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Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.IMeess.SP

A high-isolation wideband channelizer for MKID readouts: a custom HLS implementation on RFSoC

Alberto Hernandez Fernandez, David Diaz Martin, Jose Javier Diaz Garcia, Roger John Hoyland, Luis Fernando Rodriguez Ramos, Diego Portero Rodriguez, Silvestre Rodriguez Perez

We present a high-performance channelizer for Microwave Kinetic Inductance Detectors (MKIDs), designed to mitigate spectral leakage and scalloping loss through a 50% overlapping polyphase filter bank (PFB). The design is implemented on a Xilinx Zynq UltraScale+ RFSoC ZCU111 using a custom design - primarily in Vitis High-Level Synthesis (HLS), with the time-critical output serializer and glue logic in VHDL - that processes a 4.096 GSPS input stream with a per-branch super-sample rate (SSR) of 16…

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physics.space-phastro-ph.SR

Comprehensive solar eruption analyses enabled by the tools of the SOLER project

Nina Dresing, Jan Gieseler, Markus Baumgartner-Steinleitner, Carine Briand, Karin Dissauer, Annamaria Fedeli, Robert Jarolim, Jaclyn T. Lang et al.

Solar eruptions comprise of a multitude of phenomena such as flares, coronal mass ejections (CMEs), large-scale coronal waves, radio bursts, and energetic particles traveling through interplanetary space. These phenomena are observed with a variety of instrumentation, including remote sensing and in-situ detectors. Obtaining a global understanding of a solar eruption often requires the analysis of various of these different datasets, including a multitude of analysis and modeling tools and a wid…

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astro-ph.IM

Forward modelling coronagraphic images with a fully physical, differentiable digital twin of MagAO-X: first laboratory results

Matthijs Mars, Sebastiaan Y. Haffert, Louis Desdoigts, Joseph D. Long, Rico Landman, Jared R. Males, Laird M. Close, Kyle Van Gorkom et al.

Post-processing of high contrast imaging data relies on an accurate model of the stellar point spread function (PSF). Current techniques build this model from the science images themselves, using observational diversity (e.g., angular, spectral or polarimetric diversity), which can cause self-subtraction of the companion signal and constrains the observing strategy. Telemetry-based forward modelling instead builds the stellar PSF model from wavefront sensor data that is already recorded during t…

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astro-ph.IM

NEXT: The Netherlands EXoplanet Testbed I. Goals and opto-mechanical design

Rico Landman, Sebastiaan Haffert, Louis Desdoigts, Matthijs Mars, Dhwanil Patel, Daniel Smith, Remko Stuik, Adam Taras et al.

We report on the goals, design, and ongoing development of the Netherlands EXoplanet Testbed (NEXT), a high-contrast imaging testbed under construction in Leiden. NEXT is designed to develop and validate technologies and algorithms for extreme adaptive optics (XAO) and coronagraphy at the performance levels required by the next generation of high-contrast imagers on the Extremely Large Telescopes (ELTs) and future space observatories. All powered optics in the common path are custom off-axis par…

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astro-ph.IM

No need to modulate: On-sky results of a Neural Network enhanced pyramid wavefront sensor and prospects for the ELTs

Rico Landman, Liam Koning, Sebastiaan Y. Haffert, Joseph D. Long, Jared R. Males, Matthijs Mars, Laird M. Close, Olivier Guyon et al.

One of the main limitations of ground-based extreme adaptive optics systems (XAO) is the balance between the temporal and photon noise error. The unmodulated Pyramid Wavefront Sensor (uPWFS) promises significant gains in sensitivity over its modulated counterpart, but its practical use is limited by its linearity range. Nonlinear reconstructors provide a pathway to recover this dynamic range while preserving the sensitivity of the uPWFS, thereby reducing photon noise and improving contrast. We p…

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astro-ph.COastro-ph.GAgr-qc

Dark-to-black super-accretion as a spin-imprinting mechanism for supermassive Kerr black holes

Saeed Fakhry, Nicolas Sanchis-Gual, Jorge Castelo Mourelle, Darío Núñez, Juan Carlos Degollado

The existence of supermassive black holes with masses $M\gtrsim10^9\,M_{\odot}$ and large dimensionless spins $χ\sim0.9-0.99$ at high redshift remains a challenge to our understanding of the early Universe. In this work, we study the adiabatic co-evolution of a Kerr black hole seed surrounded by two ultralight scalar dark matter clouds occupying different bound states, and show that this configuration allows the black hole to grow into the supermassive mass range while imprinting a characteristi…

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astro-ph.EP

Volatile depletion in rocky planets as a chemical fingerprint of hybrid accretion

Haiyang S. Wang, Anders Johansen, Ziyan Xu, Marie-Luise Steinmeyer, Michiel Lambrechts, Elishevah van Kooten, Chao-Chin Yang, Zhaohuan Zhu et al.

Volatile depletion in rocky planets relative to their host stars is commonplace in both the Solar System and exoplanetary systems, yet the connections between planet formation and composition remain elusive. Here we model devolatilization during pebble accretion in combination with collisional growth from volatile-depleted planetesimals to explore the formation pathways of Earth and Mars. Using Bayesian inference, we find that bulk silicate Earth is best reproduced by ${\gtrsim}$75% contribution…

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astro-ph.HEastro-ph.SR

Fingerprints of thermal Comptonization in accreting neutron stars. Plasma-vacuum interplay in cyclotron lines and polarisation

E. Sokolova-Lapa, D. K. Maniadakis, J. J. R. Stierhof, E. Ambrosi, A. D'Aì, C. Ferrigno, N. Schettino, M. Middleton et al.

X-ray emission from accreting, strongly magnetised neutron stars and its pulse-phase variability probe their magnetic-field geometry, spin orientation, and emission processes. Whether the radiation emerges mainly from a hot spot or column, and whether its properties are shaped by bulk or thermal Comptonization, remain debated across luminosity regimes. We aim to disentangle intrinsic emission from visibility effects and identify observables characteristic of thermal Comptonization in hot spots a…

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astro-ph.GA

Interstellar Aromatic Infrared Bands: IR absorption spectroscopy of the lowest triplet state of naphthalene

Priyanka Arvind Paunikar, Hugo Maurer, Lars Reems, Alessandra Candian, Sandra Brunken, Jos Oomens, Piero Ferrari, Wybren Jan Buma et al.

The aromatic infrared bands (AIBs), emission features observed ubiquitously across a wide variety of interstellar objects, are commonly attributed to radiative cooling of highly-excited ground-state vibrational levels of polycyclic aromatic hydrocarbons (PAHs) that are populated after UV absorption and internal conversion. However, for neutral PAHs intersystem crossing to the triplet manifold, followed by radiative cooling of vibrational levels within the lowest excited triplet state is expected…

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astro-ph.IM

Digging dark holes on-sky with the Self-Coherent Camera: Preliminary results

Elena Tonucci, Sebastiaan Y. Haffert, Jared R. Males, Laird M. Close, Kyle van Gorkom, Olivier Guyon, Alexander D. Hedglen, Parker T. Johnson et al.

Current high-contrast imaging instruments are limited by wavefront errors originating from non-common path aberrations (NCPAs) due, for example, to manufacturing errors in the optics and temperature drifts in the system. These create quasi-static speckles in the final science image that are difficult to distinguish from companions. Therefore, focal plane wavefront sensing and control is needed to suppress speckles. The Self-Coherent Camera (SCC) is a wavefront sensor that allows us to estimate t…

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astro-ph.IM

On-sky demonstration of self-learning predictive control with MagAO-X

Sebastiaan Y. Haffert, Jared R. Males, Parker T. Johnson, Laird M. Close, Olivier Guyon, Jay Kueny, Joshua Liberman, Joseph D. Long et al.

Direct imaging of exoplanets is very tricky and requires extremely well corrected wavefronts. Especially low-order order modes are detrimental to the performance of coronagraphs at their inner-working angle. However, that is precisely where conventional AO systems have the highest residuals that are caused by servo-lag errors. This servo-lag error can be reduced with predictive control where the control anticipates the future state of the atmospheric disturbance. We use a self-learning model pre…

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

Sub-diffraction-limited coronagraphic imaging with nano-printed PIAACMC phase masks

Elena Tonucci, Sebastiaan Y. Haffert, Warren B. Foster, Jared R. Males, Olivier Guyon, Laird M. Close, Kyle van Gorkom, Alexander D. Hedglen et al.

Imaging Earth-like exoplanets in the habitable zone of their host star is among the main science objectives of future ground-based and space-based observatories. However, the extreme contrast and small separations needed to image such planets cannot be reached with current technology. The Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC) is a promising coronagraph to reach this goal. The PIAACMC uses a set of aspheric lenses to apodize the entrance pupil without throughput l…

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physics.plasm-phastro-ph.SRphysics.space-ph

Anomalous Electric Fields in Earth's Turbulent Magnetosheath: Insights From 3D Hybrid Simulations

Jeffersson A. Agudelo Rueda, Julia E. Stawarz, Luca Franci, Nobumitsu Yokoi, Camille Granier, Silvio S. Cerri

In both collisional and collisionless plasmas the presence of a broad range of electromagnetic and plasma fluctuations provides anomalous electric fields that can be important for the dynamical evolution of the system as it is the case of magnetic reconnection, plasma turbulence and dynamo theory. In the context of plasma turbulence at scales larger than the ion's inertial length, the plasma satisfies the frozen-in condition, and the anomalous electric fields are produced by correlations between…

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astro-ph.IM

The final design of GMagAO-X: the wavefront sensing and control (WFS&C) architecture of GMagAO-X

Sebastiaan Y. Haffert, Jared R. Males, Laird M. Close, Olivier Guyon, Olivier Durney, Maggie Kautz, Liam Koning, Louis Desdoigts et al.

The Giant Magellan Adaptive Optics eXtreme (GMagAO-X) instrument has now been selected as an official part of the Giant Magellan Telescope's (GMT) instrument suite. The instrument will be ready at first-light of the GMT in the mid 2030s. The instrument is now progressing towards its final design with a final design review planned for March, 2027. The high-density actuator deformable mirror with 21.000 actuators will allow GMagAO-X to create diffraction-limited images from visible to near-infrare…

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astro-ph.GA

Synchrotron filaments in radio galaxies: rarity, stability, and environmental influences from LOFAR and ROSAT observations

Geoffrey Ong'alo, Martin J. Hardcastle, Willice Obonyo, Marcus Brüggen, Paul Baki

We present a systematic investigation of filamentary synchrotron structures in radio galaxies, using deep 144 MHz observations from the LOFAR Two-Metre Sky Survey (LoTSS) in combination with archival ROSAT X-ray data. These narrow, collimated features, linking radio lobes and often aligned with jet axes, are rare: our visual inspection of 548 cluster-associated sources identified 12 candidates (~2.2%), of which three exhibit clearly resolved filaments suitable for detailed X-ray and synchrotron…

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nucl-thastro-ph.SR

Self-Consistent Determination of the Transition Temperature Between the $^{14}\mathrm{C}(n,γ)^{15}\mathrm{C}$ and $^{14}\mathrm{C}(p,γ)^{15}\mathrm{N}$ Reactions

R. Ya. Kezerashvili, N. A. Burkova, A. S. Tkachenko, S. B. Dubovichenko

We present the first self-consistent theoretical study of the competing $^{14}\mathrm{C}(n,γ)^{15}\mathrm{C}$ and $^{14}\mathrm{C}(p,γ)^{15}\mathrm{N}$ reactions within the same modified potential cluster model (MPCM). For the $^{14}$C$(p,γ_{0})^{15}$N reaction, total cross sections, astrophysical $S$ factors, and reaction rates are calculated using interaction potentials constrained by the available scattering and bound-state data. The astrophysical $S$-factor is estimated as $S(0)=4.5(1)$~keV$…

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astro-ph.IMphysics.optics

Quantum-optimal instruments for high-contrast imaging with multi-plane light converters

Sebastiaan Y. Haffert, Yinzi Xin, Rico Landman

Spatial Mode Demultiplexers (SPADE) are devices that split an incoming wavefront into a particular set of electric field modes. SPADEs have been shown to be quantum-optimal for many measurement problems including coronagraphy, wavefront sensing and interferometric (nulling) beam combiners. We will show how quantum optimal SPADEs can be implemented using Multi Plane Light Converters (MPLC). MPLCs are devices that use several phase plates in sequence to achieve arbitrary unitary transformations. T…

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astro-ph.EP

The Hot Neptune Initiative (HONEI) III. An ultra-hot super Neptune orbiting the metal-rich subgiant star TOI-5646: the largest host for a desert dweller

L. Mancini, F. Manni, D. Kubyshkina, E. A. van Dijk, L. Naponiello, M. Damasso, V. D'Orazi, K. Biazzo et al.

We report the confirmation of the TESS transiting-planet candidate orbiting the metal-rich F8\,IV-V subgiant star TOI-5646 (V=11.38 mag; T=6136 K). The planetary nature of TOI-5646b was confirmed by means of HARPS-N follow-up radial velocity measurements. We determined that the planet has an orbital period of 2.4277 days and an orbital eccentricity compatible with zero. With a mass of 45.9 Earth masses, a radius of 6.6 Earth radii, and an equilibrium temperature of 1935 K, it is one of the hotte…

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astro-ph.IM

The Photonic Lantern Nuller: from concept to laboratory and on-sky demonstrations

Yinzi Xin, Nemanja Jovanovic, Dimitri Mawet, Daniel Echeverri, Yoo Jung Kim, Jonathan Lin, Julien Lozi, Sebastien Vievard et al.

This thesis work presents the conceptual design and experimental characterization of the Photonic Lantern Nuller instrument, which uses a multimode-to-single-mode demultiplexing waveguide to cancel out starlight while maintaining planet light, allowing for the direct characterization of planets at a telescope's diffraction limit. The PLN was experimentally characterized in the lab, where it was further enhanced using common-path wavefront sensing and control techniques, and then demonstrated on…

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astro-ph.HE

The First X-Ray Polarimetry of the Typical Accretion Disk Corona Source 4U 1822-37

WanYun Wu, Fei Xie, YuShan Ling

We report the first Imaging X-ray Polarimetry Explorer (IXPE) observations of the typical accretion disk corona (ADC) source 4U 1822-37, covering 44 orbital cycles, together with simultaneous Swift-XRT data. The polarization degree (PD) of this source is found to be higher than typical low-mass X-ray binary (LMXB) values and exhibits a significant energy dependence. Within the 2--5~keV and 5--8~keV bands, PD remains constant, with average values of \(5.6\pm0.8\%\) and \(11.6\pm1.7\%\), respectiv…

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astro-ph.HE

The First X-Ray Polarimetry of the Typical Accretion Disk Corona Source 4U 1822-37

WanYun Wu, Fei Xie, YuShan Ling

We report the first Imaging X-ray Polarimetry Explorer (IXPE) observations of the typical accretion disk corona (ADC) source 4U 1822-37, covering 44 orbital cycles, together with simultaneous Swift-XRT data. The polarization degree (PD) of this source is found to be higher than typical low-mass X-ray binary (LMXB) values and exhibits a significant energy dependence. Within the 2--5~keV and 5--8~keV bands, PD remains constant, with average values of \(5.6\pm0.8\%\) and \(11.6\pm1.7\%\), respectiv…

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astro-ph.IM

Demonstration of simultaneous PIAA- coronagraphy and wavefront sensing using a single metasurface-based focal-plane optic

Dhwanil Patel, Sebastiaan Y. Haffert, Skyler Palatnick, Adam Taras, Maxwell A. Millar-Blanchaer, Matthijs Mars, Elena Tonucci, Jared R. Males et al.

Controlling residual wavefront aberrations downstream of an extreme adaptive optics (ExAO) system is a major challenge in high-contrast imaging. These aberrations produce quasi-static speckles due to differences between the wavefront-sensing and science paths. Highly sensitive wavefront sensors, such as Zernike wavefront sensors (ZWFSs), are used to mitigate these non-common path aberrations. High-performing coronagraphs, such as complex mask coronagraphs (CMCs), are also implemented in the foca…

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astro-ph.IMastro-ph.SR

Connecting Granulation and Magnetic Activity in Radial Velocities: The Next Breakthrough for High-Precision Spectroscopy

Ancy Anna John, Khaled Al Moulla, Federica Rescigno, Carmen San Nicolas Martinez, Andrew Collier Cameron, Thomas G. Wilson, Nadège Meunier, Sophia Sulis et al.

Stellar variability has become the dominant limitation to achieving the radial velocity (RV) precision required for the detection and characterization of Earth-like exoplanets. While significant progress has been made in mitigating the effects of oscillations and magnetic activity, convective granulation and its interaction with stellar magnetic fields remain among the least understood sources of RV variability. To address these challenges, we organized the splinter session `Connecting Granulati…

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astro-ph.EP

Nitrogen- and nitrogen-oxygen-bearing organic molecules in comet 67P/Churyumov-Gerasimenko: An untargeted investigation

N. Hänni, K. Altwegg, D. Baklouti, M. Combi, S. A. Fuselier, J. De Keyser, D. R. Müller, M. Rubin et al.

Comets provide a unique window into the history of the Solar System as they carry some of the best-preserved material and make it available to in situ exploration. A milestone in comet studies was the European Space Agency's Rosetta mission, which, for the first time, rendezvoused with a comet, namely 67P/Churyumov-Gerasimenko (67P), and studied it from a close range for two years. Amongst other unexpected insights, data from this mission show that comets contain a surprisingly large portion of…

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astro-ph.GA

An HI study of a large sample of ultra-diffuse galaxies

Ruilei Zhou, Ming Zhu, Chuan-Peng Zhang, Lin Du, Cheng Cheng, Qi Guo, Tian-Wen Cao, Wenzhe Xi et al.

By cross-matching the SMUDGes catalog with the FASHI and ALFALFA HI surveys, we construct an HI-detected sample of 112 ultra-diffuse galaxies (UDGs) and 48 low-surface-brightness (LSB) galaxies, providing HI-based redshifts for 76 galaxies for the first time. Using DESI DR1 redshifts, we assemble an HI-non-detected sample of 168 galaxies for stacking analysis, with detections in two stellar mass bins below 10^{8.5} M_sun. Combining optical, UV, and HI data, we investigate stellar masses, star fo…

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astro-ph.GA

SDSS-IV MaNGA: Star Formation Cessation in Low-redshift Galaxies. III. Dependence on Quenching Criteria

Zhuo Cheng, Tao Jing, Cheng Li, Renbin Yan

This paper is the third in a series of studies investigating star formation cessation in nearby galaxies on kiloparsec scales. Using the final SDSS-IV MaNGA data release, we ask how the inferred importance of global, local, and environmental properties depends on the operational definition of quenched regions. We classify spaxels as star-forming, reliably quenched, or potentially quenched by accounting for measurement uncertainties, and train random forest classifiers with a parameter set chosen…

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astro-ph.SR

Flare waiting time as a novel proxy of stellar magnetic activity

Henggeng Han, Song Wang, Chuanjie Zheng, Cunshi Wang, Xue Li, Jifeng Liu

Stellar flares have long served as stellar magnetic activity tracers. The flare waiting time, defined as the interval between two consecutive flares, provides a valuable diagnostic for probing underlying mechanisms of energy storage and release in stellar atmospheres. In this work, utilizing flaring M dwarfs observed by the Kepler satellite, we establish a simple yet effective activity proxy, i.e., median flare waiting time ($t_{\rm{w, med}}$). Our results show that the $t_{\rm{w, med}}$ can tra…

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astro-ph.HEastro-ph.GA

Molecular and Atomic Gas Associated with the Gamma Ray Supernova Remnant RCW 103

H. Inoue, Y. Asano, R. G. Bhuvana, R. Z. Alsaberi, R. Yamada, K. Tsuge, T. Murase, Y. Fukui et al.

We present a study of the interstellar molecular and atomic gas associated with the gamma-ray supernova remnant (SNR) RCW 103 using the Mopra $^{12}$CO($J$ = 1-0), Atacama Large Millimeter/submillimeter Array $^{13}$CO($J$ = 1-0), and the Australia Telescope Compact Array & Parkes HI data. We find that CO clouds in the velocity range from $-58.7$ to $-43.5$ km s$^{-1}$ show a clear spatial correspondence with the X-ray shell of RCW 103, particularly extending from the northwestern to the southea…

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astro-ph.HE

X-ray Polarization of Inverse Compton Scattering by Thermal and Nonthermal Electrons

Boting Wang, Jirong Mao, Jieying Liu, Fei Xie

X-ray emission from accretion-powered astrophysical systems is widely interpreted as inverse Compton (IC) scattering between energetic electrons and soft photons. Besides the emitted intensity, the polarization of this radiation provides important information about the physical properties of the electrons involved. We investigate how different electron populations shape both the spectrum and polarization of IC emission in the X-ray band. We consider three electron populations: purely thermal, pu…

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astro-ph.HE

Observations of ionized carbon towards the $γ$-ray-bright supernova remnant RX J1713.7-3946

A. R. Thakur, G. P. Rowell, R. Higgins, M. Burton, Y. Fukui, S. Einecke, H. Sano, G. Wong et al.

The origin of Galactic Cosmic Rays (CRs), particularly at sub-GeV energies, remains uncertain due to their difficulty in being traced. One possible tracer of low-energy CRs is ionised carbon ([C II]), which may be enhanced in regions affected by CR-induced ionisation. We present observations of [C II] 158 $μ$m line emission across the $γ$-ray-bright supernova remnant (SNR) RX J1713.7-3946 obtained with SOFIA. These data are compared with molecular and atomic gas from Mopra ($^{12}$CO), Nanten ($…

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