets orbit within 1 au of a main-sequence (MS) star. When their stellar hosts evolve off the MS, many of these planets will be engulfed and destroyed, creating empty "forbidden" zones around the stars as they evolve to their final state as a white dwarf (WD). However, several confirmed and candidate WD planets have been found within this forbidden zone. Two formation scenarios have been proposed to explain the existence of these close-in planets: high-eccentricity…

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astro-ph.GAastro-ph.CO

Searching for Population III stars with line intensity mapping cross-correlations

Sahil Hegde, Guochao Sun, Julian B. Muñoz, Steven R. Furlanetto

Decades of searches for Population III stars in individual galaxies have yielded a few potential candidates, but a statistically robust characterization of the demographics of the first stars in the lowest-mass systems remains elusive. Line intensity mapping (LIM), an observational technique that measures fluctuations in the aggregate emission from the entire galaxy population --- including the faintest sources --- offers an alternative strategy that is especially well-suited for the Pop III era…

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astro-ph.HE

Peering through the dip: IXPE unveils the extended scattering environment of GX 13+1

Alessandro Di Marco, Fabio La Monaca, Luigi Stella, Anagha P. Nitindala, Alexandra Veledina, Anna Bobrikova, Eleonora Veronica Lai, Alessandro Papitto et al.

Neutron star low-mass X-ray binaries feature complex accretion geometries, often including an accretion disk corona or disk winds. Here, a study of the highly inclined dipping source GX 13+1, using coordinated observations from the IXPE, NuSTAR, and Swift-XRT, is presented; this is the first time that such a campaign was conducted to monitor its periodic dip. Our analysis reveals significant variations in polarimetric properties tracking the dip. At the center of the dip, the polarization degree…

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astro-ph.GA

Misaligned or chaotic? A strong break of axial symmetry in the local LRD J1025 revealed with VLT/FORS2 spectropolarimetry

Francesco D'Eugenio, Gabriele Pezzulli, Roberto Maiolino, Alessandro Marconi, Xihan Ji, Cristina Ramos Almeida, Andrea Ferrara, Piero Madau et al.

Little Red Dots (LRDs) are compact active galactic nuclei (AGN) with unusual spectral energy distributions and broad Balmer emission, candidate signposts of rapid black-hole growth. We present VLT/FORS2 optical linear spectropolarimetry of the closest known LRD, SDSS J102530.29+140207.3, at z=0.1. In total light, we detect spatially extended narrow-H$α$ emission, probably tracing the host galaxy. We measure a nearly grey continuum polarisation $p_{\rm cont}=1.53\pm0.04$(rand.)$\pm$0.20(syst.) pe…

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astro-ph.HEgr-qc

A Four-dimensional Model-agnostic Probe into the Astrophysical Origins of Binary Black Hole Subpopulations

Anarya Ray, Vicky Kalogera

There is strong evidence of multiple binary black hole~(BBH) subpopulations in the cumulative gravitational wave catalog by the LIGO-Virgo-KAGRA collaboration that likely originate through distinct evolutionary channels. The astrophysical interpretation of this complex underlying population is subject to theoretical uncertainties in treatments of binary stellar evolution, core collapse, and host environments. Due to a lack of robust predictions and the sheer diversity of plausible features, stro…

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astro-ph.IMastro-ph.EP

Laboratory demonstration of low order wavefront control using light reflected off the vortex coronagraph

Clarissa R. Do Ó, Kane Sjoberg, Luke Lamitina, Susan Redmond, Dimitri Mawet, Jorge Llop-Sayson, Siria Alicata

The Astro2020 Decadal Survey identified exoplanet imaging as a high priority for the Habitable Worlds Observatory (HWO), which must image and characterize exo-Earths at contrasts of $1\times10^{-10}$. The vector vortex coronagraph (VVC) is a leading architecture for this task owing to its small inner working angle and high throughput. Using light reflected from the VVC for wavefront sensing and control provides a potential path to improving robustness to residual wavefront errors and minimizing…

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astro-ph.GA

Characterizing the disruption of Böotes III: a missing link in the Galactic halo?

Jaclyn Jensen, Daniel A. Boyea, Alan W. McConnachie, Raphaël Errani, Akshara Viswanathan, Nicolas Martin, Zhen Yuan, Guillaume F. Thomas et al.

The Böotes III (Boo3) dwarf galaxy has long been suspected of being the progenitor of Styx, a ~50°-long stellar stream that was simultaneously discovered in the same region of sky. Boo3's diffuse morphology, large velocity dispersion, small pericenter, and excess of candidate stars at large radii suggest it is undergoing active tidal disruption. A link to Styx is therefore logical; however, a clear connection between these structures has not yet been clearly demonstrated. Here, we re-examine the…

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astro-ph.COastro-ph.GAhep-ph

Dark Matter Constraints from Small-Scale Cosmic Structure

Ethan O. Nadler, Keir K. Rogers, Alex Drlica-Wagner

Small-scale cosmic structure provides a powerful test of the fundamental nature of dark matter (DM). A wide range of DM models impact matter clustering on small scales, including warm, fuzzy, and (self-)interacting DM. In these scenarios, DM physics such as free-streaming, wave interference, and self/Standard Model interactions alter the abundance and internal structure of DM halos. Cosmological and astrophysical probes of nonlinear structure---including dwarf galaxies, strong lensing, the Lyman…

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astro-ph.IMastro-ph.EP

Upgrading LBTI/NOMIC with a quadruple annular groove phase mask and GeoSnap detector for imaging nearby, habitable-zone exoplanets

Kevin Wagner, Manny Montoya, Steve Ertel, Jarron Leisenring, Pontus Forsberg, Samuel Ronayette, Andre Wong, Mikael Karlsson et al.

The Large Binocular Telescope Interferometer (LBTI)'s Nulling-Optimized Mid-Infrared Camera (NOMIC) is among the most capable thermal-infrared imaging systems available for high-contrast, high-angular-resolution astronomical observations. Here we describe two in-progress upgrades to LBTI/NOMIC: (1) the design, fabrication, and installation of a quadruple annular groove phase mask (Q-AGPM) coronagraph, and (2) the installation of a 13 micron-cutoff Teledyne GeoSnap array. The Q-AGPM is the first…

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astro-ph.HE

Spinning down neutron-star merger remnants with the Tayler-Spruit dynamo: Global simulations reveal the formation of massive disks and neutron-rich ejecta

Harry Ho-Yin Ng, Elias R. Most

Magnetic-field amplification and angular momentum (AM) transport critically shape the secular evolution, lifetime, and electromagnetic signatures of binary neutron-star merger remnants. While the magnetorotational instability can operate in the outer negative-shear regions of the neutron-star remnant and accretion disk, the positive-shear, stably stratified core may instead be susceptible to the Tayler-Spruit dynamo. We present the first global, long-term general-relativistic neutrino-radiation…

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astro-ph.HEgr-qc

Search for gravitational waves associated with high-energy neutrinos detected by IceCube during the third observing run of LIGO-Virgo

Matthias Vereecken, Matteo Pracchia, Kara Merfeld, Iara Tosta e Melo, Wasim Javed, Patrick Sutton

We search for generic gravitational-wave transients associated with high-energy neutrinos detected by the IceCube Neutrino Observatory during the third Observing Run (O3) of Advanced LIGO, Advanced Virgo, and KAGRA. We perform an unmodeled, targeted search, which is sensitive to gravitational-wave signals weaker than those reported in real time or in the gravitional-wave transient catalog, and can thus uncover coincidences missed by typical neutrino follow-up searches. We find no statistically s…

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astro-ph.SRphysics.plasm-ph

The Diagnostic Temperature Discrepancy as a Kinetic Measurement: Shape, Transport, and Termination of the Suprathermal Electron Tail

Victor Edmonds

Two standard thermometers applied to the same quiet-Sun corona disagree by a stable factor: radio brightness reads about 0.6 MK while ionization- and scale-height-based diagnostics read about 1.5 MK, a ratio of 2.4 +/- 0.3 over eight years. We argue this discrepancy is not an anomaly awaiting reconciliation but a kinetic measurement, and we read it three times: for the shape of the electron distribution, for its origin, and for the energy where it must end. First, a temperature diagnostic is a p…

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