Instrumentation and Methods for Astrophysics

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New submissions for Friday, 21 June 2024 (showing 12 of 12 entries )

[1] arXiv:2406.12917 [pdf, html, other]

Title: The Black Hole Explorer: Motivation and Vision

Michael D. Johnson, Kazunori Akiyama, Rebecca Baturin, Bryan Bilyeu, Lindy Blackburn, Don Boroson, Alejandro Cardenas-Avendano, Andrew Chael, Chi-kwan Chan, Dominic Chang, Peter Cheimets, Cathy Chou, Sheperd S. Doeleman, Joseph Farah, Peter Galison, Ronald Gamble, Charles F. Gammie, Zachary Gelles, Jose L. Gomez, Samuel E. Gralla, Paul Grimes, Leonid I. Gurvits, Shahar Hadar, Kari Haworth, Kazuhiro Hada, Michael H. Hecht, Mareki Honma, Janice Houston, Ben Hudson, Sara Issaoun, He Jia, Svetlana Jorstad, Jens Kauffmann, Yuri Y. Kovalev, Peter Kurczynski, Robert Lafon, Alexandru Lupsasca, Robert Lehmensiek, Chung-Pei Ma, Daniel P. Marrone, Alan P. Marscher, Gary J. Melnick, Ramesh Narayan, Kotaro Niinuma, Scott C. Noble, Eric J. Palmer, Daniel C. M. Palumbo, Lenny Paritsky, Eliad Peretz, Dominic Pesce, Alexander Plavin, Eliot Quataert, Hannah Rana, Angelo Ricarte, Freek Roelofs, Katia Shtyrkova, Laura C. Sinclair, Jeffrey Small, Sridharan Tirupati Kumara, Ranjani Srinivasan, Andrew Strominger, Paul Tiede, Edward Tong, Jade Wang, Jonathan Weintroub, Maciek Wielgus, George Wong, Xinyue Alice Zhang

Comments: Proceedings for SPIE Astronomical Telescopes and Instrumentation

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

We present the Black Hole Explorer (BHEX), a mission that will produce the sharpest images in the history of astronomy by extending submillimeter Very-Long-Baseline Interferometry (VLBI) to space. BHEX will discover and measure the bright and narrow "photon ring" that is predicted to exist in images of black holes, produced from light that has orbited the black hole before escaping. This discovery will expose universal features of a black hole's spacetime that are distinct from the complex astrophysics of the emitting plasma, allowing the first direct measurements of a supermassive black hole's spin. In addition to studying the properties of the nearby supermassive black holes M87* and Sgr A*, BHEX will measure the properties of dozens of additional supermassive black holes, providing crucial insights into the processes that drive their creation and growth. BHEX will also connect these supermassive black holes to their relativistic jets, elucidating the power source for the brightest and most efficient engines in the universe. BHEX will address fundamental open questions in the physics and astrophysics of black holes that cannot be answered without submillimeter space VLBI. The mission is enabled by recent technological breakthroughs, including the development of ultra-high-speed downlink using laser communications, and it leverages billions of dollars of existing ground infrastructure. We present the motivation for BHEX, its science goals and associated requirements, and the pathway to launch within the next decade.

[2] arXiv:2406.13156 [pdf, html, other]

Title: Development of RFSoC-based direct sampling highly multiplexed microwave SQUID readout for future CMB and submillimeter surveys

Chao Liu, Zeeshan Ahmed, Shawn W. Henderson, Ryan Herbst, Larry Ruckman, Thomas Satterthwaite

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Accelerator Physics (physics.acc-ph)

The SLAC Microresonator Radio Frequency (SMuRF) electronics is being deployed as the readout for the Cosmic Microwave Background (CMB) telescopes of the Simons Observatory (SO). A Radio Frequency System-on-Chip (RFSoC) based readout of microwave frequency resonator based cryogenic sensors is under development at SLAC as an upgrade path for SMuRF with simplified RF hardware, a more compact footprint, and lower total power consumption. The high-speed integrated data converters and digital data path in RFSoC enable direct RF sampling without analog up and down conversion for RF frequencies up to 6 GHz. A comprehensive optimization and characterization study has been performed for direct RF sampling for microwave SQUID multiplexers, which covers noise level, RF dynamic range, and linearity using a prototype implementation. The SMuRF firmware, including the implementation of closed-loop tone tracking, has been ported to the RFSoC platform and interfaced with the quadrature mixers for digital up and down conversion in the data converter data path to realize a full microwave SQUID multiplexer readout. In this paper, a selection of the performance characterization results of direct RF sampling for microwave SQUID multiplexer readout will be summarized and compared with science-driven requirements. Preliminary results demonstrating the read out of cryogenic sensors using the prototype system will also be presented here. We anticipate our new RFSoC-based SMuRF system will be an enabling readout for on-going and future experiments in astronomy and cosmology, which rely on large arrays of cryogenic sensors to achieve their science goals.

[3] arXiv:2406.13199 [pdf, html, other]

Title: New methods for ALMA angular-scale based observation scheduling, quality assessment, and beam shaping II: refinements

Dirk Petry, María Díaz Trigo, Rüdiger Kneissl, Ignacio Toledo, Atsushi Miyazaki, Toshinobu Takagi, Ashley Barnes, Francesca Bonanomi

Comments: 12 pages, 18 figures, to be published in the proceedings of SPIE Astronomical Telescopes and Instrumentation, 2024, Yokohama, paper no. 13098-27

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

The Atacama Large Millimeter/submillimeter Array remains the largest mm radio interferometer observatory world-wide. It is now conducting its 11th observing cycle. In our previous paper presented at this conference series in 2020, we outlined a number of possible improvements to the ALMA end-to-end observing and data processing procedures which could further optimize the uv coverage and thus the image quality while at the same time improving the observing efficiency. Here we report an update of our results refining our proposed adjustments to the scheduling and quality assurance processes. In particular we present new results on ways to assess the uv coverage of a given observation efficiently, methods to define and measure the maximum recoverable angular scale, and on the robustness of the deconvolution in the final interferometric imaging process w.r.t. defects in the uv coverage. Finally we present the outline of a design for integrating uv coverage assessment into the control and processing loop of observation scheduling. The results are applicable to all radio interferometers with more than approx. 10 antennas.

[4] arXiv:2406.13587 [pdf, html, other]

Title: The Precursor Small Aperture Telescope (PreSAT) CMB polarimeter

Matthew A. Petroff, Zeeshan Ahmed, James J. Bock, Marion Dierickx, Sofia Fatigoni, David C. Goldfinger, Paul K. Grimes, Shawn W. Henderson, Kirit S. Karkare, John M. Kovac, Hien T. Nguyen, Scott N. Paine, Anna R. Polish, Thibault Romand, Benjamin L. Schmitt, Abigail G. Vieregg

Comments: 12 pages, 4 figures, submitted to Proc. SPIE

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

The search for the polarized imprint of primordial gravitational waves in the cosmic microwave background (CMB) as direct evidence of cosmic inflation requires exquisite sensitivity and control over systematics. The next-generation CMB-S4 project intends to improve upon current-generation experiments by deploying a significantly greater number of highly-sensitive detectors, combined with refined instrument components based on designs from field-proven instruments. The Precursor Small Aperture Telescope (PreSAT) is envisioned as an early step to this next generation, which will test prototype CMB-S4 components and technologies within an existing BICEP Array receiver, with the aim of enabling full-stack laboratory testing and early risk retirement, along with direct correlation of laboratory component-level performance measurements with deployed system performance. The instrument will utilize new 95/155GHz dichroic dual-linear-polarization prototype detectors developed for CMB-S4, cooled to 100mK via the installation of an adiabatic demagnetization refrigerator, along with a prototype readout chain and prototype optics manufactured with wide-band anti-reflection coatings. The experience gained by integrating, deploying, and calibrating PreSAT will also help inform planning for CMB-S4 small aperture telescope commissioning, calibration, and operations well in advance of the fabrication of CMB-S4 production hardware.

[5] arXiv:2406.13673 [pdf, html, other]

Title: The EUSO-SPB2 Fluorescence Telescope for the Detection of Ultra-High Energy Cosmic Rays

James H. Adams Jr., Denis Allard, Phillip Alldredge, Luis Anchordoqui, Anna Anzalone, Matteo Battisti, Alexander A. Belov, Mario Bertaina, Peter F. Bertone, Sylvie Blin-Bondil, Julia Burton, Francesco S. Cafagna, Marco Casolino, Karel Černý, Mark J. Christ, Roberta Colalillo, Hank J. Crawford, Alexandre Creusot, Austin Cummings, Rebecca Diesing, Alessandro Di Nola, Toshikazu Ebisuzaki, Johannes Eser, Silvia Ferrarese, George Filippatos, William W. Finch, Flavia Flaminio, Claudio Fornaro, Duncan Fuehne, Christer Fuglesang, Diksha Garg, Alessio Golzio, Fausto Guarino, Claire Guépin, Tobias Heibges, Eleanor G. Judd, Pavel A. Klimov, John F. Krizmanic, Viktoria Kungel, Luke Kupari, Evgeny Kuznetsov, Massimiliano Manfrin, Wlodzimierz Marszal, John N. Matthews, Marco Mese, Stephan S. Meyer, Marco Mignone, Hiroko Miyamoto, Alexey S. Murashov, Jane M. Nachtman, Angela V. Olinto, Yasar Onel, Giuseppe Osteria, Beatrice Panico, Ètienne Parizot, Tom Paul, Miroslav Pech, Francesco Perfetto, Lech W. Piotrowski, Zbigniew Plebaniak, Jonatan Posliguaaa, Guillaume Prévôtb, Marika Przybylakae, Patrick Reardona, Mary Hall Reno, Marco Ricci, Fred Sarazin, P. Schovánek, Valentina Scotti, Kenji Shinozaki, Jorge F. Soriano, Ben K. Stillwell, Jacek Szabelski, Yoshiyuki Takizawa, Daniil Trofimov, Fredrik Unel, Laura Valore, Tonia M. Venters, John Watts Jr., Lawrence Wiencke, Hannah Wistrand, Roy Young

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE)

The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) flew on May 13$^{\text{th}}$ and 14$^{\text{th}}$ of 2023. Consisting of two novel optical telescopes, the payload utilized next-generation instrumentation for the observations of extensive air showers from near space. One instrument, the fluorescence telescope (FT) searched for Ultra-High Energy Cosmic Rays (UHECRs) by recording the atmosphere below the balloon in the near-UV with a 1~$\mu$s time resolution using 108 multi-anode photomultiplier tubes with a total of 6,912 channels. Validated by pre-flight measurements during a field campaign, the energy threshold was estimated around 2~EeV with an expected event rate of approximately 1 event per 10 hours of observation. Based on the limited time afloat, the expected number of UHECR observations throughout the flight is between 0 and 2. Consistent with this expectation, no UHECR candidate events have been found. The majority of events appear to be detector artifacts that were not rejected properly due to a shortened commissioning phase. Despite the earlier-than-expected termination of the flight, data were recorded which provide insights into the detectors stability in the near-space environment as well as the diffuse ultraviolet emissivity of the atmosphere, both of which are impactful to future experiments.

[6] arXiv:2406.13854 [pdf, html, other]

Title: Overview of the Optical Design of the CMB-S4 Large Aperture Telescopes and Camera Optics

Patricio A. Gallardo, Kathleen Harrington, Roberto Puddu, Bradford Benson, John Carlstrom, Nick Emerson, Jeff McMahon, Tyler Natoli, Johanna M. Nagy, Michael D. Niemack, John Ruhl

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

CMB-S4, the next-generation CMB observatory, will deploy hundreds of thousands of detectors to enable mapping the millimeter-wavelength sky with unprecedented speed. The large aperture telescopes for CMB-S4 consist of six-meter diameter crossed Dragone designs and a five-meter diameter three-mirror anastigmat. The two-mirror crossed Dragone design requires astigmatism corrections in the refractive optics to achieve diffraction-limited performance. We present biconic lens corrections for the CMB-S4 crossed Dragone camera optics and compare these designs to the camera optics for the three mirror anastigmat, as the optical designs of the cameras for these telescopes are being prototyped.

[7] arXiv:2406.13913 [pdf, html, other]

Title: The Blue Multi Unit Spectroscopic Explorer (BlueMUSE) on the VLT: characterization of two VPHG prototypes based on dichromated gelatin and photopolymer recording materials

Alexandre Jeanneau, Andrea Bianco, Andrew Clawson, Michele Frangiamore, Elroy Pearson, Laurent Pinard, Jürgen Schmoll, Johan Richard, Rémi Giroud, Florence Laurent, Roland Bacon

Comments: 7 pages, 5 figures, 1 table. Presented at SPIE "Astronomical Telescopes and Instrumentation", June 2024, in Yokohama, as part of "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation VI"

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

Volume-phase holographic gratings (VPHGs) are widely used in astronomical spectrographs due to their adaptability and high diffraction efficiency. Most VPHGs in operation use dichromated gelatin as a recording material, whose performance is sensitive to the coating and development process, especially in the near-UV. In this letter, we present the characterization of two UV-blue VPHG prototypes for the BlueMUSE integral field spectrograph on the VLT, based on dichromated gelatin and the Bayfol$\circledR$HX photopolymer film as recording materials. Our measurements show that both prototypes meet the required diffraction efficiency and exhibit similar performance with a wavelength-average exceeding 70% in the 350-580 nm range. Deviations from theoretical models increase towards 350 nm, consistently with previous studies on similar gratings. We also report similar performances in terms spatial uniformity and grating-to-grating consistency. Likewise, no significant differences in wavefront error or scattered light are observed between the prototypes.

[8] arXiv:2406.13914 [pdf, html, other]

Title: The Blue Multi Unit Spectroscopic Explorer (BlueMUSE) on the VLT: science drivers and overview of instrument design

Johan Richard, Rémi Giroud, Florence Laurent, Davor Krajnović, Alexandre Jeanneau, Roland Bacon, Manuel Abreu, Angela Adamo, Ricardo Araujo, Nicolas Bouché, Jarle Brinchmann, Zhemin Cai, Norberto Castro, Ariadna Calcines, Diane Chapuis, Adélaïde Claeyssens, Luca Cortese, Emanuele Daddi, Christopher Davison, Michael Goodwin, Robert Harris, Matthew Hayes, Mathilde Jauzac, Andreas Kelz, Jean-Paul Kneib, Audrey A. Lanotte, Jon Lawrence, Vianney Le Bouteiller, Rémy Le Breton, Matthew Lehnert, Angel Lopez Sanchez, Helen McGregor, Anna F. McLeod, Manuel Monteiro, Simon Morris, Cyrielle Opitom, Arlette Pécontal, David Robertson, Jesse van de Sande, Russell Smith, Matthias Steinmetz, Mark Swinbank, Tanya Urrutia, Anne Verhamme, Peter M. Weilbacher, Martin Wendt, François Wildi, Jessica Zheng, The BlueMUSE consortium

Comments: 20 pages, 10 figures, proceedings of the SPIE astronomical telescopes and instrumentation conference, Yokohama, 16-21 June

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)

BlueMUSE is a blue-optimised, medium spectral resolution, panoramic integral field spectrograph under development for the Very Large Telescope (VLT). With an optimised transmission down to 350 nm, spectral resolution of R$\sim$3500 on average across the wavelength range, and a large FoV (1 arcmin$^2$), BlueMUSE will open up a new range of galactic and extragalactic science cases facilitated by its specific capabilities. The BlueMUSE consortium includes 9 institutes located in 7 countries and is led by the Centre de Recherche Astrophysique de Lyon (CRAL). The BlueMUSE project development is currently in Phase A, with an expected first light at the VLT in 2031. We introduce here the Top Level Requirements (TLRs) derived from the main science cases, and then present an overview of the BlueMUSE system and its subsystems fulfilling these TLRs. We specifically emphasize the tradeoffs that are made and the key distinctions compared to the MUSE instrument, upon which the system architecture is built.

[9] arXiv:2406.13915 [pdf, html, other]

Title: The Blue Multi Unit Spectroscopic Explorer (BlueMUSE) on the VLT: End-To-End simulator 'BlueSi'

Martin Wendt, Norberto Castro, Sven Martens, John Pharo, Peter M. Weilbacher, Davor Krajnović, Johan Richard

Comments: 20 pages, 13 figures

Journal-ref: Proc. SPIE 13101-78, Software and Cyberinfrastructure for Astronomy VIII, (18 June 2024)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

BlueMUSE is a blue, medium spectral resolution, panoramic integral-field spectrograph under development for the Very Large Telescope (VLT). We demonstrate and discuss an early End-To-End simulation software for final BlueMUSE datacube products. Early access to such simulations is key to a number of aspects already in the development stage of a new major instrument. We outline the software design choices, including lessons learned from the MUSE instrument in operation at the VLT since 2014. The current simulation software package is utilized to evaluate some of the technical specifications of BlueMUSE as well as giving assistance in the assessment of certain trade offs regarding instrument capabilities, e.g., spatial and spectral resolution and sampling. By providing simulations of the end-user product including realistic environmental conditions such as sky contamination and seeing, BlueSi can be used to devise and prepare the science of the instrument by individual research teams.

[10] arXiv:2406.14089 [pdf, html, other]

Title: The Simons Observatory: Alarms and Detector Quality Monitoring

David V. Nguyen, Sanah Bhimani, Nicholas Galitzki, Brian J. Koopman, Jack Lashner, Laura Newburgh, Max Silva-Feaver, Kyohei Yamada

Comments: 14 pages, 6 figures, 2 tables. To be presented at SPIE Astronomical Telescopes + Instrumentation 2024

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

The Simons Observatory (SO) is a group of modern telescopes dedicated to observing the polarized cosmic microwave background (CMB), transients, and more. The Observatory consists of four telescopes and instruments, with over 60,000 superconducting detectors in total, located at ~5,200 m altitude in the Atacama Desert of Chile. During observations, it is important to ensure the detectors, telescope platforms, calibration and receiver hardware, and site hardware are within operational bounds. To facilitate rapid response when problems arise with any part of the system, it is essential that alerts are generated and distributed to appropriate personnel if components exceed these bounds. Similarly, alerts are generated if the quality of the data has become degraded. In this paper, we describe the SO alarm system we developed within the larger Observatory Control System (OCS) framework, including the data sources, alert architecture, and implementation. We also present results from deploying the alarm system during the commissioning of the SO telescopes and receivers.

[11] arXiv:2406.14101 [pdf, html, other]

Title: Peculiar Velocity Reconstruction From Simulations and Observations Using Deep Learning Algorithms

Yuyu Wang, Xiaohu Yang

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

In this paper, we introduce a Unet model of deep learning algorithms for reconstructions of the 3D peculiar velocity field, which simplifies the reconstruction process with enhanced precision. We test the adaptability of the Unet model with simulation data under more realistic conditions, including the redshift space distortion (RSD) effect and halo mass threshold. Our results show that the Unet model outperforms the analytical method that runs under ideal conditions, with a 16% improvement in precision, 13% in residuals, 18% in correlation coefficient and 27% in average coherence. The deep learning algorithm exhibits exceptional capacities to capture velocity features in non-linear regions and substantially improve reconstruction precision in boundary regions. We then apply the Unet model trained under SDSS observational conditions to the SDSS DR7 data for observational 3D peculiar velocity reconstructions.

[12] arXiv:2406.14542 [pdf, html, other]

Title: $\texttt{cunuSHT}$: GPU Accelerated Spherical Harmonic Transforms on Arbitrary Pixelizations

Sebastian Belkner, Adriaan J. Duivenvoorden, Julien Carron, Nathanael Schaeffer, Martin Reinecke

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

We present $\texttt{cunusht}$, a general-purpose Python package that wraps a highly efficient CUDA implementation of the nonuniform spin-$0$ spherical harmonic transform. The method is applicable to arbitrary pixelization schemes, including schemes constructed from equally-spaced iso-latitude rings as well as completely nonuniform ones. The algorithm has an asymptotic scaling of $\mathrm{O}{(\ell_{\rm max}^3)}$ for maximum multipole $\ell_{\rm max}$ and achieves machine precision accuracy. While $\texttt{cunusht}$ is developed for applications in cosmology in mind, it is applicable to various other interpolation problems on the sphere. We outperform the fastest available CPU algorithm by a factor of up to 5 for problems with a nonuniform pixelization and $\ell_{\rm max}>4\cdot10^3$ when comparing a single modern GPU to a modern 32-core CPU. This performance is achieved by utilizing the double Fourier sphere method in combination with the nonuniform fast Fourier transform and by avoiding transfers between the host and device. For scenarios without GPU availability, $\texttt{cunusht}$ wraps existing CPU libraries. $\texttt{cunusht}$ is publicly available and includes tests, documentation, and demonstrations.

Cross submissions for Friday, 21 June 2024 (showing 12 of 12 entries )

[13] arXiv:2406.13037 (cross-list from astro-ph.EP) [pdf, html, other]

Title: Large Interferometer For Exoplanets (LIFE): XIII. The Value of Combining Thermal Emission and Reflected Light for the Characterization of Earth Twins

E. Alei, S. P. Quanz, B. S. Konrad, E. O. Garvin, V. Kofman, A. Mandell, D. Angerhausen, P. Mollière, M. R. Meyer, T. Robinson, S. Rugheimer, the LIFE Collaboration

Comments: 16 pages (main text, incl. 12 figures) + appendix; accepted for publication in A&A (current version: post 1st revision). Thirteenth paper of LIFE telescope series

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Following the recommendations to NASA and ESA, the search for life on exoplanets will be a priority in the next decades. Two direct imaging space mission concepts are being developed: the Habitable Worlds Observatory (HWO) and the Large Interferometer for Exoplanets (LIFE). HWO focuses on reflected light spectra in the ultraviolet/visible/near-infrared (UV/VIS/NIR), while LIFE captures the mid-infrared (MIR) emission of temperate exoplanets. We assess the potential of HWO and LIFE in characterizing a cloud-free Earth twin orbiting a Sun-like star at 10 pc, both separately and synergistically, aiming to quantify the increase in information from joint atmospheric retrievals on a habitable planet. We perform Bayesian retrievals on simulated data from an HWO-like and a LIFE-like mission separately, then jointly, considering the baseline spectral resolutions currently assumed for these concepts and using two increasingly complex noise simulations. HWO would constrain H$_2$O, O$_2$, and O$_3$, in the atmosphere, with ~ 100 K uncertainty on the temperature profile. LIFE would constrain CO$_2$, H$_2$O, O$_3$ and provide constraints on the thermal atmospheric structure and surface temperature (~ 10 K uncertainty). Both missions would provide an upper limit on CH$_4$. Joint retrievals on HWO and LIFE data would accurately define the atmospheric thermal profile and planetary parameters, decisively constrain CO$_2$, H$_2$O, O$_2$, and O$_3$, and weakly constrain CO and CH$_4$. The detection significance is greater or equal to single-instrument retrievals. Both missions provide specific information to characterize a terrestrial habitable exoplanet, but the scientific yield is maximized with synergistic UV/VIS/NIR+MIR observations. Using HWO and LIFE together will provide stronger constraints on biosignatures and life indicators, potentially transforming the search for life in the universe.

[14] arXiv:2406.13463 (cross-list from astro-ph.HE) [pdf, html, other]

Title: Exploring pulsar timing precision: A comparative study of polarization calibration methods for NANOGrav data from the Green Bank Telescope

Lankeswar Dey, Maura A. McLaughlin, Haley M. Wahl, Paul B. Demorest, Zaven Arzoumanian, Harsha Blumer, Paul R. Brook, Sarah Burke-Spolaor, H. Thankful Cromartie, Megan E. DeCesar, Timothy Dolch, Justin A. Ellis, Robert D. Ferdman, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Ross J. Jennings, Megan L. Jones, Michael T. Lam, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Cherry Ng, David J. Nice, Timothy T. Pennucci, Nihan S. Pol, Scott M. Ransom, Renée Spiewak, Ingrid H. Stairs, Kevin Stovall, Joseph K. Swiggum

Comments: 21 pages, 6 figures, 1 table, submitted to Astrophysical Journal

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Pulsar timing array experiments have recently uncovered evidence for a nanohertz gravitational wave background by precisely timing an ensemble of millisecond pulsars. The next significant milestones for these experiments include characterizing the detected background with greater precision, identifying its source(s), and detecting continuous gravitational waves from individual supermassive black hole binaries. To achieve these objectives, generating accurate and precise times of arrival of pulses from pulsar observations is crucial. Incorrect polarization calibration of the observed pulsar profiles may introduce errors in the measured times of arrival. Further, previous studies (e.g., van Straten 2013; Manchester et al. 2013) have demonstrated that robust polarization calibration of pulsar profiles can reduce noise in the pulsar timing data and improve timing solutions. In this paper, we investigate and compare the impact of different polarization calibration methods on pulsar timing precision using three distinct calibration techniques: the Ideal Feed Assumption (IFA), Measurement Equation Modeling (MEM), and Measurement Equation Template Matching (METM). Three NANOGrav pulsars-PSRs J1643$-$1224, J1744$-$1134, and J1909$-$3744-observed with the 800 MHz and 1.5 GHz receivers at the Green Bank Telescope (GBT) are utilized for our analysis. Our findings reveal that all three calibration methods enhance timing precision compared to scenarios where no polarization calibration is performed. Additionally, among the three calibration methods, the IFA approach generally provides the best results for timing analysis of pulsars observed with the GBT receiver system. We attribute the comparatively poorer performance of the MEM and METM methods to potential instabilities in the reference noise diode coupled to the receiver and temporal variations in the profile of the reference pulsar, respectively.

[15] arXiv:2406.13638 (cross-list from physics.data-an) [pdf, html, other]

Title: XENONnT WIMP Search: Signal & Background Modeling and Statistical Inference

XENON Collaboration: E. Aprile, J. Aalbers, K. Abe, S. Ahmed Maouloud, L. Althueser, B. Andrieu, E. Angelino, D. Antón Martin, F. Arneodo, L. Baudis, M. Bazyk, L. Bellagamba, R. Biondi, A. Bismark, K. Boese, A. Brown, G. Bruno, R. Budnik, J. M. R. Cardoso, A. P. Cimental Chávez, A. P. Colijn, J. Conrad, J. J. Cuenca-García, V. D'Andrea, L. C. Daniel Garcia, M. P. Decowski, C. Di Donato, P. Di Gangi, S. Diglio, K. Eitel, A. Elykov, A. D. Ferella, C. Ferrari, H. Fischer, T. Flehmke, M. Flierman, W. Fulgione, C. Fuselli, P. Gaemers, R. Gaior, M. Galloway, F. Gao, S. Ghosh, R. Giacomobono, R. Glade-Beucke, L. Grandi, J. Grigat, H. Guan, M. Guida, P. Gyoergy, R. Hammann, A. Higuera, C. Hils, L. Hoetzsch, N. F. Hood, M. Iacovacci, Y. Itow, J. Jakob, F. Joerg, Y. Kaminaga, M. Kara, P. Kavrigin, S. Kazama, M. Kobayashi, A. Kopec, F. Kuger, H. Landsman, R. F. Lang, L. Levinson, I. Li, S. Li, S. Liang, Y.-T. Lin, S. Lindemann, M. Lindner, K. Liu, J. Loizeau, F. Lombardi, J. Long, J. A. M. Lopes, T. Luce, Y. Ma, C. Macolino, J. Mahlstedt, A. Mancuso, L. Manenti, F. Marignetti, T. Marrodán Undagoitia, K. Martens, J. Masbou, E. Masson, S. Mastroianni, A. Melchiorre, M. Messina, A. Michael, K. Miuchi, A. Molinario, S. Moriyama, K. Morå

Comments: 20 pages, 10 figures

Subjects: Data Analysis, Statistics and Probability (physics.data-an); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)

The XENONnT experiment searches for weakly-interacting massive particle (WIMP) dark matter scattering off a xenon nucleus. In particular, XENONnT uses a dual-phase time projection chamber with a 5.9-tonne liquid xenon target, detecting both scintillation and ionization signals to reconstruct the energy, position, and type of recoil. A blind search for nuclear recoil WIMPs with an exposure of 1.1 tonne-years yielded no signal excess over background expectations, from which competitive exclusion limits were derived on WIMP-nucleon elastic scatter cross sections, for WIMP masses ranging from 6 GeV/$c^2$ up to the TeV/$c^2$ scale. This work details the modeling and statistical methods employed in this search. By means of calibration data, we model the detector response, which is then used to derive background and signal models. The construction and validation of these models is discussed, alongside additional purely data-driven backgrounds. We also describe the statistical inference framework, including the definition of the likelihood function and the construction of confidence intervals.

[16] arXiv:2406.13697 (cross-list from astro-ph.EP) [pdf, html, other]

Title: Detection of Moving Objects in Earth Observation Satellite Images: Verification

Eric Keto, Wesley Andres Watters

Comments: Submitted to the Journal of Astronomical Instrumentation

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

In multi-spectral images made by Earth observation satellites that use push-broom scanning, such as those operated by Planet Labs Corp., moving objects can be identified by the appearance of the object at a different locations in each spectral band. The apparent velocity can be measured if the relative acquisition time between images in different spectral bands is known to millisecond accuracy. The images in the Planet Labs archive are mosaics of individual exposures acquired at different times. Thus there is not a unique acquisition time for each spectral band. In an earlier paper, we proposed a method to determine the relative acquisition times from the information in the images themselves. High altitude balloons provide excellent targets to test our proposed method because of their high apparent velocity due to the orbital velocity of the satellite and geometric parallax in images aligned to the level of the ground. We use images of the Chinese balloon that crossed the US in February, 2024 as well as images of an identical balloon over Colombia to test our method. Our proposed method appears to be successful and allows the measurement of the apparent velocity of moving objects from the information available in the archive.

[17] arXiv:2406.13710 (cross-list from astro-ph.EP) [pdf, html, other]

Title: Velocity Analysis of Moving Objects in Earth Observation Satellite Images Using Multi-Spectral Push Broom Scanning

Eric Keto, Wesley Andres Watters

Comments: Submitted to Remote Sensing

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

In this study, we present a method for detecting and analyzing the velocities of moving objects in Earth observation satellite images, specifically using data from Planet Labs' push broom scanning satellites. By exploiting the sequential acquisition of multi-spectral images, we estimate the relative differences in acquisition times between spectral bands. This allows us to determine the velocities of moving objects, such as aircraft, even without precise timestamp information from the image archive. We validate our method by comparing the velocities of aircraft observed in satellite images with those reported by onboard ADS-B transponders. The results demonstrate the potential, despite challenges posed by proprietary data limitations, of a new, useful application of commercial satellite data originally intended as an ongoing, once-daily survey of single images covering the entire land-area of the Earth. Our approach extends the applicability of satellite survey imagery for dynamic object tracking and contributes to the broader use of commercial satellite data in scientific research.

[18] arXiv:2406.13959 (cross-list from physics.optics) [pdf, html, other]

Title: Multifrequency-resolved Hanbury Brown-Twiss Effect

Joseph Ferrantini, Jesse Crawford, Sergei Kulkov, Jakub Jirsa, Aaron Mueninghoff, Lucas Lawrence, Stephen Vintskevich, Tommaso Milanese, Samuel Burri, Ermanno Bernasconi, Claudio Bruschini, Michal Marcisovsky, Peter Svihra, Andrei Nomerotski, Paul Stankus, Edoardo Charbon, Raphael A. Abrahao

Subjects: Optics (physics.optics); Instrumentation and Methods for Astrophysics (astro-ph.IM); Quantum Physics (quant-ph)

The Hanbury Brown-Twiss (HBT) effect holds a pivotal place in intensity interferometry and gave a seminal contribution to the development of quantum optics. To observe such an effect, both good spectral and timing resolutions are necessary. Most often, the HBT effect is observed for a single frequency at a time, due to limitations in dealing with multifrequencies simultaneously, halting and limiting some applications. Here, we report a fast and data-driven spectrometer built with a one-dimensional array of single-photon-sensitive avalanche diodes. We report observing the HBT effect for multifrequencies at the same time. Specifically, we observed the HBT for up to 5 lines of the Ne spectrum, but this can be improved even further. Our work represents a major step to make spectral binning and multifrequencies HBT more widely available. The technology we present can benefit both classical and quantum applications.

[19] arXiv:2406.14173 (cross-list from gr-qc) [pdf, html, other]

Title: Time-Delay Interferometry for ASTROD-GW

Gang Wang

Comments: This master's thesis was originally written in Chinese and submitted in 2011. This version is quickly translated with the assistance of ChatGPT. In Chapter 7, a second-generation TDI bank was developed, and some of the TDI observables are related to recent works (arXiv:2403.01490 and arXiv:2406.11305). Comments and feedback are welcome

Subjects: General Relativity and Quantum Cosmology (gr-qc); Instrumentation and Methods for Astrophysics (astro-ph.IM)

In the detection of gravitational waves in space, the arm lengths between spacecraft are not equal due to their orbital motion. Consequently, the equal arm length Michelson interferometer used in Earth laboratories is not suitable for space. To achieve the necessary sensitivity for space gravitational wave detectors, laser frequency noise must be suppressed below secondary noise sources such as optical path noise and acceleration noise. To suppress laser frequency noise, time-delay interferometry (TDI) is employed to match the two optical paths and retain gravitational wave signals. Since planets and other solar system bodies perturb the orbits of spacecraft and affect TDI performance, we simulate the time delay numerically using the CGC2.7 ephemeris framework. To examine the feasibility of TDI for the ASTROD-GW mission, we devised a set of 10-year and a set of 20-year optimized mission orbits for the three spacecraft starting on June 21, 2028, and calculated the path mismatches in the first- and second-generation TDI channels. The results demonstrate that all second-generation TDI channels meet the ASTROD-GW requirements. A geometric approach is used in the analysis and synthesis of both first-generation and second-generation TDI to clearly illustrate the construction process.

[20] arXiv:2406.14268 (cross-list from astro-ph.HE) [pdf, html, other]

Title: A hierarchical Bayesian approach to point source analysis in high-energy neutrino telescopes

F. Capel, J. Kuhlmann, C. Haack, M. Ha Minh, H. Niederhausen, L. Schumacher

Comments: Submitted to ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

We propose a novel approach to the detection of point-like sources of high-energy neutrinos. Motivated by evidence for emerging sources in existing data, we focus on the characterisation and interpretation of these sources. The hierarchical Bayesian model is implemented in the Stan platform, enabling computation of the posterior distribution with Hamiltonian Monte Carlo. We simulate a population of weak neutrino sources detected by the IceCube experiment and use the resulting data set to demonstrate and validate our framework. We show that even for the challenging case of sources at the threshold of detection and using limited prior information, it is possible to correctly infer the source properties. Additionally, we demonstrate how modelling flexible connections between similar sources can be used to recover the contribution of sources that would not be detectable individually, going beyond what is possible with existing stacking methods.

[21] arXiv:2406.14291 (cross-list from gr-qc) [pdf, html, other]

Title: Post-Newtonian expansions of extreme mass ratio inspirals of spinning bodies into Schwarzschild black holes

Viktor Skoupý, Vojtěch Witzany

Comments: 22 pages, 8 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Space-based gravitational-wave detectors such as LISA are expected to detect inspirals of stellar-mass compact objects into massive black holes. Modeling such inspirals requires fully relativistic computations to achieve sufficient accuracy at leading order. However, subleading corrections such as the effects of the spin of the inspiraling compact object may potentially be treated in weak-field expansions such as the post-Newtonian (PN) approach.
In this work, we calculate the PN expansion of eccentric orbits of spinning bodies around Schwarzschild black holes. Then we use the Teukolsky equation to compute the energy and angular momentum fluxes from these orbits up to the 5PN order. Some of these PN orders are exact in eccentricity, while others are expanded up to the tenth power in eccentricity. Then we use the fluxes to construct a hybrid inspiral model, where the leading part of the fluxes is calculated numerically in the fully relativistic regime, while the part linear in the small spin is analytically approximated using the PN series. We calculate LISA-relevant inspirals and respective waveforms with this model and a fully relativistic model. Through the calculation of mismatch between the waveforms from both models we conclude that the PN approximation of the linear-in-spin part of the fluxes is sufficient for lower eccentricities.

[22] arXiv:2406.14297 (cross-list from cs.AI) [pdf, html, other]

Title: AI in Space for Scientific Missions: Strategies for Minimizing Neural-Network Model Upload

Jonah Ekelund, Ricardo Vinuesa, Yuri Khotyaintsev, Pierre Henri, Gian Luca Delzanno, Stefano Markidis

Subjects: Artificial Intelligence (cs.AI); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Artificial Intelligence (AI) has the potential to revolutionize space exploration by delegating several spacecraft decisions to an onboard AI instead of relying on ground control and predefined procedures. It is likely that there will be an AI/ML Processing Unit onboard the spacecraft running an inference engine. The neural-network will have pre-installed parameters that can be updated onboard by uploading, by telecommands, parameters obtained by training on the ground. However, satellite uplinks have limited bandwidth and transmissions can be costly. Furthermore, a mission operating with a suboptimal neural network will miss out on valuable scientific data. Smaller networks can thereby decrease the uplink cost, while increasing the value of the scientific data that is downloaded. In this work, we evaluate and discuss the use of reduced-precision and bare-minimum neural networks to reduce the time for upload. As an example of an AI use case, we focus on the NASA's Magnetosperic MultiScale (MMS) mission. We show how an AI onboard could be used in the Earth's magnetosphere to classify data to selectively downlink higher value data or to recognize a region-of-interest to trigger a burst-mode, collecting data at a high-rate. Using a simple filtering scheme and algorithm, we show how the start and end of a region-of-interest can be detected in on a stream of classifications. To provide the classifications, we use an established Convolutional Neural Network (CNN) trained to an accuracy >94%. We also show how the network can be reduced to a single linear layer and trained to the same accuracy as the established CNN. Thereby, reducing the overall size of the model by up to 98.9%. We further show how each network can be reduced by up to 75% of its original size, by using lower-precision formats to represent the network parameters, with a change in accuracy of less than 0.6 percentage points.

[23] arXiv:2406.14444 (cross-list from astro-ph.EP) [pdf, html, other]

Title: Combining reference-star and angular differential imaging for high-contrast imaging of extended sources

Sandrine Juillard, Sophia Stasevic, Valentin Christiaens, Olivier Absil, Julien Milli

Comments: 21 pages, 18 figures, Accepted to A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

High-contrast imaging (HCI) is a technique designed to observe faint signals near bright sources, such as exoplanets and circumstellar disks. The primary challenge in revealing the faint circumstellar signal near a star is the presence of quasi-static speckles, which can produce patterns on the science images that are as bright, or even brighter, than the signal of interest. Strategies such as angular differential imaging (ADI) or reference-star differential imaging (RDI) aim to provide a means of removing the quasi-static speckles in post-processing. In this paper, we present and discuss the adaptation of state-of-the-art algorithms, initially designed for ADI, to jointly leverage angular and reference-star differential imaging (ARDI) for direct high-contrast imaging of circumstellar disks. Using a collection of high-contrast imaging data sets, we assess the performance of ARDI in comparison to ADI and RDI based on iterative principal component analysis (IPCA). These diverse data sets are acquired under various observing conditions and include the injection of synthetic disk models at various contrast levels. Our results demonstrate that ARDI with IPCA improves the quality of recovered disk images and the sensitivity to planets embedded in disks, compared to ADI or RDI individually. This enhancement is particularly pronounced when dealing with extended sources exhibiting highly ambiguous structures that cannot be accurately retrieved using ADI alone, and when the quality of the reference frames is suboptimal, leading to an underperformance of RDI. We finally apply our method to a sample of real observations of protoplanetary disks taken in star-hopping mode, and propose to revisit the protoplanetary claims associated with these disks.

[24] arXiv:2406.14531 (cross-list from astro-ph.EP) [pdf, html, other]

Title: Roman FFP Revolution: Two, Three, Many Plutos

Andrew Gould (OSU, MPIA), Jennifer C. Yee (CfA), Subo Dong (PKU, Kavli)

Comments: 46 pages, 4 figures

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Roman microlensing stands at a crossroads between its originally charted path of cataloging a population of cool planets that has subsequently become well-measured down to super-Earths, and the path of free-floating planets (FFPs), which did not exist when Roman was chosen in 2010, but by now promises revolutionary insights into planet formation and evolution via their possible connection to a spectrum of objects spanning 18 decades in mass. Until now, it was not even realized that the 2 paths are in conflict: Roman strategy was optimized for bound-planet detections, and FFPs were considered only in the context of what could be learned about them given this strategy. We derive a simple equation that mathematically expresses this conflict and explains why the current approach severely depresses detection of 2 of the 5 decades of potential FFP masses, i.e., exactly the two decades, $M_{\rm Pluto}< M <2\,M_{\rm Mars}$, that would tie terrestrial planets to the proto-planetary material out of which they formed. FFPs can be either truly free floating or can be bound in "Wide", "Kuiper", and "Oort" orbits, whose separate identification will allow further insight into planet formation. In the (low-mass) limit that the source radius is much bigger than the Einstein radius, $\theta_*\gg\theta_{\rm E}$, the number of significantly magnified points on the FFP light curve is $N=2\Gamma\theta_*\sqrt{1-z^2}/\mu$ --> 3.0, when normalized to the adopted Roman cadence $\Gamma=4/$hr, and to source radius $\theta_*=0.3\,\mu$as, lens-source proper motion $\mu=6\,$mas/yr, and source impact parameter $z=0.5$, which are all typical values. By contrast $N=6$ are needed for an FFP detection. Thus, unless $\Gamma$ is doubled, FFP detection will be driven into the (large-$\theta_*$, small-$\mu$) corner of parameter space, reducing the detections by a net factor of 2 and cutting off the lowest-mass FFPs.

Replacement submissions for Friday, 21 June 2024 (showing 11 of 11 entries )

[25] arXiv:2306.15728 (replaced) [pdf, html, other]

Title: Physics-inspired spatiotemporal-graph AI ensemble for the detection of higher order wave mode signals of spinning binary black hole mergers

Minyang Tian, E.A. Huerta, Huihuo Zheng, Prayush Kumar

Comments: 14 pages, 6 figures, and 3 tables

Journal-ref: Mach. Learn.: Sci. Technol. 5 025056 (2024) Mach. Learn.: Sci. Technol. 5 025056 Mach. Learn.: Sci. Technol. 5 025056

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Artificial Intelligence (cs.AI); General Relativity and Quantum Cosmology (gr-qc)

We present a new class of AI models for the detection of quasi-circular, spinning, non-precessing binary black hole mergers whose waveforms include the higher order gravitational wave modes $(l, |m|)=\{(2, 2), (2, 1), (3, 3), (3, 2), (4, 4)\}$, and mode mixing effects in the $l = 3, |m| = 2$ harmonics. These AI models combine hybrid dilated convolution neural networks to accurately model both short- and long-range temporal sequential information of gravitational waves; and graph neural networks to capture spatial correlations among gravitational wave observatories to consistently describe and identify the presence of a signal in a three detector network encompassing the Advanced LIGO and Virgo detectors. We first trained these spatiotemporal-graph AI models using synthetic noise, using 1.2 million modeled waveforms to densely sample this signal manifold, within 1.7 hours using 256 A100 GPUs in the Polaris supercomputer at the ALCF. Our distributed training approach had optimal performance, and strong scaling up to 512 A100 GPUs. With these AI ensembles we processed data from a three detector network, and found that an ensemble of 4 AI models achieves state-of-the-art performance for signal detection, and reports two misclassifications for every decade of searched data. We distributed AI inference over 128 GPUs in the Polaris supercomputer and 128 nodes in the Theta supercomputer, and completed the processing of a decade of gravitational wave data from a three detector network within 3.5 hours. Finally, we fine-tuned these AI ensembles to process the entire month of February 2020, which is part of the O3b LIGO/Virgo observation run, and found 6 gravitational waves, concurrently identified in Advanced LIGO and Advanced Virgo data, and zero false positives. This analysis was completed in one hour using one A100 GPU.

[26] arXiv:2401.11625 (replaced) [pdf, html, other]

Title: Efficient PSF Modeling with ShOpt.jl: A PSF Benchmarking Study with JWST NIRCam Imaging

Edward Berman, Jacqueline McCleary, Anton M. Koekemoer, Maximilien Franco, Nicole E. Drakos, Daizhong Liu, James W. Nightingale, Marko Shuntov, Diana Scognamiglio, Richard Massey, Guillaume Mahler, Henry Joy McCracken, Brant E. Robertson, Andreas L. Faisst, Caitlin M. Casey, Jeyhan S. Kartaltepe

Comments: 53 pages, 27 figures, submitted to Astronomical Journal. Same as v2 with a corrected typo, which contained revisions from v1

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

With their high angular resolutions of 30--100 mas, large fields of view, and complex optical systems, imagers on next-generation optical/near-infrared space observatories, such as the Near-Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST), present both new opportunities for science and also new challenges for empirical point spread function (PSF) characterization. In this context, we introduce ShOpt, a new PSF fitting tool developed in Julia and designed to bridge the advanced features of PIFF (PSFs in the Full Field of View) with the computational efficiency of PSFEx (PSF Extractor). Along with ShOpt, we propose a suite of non-parametric statistics suitable for evaluating PSF fit quality in space-based imaging. Our study benchmarks ShOpt against the established PSF fitters PSFEx and PIFF using real and simulated COSMOS-Web Survey imaging. We assess their respective PSF model fidelity with our proposed diagnostic statistics and investigate their computational efficiencies, focusing on their processing speed relative to the complexity and size of the PSF models. We find that ShOpt can already achieve PSF model fidelity comparable to PSFEx and PIFF while maintaining competitive processing speeds, constructing PSF models for large NIRCam mosaics within minutes.

[27] arXiv:2404.17311 (replaced) [pdf, html, other]

Title: Energy Recovery System for Large Telescopes

Aleksej Kiselev, Matthias Reichert, Tony Mroczkowski

Comments: 9 pages, 8 figures; Submitted to as an SPIE Proceedings paper for the 2024 SPIE Astronomical Telescopes + Instrumentation meeting

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

In this paper, a kinetic energy recovery system for large telescopes is presented, with the Atacama Large Aperture Submm Telescope (AtLAST) as a possible target application. The system consists of supercapacitors integrated in the DC-link of motor inverters through a bidirectional DC-DC converter. The optimal system design, based on the energy flow analysis within the telescope's power electronics, is introduced. The proposed system is simulated as part of the telescope's drives, providing not only a significant reduction in energy consumption of the telescope due to motion, but also remarkably reducing (or shaving) grid power peaks. We find that the system presented here can contribute to making both current and future observatories more sustainable.

[28] arXiv:2404.19589 (replaced) [pdf, html, other]

Title: Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade

R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J.M. Alameddine, N. M. Amin, K. Andeen, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, S. Bash, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, E. Blaufuss, L. Bloom, S. Blot, F. Bontempo, J. Y. Book Motzkin, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, J. Braun, B. Brinson, J. Brostean-Kaiser, L. Brusa, R. T. Burley, D. Butterfield, M. A. Campana, I. Caracas, K. Carloni, J. Carpio, S. Chattopadhyay, N. Chau, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, R. Corley, P. Correa, D. F. Cowen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado, S. Deng, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, P. Dierichs, M. Dittmer, A. Domi, L. Draper, H. Dujmovic, K. Dutta, M. A. DuVernois, T. Ehrhardt, L. Eidenschink, A. Eimer, P. Eller, E. Ellinger, S. El Mentawi, D. Elsässer, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster

Comments: 24 pages, 19 figures, 2 tables, submitted to JINST

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)

More than 10,000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests.

[29] arXiv:2405.01977 (replaced) [pdf, html, other]

Title: PINT: Maximum-likelihood estimation of pulsar timing noise parameters

Abhimanyu Susobhanan, David Kaplan, Anne Archibald, Jing Luo, Paul Ray, Timothy Pennucci, Scott Ransom, Gabriella Agazie, William Fiore, Bjorn Larsen, Patrick O'Neill, Rutger van Haasteren, Akash Anumarlapudi, Matteo Bachetti, Deven Bhakta, Chloe Champagne, H. Thankful Cromartie, Paul Demorest, Ross Jennings, Matthew Kerr, Sasha Levina, Alexander McEwen, Brent Shapiro-Albert, Joseph Swiggum

Comments: Accepted for publication in ApJ

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE)

PINT is a pure-Python framework for high-precision pulsar timing developed on top of widely used and well-tested Python libraries, supporting both interactive and programmatic data analysis workflows. We present a new frequentist framework within PINT to characterize the single-pulsar noise processes present in pulsar timing datasets. This framework enables the parameter estimation for both uncorrelated and correlated noise processes as well as the model comparison between different timing and noise models in a computationally inexpensive way. We demonstrate the efficacy of the new framework by applying it to simulated datasets as well as a real dataset of PSR B1855+09. We also describe the new features implemented in PINT since it was first described in the literature.

[30] arXiv:2012.13946 (replaced) [pdf, html, other]

Title: Broadband Dark Matter Axion Detection using a Cylindrical Capacitor

Wenming Chen, Yu Gao, Qiaoli Yang

Comments: 9 pages, 9 figures, 2 tables; matches published version

Journal-ref: Nucl. Phys. B 1005 (2024) 116602

Subjects: High Energy Physics - Phenomenology (hep-ph); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex)

Cosmological axions/axion-like particles can compose a significant part of dark matter; however, the uncertainty of their mass is large. Here, we propose to search the axions using a cylindrical capacitor, in which the static electric field converts dark matter axions into an oscillating magnetic field. Due to the odd CPs, the axions couple to the electric field differently compared to the magnetic field. The axion couples to the electric field via a derivative that carries spatial information of incoming dark matter flux, while the coupling to the magnetic field depends on the dark matter density. This difference could be helpful in searching the axions and studies of the integrity of the theory, especially when the axions are very light, in which case the magnetic field-induced signal is DC-like. Orientation dependence could also be used to reduce the kinetic fluctuation-induced noise when multiple detectors operate simultaneously. In addition, a cylindrical setup shields the electric field to the laboratory and encompasses the axion-induced magnetic field within the capacitor. The induced oscillating magnetic field can then be picked up by a sensitive magnetometer. Adding a superconductor ring-coil system into the scheme can further boost the sensitivity and maintain the axion dark matter inherent bandwidth. This proposed setup could be capable of wide mass range searches.

[31] arXiv:2311.14987 (replaced) [pdf, other]

Title: Reconstruction of a Long-term spatially Contiguous Solar-Induced Fluorescence (LCSIF) over 1982-2022

Jianing Fang, Xu Lian, Youngryel Ryu, Sungchan Jeong, Chongya Jiang, Pierre Gentine

Subjects: Geophysics (physics.geo-ph); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Satellite-observed solar-induced chlorophyll fluorescence (SIF) is a powerful proxy for diagnosing the photosynthetic characteristics of terrestrial ecosystems. Despite the increasing spatial and temporal resolutions of these satellite retrievals, records of SIF are primarily limited to the recent decade, impeding their application in detecting long-term dynamics of ecosystem function and structure. In this study, we leverage the two surface reflectance bands (red and near-infrared) available both from Advanced Very High-Resolution Radiometer (AVHRR, 1982-2022) and MODerate-resolution Imaging Spectroradiometer (MODIS, 2001-2022). Importantly, we calibrate and orbit-correct the AVHRR bands against their MODIS counterparts during their overlapping period. Using the long-term bias-corrected reflectance data, a neural network is then built to reproduce the Orbiting Carbon Observatory-2 SIF using AVHRR and MODIS, and used to map SIF globally over the entire 1982-2022 period. Compared with the previous MODIS-based CSIF product relying on four reflectance bands, our two-band-based product has similar skill but can be advantageously extended to the bias-corrected AVHRR period. Further comparison with three widely used vegetation indices (NDVI, kNDVI, NIRv; all based empirically on red and near-infrared bands) shows a higher or comparable correlation of LCSIF with satellite SIF and site-level GPP estimates across vegetation types, ensuring a greater capacity of LCSIF for representing terrestrial photosynthesis. Globally, LCSIF-AVHRR shows an accelerating upward trend since 1982, with an average rate of 0.0025 mW m-2 nm-1 sr-1 per decade during 1982-2000 and 0.0038 mW m-2 nm-1 sr-1 per decade during 2001-2022. Our LCSIF data provide opportunities to better understand the long-term dynamics of ecosystem photosynthesis and their underlying driving processes.

[32] arXiv:2401.16142 (replaced) [pdf, html, other]

Title: Stellar Evolution in Real Time II: R Hydrae and an Open-Source Grid of >3000 Seismic TP-AGB Models Computed with MESA

Meridith Joyce, László Molnár, Giulia Cinquegrana, Amanda Karakas, Jamie Tayar, Dóra Tarczay-Nehéz

Comments: accepted to ApJ March 2024. Final revisions complete. Github repository associated to this project: this https URL All grids available on Zenodo: this https URL There are FOUR Zenodo DOIs associated to this project, the first of which is above

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Instrumentation and Methods for Astrophysics (astro-ph.IM)

We present a comprehensive characterization of the evolved thermally pulsing asymptotic giant branch (TP-AGB) star R Hydrae, building on the techniques applied in Stellar Evolution in Real Time I (Molnár et al. 2019) to T Ursae Minoris. We compute over 3000 theoretical TP-AGB pulse spectra using MESA and GYRE and combine these with classical observational constraints and nearly 400 years of measurements of R Hya's period evolution to fit R Hya's evolutionary and asteroseismic features. Two hypotheses for the mode driving R Hya's period are considered. Solutions that identify this as the fundamental mode (FM) as well as the first overtone (O1) are consistent with observations. Using a variety of statistical tests, we find that R Hya is most likely driven by the FM and currently occupies the ``power down'' phase of an intermediate pulse (TP ~ 9-16). We predict that its pulsation period will continue to shorten for millennia. Using supplementary calculations from the Monash stellar evolution code, we also find that R Hya is likely to have undergone third dredge-up in its most recent pulse. The MESA+GYRE model grid used in this analysis includes exact solutions to the adiabatic equations of stellar oscillation for the first 10 radial-order pressure modes for every time step in every evolutionary track. The grid is fully open-source and packaged with a data visualization application. This is the first publicly available grid of TP-AGB models with seismology produced with MESA.

[33] arXiv:2403.08546 (replaced) [pdf, html, other]

Title: Semantic Segmentation of Solar Radio Spikes at Low Frequencies

Pearse C. Murphy, Stéphane Aicardi, Baptiste Cecconi, Carine Briand, Thibault Peccoux

Comments: 7 pages, 7 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Solar radio spikes are short lived, narrow bandwidth features in low frequency solar radio observations. The timing of their occurrence and the number of spikes in a given observation is often unpredictable. The high temporal and frequency of resolution of modern radio telescopes such as NenuFAR mean that manually identifying radio spikes is an arduous task. Machine learning approaches to data exploration in solar radio data is on the rise. Here we describe a convolutional neural network to identify the per pixel location of radio spikes as well as determine some simple characteristics of duration, spectral width and drift rate. The model, which we call SpikeNet, was trained using an Nvidia Tesla T4 16GB GPU with ~100000 sample spikes in a total time of 2.2 hours. The segmentation performs well with an intersection over union in the test set of ~0.85. The root mean squared error for predicted spike properties is of the order of 23%. Applying the algorithm to unlabelled data successfully generates segmentation masks although the accuracy of the predicted properties is less reliable, particularly when more than one spike is present in the same 64 X 64 pixel time-frequency range. We have successfully demonstrated that our convolutional neural network can locate and characterise solar radio spikes in a number of seconds compared to the weeks it would take for manual identification.

[34] arXiv:2404.15405 (replaced) [pdf, html, other]

Title: Photometry of Saturated Stars with Neural Networks

Dominik Winecki (1)Christopher S. Kochanek (2) ((1) Dept. of Computer Science and Engineeering, The Ohio State University (2) Dept. of Astronomy, The Ohio State University)

Comments: accepted by ApJ

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Instrumentation and Methods for Astrophysics (astro-ph.IM); Computer Vision and Pattern Recognition (cs.CV)

We use a multilevel perceptron (MLP) neural network to obtain photometry of saturated stars in the All-Sky Automated Survey for Supernovae (ASAS-SN). The MLP can obtain fairly unbiased photometry for stars from g~4 to 14~mag, particularly compared to the dispersion (15%-85% 1sigma range around the median) of 0.12 mag for saturated (g<11.5 mag) stars. More importantly, the light curve of a non-variable saturated star has a median dispersion of only 0.037 mag. The MLP light curves are, in many cases, spectacularly better than those provided by the standard ASAS-SN pipelines. While the network was trained on g band data from only one of ASAS-SN's 20 cameras, initial experiments suggest that it can be used for any camera and the older ASAS-SN V band data as well. The dominant problems seem to be associated with correctable issues in the ASAS-SN data reduction pipeline for saturated stars more than the MLP itself. The method is publicly available as a light curve option on ASAS-SN Sky Patrol v1.0.

[35] arXiv:2406.12379 (replaced) [pdf, html, other]

Title: The projected sensitivity of SCEP experiment to Magnetic Monopole

Changqing Ye, Beige Liu, Zhe Cao, Lingzhi Han, Xinming Huang, Min Jiang, Dong Liu, Qing Lin, Shitian Wan, Yusheng Wu, Lei Zhao, Yue Zhang, Xinhua Peng, Zhengguo Zhao

Subjects: High Energy Physics - Experiment (hep-ex); Instrumentation and Methods for Astrophysics (astro-ph.IM)

The investigation of beyond-Standard-Model particles is a compelling direction in the pursuit of new physics. One such hypothetical particle, the magnetic monopole, has garnered considerable attention due to its strong theoretical motivation and potential to unveil profound physical phenomena. The magnetic monopole is intricately linked to the long-standing enigma surrounding the quantization of electric charge. In this manuscript, we propose a novel detection scenario for magnetic monopoles by employing a coincidence measurement technique that combines a room-temperature magnetometer with plastic scintillators. This setup allows for the collection of both the induction and scintillation signals generated by the passage of a monopole. The estimation of the sensitivity using a simple benchmark setup is given.