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Physics Astrophysics Instrumentation and Methods for Astrophysics

astro-ph.IM Watch Instrumentation and Methods for Astrophysics

Saturday 12 September

Instrumentation and Methods for Astrophysics · Cross-listed from gr-qc

Frequency shift in gravitational lensing by Kerr metric

Samaneh Sarbaz and Sohrab Rahvar

In this study, we calculate the relative frequency shift ($\Delta \nu / \nu$) caused by gravitational lensing resulting from the transverse motion of a spinning lens described by the Kerr metric \cite{Kerr:1963ud}. While the effect of transverse velocity on the frequency shift has previously been investigated using the Schwarzschild metric \cite{Rahvar_2020,10.1093/mnras/stae1938}, extending this to the Kerr metric provides a new window for measuring the transverse velocity of a lens or its spin parameter, a parameter often subject to degeneracy in gravitational microlensing observations. Recent microlensing observations have revealed black holes as viable lensing candidates \cite{2022ApJ...933...83S}. Since spinning black holes form naturally from stellar evolution, astrophysical black hole lenses are best described by the Kerr metric. Furthermore, recent observations of supermassive black holes at the centers of galaxies provide an ideal laboratory for testing the observational effects of the Kerr metric by measuring the frequency shifts of lensed sources.
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Instrumentation and Methods for Astrophysics

Consistency and precision of very long baseline interferometry source coordinate time series

X.-X. Zhang, N. Liu, S. B. Lambert et al. (+18 more)

Coordinate time series of extragalactic radio sources from very long baseline interferometry observations are widely used to evaluate source positional stability, select stable sources for celestial reference frames, assess reference-frame axis stability, and investigate source-related astrometric variability. Their external consistency, realistic errors, and relation to processing strategies and analysis configurations remain to be investigated. We aim to compare coordinate time series solutions from different analysis centers and investigate how processing strategies and configurations contribute to their differences. We collected eight solutions from seven analysis centers and selected 496 common sources after data selection, reference-frame alignment, and extraction of common observing sessions. Inter-solution differences were characterized with pairwise positional offsets and correlation analysis, and realistic positional errors with the N-cornered-hat (NCH) method and bootstrap resampling. Most solutions have median weighted root mean square (WRMS) values of a few hundred microarcseconds $(\mathrm{\mu as})$, and the median NCH-derived precision is about 200-300 $\mathrm{\mu as}$ in right ascension and 250-400 $\mathrm{\mu as}$ in declination. Solutions with similar strategies, software, or source constraints show higher consistency, with more similar WRMS values, stronger correlations, and closer precision estimates. Consistency is affected not only by the global or independent mode distinction but also by detailed analysis configuration. NCH-derived precision depends on declination, being poorer in the southern sky, and stabilizes with more observing sessions. Processing strategies and configurations introduce marginal differences; solutions remain generally consistent. Inter-solution comparisons independently estimate realistic stochastic errors beyond formal errors.
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All authors X.-X. Zhang, N. Liu, S. B. Lambert, K. Le Bail, H. Krásná, O. Titov, M. Karbon, T. Nilsson, Z. Zhu, J.-C. Liu, I. N. Huda, J. Yang, X.-P. Cheng, B.-W. Sohn, F.-C. Shu, X. He, Z.-W. Wang, Z.-Y. Zhang, H.-F. Yu, J. Yao, D.-D. Zhang

Instrumentation and Methods for Astrophysics

A Two-Stage Physically Grounded Optical Design Framework with Application to a Multi-Channel Focal Reducer

M. R. Najera, J. Herrera, Esteban Luna et al. (+1 more)

We present a two-stage optimization framework that formalizes classical optical design strategies within a reproducible computational workflow. Starting point designs are constructed from paraxial and third-order models, providing optically consistent initial configurations. These configurations are refined through a physically grounded residual merit function evaluated by exact ray tracing, followed by RMS-based image refinement. Applied to a multi-channel astronomical focal reducer, the methodology provides a structured transition from aberration-based modeling to numerical optimization while preserving physically interpretable intermediate stages. By embedding classical optical design principles into an open computational pipeline, the approach reduces reliance on heuristic initial conditions and improves the reproducibility and interpretability of the design process.
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All authors M. R. Najera, J. Herrera, Esteban Luna, Erika Sohn

Friday 11 September

Instrumentation and Methods for Astrophysics

Sensing ELT petal modes with a discrete beam combiner: an end-to-end theoretical model

Kalaga V. Madhav, Abani Shankar Nayak, Lucas Labadie et al. (+1 more)

The European Southern Observatory's Extremely Large Telescope (ELT), the 39-m telescope under construction in Chile, forms its entrance pupil from 798 hexagonal segments that the six 0.5-m-wide spider arms fragment into six "petals". The low-wind / island effect, adaptive-optics residuals, and mechanical drift imprint an independent piston on each petal. These differential-piston (petal) modes remain largely undetected by the ELT's baseline continuous-pupil wavefront sensors, a major bottleneck for diffraction-limited, high-contrast imaging. This paper presents a complete theoretical model of a single-mode photonic discrete beam combiner (DBC) configured to sense the six petal pistons. The model constructs the coupled-mode description of a two-dimensional evanescently coupled waveguide lattice with six inputs and forty-five outputs and derives its visibility-to-pixel matrix (V2PM); treats the pupil remapping that routes one sub-aperture per petal into the six inputs; develops the five-dimensional petal-mode basis of the fragmented pupil; and propagates the petal modes through the DBC to quantify the sensitivity. Optimising the input-port spacing and interaction length by minimising the V2PM condition number yields a well-conditioned device (CN = 10.4). It recovers petal pistons with unit linear gain over the full +/-lambda/2 (+/-800 nm) unambiguous range and separates the five modes with negligible cross-talk (< 10^-3). For 1% photometric noise, the reconstructed-piston error is 4.7 nm rms at lambda_0 = 1.6 micron. Tested against petal amplitudes from end-to-end ELT simulations (~40-300 nm rms atmospheric residual; ~0.3-1 micron low-wind events), the DBC recovers each piston to a few nm rms at H band, with a two-wavelength extension capturing the larger events. The DBC is therefore a compact, chromatically robust petalometer for the fragmented ELT pupil.
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All authors Kalaga V. Madhav, Abani Shankar Nayak, Lucas Labadie, Robert R. Thomson

Instrumentation and Methods for Astrophysics · Cross-listed from cs.LG

Operational Range Bounding in Spectroscopy: A Safety Cage Framework for Machine Learning Models

Nikki Grens, Luís F. Simões, Kai Hou Yip et al. (+1 more)

Ensuring the reliability of black-box machine learning models in safety-critical space missions remains a significant challenge, particularly when ground-truth is unavailable for validation. Although machine learning models offer a powerful means to augment standard pipelines by extracting transmission spectra from complex exoplanetary light curves, their susceptibility to unmodelled instrument anomalies, stellar activity, and domain shifts introduces unquantified risks. This study evaluates a modular safety cage architecture that operates as a parallel monitoring layer to assess the validity of a prediction without modifying the underlying estimator. By monitoring different runtime indicators, including uncertainty quantification, out-of-domain detection, and influence functions, the framework constrains the model's operational domain to a verified region. A controlled evaluation is conducted under both in-domain and cross-domain conditions, using datasets from the 2019 and 2021 editions of the Ariel Data Challenges. The results reveal that model failure is multifaceted and that no single indicator captures all failure modes, demonstrating the need for indicator fusion. The application of safety-driven rejection strategies shows that a modest 20% reduction in data coverage results in error reductions between 45% and 65% across different domains and evaluation metrics. Using a formalised coverage-risk framework, a systematic analysis of indicator combinations is performed to identify configurations that maximise risk-ranking accuracy and optimise the trade-off between data coverage and scientific performance. Safety cages provide a transparent mechanism for detecting unreliable predictions and represent a critical step towards the safe deployment of data-driven models in scientific applications, such as astrophysics, where ground truth is seldom available.
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All authors Nikki Grens, Luís F. Simões, Kai Hou Yip, Theresa Lueftinger

Instrumentation and Methods for Astrophysics

Photonic Integrated Circuits for the Habitable Worlds Observatory: Science Drivers, Material Platforms, Arrayed-Waveguide Spectrographs, and a Space-Qualification Roadmap

Kalaga Madhav

NASA's Habitable Worlds Observatory (HWO) will require ultraviolet, optical, and near-infrared instruments that are simultaneously compact, mechanically and thermally stable, high-throughput, and replicable at large channel counts. Space-qualified photonic integrated circuits (PICs) and optical fibres are key platforms that can deliver these properties: they manipulate light at the diffraction limit within micron-scale single-mode waveguide circuits. An astrophotonic instrument fully guides the starlight from focal plane to detector, eliminating scatter and ghosts and offering excellent stability with no moving parts. This paper examines how astrophotonics can address the principal science drivers of HWO through four topics: (I) the HWO observing modes best implemented with photonic instruments; (II) the waveguide and fibre materials that can span the demanding 100nm-2.5{\mu}m HWO wavelength range; (III) the potential of arrayed-waveguide-grating (AWG) spectrographs to reach the resolving powers and throughputs HWO science requires; and (IV) the steps needed to space-qualify PICs and fibres against radiation, thermal cycling, vacuum, and launch loads. For each topic, concrete technical requirements are extracted and the current Technology Readiness Level (TRL) is assessed. The main contribution of this paper is to unify these science drivers, candidate-aperture photon budgets, UV-to-near-infrared material platforms, AWG architectures, and space-qualification requirements within a single photon-budget framework that pairs each claimed benefit with a measurable requirement, a TRL, and an environmental test that can retire it. A phased roadmap advances the critical photonic components from their present TRL~2 to -5, depending on platform and application, to the TRL~6 needed at HWO's instrument-definition gate.
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Instrumentation and Methods for Astrophysics

Spectro-polarimetry of HAbitable Planet Earth (SHAPE) on Chandrayaan-3: Instrument characteristics, calibration and onboard performance

Bhavesh Jaiswal, Swapnil Singh, Ravishankar B T et al. (+20 more)

The orbiter of the Chandrayaan-3 mission of the Indian Space Research Organisation (ISRO) carries an experimental payload called SHAPE (Spectro-polarimetry of HAbitable Planet Earth). This payload makes disc-integrated observations of Earth as an exoplanet, from the Moon as well as from the high altitude Earth orbit. The instrument consists of an Acousto-Optic Tunable Filter (AOTF) based near-infrared spectro-polarimeter making the measurements in the two orthogonally polarized directions using a pair of Indium-Gallium-Arsenide (InGaAs) detectors. The laboratory characterization of the flight model of the instrument included a relative measurement of the response of the two channels of the instrument. The field measurements of the instrument revealed a non-uniformity in the field response. In the light of non-identical response of the two channels and the non-uniformity of the field response, a theoretical model of such a polarimeter is developed to gain insights into the performance of a polarimeter. Analysis of lunar observations obtained within the SHAPE field of view indicates that the transmission ratio between the two polarized channels lies in the range 0.8-1.2. Such deviations from unity can introduce offsets in the measured polarization of up to about 10%. The suitability of SHAPE for studying the band polarization, defined as the relative polarization within a spectral absorption band, is studied. Using the Moon observations and the theoretical instrumental model, the suitability of measuring the relative band polarization is demonstrated. A study of systematic biases in the band polarization demonstrates a maximum offset of less than 1% in the measured value of the band polarization. The initial results of Earth observations, spectra and flux measurements across phase angles, and the methodology for retrieving the band polarization from these observations are also discussed.
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All authors Bhavesh Jaiswal, Swapnil Singh, Ravishankar B T, Anand Jain, Smrati Verma, Reenu Palawat, Brajpal Singh, Bijoy Raha, Sathyanarayana Raju, Bhavesh Mendhekar, Srinivasa Rao Kondapi, Priyanka Das, Rahul Waghmare, Supratik Bose, Supriya Verma, Yogesh Prasad K R, Praloy Karmakar, Abhishek Kumar Singh, Honey Gupta, Balaraman Prabakaran, Motamarri Srikanth, Sankarasubramanian Kasiviswanathan, Anuj Nandi

Instrumentation and Methods for Astrophysics · Cross-listed from gr-qc

cWB-space: A time-frequency transient-search pipeline for LISA

Shubhanshu Tiwari, Yumeng Xu and Giovanni A. Prodi

Gravitational-wave observations can reveal sources whose signals are not known in advance. Searches that do not require a predicted waveform are therefore an important complement to searches for specific source classes. For the Laser Interferometer Space Antenna (LISA), the challenge is to find such signals among overlapping astrophysical sources and disturbances in the instrument. We present cWB-space, which identifies candidate signals by following how their power is distributed in time and frequency, and then reconstructs parts of their waveforms without imposing a source model. Simulations of merging massive black holes, other burst signals, and instrumental disturbances test both candidate identification and the information carried by the detector's response. The response comparison estimates its background from the observed data. Tests of disturbances in several laser measurements examine where a similar response can arise from an instrumental origin. Searching the Sangria simulated LISA data, we recover all six injected massive-black-hole binaries as the six highest-ranked candidates. Their reconstructed waveforms agree well with the injected signals over the intervals studied. The results demonstrate another route to investigating transients, while leaving the rate of false detections and general discrimination of instrumental disturbances to future validation.
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Instrumentation and Methods for Astrophysics

XMST: An Extended Minimum Spanning Tree Framework with Objective Fracture-Scale Selection

Mark Gallaway

We present XMST, an extended minimum spanning tree framework for identifying spatially coherent stellar structures using an objective, data-driven fracture-scale criterion. XMST combines percolation analysis with Jenks Natural Breaks optimisation, restricting the MST edge-length distribution to the subcritical regime before determining the final fracture scale. The method was validated using 1000 controlled Monte Carlo realisations containing eight empirical stellar-association templates, including a deliberately overlapping pair. The Percolation-Jenks fracture scale was highly reproducible, with a median of 17.028 pc and a between-realisation standard deviation of 0.066 pc. The injected structures were recovered with a mean completeness of 0.9996 and mean purity of 0.7413, while alternative CDF and Mean Edge criteria selected substantially larger fracture scales and produced markedly lower purities. Propagation of the published distance uncertainties through 10,000 additional XMST reconstructions produced a median absolute fracture-scale change of only 0.282 pc. Under these perturbations, mean completeness was 0.8605 and mean purity 0.7126, while 99.30 per cent of injected-template cases continued to satisfy the adopted detection criterion. Individual membership was less stable, with peripheral and locally sparse members showing lower persistence than structural cores. The deliberately overlapping pair was resolved spatially in only 15 of 1000 realisations; a reddening-based post-processing diagnostic increased this to 446, although with a corresponding completeness-purity trade-off. XMST therefore provides a robust method for identifying candidate stellar structures and their stable cores, while detailed outer membership and strongly overlapping populations require additional astrophysical information.
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Instrumentation and Methods for Astrophysics · Cross-listed from gr-qc

The Wavelet Detection Filter: a real time unmodeled pipeline for gravitational wave transients, ranking coincidences with a graph neural network

Elena Cuoco

Accurate waveform models are unavailable for many potential sources of gravitational wave transients, motivating searches that do not assume a predefined template family. The Wavelet Detection Filter (WDF) is an unmodeled pipeline that identifies excess energy in the wavelet coefficients of whitened detector data. Here, we develop WDF into a low latency pipeline for both detection and reconstruction and this paper describes and validates that pipeline. We use a zero phase streaming autoregressive whitening filter that preserves transient morphology with a fixed latency and we use the retained wavelet coefficients to provide both a detection statistic and a sparse representation of the signal. By combining coefficients across consecutive analysis windows, the pipeline reconstructs transients longer than a single window. We represent candidate coincidences between detectors with a trigger graph and rank them with supervised and unsupervised graph neural networks (GNNs). We estimate the significance of the ranked coincidences from time shifted data. We validate the pipeline on Gaussian noise colored according to the Advanced LIGO sensitivity curve and on real O4 strain containing compact binary and core collapse supernova injections. Applied to GW250114, WDF identifies the event as the loudest zero lag candidate in the analyzed segment without using waveform templates. We measure the computational cost of the pipeline and the latency it introduces. Both are compatible with a low latency search,so WDF can run on a stream in real time.
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Instrumentation and Methods for Astrophysics · Cross-listed from astro-ph.EP

Limits on a Host Star around a Saturn-mass Free-floating Planet Candidate KMT-2024-BLG-0792/OGLE-2024-BLG-0516

Przemek Mróz, Klara Piotrowska, Antoine Mérand et al. (+2 more)

Recent studies found a number of short-timescale microlensing events that are thought to be produced by free-floating or wide-orbit planets. The microlensing event KMT-2024-BLG-0792/OGLE-2024-BLG-0516 is currently the only free-floating planet candidate with a directly measured mass ($0.73^{+0.25}_{-0.15}$ Saturn masses), derived from joint ground-based and Gaia satellite observations. However, it remains unclear whether the lens is truly isolated or bound to a widely separated host star. Here, we report high-angular-resolution interferometric observations of the event obtained with the Very Large Telescope Interferometer/GRAVITY instrument two years after peak magnification. We detect no luminous host star up to a projected separation of 90 au, supporting the hypothesis that the lens is indeed a free-floating planet. We derive a 5 sigma upper limit on the mass of a putative host star of approximately 0.5-0.6 M_solar. This work demonstrates that interferometry provides a powerful method for directly searching for or constraining host stars in short-duration and planetary microlensing events.
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All authors Przemek Mróz, Klara Piotrowska, Antoine Mérand, Subo Dong, Zexuan Wu

Instrumentation and Methods for Astrophysics · Cross-listed from gr-qc

A semicoherent resampling method for long-transient gravitational wave searches with applications to subsolar-mass primordial black-hole binaries

Neil Lu, Cristiano Palomba, Ornella J. Piccinni et al. (+1 more)

Resampling removes the modeled phase evolution of a frequency-evolving signal, transforming it into a monochromatic one. We introduce a novel implementation for long-transient gravitational-wave searches that evaluates the Fourier spectrum of the resampled data using a type-I non-uniform fast Fourier transform (NUFFT). This implementation can be up to two orders of magnitude faster than some previous implementations, depending on coherent length, sampling rate, and desired accuracy. To demonstrate its application, we benchmark the method with a semicoherent search for long-duration inspiral signals from subsolar-mass primordial black hole binaries. For a search over $40$–$60\,\mathrm{Hz}$ and chirp masses of $5\times10^{-4}$–$10^{-1}\,M_\odot$, with a coherent duration of $30\,\mathrm{s}$ and a realistic computing cost, the estimated horizon distance exceeds the Galactic Center for all of the parameter space considered and exceeds Andromeda for chirp masses above approximately $2\times10^{-2}M_\odot$. These results establish NUFFT-based resampling as a computationally efficient and broadly applicable approach for searches for modeled, frequency-evolving gravitational-wave signals.
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All authors Neil Lu, Cristiano Palomba, Ornella J. Piccinni, Ling Sun

Thursday 10 September

Instrumentation and Methods for Astrophysics

The Preprint Evolution: The Rise of Unreviewed Drafts on arXiv and its Implications for Astronomy

Luigi Rolly Bedin

The arXiv preprint server originally democratized astronomical research by digitizing the circulation of early manuscripts and removing the financial barriers of journal subscriptions. However, a system designed for the lower publication volumes of the 1990s has fractured under modern research output. Today, the sheer volume of unreviewed manuscripts—often tagged as “submitted,”, “under review”, or “comments welcome”—imposes a severe cognitive “tax” on the community. Researchers are forced to track multiple, unvetted versions of the same work, creating a massive redundant workload. This practice also bypasses the blinded peer-review process by establishing premature precedence, and it takes a heavy toll on early-career researchers. The pressure to rapidly post unvetted results stifles independent research, pushing young scientists toward massive mainstream collaborations where individual creativity gets lost. In this Short Communication, I analyze a decade of astro-ph metadata to quantify this trend. To safeguard both researchers' time and research freedom, I propose bifurcating submissions into two separate streams. Level-1 (peer-reviewed science) would host peer-reviewed science (accompanied by a journal acceptance or final DOI), while Level-2 (pre-review drafts) would be reserved for discussion drafts. This distinction would remove the unfair advantage of establishing false precedence through drafts and drastically cut the daily reading burden by allowing researchers to opt out of tracking unvetted versions.
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Instrumentation and Methods for Astrophysics

An X-ray Data Primer: What I Wish I Knew When Starting X-ray Astronomy

Nicholas P. Lee, Jonathan C. McDowell, Evan D. Tingle et al. (+1 more)

This guide is intended for astronomers new to X-ray astronomy. It provides a brief overview of the data products typically encountered by the user and highlights analysis considerations usually not discussed in more formal introductions to the discipline. In X-ray and $\gamma$-ray astronomy the primary data set is an event list (a table of individually detected photons with position, arrival time, and an instrumental energy estimate) rather than the image or visibility array familiar from other wavelength bands. We describe the files a user typically encounters, including: event lists, the aspect solution, spectra, instrumental responses, exposure maps, lightcurves, source lists, and calibration databases. These data are generally photon-limited and follow Poisson rather than Gaussian statistics. Combined with the coarse energy resolution of X-ray instruments, this means physical models must be fitted by "forward-folding"; we outline this technique and the systematic uncertainties introduced by calibration. Additional topics include: point spread function morphology, cosmic and instrumental backgrounds, pileup, contamination, binning conventions, the Chandra X-Ray Observatory focal plane, and sub-pixel event repositioning. This primer is intended to be generalized, not specific to any telescope or science subject area, although examples draw on Chandra. It was inspired by interactions with the astronomical community over several conferences and through the Chandra X-ray Center (CXC) HelpDesk.
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All authors Nicholas P. Lee, Jonathan C. McDowell, Evan D. Tingle, Karla M. Guardado

Instrumentation and Methods for Astrophysics

Astrophysics in the Era of Artificial Intelligence powered by Large Language Models

A. R. Rao

In recent times there is considerable unease about the way Artificial Intelligence (AI) powered by large language models is used to do astrophysics, and, assuming that these AIs will get far better in future, several alarming situations are also discussed. In a “white paper,” Hogg argues that extreme cases like allowing AI to write all astrophysics papers or strictly controlling AI are not good choices and posits that it is difficult to adopt moderate policies. I examine the impact of AI on astrophysics by making two rather extreme assumptions: first, that the modern astrophysicist has become increasingly preoccupied with the administrative task of publication over the act of physical discovery (astrophysicists are busy writing papers and have stopped doing astrophysics); and second, that while AI possesses the capacity to synthesize literature and generate manuscripts, they lack the intrinsic ability to perform original astrophysical inquiry (AI can write papers but cannot do astrophysics). I provide some plausible reasons for adopting these assumptions, but, more importantly, extrapolate the implications of these assumptions to argue that AI can have a very positive impact on astrophysics. By situating AI as agents of publication rather than discovery, the focus of the human researcher can be directed towards fundamental astrophysics, leading to very positive growth in the field.
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Instrumentation and Methods for Astrophysics · Cross-listed from astro-ph.EP

OSIRIS-REx Returned a Pristine Sample of Asteroid Bennu: Takeaways from the Mission's Contamination Control and Knowledge Program

Jason P. Dworkin, Scott A. Sandford, Nicole G. Lunning et al. (+81 more)

NASA's OSIRIS-REx mission had the objective of delivering a pristine sample from asteroid (101955) Bennu to Earth for scientific analysis–where "pristine" signifies the absence of foreign materials that could affect sample measurements. OSIRIS-REx returned 121.6 g of regolith in September 2023; this study documents the systematic investigation of suspected contaminants encountered during the mission's sample analysis phase. Most suspected contaminants did not originate from the spacecraft or sample curation. Some were introduced during laboratory analyses, reinforcing the importance of procedural blanks and a strategic approach to sharing samples across laboratories with different analytical targets. Several suspected contaminants, such as phosphate and sodium fluoride particles, were ultimately identified as indigenous to Bennu, highlighting the critical role of contamination knowledge in preventing the dismissal of valuable scientific data. We find that the returned sample meets the definition of pristine, except for an isolated 1.24% (by mass) that escaped the sample container and was thereby contaminated with spacecraft particulates. These findings demonstrate the effectiveness of systematically applied contamination science and engineering practices and provide lessons and approaches to help maximize the scientific integrity of future planetary sample return missions.
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All authors Jason P. Dworkin, Scott A. Sandford, Nicole G. Lunning, Kevin Righter, Charles C. Lorentson, Daniel P. Glavin, Kathie L. Thomas-Keprta, Loan Le, Catherine M. Corrigan, Timothy J. McCoy, Edward B. Bierhaus, Jose C. Aponte, Angel Mojarro, Hannah L. McLain, Eric T. Parker, Denise K. Buckner, Frédéric Seguin, Radford L. Perry, Heather V. Graham, Havishk Tripathi, Pierre Haenecour, Piers Koefoed, Kun Wang, Cody Schultz, Takahiro Hiroi, Ralph E. Milliken, Simon J. Clemett, Bumsoo Kim, Christopher J. Snead, Eve L. Berger, Michael Liss, Jessica J. Barnes, Sandra Freund, Zoe A. Wilson, Ryan D. Dubisher, Natasha V. Almeida, Kimberly K. Allums, Erika H. Blumenfeld, Joseph E. Aebersold, Rachel C. Funk, Carla P. Gonzales, Julia L. Plummer, Maritza Montoya, Daniel J. Rohmer, Erika V. Rivera, Jannatul Ferdous, Gabriel C. Garcia, Melissa Rodriguez, Jose L. Ponce, Ronald Bastien, Wayland D. Connelly, Jemma Davidson, Marghaleray Amini, Vivian Lai, Dominique Weis, Josh Wimpenny, Jan Render, Gregory A. Brennecka, Yoshihiro Furukawa, Toshiki Koga, Yoshinori Takano, Hiroshi Naraoka, Yasuhiro Oba, Kenneth J. Domanik, Yao-Jen Chang, Zoe Zeszut, Thomas J. Zega, George D. Cody, Conel M. O'D. Alexander, Ian A. Franchi, Monica M. Grady, Danielle N. Simkus, Jamie E. Elsila, Philippe Schmitt-Kopplin, Allison A. Baczynski, Katherine H. Freeman, Amy E. Hofmann, Aaron S. Burton, Lindsay P. Keller, Sara S. Russell, Anjani T. Polit, Francis M. McCubbin, Harold C. Connolly Jr., Dante S. Lauretta

Instrumentation and Methods for Astrophysics · Cross-listed from quant-ph

Path-Degenerate Quantum Interferometry for Decoherence Mitigation in Gravitational-Wave Detectors

Jonas Rittmeyer, Niels Boettner, Farid Khalili et al. (+2 more)

Optical decoherence degrades quantum correlations in squeezed states of light, severely limiting the quantum-nondemolition (QND) sensitivity of gravitational-wave detectors. Here, we propose the path-degenerate quantum interferometry scheme that obviates the need for entire optical subsystems—including additional filter cavities, auxiliary parametric amplifiers, and Faraday isolators—thereby drastically reducing spatial mode mismatches while inherently integrating variational output, a long-standing theoretical proposal to further deepen the QND regime. We experimentally demonstrate a core aspect of this scheme, achieving a shot-noise-preserving signal enhancement that directly counteracts the detrimental effects of readout loss. By delivering an improved signal-to-quantum-noise ratio solely through the consolidation and reduction of currently considered optical subsystems, our approach offers a highly optimized route toward enhanced quantum-noise reduction in upcoming LIGO upgrades and next-generation gravitational-wave observatories.
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All authors Jonas Rittmeyer, Niels Boettner, Farid Khalili, Mikhail Korobko, Roman Schnabel

Instrumentation and Methods for Astrophysics

A Proliferated Space Architecture for Time-Domain Astrophysics

Daniel Kocevski, Eric Burns, Thomas Barclay et al. (+58 more)

Time-Domain and Multi-Messenger Astrophysics (TDAMM) is entering a discovery-rich but follow-up-limited era, creating an urgent need for responsive, multiwavelength space-based capabilities. The Hydra constellation is a concept for a proliferated space architecture for time-domain astrophysics. The constellation would act as a disaggregated observatory composed of coordinated, relatively low-cost spacecraft that collectively provide capabilities traditionally concentrated within a single large mission. The architecture would combine persistent wide-field gamma-ray monitoring, wide-field and focused X-ray observations, and rapid-response ultraviolet, optical, and infrared imaging and spectroscopy. The constellation would both discover high-energy transients and respond to external alerts from gravitational-wave detectors, neutrino observatories, and ground- and space-based surveys, using low-latency communications, automated event prioritization, and community coordination frameworks to rapidly assign observing resources. A proliferated architecture would offer operational advantages over a single larger mission, including simultaneous observations of multiple targets, graceful degradation following individual spacecraft failures, recurring technology refresh, and opportunities for commercial, international, and philanthropic contributed nodes to join the network. The constellation would address fundamental questions concerning cosmic accelerators, the origin and evolution of the elements, the behavior of matter at extreme density, and the nature of dark energy through gravitational-wave standard sirens. This white paper presents the Hydra concept description that was submitted to NASA's ASTRA initiative for consideration by the Cosmic Origins Program Analysis Group (CoPAG) and Physics of the Cosmos Program Analysis Group (PhysPAG).
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All authors Daniel Kocevski, Eric Burns, Thomas Barclay, Nicholas E. White, Massimiliano Galeazzi, Brendan O'Connor, Amy Lien, Chris Fryer, Hallie Fausey, Fe McBride, Neil Cornish, Dheeraj Pasham, Kip Kuntz, Anya Nugent, Scott Porter, Tzu-Ching Chang, Adam Lidz, Alexander van der Horst, Sylvain Guiriec, Ed Cackett, Dieter Hartmann, Brad Cenko, C. Michelle Hui, Tyler Parsotan, Michael W. Coughlin, Eliza Neights, Zorawar Wadiasingh, Catherine Grant, Oindabi Mukherjee, Francesco Longo, Eric Bellm, Alec Habig, George Younes, Kim Page, Shivam Kumar Sharma, Oliver J. Roberts, Rachel Hamburg, Rahul Gupta, Colleen A. Wilson-Hodge, William Cleveland, Breann Sitarski, Vikas Chand, Raffaella Margutti, Adam Goldstein, Ryan J. Foley, Vidushi Sharma, Yi-Jung Yang, Elisabetta Bissaldi, M. Coleman Miller, T. A. Pritchard, D. J. Sand, Tomas Ahumada, Judith Racusin, Noah Franz, Kate D. Alexander, Brenna Mockler, D. Andrew Howell, Elisa Quintana, Chin-Ping Hu, Igor Andreoni, Boyan Hristov

Instrumentation and Methods for Astrophysics

Continuous Learning of Gravity Field Irregularities Around Small Bodies via Neural Hamiltonian ODEs

Giacomo Acciarini and Dario Izzo

We propose to learn the unknown dynamics in the proximity of a small body directly from tracking data, representing them as a feed-forward neural network embedded in the system Hamiltonian. The equations of motion form a Neural Hamiltonian Ordinary Differential Equation, whose variational equations provide exact training gradients: estimation uses position and velocity arcs at realistic noise levels, without acceleration or potential labels, and a continual learning approach warm-starts the network as new data are acquired. The known part of the Hamiltonian carries whatever is available, from the central term and spin state to the constant-density model of the imaged shape. We assess the method against a normalized spherical harmonics expansion estimated from identical arcs through the same machinery, on scenarios built on the shapes of Itokawa, 67P, Bennu and Eros. The network remains usable inside the Brillouin sphere: it plans ballistic descents at Itokawa to \SI{4.6}{m} median touchdown error from tracking alone, against 5.1–\SI{48.9}{m} for harmonics of degree 4–12, and to \SI{0.9}{m} with the imaged shape as prior, a configuration that also recovers localised density anomalies invisible to any harmonics degree. The two representations are complementary, and we discuss their combined use across the phases of a small-body mission.
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Instrumentation and Methods for Astrophysics

A Framework for Evaluating Forward Contamination Risk for Bio-ISRU Microorganisms

Una Nattermann, Devon A. Stork, Tom Pedersen et al. (+9 more)

NASA planetary protection policy seeks to avoid inadvertent forward contamination of celestial bodies and backward contamination of Earth during space exploration. For Mars missions, it has historically focused on sterilization of landers and rovers. Current policy provides no framework for assessing the forward contamination risk of missions that deliberately include living organisms and must not be sterilized, such as a human crew, agriculture, or biotechnology for manufacturing and life support. We propose the PRIM (Propagation Restricted, Inert on Mars) framework to evaluate the forward-contamination risk posed by known organisms. Building on the biocontainment literature and probability-of-contamination model, PRIM bounds the ability of an organism released from a worst-case off-nominal event to sustain growth on the Martian surface at a probability under P_c <= 10^-4 using independent single-stressor propagation assays. We apply the PRIM framework to two engineered Mars biological in situ resource utilization (bio-ISRU) chassis organisms, using low water activity and carbon starvation to qualify them for low forward contamination risk even at high bioburden, and outline how to extend the assays to phototrophs and anaerobes. PRIM offers a path to flight-qualify living organisms for Mars based on laboratory assays rather than bioburden alone. This enables biological life support infrastructure for a sustained presence on Mars while keeping forward contamination risk demonstrably low.
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All authors Una Nattermann, Devon A. Stork, Tom Pedersen, Nathan D. Hicks, Jordan E. Mancuso, Keren Isaev, Max G. Schubert, Fatima R. Martin, Jonathan Liu, Harley Greene, Edward Sukarto, Erika A. DeBenedictis

Instrumentation and Methods for Astrophysics · Cross-listed from astro-ph.SR

The Dyn-Atmo Survey: JWST/NIRSpec spectroscopy of dynamical benchmark GJ 758 B

Alexander Madurowicz, Emily Rickman, Daniella Bardalez Gagliuffi et al. (+22 more)

We present new JWST/NIRSpec IFU high contrast spectroscopic observations of the brown dwarf companion GJ 758 B. Extensive radial velocity monitoring of the primary has enabled high-precision measurements of the companion mass through characterization of their joint orbital dynamics. The combination of prior space- and ground-based photometry and spectroscopic observations in concert with a spectral model-independent mass makes this target an ideal benchmark for calibrating evolutionary models with known mass-age-luminosity degeneracies. A template-matching analysis on the NIRSpec/IFU data (F290LP,G395H; $\lambda \in$ [2.87-5.27] $\mu$m) detects the companion at the expected orbital position with incredible significance (265.2$\sigma$). Comprehensive spectral analysis including published datasets over a variety of different spectral model families reveal that an inference using a uniform radius prior is plagued by inaccurate posteriors. The atmospheric model degeneracy between metallicity, gravity, and clouds pull the inferred mass/gravity/radius to an unphysical portion of parameter space for all model families tested. A constrained inference with a gaussian prior on the mass can mitigate this issue but models without clouds still struggle to accurately reproduce the K-band photometry and result in mass inferences which are inconsistent with the dynamics. We explore modifying the spectral models with custom post-processed clouds and molecular abundance perturbations of ammonia and hydrogen sulfide. We find the best-fitting model includes clouds with no patchiness (hole fraction f$_\mathrm{hole}$ = 0), a small fractional depletion in ammonia and moderate enhancement in hydrogen sulfide.
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All authors Alexander Madurowicz, Emily Rickman, Daniella Bardalez Gagliuffi, James Mang, Kim Ward-Duong, William O. Balmer, Brendan P. Bowler, Emily Calamari, Henry Dennen, Jacqueline K Faherty, Kyle Franson, Mark R. Giovinazzi, Lisseth Gonzales Quevedo, Kielan K. W. Hoch, Piper Lentz, Elena Manjavacas, Klara Matuszewska, Ashley Messier, Caroline V. Morley, Evert Nasedkin, Marshall Perrin, Laurent Pueyo, Jean-Baptiste Ruffio, Christopher A. Theissen, Jerry W. Xuan

Instrumentation and Methods for Astrophysics · Cross-listed from astro-ph.SR

The Dyn-Atmo Survey: High-contrast Imaging Spectroscopy of the Substellar Companion HD 13724 B with the JWST NIRSpec IFU

Kielan K. W. Hoch, Alex Madurowicz, Evert Nasedkin et al. (+22 more)

We present the first spectral analysis from the JWST Cycle 3 GO Program #6362, the Dyn-Atmo Survey of dynamical-atmospheric benchmarks, characterizing the atmospheres of directly-imaged companions with dynamical masses and measured orbits. This program has obtained moderate-resolution spectra (R$\sim$2700, 3-5$\mu$m) using the NIRSpec/G395H IFU. We observe the T4-dwarf companion, HD 13724 B, companion to a G-type star at a projected angular separation of 0”2. Updated orbital monitoring constrains the mass to $38.3\pm0.6~M_{\rm{Jup}}$, which we use as a Gaussian prior when inferring the atmospheric state. We fit the continuum-subtracted spectrum using the BT-SETTL, Sonora Diamondback, Sonora Flame Skimmer, and NEWERA-PHOENIX self-consistent model grids, together with petitRADTRANS atmospheric retrievals. We adopt bulk parameter values of $T_\mathrm{eff}$=$1150\pm$195 K, $\log g$=5.1$\pm0.3$ dex, [M/H]=0.4$\pm$0.4, $\log_{10}(K_{zz})$=6.33$_{-2.22}^{+2.59}$, and C/O=$0.50\pm0.13$ using a bayesian average across model grids. We find degeneracies in the models between surface gravity, metallicity, and $K_{zz}$ for Sonora Diamondback and Flame Skimmer. The Flame Skimmer and NEWERA-PHOENIX vertical mixing strengths are incompatible, with Flame Skimmer finding a systematically lower value. The retrievals favor an atmosphere in chemical equilibrium, with enhanced metallicity and a solar C/O ratio, but with no detection of disequilibrium chemistry, and no detection of trace gases other than CH$_4$, CO$_{2}$, $^{12}$CO and H$_{2}$O. Ultimately, we identify critical challenges in forward modeling continuum-subtracted G395H spectra in the low signal-to-noise regime. We find that including independent dynamical mass measurements better constrains atmospheric parameters, but degeneracies between self-consistent model parameters limit accurate atmospheric parameter inferences.
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All authors Kielan K. W. Hoch, Alex Madurowicz, Evert Nasedkin, Emily Rickman, Daniella C. Bardalez Gagliuffi, James Mang, Caroline V. Morley, Christopher A. Theissen, William O. Balmer, Brendan P. Bowler, Emily Calamari, Henry Dennen, Jacqueline K. Faherty, Kyle Franson, Mark R. Giovinazzi, Lisseth Gonzales Quevedo, Elena Manjavacas, Piper Lentz, Klara Matuszewska, Ashley Messier, Marshall Perrin, Laurent Pueyo, Jean-Baptiste Ruffio, Kimberly Ward-Duong, Jerry W. Xuan

Instrumentation and Methods for Astrophysics

Bayesian Superiority in On/Off analysis

Gleb Babenov and Petr Satunin

We present a detailed comparison of Bayesian criteria with three non-informative priors - flat, Jeffreys, and scale-invariant - for testing a signal against an unknown background and compare them with the classical frequentist Li-Ma approach in the On/Off problem. We perform Monte Carlo simulations for various background levels and evaluate the Li-Ma and Bayesian criteria by their Type I error rates. We then simulate a nonzero signal and compare the criteria in terms of Type II error rates. We find that both the Li-Ma criterion and the Bayesian criterion with the Jeffreys prior control Type I error well, excluding the case of small background $b < 0.5$; the Bayesian criterion with the Jeffreys prior is statistically more powerful than the Li-Ma criterion for $b \lesssim 40$.
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Instrumentation and Methods for Astrophysics

The Balloon-borne VLBI Experiment (BVEX) Radio Telescope and Position Tracking System

Felix M. Thiel, Mayukh Bagchi, Laura M. Fissel et al. (+17 more)

Very Long Baseline Interferometry (VLBI) is a technique in radio astronomy that vastly increases the diffraction limited angular resolution of radio observations by correlating simultaneous observations of radio telescopes separated by thousands of kilometers. Ground-based high-frequency VLBI is limited in baseline length by the diameter of the Earth and in sensitivity by molecular absorption of the Earth's atmosphere. One of the ways to improve VLBI is with balloon telescopes, which are much cheaper than space VLBI telescopes. In addition balloon-VLBI stations could also improve image quality due to increased uv-coverage. As a first step to achieving VLBI from a balloon-borne platform we present the Balloon-borne VLBI Experiment (BVEX). This is a novel, first-generation balloon-borne VLBI station observing at K-band (22 GHz) which launched as part of the Canadian Space Agency (CSA) STRATOS campaign from Timmins, Ontario, Canada in August 2025, with the aim to demonstrate VLBI from a balloon-borne platform by correlating with a large ground based telescope. We discuss the design of the 36 inch (91 cm) radio telescope and receiver with a 2 GHz bandwidth built from commercial-off-the-shelf (COTS) components as well as the telescope pointing system capable of interfacing with the CSA's CARMENCITA gondola. We also present a novel high precision position tracking system built from COTS components giving <1 mm precision on 1 s time scales which is required for achieving phase tracking at 22 GHz. We further show on-the-ground testing results from the 2025 Timmins campaign. The 2025 flight from Timmins was not successful due to a leak in the balloon preventing the payload from reaching its target altitude where accurate gondola pointing is possible. We therefore wrap up by presenting plans to upgrade the telescope for a potential next flight opportunity from Palmas, Tocantins, Brazil in 2027.
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All authors Felix M. Thiel, Mayukh Bagchi, Laura M. Fissel, Aarchi Shah, Lindy Blackburn, Emily Butler, Rafael Costa, Thomas Emo, Vincent L. Fish, Daryl Haggard, Michael D. Johnson, Jessica Lo, Maggie Oxford, Dominic W. Pesce, Ganesh Rajagopalan, Javier L. Romualdez, Adrian K. Sinclair, Bonnie Slocombe, Stephanie St-Jean, Terry Yang

Instrumentation and Methods for Astrophysics

An RFSoC-based Backend and Timing System for the Balloon-borne Very Long Baseline Interferometry Experiment

Mayukh Bagchi, Felix M. Thiel, Laura M. Fissel et al. (+13 more)

We present the design and performance characterization of the digital backend and precision-timing system for the Balloon-borne Very Long Baseline Interferometry Experiment (BVEX), a pathfinder for high-frequency stratospheric VLBI at 22 GHz. The backend uses one of the four 14-bit analog-to-digital converter inputs on an AMD-Xilinx RFSoC 4x2. Although the converters support sampling rates up to 5 GSPS, the flight configuration digitizes the 2-4 GHz intermediate frequency at 4.096 GSPS. CASPER firmware provides both a high-resolution spectrometer for pointing and receiver verification, and a VLBI acquisition chain with two-bit requantization that records at a rate of about 8.2 Gbps. The timestamped data packets are sent over 100 Gigabit Ethernet (GbE) to a 16 TB NVMe array in a storage computer that draws approximately 70-80 W. The timing chain uses a Rakon oven-controlled crystal oscillator as a timing reference while a time-interval counter measures its drift relative to a GPS reference with approximately 60 ps resolution. This is the first deployment of an RFSoC-based VLBI backend and precision-timing system on a stratospheric balloon. Ground tests validated the backend, spectrometer, and timing chain. The August 2025 CSA STRATOS flight ended before reaching the target float altitude because of a balloon failure, and as a result no science observations were obtained. For the planned 2027 reflight, we are developing a conduction-cooled data storage computer with 24 TB of NVMe capacity and a direct data path from the 100 GbE interface to the NVMe array.
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All authors Mayukh Bagchi, Felix M. Thiel, Laura M. Fissel, Maggie Oxford, Lindy Blackburn, Rafael Costa, Vincent L. Fish, Daryl Haggard, Michael D. Johnson, Dominic W. Pesce, Ganesh Rajagopalan, Javier L. Romualdez, Aarchi Shah, Adrian K. Sinclair, Stephanie St-Jean, Terry Yang

Instrumentation and Methods for Astrophysics

Towards First Light for MICADO: Validation of the PSF-R service with real data

Matteo Simioni, Luca Cortese, Roland Wagner et al. (+12 more)

MICADO, one of the ELT first-light instruments, will rely on point-spread-function reconstruction (PSF-R) to meet scientific requirements, especially for SCAO observations of targets that lack bright reference stars nearby. PSF-R will be performed in post-processing using only AO telemetry, recorded simultaneously with the science data. For SCAO observations, both on- and off-axis PSFs will be delivered. We present the current status and results from an ESO TTR campaign begun in 2023, targeting a sparse three-star asterism under varying conditions with the ERIS instrument at VLT. Reconstructed PSFs reach ~10% accuracy in Strehl ratio and FWHM at separations up to half the size of the isoplanatic patch. The current results suggest the telemetry-driven approach can reproduce not only the core PSF structure but also the extended wings, which are essential for reliable photometry and morphological analysis of bright extended sources. The obtained results also corroborate the key role of wind as a limiting factor of the method, reducing the amount of recovered information on specific directions.
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All authors Matteo Simioni, Luca Cortese, Roland Wagner, Carmelo Arcidiacono, Andrea Grazian, Marco Gullieuszik, Elena Masciadri, Elisa Portaluri, Benedetta Vulcani, Anita Zanella, Richard Davies, Johanna Hartke, Roberto Piazzesi, Stefan Raffetseder, Piero Vaccari

Instrumentation and Methods for Astrophysics

The MICADO first light imager for the ELT: the PSF Reconstruction Software

Andrea Grazian, Fernando Pedichini, Matteo Simioni et al. (+14 more)

The MICADO instrument for the ESO ELT will provide Adaptive Optics (AO) diffraction-limited NIR imaging and spectroscopy. A critical component of MICADO is the Point Spread Function Reconstruction (PSF-R) Software, which is designed to perform a blind reconstruction of the PSF for all observations using AO telemetry data only, both with the Single Conjugate (SCAO) and Multi-Conjugate Adaptive Optics (MCAO) modes of MICADO. The SCAO PSF-R Pipeline is currently being completed, and validation with ERIS at VLT and SOUL+LUCI at LBT has demonstrated high accuracy, of percent-level on-axis and 5-20% off-axis. Initial scientific simulations confirm that the PSF-R software meets the necessary precision for high-quality analysis, securing its role for MICADO's first light and future ELT operations.
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All authors Andrea Grazian, Fernando Pedichini, Matteo Simioni, Jani Achren, Carmelo Arcidiacono, Luca Cortese, Ric Davies, Marco Gullieuszik, Johanna Hartke, Hanindyo Kuncarayakti, Roberto Piazzesi, Elisa Portaluri, Stefan Raffetseder, Piero Vaccari, Benedetta Vulcani, Roland Wagner, Anita Zanella

Instrumentation and Methods for Astrophysics · Cross-listed from astro-ph.CO

SMART : Spherical Mass ApeRture Toolkit

Igor Bezmaternykh, Sandrine Pires, Nicolas Dagoneau et al. (+3 more)

The aperture mass filter is a widely used tool in weak lensing studies. While previous surveys have typically relied on the flat-sky approximation, forthcoming Stage IV surveys such as Euclid will cover sufficiently large areas to require the construction of curved-sky aperture mass maps. In this paper, we extend the shear-based aperture mass formalism to the sphere and introduce a software package for a fast and precise computation of spherical aperture mass maps from the shear field, defined directly on the celestial sphere. Unlike existing approaches, our method does not rely on planar projections and does not require the reconstruction of convergence maps. The software provides four different implementations, all of which are independent of the choice of aperture mass filter function. Starting from the brute-force approach, whose computational cost renders it impractical for future surveys covering more than 10,000 deg2, we investigate alternative galaxy-grouping strategies to improve computational efficiency. We demonstrate speed-up factors of up to 40 at a resolution of NSIDE = 4096 while achieving significantly higher precision than existing state-of-the-art methods. In particular, we show that the spherical shear-based implementations using a pixel-based approach outperforms the existing methods in terms of both precision and computational time. Finally, we show that, for weak-lensing cluster detection, the cluster sample produced using the spherical shear-based aperture mass method consistently outperforms those obtained using projected shear-based approaches in the purity-completeness plane, while simplifying the resulting selection function. Our spherical mass aperture software, called SMART, is made available on GitHub.
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All authors Igor Bezmaternykh, Sandrine Pires, Nicolas Dagoneau, Gabriel W. Pratt, Loris Chappuis, Gavin Leroy

Instrumentation and Methods for Astrophysics

The EDD Radio Astronomy Backend Framework

Ewan D. Barr, Amit Bansod, Jan Behrend et al. (+16 more)

Modern digital radio astronomy receivers produce increasingly wide-bandwidth, high bit-rate data streams that necessitate the development of flexible, scalable, and maintainable backend processing and recording systems. Historically, such backend instrumentation has been tightly coupled to telescope observing modes, limiting reuse between observatories and science cases. We present the Effelsberg Direct Digitisation (EDD) backend framework, a software-defined architecture for constructing real-time radio astronomy backends on commodity off-the-shelf computing infrastructure. We describe its design, implementation, supported observing modes, and operational deployments. EDD separates a common core framework from plugin-provided observing capabilities. The core provides orchestration, telescope interfaces, pipeline lifecycle management, monitoring, and deployment tooling, while plugins implement processing pipelines for specific observing modes. The framework is designed to support both single-dish and interferometric instruments through site-specific configuration and plugin selection. EDD currently supports spectroscopy and spectropolarimetry, pulsar timing and searching, baseband recording, very long baseline interferometry, correlation, and beamforming. Operational deployments include the Effelsberg 100-m telescope, the SKA-MPI prototype dish, the Thai National Radio Telescope, and the ARGOS interferometric prototype array. By separating common services, observing-mode plugins, and site-specific configuration, it allows backend capabilities to be deployed across heterogeneous telescope environments and provides a community resource for broadband radio astronomy instrumentation.
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All authors Ewan D. Barr, Amit Bansod, Jan Behrend, Weiwei Chen, Niclas Esser, Yungpen Men, Tobias Winchen, Jason Wu, Uwe Bach, Claus Connot, Matthias Heininger, Jedrzej Jawor, Christoph Kasemann, Michael Kramer, Alex Kraus, Eddy Nussbaum, Oliver Polch, Jan Wagner, Gundolf Wieching

Instrumentation and Methods for Astrophysics · Cross-listed from astro-ph.SR

Science operation, data handling, and ground support system of the SOLAR-C mission

Shin Toriumi, Mari Nishiyama, Keiichi Matsuzaki et al. (+16 more)

SOLAR-C is an international solar-observing satellite mission led by Japan Aerospace Exploration Agency (JAXA). It aims to elucidate mass and energy transport in solar atmospheres through extreme ultraviolet (EUV) spectroscopy. The mission carries the EUV High-throughput Spectroscopic Telescope (EUVST) and the Solar Spectral Irradiance Monitor (SoSpIM), enabling comprehensive observations across a wide temperature range (10^4 K to 10^7 K) with minimum temperature gaps and high spatial and temporal resolution. To achieve its science objectives regarding atmospheric heating and solar flare eruptions, SOLAR-C implements a flexible and responsive operational procedure and a data processing system, while building on the heritage of the Hinode and IRIS satellites. The Chief Observer creates observation timelines that include core observation plans and approved proposed plans while taking into account the solar activity levels. A SpaceWire communication architecture is employed onboard the spacecraft, and a method is implemented in which the mission instrument temporarily acts as the network master during data transfer to support the high data rate requirements. Telemetry is downlinked at ground stations worldwide and gathered at the Institute of Space and Astronautical Science, JAXA. The EUVST data are calibrated at the SOLAR-C Science Center at Nagoya University, while the SoSpIM data are calibrated at the Processing and Archiving Facility before being integrated into the science data products. The data will be made publicly available immediately. The integrated operational scheme for this mission is expected to advance our understanding of solar atmospheric heating and flare processes.
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All authors Shin Toriumi, Mari Nishiyama, Keiichi Matsuzaki, Toshifumi Shimizu, Hideki Kato, Jun Matsumoto, Mizuho Uchiyama, Kota Miyoshi, Daiki Yamasaki, Hirohisa Hara, Yukio Katsukawa, Masahito Kubo, Ryohko Ishikawa, Takenori J. Okamoto, Shinsuke Imada, Satoshi Masuda, Kyoko Watanabe, Yusuke Iida, Ayumi Asai