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Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.COastro-ph.GA

Where Cluster Galaxies Reside and How Strongly They Lens

Isaque Dutra, Priyamvada Natarajan, Cian Roche

The efficiency of galaxy-galaxy strong lensing (GGSL) in clusters depends jointly on the inner mass distributions of member galaxies and their locations within the cluster potential. Observed GGSL probabilities exceed $Λ$CDM predictions by nearly an order of magnitude, but the relative roles of internal structure and environment remain unclear. We disentangle these effects by comparing HST strong-lensing clusters with TNG-Cluster analogs at similar lens redshifts, matched by their primary Einste…

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astro-ph.SRastro-ph.GA

A Spectroscopic Census of Cluster White Dwarfs from DESI, LAMOST, and SDSS

David R. Miller, Jeremy Heyl, Huahui Yan, Chengyuan Li, Pier-Emmanuel Tremblay

Gaia has substantially expanded the sample of candidate white dwarfs (WDs) in open clusters, but many remain without spectroscopic characterization. We leverage the increasingly extensive archives of large public spectroscopic surveys to identify 62 candidate cluster WDs with available spectra from DESI, LAMOST, and SDSS. After discarding sources with very low S/N and unreliable host clusters, 44 candidates remain, including 37 non-magnetic DA WDs, of which 15 had not previously been characteriz…

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

OGLE-2016-BLG-0523: A Low-mass Brown Dwarf or super-Jupiter in a $>100$ au Orbit

Hongjing Yang, Weicheng Zang, Yoon-Hyun Ryu, Andrzej Udalski, Yuchen Tang, Michael D. Albrow, Sun-Ju Chung, Andrew Gould et al.

To search for very wide-orbit binary-lens events, we cross-match microlensing events detected by OGLE-IV and KMTNet between 2011 and 2024. After removing contaminants from variable stars, we identify OGLE-2016-BLG-0523 as a microlensing event showing two short-lived bumps in its light curve, with the two separated by 8.36 yr. We investigate three scenarios to explain the two bumps, including a binary-lens single-source (2L1S), a single-lens binary-source (1L2S), and two unrelated single-lens sin…

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

OGLE-2016-BLG-0523: A Low-mass Brown Dwarf or super-Jupiter in a $>100$ au Orbit

Hongjing Yang, Weicheng Zang, Yoon-Hyun Ryu, Andrzej Udalski, Yuchen Tang, Michael D. Albrow, Sun-Ju Chung, Andrew Gould et al.

To search for very wide-orbit binary-lens events, we cross-match microlensing events detected by OGLE-IV and KMTNet between 2011 and 2024. After removing contaminants from variable stars, we identify OGLE-2016-BLG-0523 as a microlensing event showing two short-lived bumps in its light curve, with the two separated by 8.36 yr. We investigate three scenarios to explain the two bumps, including a binary-lens single-source (2L1S), a single-lens binary-source (1L2S), and two unrelated single-lens sin…

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astro-ph.HEnucl-th

Adiabatic evolution of hadronic neutron stars

Domenico Logoteta, Francesco Zeno Constanzo, Ignazio Bombaci, Sebastiano Bernuzzi, Albino Perego, David Radice

In this paper we compute several structural properties of static and rotating neutron stars, considering both rigid and differential rotation. To this end, we use a finite-temperature beta-stable equation of state (EOS) extending the zero-temperature hadronic EOS derived by Fortin et al. (2017). We account for the formation of hyperons and the presence of a neutrino-trapped component. Our goal is to provide insights into the long-term evolution of a protoneutron star (PNS) formed after a core-co…

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astro-ph.GA

A Comprehensive JWST Slitless Spectroscopic Census of $\sim$12,000 Emission-Line Galaxies at Redshift $0\sim9$ in COSMOS

Shuqi Fu, Zijian Zhang, Danyang Jiang, Jie Chen, Linhua Jiang, Chenxi Bao, Yihe Wang, Ronaldo Laishram et al.

Emission-line galaxies provide key diagnostics of star formation, chemical enrichment, and AGN activity across cosmic time. We present a systematic census of emission-line sources using JWST/NIRCam wide-field slitless spectroscopy (WFSS) from the COSMOS-3D program, which covers a large contiguous area of 0.33 deg$^2$ and provides F444W grism spectroscopy over $3.9$--$5.1\ μ$m. By combining slitless spectroscopy with deep multi-band imaging data, we construct a homogeneous spectroscopic sample of…

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nucl-thastro-ph.HEnucl-ex

Impact of ab initio E1 strength on neutron capture rates along the nickel isotopic chain

Francesca Bonaiti, Joanna E. Sobczyk

Nucleosynthesis simulations of the r-process require neutron capture rates for neutron-rich nuclei, many of which lie beyond experimental reach. Predicting these rates relies on theoretical calculations of the low-energy electric dipole (E1) strength near the neutron threshold. We present the first ab initio computation of the E1 strength along the nickel isotopic chain, for $^{58}$Ni and the even-even isotopes $^{68-80}$Ni. The E1 strength is obtained with the Lorentz integral transform coupled…

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astro-ph.HE

Perpendicular transport in isotropic magnetic turbulence. The role of stochastic drifts

F. Pucci, P. Blasi, O. Pezzi, C. Evoli, F. Malara

In cosmic ray propagation through turbulent magnetic fields, transport perpendicular to the mean field plays an important role in various astrophysical environments. Numerical simulations have shown that parallel and perpendicular diffusion coefficients exhibit different energy scalings, causing their ratio to increase with energy, but a comprehensive theoretical explanation remains elusive. Here, we investigate perpendicular diffusion using test particle simulations in synthetic isotropic turbu…

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astro-ph.GA

Insights from the stability of methanol maser flare properties I: G9.62+0.20E

S. P. van den Heever, D. J. van der Walt

The brightest 6.7 GHz methanol maser in the Galaxy is associated with the high-mass star-forming region (HMSFR) G009.62+0.20E. Additionally, this methanol maser shows periodic flaring observed at 6.7 and 12.2 GHz. Several models have been hypothesized to explain the periodicity, including periodic accretion, spiral shocks in the gaps of circumbinary disks, pulsating stars, dicke's superradiance, and a colliding wind binary (CWB) system. We analyzed the time series of the 1.22 km s-1 feature of t…

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astro-ph.HE

TeV Gamma-Ray Emission in the DA 495 Region from HAWC Observations of J1952+2924, J1954+2837, and J1958+2848

R. Alfaro, C. Alvarez, E. Anita-Rangel, M. Araya, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu et al.

Previous observations of the DA 495 region, which contains the pulsar wind nebula (PWN) DA 495 and other very-high-energy (VHE; $>100~\textrm{GeV}$) gamma-ray emitters, showed inconsistent results across different VHE experiments, including differences in the measured flux of DA 495 and in the number of reported sources. Our new dedicated analysis using 3071 days of HAWC data resolves these discrepancies. We identify three extended sources, HAWC J1952+2924 (DA 495), HAWC J1954+2837, and HAWC J19…

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astro-ph.EP

The origin of the large heavy element contents of warm Jupiters

Bertram Bitsch

Planet interior models have revealed that warm Jupiters should harbor large heavy element masses (up to 30-40% of the planetary mass). Within the pebble drift and evaporation scenario, inward drifting pebbles can evaporate and enrich the inner disc with vapor to super-stellar values, accreteable by giant planets. As H$_2$O ice evaporates in the inner disc, while CO$_2$, CH$_4$ and CO evaporate in the outer disc, the enrichment of the disc with vapor decreases with increasing orbital distance. We…

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astro-ph.GA

A dust-reddened quasar in a [C II]-luminous host at z=6.55

Daming Yang, Joseph F. Hennawi, Rychard Bouwens, Timo Kist, Eduardo Bañados, Hiddo S. B. Algera, Aaron J. Barth, Sarah E. I. Bosman et al.

Most known quasars at $z>6$ were selected through their rest-frame UV emission. Only a small number of reddened quasars have been identified at these redshifts, leaving their nuclear and host-galaxy properties poorly constrained. We present JWST/NIRSpec spectroscopy and ALMA band 6 observations of the quasar J1440+0019 at $z=6.5488$, revealing its dust-reddened nature and jointly characterizing its nucleus and host galaxy. The continuum is best described by an SMC-like extinction law with $E(B-V…

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astro-ph.GA

A strategy for astrometric quasar selection with Gaia DR3 and its application to discover new luminous $z>2$ quasars

J. Li, J. P. U. Fynbo

We aim to provide a cookbook for purely astrometric selection of quasars with Gaia DR3 and to provide an example of its use for the identification of very luminous $z>2$ quasars. We analyse the Gaia DR3 astrometry of confirmed quasars and stationary sources. We show that the proper motion signal to noise $μ/σ_μ$ follows a Rayleigh-like distribution. We also show the importance of properly taking into account the correlation between proper motions in right ascension and declination, as well as th…

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astro-ph.GA

Turbulence modes in molecular clouds in M33: a challenging test of the Brunt-Federrath framework

Raffaele Rani, Ayu Konishi, Kazuyuki Muraoka, Toby J. T. Moore, David J. Eden, Karan Fernandes, Yueh-Ning Lee, Shih-Ping Lai et al.

Understanding the turbulent structure of molecular clouds is essential for linking galactic environment to the regulation of star formation. Although Galactic molecular clouds have been studied extensively, extending turbulence-mode analysis beyond the Milky Way remains challenging because of the limited spatial resolution and dynamic range of extragalactic observations. We assess the applicability of the Brunt \& Federrath (2014; BF14) framework to molecular clouds in M33. We apply BF14 to 128…

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astro-ph.GA

High Resolution Spectro-Polarimetric Observations of the Optical Filaments surrounding NGC 1275 with ESPaDOnS

Benjamin Vigneron, Julie Hlavacek-Larrondo, Luca Fabiani, Lison Malo, Carter Lee Rhea, Megan Donahue, Jorge Karolt Barrera Ballesteros, Hyunseop Choi et al.

We analyze archival high spectral resolution ESPaDOnS spectropolarimetric observations (R = $λ/Δλ$ = 68000) of three targeted locations within the filamentary nebula surrounding NGC 1275. We present here the analysis of the main filaments emission lines, namely: [NII]$\lambda6584$, H$α$, and [NII]$\lambda6548$, across our three pointings displaying clear detectable emission, with one also showing additional [SII]$\lambda6716$ and [SII]$\lambda6731$ emission line doublet. Using a Markov Chain Mon…

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astro-ph.EPastro-ph.IM

Assessing PLATO's Discovery Potential across Different Observing Strategies

Yoshi Nike Emilia Eschen, Michelle Kunimoto, Juan Cabrera, Adrien Leleu, Thomas G. Wilson, Heike Rauer, Alex Romanec, François Bouchy et al.

The PLATO mission, planned to launch in spring 2027, will observe a fixed Southern field, LOPS2, for at least 2 years with the goal of discovering and deriving precise parameters for planets as small as Earth around FGK dwarfs and sub-giants. Afterwards, PLATO could continue to monitor the same field or move to a Northern field, LOPN1, overlapping with the Kepler field. We assess these two observing strategies in terms of sensitivity of detecting small and long period planets, and subsequently w…

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astro-ph.EP

How long could volcanic plumes persist in the Venus atmosphere?

Maureen Cohen, James Holmes, Joanna Egan, Stephen Lewis, Manish R. Patel

Resolving the ambiguity surrounding current Venusian volcanism is a primary objective for upcoming missions like EnVision and VERITAS. This study uses the Venus Planetary Climate Model to simulate the dispersal and detectability of volcanic plumes containing water vapour (H2O), hydrogen chloride (HCl), carbon monoxide (CO), and carbonyl sulphide (OCS) within a three-dimensional atmospheric environment. We model localised gas enhancements at altitudes probed by nightside spectral windows (8.62, 2…

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astro-ph.SRphysics.space-ph

Magnetic connectivity from the Sun to the Earth with MHD models II. Impact of input magnetic maps

Barbara Perri, Silke Kennis, Brigitte Schmieder, Stefaan Poedts

Connectivity estimation needs to be fast and thus usually relies on semi-empirical models. We previously established that optimised magnetohydrodynamics (MHD) models can also be used to derive magnetic connectivity, yielding good results, especially for complex configurations. However, the modelling is not the only factor that can impact the connectivity estimation. Models' results, both semi-empirical and MHD, depend heavily on the input data used to drive the simulation. In order to quantify t…

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astro-ph.SRastro-ph.GA

X-Shooter view of planetary nebulae microstructures I: The case of NGC 7009 knots

L. Konstantinou, S. Akras, K. Bouvis, P. Boumis, J. Garcia-Rojas, D. R. Gonçalves, K. N. Gourgouliatos

The properties of NGC 7009 knots are investigated by employing UV-to-near-infrared data from the X-Shooter spectrograph. These structures belong to the category of low-ionization structures (LISs), which are characterized by enhanced emission from low-ionization species and whose origin remains enigmatic. Our main goal is to conduct the first dedicated spectroscopic study of LISs using X-Shooter, that covers a wide spectral range from the UV to the near-IR, simultaneously. As a pilot study, we f…

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astro-ph.IMphysics.space-ph

First Experimental Results of Space Object Detection Using the InteRFeX Array

Bhaskar Ahuja, Thomas Crowther, Steven Tingay, Andrew Guidi, Luca Gentile, Marco Martorella

This paper presents the first experimental validation of InteRFeX, a non-uniform receive only (passive) array located at the Nova Systems Space Precinct in Peterborough, Australia, designed for space domain awareness applications. It operates over a frequency range of 70 to 300 MHz and is capable of functioning in a range of observational modes, including as a coherent passive bistatic radar for space surveillance, which is the focus of this work. InteRFeX exploits commercial broadcast transmiss…

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astro-ph.EPphysics.ao-ph

The Hydrological Cycle and Circulation of Tidally-Locked Planets with a Finite Moisture Inventory

Daniel A. Williams, Geoffrey K. Vallis, Stephen I. Thomson, William J. M. Seviour

Tidally-locked planets express a range of climate regimes distinct from those found in our solar system. Their atmospheres are often dominated by planetary-wide overturning circulations and super- rotating jets. In this paper we explore the hydrological cycle of such planets and how it might depend on the total inventory of condensate. To this end we use a set of idealised GCM simulations to probe the response of the hydrological cycle to the surface moisture budget in their atmospheres. We find…

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gr-qcastro-ph.HEhep-th

The School on Gravity: from motion to commotion

Vitor Cardoso, Jose María Ezquiaga, Julio Parra-Martinez, Laura Sberna, Gustavo J. Turiaci, Lieke van Son

Understanding the gravitational interaction is one of the great scientific endeavors of the 21st century. The Nobel Prize-winning discovery of gravitational waves in 2015, and subsequent detections by the LIGO-Virgo-KAGRA Collaboration, have marked a revolutionary step forward in physics and astrophysics by opening an entirely new window for exploring the Universe. Future upgrades to these detectors, along with upcoming facilities such as LISA, the Einstein Telescope, and radio and optical instr…

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astro-ph.IM

An empirical calibration of the spectral resolution of JWST NIRSpec PRISM

Hang Zhou, Xin Wang, Yuxuan Pang, Shengzhe Wang, Karl Glazebrook, Themiya Nanayakkara, Hu Zhan

We present an empirical calibration of the effective spectral resolution of the JWST NIRSpec PRISM disperser based on a large sample of galaxies drawn from archival observations. Our sample spans a wide redshift range, $0.5 \lesssim z \lesssim 10$, enabling a wavelength-dependent characterization of the PRISM resolving power across the full bandpass using the [O III]$λ\lambda4959,5007$ doublets. To ensure robust measurements, we impose strict signal-to-noise requirements on both continuum and em…

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astro-ph.IM

An empirical calibration of the spectral resolution of JWST NIRSpec PRISM

Hang Zhou, Xin Wang, Yuxuan Pang, Shengzhe Wang, Karl Glazebrook, Themiya Nanayakkara, Hu Zhan

We present an empirical calibration of the effective spectral resolution of the JWST NIRSpec PRISM disperser based on a large sample of galaxies drawn from archival observations. Our sample spans a wide redshift range, $0.5 \lesssim z \lesssim 10$, enabling a wavelength-dependent characterization of the PRISM resolving power across the full bandpass using the [O III]$λ\lambda4959,5007$ doublets. To ensure robust measurements, we impose strict signal-to-noise requirements on both continuum and em…

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cond-mat.stat-mechastro-ph.HEhep-ph

IceCube data for astrophysical neutrinos exhibit q-statistical behavior

Constantino Tsallis, Ugur Tirnakli

Relevant IceCube recent data for astrophysical neutrinos are analyzed. Similarly to cosmic rays and proton-proton LHC collisions, the corresponding spectra are satisfactorily described, for the entire interval of measured energies, through q-Gaussians. This fact reinforces the already available evidence that nonadditive entropies (either of the $S_q$ class or of the $S_{delta}$ one, or even alternative ones) appear to play a crucial role in systems such as black holes and related cosmological ph…

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astro-ph.EP

Fermentation heterotrophy can reproduce Enceladus's H2 and CH4 under limited serpentiniaztion

Sam Nasreldine, Antonin Affholder, Laura Molares Moncayo, Régis Ferrière, François Guyot

Saturn's icy moon Enceladus is a prime target in the search for life beyond Earth. Abundant H2 and CH4 in Enceladus's south-polar plume have been shown to be consistent with hydrogenotrophic methanogens feeding on products of long-lived serpentinization. However, thermo-permeability models make sustained core-wide H2 production by serpentinization uncertain. We therefore explore whether an alternative metabolism based on fermentation-driven heterotrophy could reproduce Cassini H2 and CH4 escape…

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astro-ph.EP

Fermentation heterotrophy can reproduce Enceladus's plume H2 and CH4 under limited serpentinization

Sam Nasreldine, Antonin Affholder, Laura Molares Moncayo, Régis Ferrière, François Guyot

Saturn's icy moon Enceladus is a prime target in the search for life beyond Earth. Abundant H2 and CH4 in Enceladus's south-polar plume have been shown to be consistent with hydrogenotrophic methanogens feeding on products of long-lived serpentinization. However, thermo-permeability models make sustained core-wide H2 production by serpentinization uncertain. We therefore explore whether an alternative metabolism based on fermentation-driven heterotrophy could reproduce Cassini H2 and CH4 escape…

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astro-ph.HEgr-qc

Flip-Flop Shocks and Tori in Bondi-Hoyle-Lyttleton Accretion onto Rotating Kerr-Weyl Black Holes and Their Quasi-Periodic Variability

Orhan Donmez, Imtiaz Khan, G. Mustafa

We present GRHD simulations of Bondi-Hoyle-Lyttleton accretion onto a rotating black hole in Weyl conformal gravity, described by the Kerr-Weyl metric. The equatorial flow is evolved for spins a=0.9M and a=0.5M and several Weyl coefficients, which enter through an effective curvature parameter k, and is compared with Kerr runs sharing the same setup. For the k considered, the horizon, ISCO and test-particle frequencies differ from Kerr by at most ~2%. However, the curvature term grows as kr^2 an…

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astro-ph.GA

The Silk Nebula: A Newly Discovered Giant [OIII] Emission Filament

Yi-Fei Wu, Songyu Jia, Chao-Jian Wu, Chao Zhang, Li-Yue Zhang, Shu Wang, Juan-Juan Ren, Quzhen Dongyang et al.

We report [O\,\textsc{iii}] narrow-band imaging of an extremely large-scale nebula, the Silk Nebula, discovered by the SWONS (Super Wide-Field [O\,\textsc{iii}] Narrow-band Survey), together with multi-fiber medium-resolution spectroscopic data covering the H$α$, [N\,\textsc{ii}], [S\,\textsc{ii}], and [O\,\textsc{iii}] emission lines, acquired with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) as part of the Medium-Resolution Spectroscopic Survey of Nebulae (MRS-N). Bas…

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astro-ph.HE

Extreme mass ratio inspirals from the Hills mechanism, The eccentricity distribution of Hills EMRIs in LISA

Biancamaria Sersante, Davide Mancieri, Kevin Leopoldo Muñoz Zavala, Luca Broggi, Zephyr Penoyre, Elena Maria Rossi, Alberto Sesana

Extreme mass ratio inspirals (EMRIs) are promising sources for future space-based gravitational-wave detectors. We investigate EMRIs produced through the Hills mechanism, in which a stellar-mass black-hole binary (BBH) is tidally separated by a massive black hole (MBH), leaving one component bound to it. We present the first self-consistent modelling of this channel, combining an orbit-averaged Fokker-Planck treatment of the nuclear star cluster (NSC), three-body modelling of the binary-MBH enco…

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