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1,758 results on '"Michalik, P."'

1. Backbone coloring for graphs with degree 4

Author

Michalik, Krzysztof and Turowski, Krzysztof

Subjects
Mathematics - Combinatorics, 05C15, 05C78, 68R05, G.2.2
Abstract

The $\lambda$-backbone coloring of the graph $G$ with backbone $H$ is a graph-coloring problem in which we are given a graph $G$ and a subgraph $H$, and we want to assign colors to vertices in such a way that the endpoints of every edge from $G$ have different colors, and the endpoints of every edge from $H$ are assigned colors which differ by at least $\lambda$. In this paper we pursue research on backbone coloring of bounded-degree graphs with well-known classes of backbones. Our result is an almost complete classification of problems in the form $BBC_{\lambda}(G, H) \le \lambda + k$ for graphs with maximum degree $4$ and backbones from the following classes: paths, trees, matchings, and galaxies.

Published
2024

2. Short range order and topology of Te-rich amorphous Ge-Sb-Te alloys

Author

Pethes, Ildikó, Piarristeguy, Andrea, Pradel, Annie, Escalier, Raphael, Micoulaut, Matthieu, Michalik, Stefan, Darpentigny, Jacques, Zitolo, Andrea, and Jóvári, Pál

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

The structure of evaporated amorphous Ge$_x$Sb$_x$Te$_{100-2x}$ ($x =$ 6, 9, 13) alloys was investigated by neutron diffraction, X-ray diffraction and extended X-ray absorption spectroscopy (EXAFS) at the Ge, Sb and Te K-edges. Large scale structural models were generated by fitting the experimental datasets (5 for each composition) simultaneously in the framework of the reverse Monte Carlo simulation technique. It was found that the alloys are chemically ordered (Ge and Sb have predominantly Te neighbors) and within the experimental uncertainty each component satisfies the $8-N$ rule. A comparison with the pair correlation functions of melt quenched Ge$_{20}$Te$_{80}$ revealed that the first minimum of $g_{\mathrm{TeTe}}(r)$ is shallower in the ternary alloys than in Ge$_{20}$Te$_{80}$. On the other hand, the separation of the first and second coordination environments of Ge atoms is stronger in the Ge-Sb-Te alloys investigated., Comment: 32 pages, submitted to Journal of Alloys and Compounds

Published
2024

3. Ordered magnetic fields around the 3C 84 central black hole

Author

Paraschos, G. F., Kim, J. -Y., Wielgus, M., Röder, J., Krichbaum, T. P., Ros, E., Agudo, I., Myserlis, I., Moscibrodzka, M., Traianou, E., Zensus, J. A., Blackburn, L., Chan, C. -K., Issaoun, S., Janssen, M., Johnson, M. D., Fish, V. L., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Baloković, M., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chang, D. O., Chatterjee, K., Chatterjee, S., Chen, M. T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Dahale, R., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fomalont, E., Ford, H. A., Foschi, M., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gómez-Ruiz, A. I., Gómez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., James, D. J., Jannuzi, B. T., Jeter, B., Jaing, W., Jiménez-Rosales, A., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, J. A., Kramer, M., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lowitz, A. E., Lu, R. -S., MacDonald, N. R., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Mulaudzi, W., Müller, C., Müller, H., Mus, A., Musoke, G., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. Navarro, Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Özel, F., Palumbo, D. C. M., Park, J., Parsons, H., Patel, N., Pen, U. -L., Piétu, V., Plambeck, R., PopStefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Romero-Cañizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K., Shao, L., Shen, Z., Small, D., Sohn, B. W., SooHoo, J., Salas, L. D. Sosapanta, Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Toscano, T., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Washington, J. E., Weintroub, J., Wharton, R., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yadlapalli, N., Yamaguchi, P., Yfantis, A., Yoon, D., Young, A., Young, K., Younsi, Z., Yu, W., Yuan, F., Yuan, Y. -F., Zhang, S., Zhao, G. Y., and Zhao, S. -S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

3C84 is a nearby radio source with a complex total intensity structure, showing linear polarisation and spectral patterns. A detailed investigation of the central engine region necessitates the use of VLBI above the hitherto available maximum frequency of 86GHz. Using ultrahigh resolution VLBI observations at the highest available frequency of 228GHz, we aim to directly detect compact structures and understand the physical conditions in the compact region of 3C84. We used EHT 228GHz observations and, given the limited (u,v)-coverage, applied geometric model fitting to the data. We also employed quasi-simultaneously observed, multi-frequency VLBI data for the source in order to carry out a comprehensive analysis of the core structure. We report the detection of a highly ordered, strong magnetic field around the central, SMBH of 3C84. The brightness temperature analysis suggests that the system is in equipartition. We determined a turnover frequency of $\nu_m=(113\pm4)$GHz, a corresponding synchrotron self-absorbed magnetic field of $B_{SSA}=(2.9\pm1.6)$G, and an equipartition magnetic field of $B_{eq}=(5.2\pm0.6)$G. Three components are resolved with the highest fractional polarisation detected for this object ($m_\textrm{net}=(17.0\pm3.9)$%). The positions of the components are compatible with those seen in low-frequency VLBI observations since 2017-2018. We report a steeply negative slope of the spectrum at 228GHz. We used these findings to test models of jet formation, propagation, and Faraday rotation in 3C84. The findings of our investigation into different flow geometries and black hole spins support an advection-dominated accretion flow in a magnetically arrested state around a rapidly rotating supermassive black hole as a model of the jet-launching system in the core of 3C84. However, systematic uncertainties due to the limited (u,v)-coverage, however, cannot be ignored., Comment: 15 pages, 6 figures, published in A&A

Published
2024
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4. Pre-Service Primary School Teachers' Interdisciplinary Competence and Their Interest, Self-Concept, and Sense of Belonging Regarding Natural and Social Sciences: Findings from a Longitudinal Study in Germany

Author

Feser, Markus Sebastian and Michalik, Kerstin

Abstract

In German primary schools, natural sciences and social studies are learned and taught in an integrative manner within a subject called Sachunterricht. To teach Sachunterricht in a high-quality manner, it is reasonable to assume that primary school teachers themselves require-- among other things, such as knowledge about pedagogy, teaching Sachunterricht, and the various content areas of Sachunterricht--a distinct interest, academic self-concept, and sense of belonging regarding natural and social sciences. Furthermore, they should possess a solid interdisciplinary competence that enables them to teach natural and social sciences in an integrative way. In the present study, we conducted a longitudinal survey of pre-service primary school teachers from a German university over a period of 2 years to investigate the changes in their (self-evaluated) interdisciplinary competence; the changes in their interest, academic self-concept, and sense of belonging regarding natural and social sciences; and the correlations between these constructs. Our data analysis revealed a decrease over time in participants' sense of belonging to natural and social sciences, as well as their (self-evaluated) interdisciplinary competence, while their academic self-concept in natural and social sciences remained stable. Participants' interest in social sciences decreased, while their interest in natural sciences increased. Moreover, we found varying degrees of correlation between these constructs. In summary, the results of the present study provide important insights into the professional development of pre-service primary school teachers within university-based teacher education for teaching natural and social sciences in primary school. The implications of these findings are discussed in detail at the end of this paper.

Published
2023

5. Increases in regional brain volume across two native South American male populations

Author

Chaudhari, Nikhil N., Imms, Phoebe E., Chowdhury, Nahian F., Gatz, Margaret, Trumble, Benjamin C., Mack, Wendy J., Law, E. Meng, Sutherland, M. Linda, Sutherland, James D., Rowan, Christopher J., Wann, L. Samuel, Allam, Adel H., Thompson, Randall C., Michalik, David E., Miyamoto, Michael, Lombardi, Guido, Cummings, Daniel K., Seabright, Edmond, Alami, Sarah, Garcia, Angela R., Rodriguez, Daniel E., Gutierrez, Raul Quispe, Copajira, Adrian J., Hooper, Paul L., Buetow, Kenneth H., Stieglitz, Jonathan, Gurven, Michael D., Thomas, Gregory S., Kaplan, Hillard S., Finch, Caleb E., and Irimia, Andrei

Published
2024
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10. sec-certs: Examining the security certification practice for better vulnerability mitigation

Author

Janovsky, Adam, Jancar, Jan, Svenda, Petr, Chmielewski, Łukasz, Michalik, Jiri, and Matyas, Vashek

Subjects
Computer Science - Cryptography and Security
Abstract

Products certified under security certification frameworks such as Common Criteria undergo significant scrutiny during the costly certification process. Yet, critical vulnerabilities, including private key recovery (ROCA, Minerva, TPM-Fail...), get discovered in certified products with high assurance levels. Furthermore, assessing which certified products are impacted by such vulnerabilities is complicated due to the large amount of unstructured certification-related data and unclear relationships between the certified products. To address these problems, we conducted a large-scale automated analysis of Common Criteria certificates. We trained unsupervised models to learn which vulnerabilities from NIST's National Vulnerability Database impact existing certified products and how certified products reference each other. Our tooling automates the analysis of tens of thousands of certification-related documents, extracting machine-readable features where manual analysis is unattainable. Further, we identify the security requirements that are associated with products being affected by fewer and less severe vulnerabilities. This indicates which aspects of certification correlate with higher security. We demonstrate how our tool can be used for better vulnerability mitigation on four case studies of known, high-profile vulnerabilities. All tools and continuously updated results are available at https://seccerts.org

Published
2023
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11. Grain-level effects on in-situ deformation-induced phase transformations in a complex-phase steel using 3DXRD and EBSD

Author

Ball, James A. D., Davis, Claire, Slater, Carl, Vashishtha, Himanshu, Said, Mohammed, Hébrard, Louis, Steinhilber, Florian, Wright, Jonathan P., Connolley, Thomas, Michalik, Stefan, and Collins, David M.

Subjects
Condensed Matter - Materials Science
Abstract

A novel complex-phase steel alloy is conceived with a deliberately unstable austenite, $\gamma$, phase that enables the deformation-induced martensitic transformations (DIMT) to be explored at low levels of plastic strain. The DIMT was thus explored, in-situ and non-destructively, using both far-field Three-Dimensional X-Ray Diffraction (3DXRD) and Electron Back-Scatter Diffraction (EBSD). Substantial $\alpha'$ martensite formation was observed under 10% applied strain with EBSD, and many $\varepsilon$ grain formation events were captured with 3DXRD, indicative of the indirect transformation of martensite via the reaction $\gamma \rightarrow \varepsilon \rightarrow \alpha'$. Using $\varepsilon$ grain formation as a direct measurement of $\gamma$ grain stability, the influence of several microstructural properties, such as grain size, orientation and neighbourhood configuration, on $\gamma$ stability have been identified. Larger $\gamma$ grains were found to be less stable than smaller grains. Any $\gamma$ grains oriented with {100} parallel to the loading direction preferentially transformed with lower stresses. Parent $\varepsilon$-forming $\gamma$ grains possessed a neighbourhood with increased ferritic/martensitic volume fraction. This finding shows, unambiguously, that $\alpha$/$\alpha'$ promotes $\varepsilon$ formation in neighbouring grains. The minimum strain work criterion model for $\varepsilon$ variant prediction was also evaluated, which worked well for most grains. However, $\varepsilon$-forming grains with a lower stress were less well predicted by the model, indicating crystal-level behaviour must be considered for accurate $\varepsilon$ formation. The findings from this work are considered key for the future design of alloys where the deformation response can be controlled by tailoring microstructure and local or macroscopic crystal orientations., Comment: 20 pages, 3 supplementary pages, 14 figures, 3 supplementary figures. Preprint submitted to Acta Materialia. Updated to correct Figure 14

Published
2023
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13. BepiColombo observations of cold oxygen and carbon ions in the flank of the induced magnetosphere of Venus

Author

Hadid, L. Z., Delcourt, D., Saito, Y., Fränz, M., Yokota, S., Fiethe, B., Verdeil, C., Katra, B., Leblanc, F., Fischer, H., Persson, M., Aizawa, S., André, N., Harada, Y., Fedorov, A., Fontaine, D., Krupp, N., Michalik, H., Berthelier, J-J., Krüger, H., Murakami, G., Matsuda, S., Heyner, D., Auster, H.-U., Richter, I., Mieth, J. Z. D., Schmid, D., and Fischer, D.

Published
2024
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16. The prevalence of cardiovascular disease risk factors among adults living in extreme poverty

Author

Geldsetzer, Pascal, Tisdale, Rebecca L., Stehr, Lisa, Michalik, Felix, Lemp, Julia, Aryal, Krishna K., Damasceno, Albertino, Houehanou, Corine, Jørgensen, Jutta Mari Adelin, Lunet, Nuno, Mayige, Mary, Saeedi Moghaddam, Sahar, Mwangi, Kibachio Joseph, Bommer, Christian, Marcus, Maja-Emilia, Theilmann, Michaela, Ebert, Cara, Atun, Rifat, Davies, Justine Ina, Flood, David, Manne-Goehler, Jennifer, Seiglie, Jacqueline, Bärnighausen, Till, and Vollmer, Sebastian

Published
2024
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18. Gaia Focused Product Release: Sources from Service Interface Function image analysis -- Half a million new sources in omega Centauri

Author

Gaia Collaboration, Weingrill, K., Mints, A., Castañeda, J., Kostrzewa-Rutkowska, Z., Davidson, M., De Angeli, F., Hernández, J., Torra, F., Ramos-Lerate, M., Babusiaux, C., Biermann, M., Crowley, C., Evans, D. W., Lindegren, L., Martín-Fleitas, J. M., Palaversa, L., Mieres, D. Ruz, Tisanić, K., Brown, A. G. A., Vallenari, A., Prusti, T., de Bruijne, J. H. J., Arenou, F., Barbier, A., Creevey, O. L., Ducourant, C., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U., Luri, X., Mignard, F., Randich, S., Sartoretti, P., Smiljanic, R., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Bastian, U., Cropper, M., Drimmel, R., Katz, D., Soubiran, C., van Leeuwen, F., Audard, M., Bakker, J., Blomme, R., Fabricius, C., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Masana, E., Messineo, R., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Roux, W., Seabroke, G. M., Sordo, R., Thévenin, F., Gracia-Abril, G., Portell, J., Teyssier, D., Altmann, M., Benson, K., Berthier, J., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cheek, N., Clementini, G., Damerdji, Y., de Teodoro, P., Delchambre, L., DellÓro, A., Garcia, E. Fraile, Garabato, D., García-Lario, P., Torres, N. Garralda, Gavras, P., Haigron, R., Hambly, N. C., Harrison, D. L., Hatzidimitriou, D., Hodgkin, S. T., Holl, B., Jamal, S., Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Lorca, A., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Campos, M. Nuñez, Oreshina-Slezak, I., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Riello, M., Rimoldini, L., Robin, A. C., Roegiers, T., Sarro, L. M., Schultheis, M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Aramburu, A. Abreu, Aerts, C., Altavilla, G., Álvarez, M. A., Alves, J., Anders, F., Anderson, R. I., Antoja, T., Baines, D., Baker, S. G., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bartolomé, S., Bashi, D., Bauchet, N., Baudeau, N., Becciani, U., Bedin, L. R., Bellas-Velidis, I., Bellazzini, M., Beordo, W., Berihuete, A., Bernet, M., Bertolotto, C., Bertone, S., Bianchi, L., Binnenfeld, A., Blazere, A., Boch, T., Bombrun, A., Bouquillon, S., Bragaglia, A., Braine, J., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cannizzo, S., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Carretero, J., Carton, S., Casamiquela, L., Castellani, M., Castro-Ginard, A., Cesare, V., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Collins, R., Contursi, G., Cooper, W. J., Cornez, T., Crosta, M., Dafonte, C., de Laverny, P., De Luise, F., De March, R., de Souza, R., de Torres, A., del Peloso, E. F., Delbo, M., Delgado, A., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Dsilva, K., Durán, J., Enke, H., Esquej, P., Fabre, C., Fabrizio, M., Faigler, S., Fatović, M., Fedorets, G., Fernández-Hernández, J., Fernique, P., Figueras, F., Fournier, Y., Fouron, C., Gai, M., Galinier, M., Garcia-Gutierrez, A., García-Torres, M., Garofalo, A., Gerlach, E., Geyer, R., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., Gosset, E., Granvik, M., Barrera, V. Gregori, Gutiérrez-Sánchez, R., Haywood, M., Helmer, A., Helmi, A., Henares, K., Hidalgo, S. L., Hilger, T., Hobbs, D., Hottier, C., Huckle, H. E., Jabłońska, M., Jansen, F., Jiménez-Arranz, Ó., Campillo, J. Juaristi, Khanna, S., Kordopatis, G., Kóspál, Á, Kun, M., Lambert, S., Lanza, A. F., Campion, J. -F. Le, Lebreton, Y., Lebzelter, T., Leccia, S., Lecoeur-Taibi, I., Lecoutre, G., Liao, S., Liberato, L., Licata, E., Lindstrøm, H. E. P., Lister, T. A., Livanou, E., Lobel, A., Loup, C., Mahy, L., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Pina, D. Marín, Marinoni, S., Marshall, D. J., Lozano, J. Martín, Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., McMillan, P. J., Meichsner, J., Messina, S., Michalik, D., Millar, N. R., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Mowlavi, N., Munoz, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Nieto, S., Noval, L., Ogden, A., Ordenovic, C., Pagani, C., Pagano, I., Palicio, P. A., Pallas-Quintela, L., Panahi, A., Panem, C., Payne-Wardenaar, S., Pegoraro, L., Penttilä, A., Pesciullesi, P., Piersimoni, A. M., Pinamonti, M., Pineau, F. -X., Plachy, E., Plum, G., Poggio, E., Pourbaix, D., Prša, A., Pulone, L., Racero, E., Rainer, M., Raiteri, C. M., Ramos, P., Ratajczak, M., Fiorentin, P. Re, Regibo, S., Reylé, C., Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, C., Romero-Gómez, M., Rowell, N., Royer, F., Rybicki, K. A., Sadowski, G., Núñez, A. Sáez, Sellés, A. Sagristà, Sahlmann, J., Gimenez, V. Sanchez, Sanna, N., Santoveña, R., Sarasso, M., Riera, C. Sarrate, Sciacca, E., Segovia, J. C., Ségransan, D., Shahaf, S., Siebert, A., Siltala, L., Slezak, E., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spina, L., Spitoni, E., Spoto, F., Squillante, L. A., Steele, I. A., Steidelmüller, H., Surdej, J., Szabados, L., Taris, F., Taylor, M. B., Teixeira, R., Tolomei, L., Elipe, G. Torralba, Trabucchi, M., Tsantaki, M., Ulla, A., Unger, N., Vanel, O., Vecchiato, A., Vicente, D., Voutsinas, S., Weiler, M., Wyrzykowski, Ł., Zhao, H., Zorec, J., Zwitter, T., Balaguer-Núñez, L., Leclerc, N., Morgenthaler, S., Robert, G., and Zucker, S.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

Gaia's readout window strategy is challenged by very dense fields in the sky. Therefore, in addition to standard Gaia observations, full Sky Mapper (SM) images were recorded for nine selected regions in the sky. A new software pipeline exploits these Service Interface Function (SIF) images of crowded fields (CFs), making use of the availability of the full two-dimensional (2D) information. This new pipeline produced half a million additional Gaia sources in the region of the omega Centauri ($\omega$ Cen) cluster, which are published with this Focused Product Release. We discuss the dedicated SIF CF data reduction pipeline, validate its data products, and introduce their Gaia archive table. Our aim is to improve the completeness of the {\it Gaia} source inventory in a very dense region in the sky, $\omega$ Cen. An adapted version of {\it Gaia}'s Source Detection and Image Parameter Determination software located sources in the 2D SIF CF images. We validated the results by comparing them to the public {\it Gaia} DR3 catalogue and external Hubble Space Telescope data. With this Focused Product Release, 526\,587 new sources have been added to the {\it Gaia} catalogue in $\omega$ Cen. Apart from positions and brightnesses, the additional catalogue contains parallaxes and proper motions, but no meaningful colour information. While SIF CF source parameters generally have a lower precision than nominal {\it Gaia} sources, in the cluster centre they increase the depth of the combined catalogue by three magnitudes and improve the source density by a factor of ten. This first SIF CF data publication already adds great value to the {\it Gaia} catalogue. It demonstrates what to expect for the fourth {\it Gaia} catalogue, which will contain additional sources for all nine SIF CF regions.

Published
2023
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19. Gaia Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars

Author

Gaia Collaboration, Krone-Martins, A., Ducourant, C., Galluccio, L., Delchambre, L., Oreshina-Slezak, I., Teixeira, R., Braine, J., Campion, J. -F. Le, Mignard, F., Roux, W., Blazere, A., Pegoraro, L., Brown, A. G. A., Vallenari, A., Prusti, T., de Bruijne, J. H. J., Arenou, F., Babusiaux, C., Barbier, A., Biermann, M., Creevey, O. L., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U., Lindegren, L., Luri, X., Randich, S., Sartoretti, P., Smiljanic, R., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Bastian, U., Cropper, M., Drimmel, R., Katz, D., Soubiran, C., van Leeuwen, F., Audard, M., Bakker, J., Blomme, R., Castaneda, J., De Angeli, F., Fabricius, C., Fouesneau, M., Fremat, Y., Guerrier, A., Masana, E., Messineo, R., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Seabroke, G. M., Sordo, R., Thevenin, F., Gracia-Abril, G., Portell, J., Teyssier, D., Altmann, M., Benson, K., Berthier, J., Burgess, P. W., Busonero, D., Busso, G., Canovas, H., Carry, B., Cheek, N., Clementini, G., Damerdji, Y., Davidson, M., de Teodoro, P., Dell'Oro, A., Garcia, E. Fraile, Garabato, D., Garcia-Lario, P., Torres, N. Garralda, Gavras, P., Haigron, R., Hambly, N. C., Harrison, D. L., Hatzidimitriou, D., Hernandez, J., Hodgkin, S. T., Holl, B., Jamal, S., Jordan, S., Lanzafame, A. C., Loffler, W., Lorca, A., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Campos, M. Nunez, Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Riello, M., Rimoldini, L., Robin, A. C., Roegiers, T., Sarro, L. M., Schultheis, M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Weingrill, K., Abbas, U., Abraham, P., Aramburu, A. Abreu, Aerts, C., Altavilla, G., Alvarez, M. A., Alves, J., Anderson, R. I., Antoja, T., Baines, D., Baker, S. G., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bartolome, S., Bashi, D., Bauchet, N., Baudeau, N., Becciani, U., Bedin, L. R., Bellas-Velidis, I., Bellazzini, M., Beordo, W., Berihuete, A., Bernet, M., Bertolotto, C., Bertone, S., Bianchi, L., Binnenfeld, A., Boch, T., Bombrun, A., Bouquillon, S., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cannizzo, S., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Carretero, J., Carton, S., Casamiquela, L., Castellani, M., Castro-Ginard, A., Cesare, V., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Collins, R., Contursi, G., Cooper, W. J., Cornez, T., Crosta, M., Crowley, C., Dafonte, C., de Laverny, P., De Luise, F., De March, R., de Souza, R., de Torres, A., del Peloso, E. F., Delbo, M., Delgado, A., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Dsilva, K., Duran, J., Enke, H., Esquej, P., Fabre, C., Fabrizio, M., Faigler, S., Fatovic, M., Fedorets, G., Fernandez-Hernandez, J., Fernique, P., Figueras, F., Fournier, Y., Fouron, C., Gai, M., Galinier, M., Garcia-Gutierrez, A., Garcia-Torres, M., Garofalo, A., Gerlach, E., Geyer, R., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., Gonzalez-Nunez, J., Gonzalez-Santamaria, I., Gosset, E., Granvik, M., Barrera, V. Gregori, Gutierrez-Sanchez, R., Haywood, M., Helmer, A., Helmi, A., Henares, K., Hidalgo, S. L., Hilger, T., Hobbs, D., Hottier, C., Huckle, H. E., Jablonska, M., Jansen, F., Jimenez-Arranz, O., Campillo, J. Juaristi, Khanna, S., Kordopatis, G., Kospal, A., Kostrzewa-Rutkowska, Z., Kun, M., Lambert, S., Lanza, A. F., Lebreton, Y., Lebzelter, T., Leccia, S., Lecoeur-Taibi, I., Lecoutre, G., Liao, S., Liberato, L., Licata, E., Lindstrom, H. E. P., Lister, T. A., Livanou, E., Lobel, A., Loup, C., Mahy, L., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Pina, D. Marin, Marinoni, S., Marshall, D. J., Lozano, J. Martin, Martin-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., McMillan, P. J., Meichsner, J., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnar, L., Monari, G., Monguio, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Mowlavi, N., Munoz, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Nieto, S., Noval, L., Ogden, A., Ordenovic, C., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, L., Panahi, A., Panem, C., Payne-Wardenaar, S., Penttila, A., Pesciullesi, P., Piersimoni, A. M., Pinamonti, M., Pineau, F. -X., Plachy, E., Plum, G., Poggio, E., Pourbaix, D., Prsa, A., Pulone, L., Racero, E., Rainer, M., Raiteri, C. M., Ramos, P., Ramos-Lerate, M., Ratajczak, M., Fiorentin, P. Re, Regibo, S., Reyle, C., Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, C., Romero-Gomez, M., Rowell, N., Royer, F., Mieres, D. Ruz, Rybicki, K. A., Sadowski, G., Nunez, A. Saez, Selles, A. Sagrista, Sahlmann, J., Gimenez, V. Sanchez, Sanna, N., Santovena, R., Sarasso, M., Riera, C. Sarrate, Sciacca, E., Segovia, J. C., Segransan, D., Shahaf, S., Siebert, A., Siltala, L., Slezak, E., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spina, L., Spitoni, E., Spoto, F., Squillante, L. A., Steele, I. A., Steidelmuller, H., Surdej, J., Szabados, L., Taris, F., Taylor, M. B., Tisanic, K., Tolomei, L., Torra, F., Elipe, G. Torralba, Trabucchi, M., Tsantaki, M., Ulla, A., Unger, N., Vanel, O., Vecchiato, A., Vicente, D., Voutsinas, S., Weiler, M., Wyrzykowski, L., Zhao, H., Zorec, J., Zwitter, T., Balaguer-Nunez, L., Leclerc, N., Morgenthaler, S., Robert, G., and Zucker, S.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Context. Strongly lensed quasars are fundamental sources for cosmology. The Gaia space mission covers the entire sky with the unprecedented resolution of $0.18$" in the optical, making it an ideal instrument to search for gravitational lenses down to the limiting magnitude of 21. Nevertheless, the previous Gaia Data Releases are known to be incomplete for small angular separations such as those expected for most lenses. Aims. We present the Data Processing and Analysis Consortium GravLens pipeline, which was built to analyse all Gaia detections around quasars and to cluster them into sources, thus producing a catalogue of secondary sources around each quasar. We analysed the resulting catalogue to produce scores that indicate source configurations that are compatible with strongly lensed quasars. Methods. GravLens uses the DBSCAN unsupervised clustering algorithm to detect sources around quasars. The resulting catalogue of multiplets is then analysed with several methods to identify potential gravitational lenses. We developed and applied an outlier scoring method, a comparison between the average BP and RP spectra of the components, and we also used an extremely randomised tree algorithm. These methods produce scores to identify the most probable configurations and to establish a list of lens candidates. Results. We analysed the environment of 3 760 032 quasars. A total of 4 760 920 sources, including the quasars, were found within 6" of the quasar positions. This list is given in the Gaia archive. In 87\% of cases, the quasar remains a single source, and in 501 385 cases neighbouring sources were detected. We propose a list of 381 lensed candidates, of which we identified 49 as the most promising. Beyond these candidates, the associate tables in this Focused Product Release allow the entire community to explore the unique Gaia data for strong lensing studies further., Comment: 35 pages, 60 figures, accepted for publication by Astronomy and Astrophysics

Published
2023
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20. Gaia Focused Product Release: Radial velocity time series of long-period variables

Author

Gaia Collaboration, Trabucchi, M., Mowlavi, N., Lebzelter, T., Lecoeur-Taibi, I., Audard, M., Eyer, L., García-Lario, P., Gavras, P., Holl, B., de Fombelle, G. Jevardat, Nienartowicz, K., Rimoldini, L., Sartoretti, P., Blomme, R., Frémat, Y., Marchal, O., Damerdji, Y., Brown, A. G. A., Guerrier, A., Panuzzo, P., Katz, D., Seabroke, G. M., Benson, K., Haigron, R., Smith, M., Lobel, A., Vallenari, A., Prusti, T., de Bruijne, J. H. J., Arenou, F., Babusiaux, C., Barbier, A., Biermann, M., Creevey, O. L., Ducourant, C., Evans, D. W., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U., Lindegren, L., Luri, X., Mignard, F., Randich, S., Smiljanic, R., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Bastian, U., Cropper, M., Drimmel, R., Lattanzi, M. G., Soubiran, C., van Leeuwen, F., Bakker, J., Castañeda, J., De Angeli, F., Fabricius, C., Fouesneau, M., Galluccio, L., Masana, E., Messineo, R., Nicolas, C., Pailler, F., Riclet, F., Roux, W., Sordo, R., Thévenin, F., Gracia-Abril, G., Portell, J., Teyssier, D., Altmann, M., Berthier, J., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cheek, N., Clementini, G., Davidson, M., de Teodoro, P., Delchambre, L., Dell'Oro, A., Garcia, E. Fraile, Garabato, D., Torres, N. Garralda, Hambly, N. C., Harrison, D. L., Hatzidimitriou, D., Hernández, J., Hodgkin, S. T., Jamal, S., Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Lorca, A., Marrese, P. M., Moitinho, A., Muinonen, K., Campos, M. Nuñez, Oreshina-Slezak, I., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Riello, M., Robin, A. C., Roegiers, T., Sarro, L. M., Schultheis, M., Siopis, C., Sozzetti, A., Utrilla, E., van Leeuwen, M., Weingrill, K., Abbas, U., Ábrahám, P., Aramburu, A. Abreu, Aerts, C., Altavilla, G., Álvarez, M. A., Alves, J., Anders, F., Anderson, R. I., Antoja, T., Baines, D., Baker, S. G., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bartolomé, S., Bashi, D., Bauchet, N., Baudeau, N., Becciani, U., Bedin, L. R., Bellas-Velidis, I., Bellazzini, M., Beordo, W., Berihuete, A., Bernet, M., Bertolotto, C., Bertone, S., Bianchi, L., Binnenfeld, A., Blazere, A., Boch, T., Bombrun, A., Bouquillon, S., Bragaglia, A., Braine, J., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cannizzo, S., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Carretero, J., Carton, S., Casamiquela, L., Castellani, M., Castro-Ginard, A., Cesare, V., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Collins, R., Contursi, G., Cooper, W. J., Cornez, T., Crosta, M., Crowley, C., Dafonte, C., David, M., de Laverny, P., De Luise, F., De March, R., De Ridder, J., de Souza, R., de Torres, A., del Peloso, E. F., Delbo, M., Delgado, A., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Dsilva, K., Durán, J., Enke, H., Esquej, P., Fabre, C., Fabrizio, M., Faigler, S., Fatović, M., Fedorets, G., Fernández-Hernández, J., Fernique, P., Figueras, F., Fournier, Y., Fouron, C., Gai, M., Galinier, M., Garcia-Gutierrez, A., García-Torres, M., Garofalo, A., Gerlach, E., Geyer, R., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., Gosset, E., Granvik, M., Barrera, V. Gregori, Gutiérrez-Sánchez, R., Haywood, M., Helmer, A., Helmi, A., Henares, K., Hidalgo, S. L., Hilger, T., Hobbs, D., Hottier, C., Huckle, H. E., Jabłońska, M., Jansen, F., Jiménez-Arranz, Ó., Campillo, J. Juaristi, Khanna, S., Kordopatis, G., Kóspál, Á, Kostrzewa-Rutkowska, Z., Kun, M., Lambert, S., Lanza, A. F., Campion, J. -F. Le, Lebreton, Y., Leccia, S., Lecoutre, G., Liao, S., Liberato, L., Licata, E., Lindstrøm, H. E. P., Lister, T. A., Livanou, E., Loup, C., Mahy, L., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Pina, D. Marín, Marinoni, S., Marshall, D. J., Lozano, J. Martín, Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., McMillan, P. J., Meichsner, J., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Munoz, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Nieto, S., Noval, L., Ogden, A., Ordenovic, C., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, L., Panahi, A., Panem, C., Payne-Wardenaar, S., Pegoraro, L., Penttilä, A., Pesciullesi, P., Piersimoni, A. M., Pinamonti, M., Pineau, F. -X., Plachy, E., Plum, G., Poggio, E., Pourbaix, D., Prša, A., Pulone, L., Racero, E., Rainer, M., Raiteri, C. M., Ramos, P., Ramos-Lerate, M., Ratajczak, M., Fiorentin, P. Re, Regibo, S., Reylé, C., Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, C., Romero-Gómez, M., Rowell, N., Royer, F., Mieres, D. Ruz, Rybicki, K. A., Sadowski, G., Núñez, A. Sáez, Sellés, A. Sagristà, Sahlmann, J., Gimenez, V. Sanchez, Sanna, N., Santoveña, R., Sarasso, M., Riera, C. Sarrate, Sciacca, E., Segovia, J. C., Ségransan, D., Shahaf, S., Siebert, A., Siltala, L., Slezak, E., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spina, L., Spitoni, E., Spoto, F., Squillante, L. A., Steele, I. A., Steidelmüller, H., Surdej, J., Szabados, L., Taris, F., Taylor, M. B., Teixeira, R., Tisanić, K., Tolomei, L., Torra, F., Elipe, G. Torralba, Tsantaki, M., Ulla, A., Unger, N., Vanel, O., Vecchiato, A., Vicente, D., Voutsinas, S., Weiler, M., Wyrzykowski, Ł., Zhao, H., Zorec, J., Zwitter, T., Balaguer-Núñez, L., Leclerc, N., Morgenthaler, S., Robert, G., and Zucker, S.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The third Gaia Data Release (DR3) provided photometric time series of more than 2 million long-period variable (LPV) candidates. Anticipating the publication of full radial-velocity (RV) in DR4, this Focused Product Release (FPR) provides RV time series for a selection of LPVs with high-quality observations. We describe the production and content of the Gaia catalog of LPV RV time series, and the methods used to compute variability parameters published in the Gaia FPR. Starting from the DR3 LPVs catalog, we applied filters to construct a sample of sources with high-quality RV measurements. We modeled their RV and photometric time series to derive their periods and amplitudes, and further refined the sample by requiring compatibility between the RV period and at least one of the $G$, $G_{\rm BP}$, or $G_{\rm RP}$ photometric periods. The catalog includes RV time series and variability parameters for 9\,614 sources in the magnitude range $6\lesssim G/{\rm mag}\lesssim 14$, including a flagged top-quality subsample of 6\,093 stars whose RV periods are fully compatible with the values derived from the $G$, $G_{\rm BP}$, and $G_{\rm RP}$ photometric time series. The RV time series contain a mean of 24 measurements per source taken unevenly over a duration of about three years. We identify the great most sources (88%) as genuine LPVs, with about half of them showing a pulsation period and the other half displaying a long secondary period. The remaining 12% consists of candidate ellipsoidal binaries. Quality checks against RVs available in the literature show excellent agreement. We provide illustrative examples and cautionary remarks. The publication of RV time series for almost 10\,000 LPVs constitutes, by far, the largest such database available to date in the literature. The availability of simultaneous photometric measurements gives a unique added value to the Gaia catalog (abridged), Comment: 36 pages, 38 figures

Published
2023

21. A search for pulsars around Sgr A* in the first Event Horizon Telescope dataset

Author

Torne, Pablo, Liu, Kuo, Eatough, Ralph P., Wongphechauxsorn, Jompoj, Cordes, James M., Desvignes, Gregory, De Laurentis, Mariafelicia, Kramer, Michael, Ransom, Scott M., Chatterjee, Shami, Wharton, Robert, Karuppusamy, Ramesh, Blackburn, Lindy, Janssen, Michael, Chan, Chi-kwan, Crew, Geoffrey B., Matthews, Lynn D., Goddi, Ciriaco, Rottmann, Helge, Wagner, Jan, Sanchez, Salvador, Ruiz, Ignacio, Abbate, Federico, Bower, Geoffrey C., Salamanca, Juan J., Gomez-Ruiz, Arturo I., Herrera-Aguilar, Alfredo, Jiang, Wu, Lu, Ru-Sen, Pen, Ue-Li, Raymond, Alexander W., Shao, Lijing, Shen, Zhiqiang, Paubert, Gabriel, Sanchez-Portal, Miguel, Kramer, Carsten, Castillo, Manuel, Navarro, Santiago, John, David, Schuster, Karl-Friedrich, Johnson, Michael D., Rygl, Kazi L. J., Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bauboeck, Michi, Benson, Bradford A., Bintley, Dan, Blundell, Raymond, Bouman, Katherine L., Boyce, Hope, Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Broguiere, Dominique, Bronzwaer, Thomas, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E., Ceccobello, Chiara, Chael, Andrew, Chang, Dominic O., Chatterjee, Koushik, Chen, Ming-Tang, Chen, Yongjun, Cheng, Xiaopeng, Cho, Ilje, Christian, Pierre, Conroy, Nicholas S., Conway, John E., Crawford, Thomas M., Cruz-Osorio, Alejandro, Cui, Yuzhu, Dahale, Rohan, Davelaar, Jordy, Deane, Roger, Dempsey, Jessica, Dexter, Jason, Dhruv, Vedant, Doeleman, Sheperd S., Dougal, Sean, Dzib, Sergio A., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Gold, Roman, Gomez, Jose L., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Haworth, Kari, Hecht, Michael H., Hesper, Ronald, Heumann, Dirk, Ho, Luis C., Ho, Paul, Honma, Mareki, Huang, Chih-Wei L., Huang, Lei, Hughes, David H., Ikeda, Shiro, Impellizzeri, C. M. Violette, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Jeter, Britton, Jimenez-Rosales, Alejandra, Jorstad, Svetlana, Joshi, Abhishek V., Jung, Taehyun, Karami, Mansour, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofuji, Yutaro, Koyama, Shoko, Krichbaum, Thomas P., Kuo, Cheng-Yu, La Bella, Noemi, Lauer, Tod R., Lee, Daeyoung, Lee, Sang-Sung, Leung, Po Kin, Levis, Aviad, Li, Zhiyuan, Lico, Rocco, Lindahl, Greg, Lindqvist, Michael, Lisakov, Mikhail, Liu, Jun, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin J., MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Medeiros, Lia, Menten, Karl M., Michalik, Daniel, Mizuno, Izumi, Mizuno, Yosuke, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Muller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Neilsen, Joey, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A., Oh, Junghwan, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Paraschos, Georgios Filippos, Park, Jongho, Parsons, Harriet, Patel, Nimesh, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Potzl, Felix M., Prather, Ben, Preciado-Lopez, Jorge A., Psaltis, Dimitrios, Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Rezzolla, Luciano, Ricarte, Angelo, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, Ros, Eduardo, Romero-Cañizales, Cristina, Roshanineshat, Arash, Roy, Alan L., Ruszczyk, Chet, Sanchez-Arguelles, David, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfeld, Jonathan, Small, Des, Sohn, Bong Won, SooHoo, Jason, Souccar, Kamal, Sun, He, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toscano, Teresa, Traianou, Efthalia, Trent, Tyler, Trippe, Sascha, Turk, Matthew, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Vos, Jesse, Ward-Thompson, Derek, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wielgus, Maciek, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, Andre, Young, Ken, Younsi, Ziri, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Event Horizon Telescope (EHT) observed in 2017 the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), at a frequency of 228.1 GHz ($\lambda$=1.3 mm). The fundamental physics tests that even a single pulsar orbiting Sgr A* would enable motivate searching for pulsars in EHT datasets. The high observing frequency means that pulsars - which typically exhibit steep emission spectra - are expected to be very faint. However, it also negates pulse scattering, an effect that could hinder pulsar detections in the Galactic Center. Additionally, magnetars or a secondary inverse Compton emission could be stronger at millimeter wavelengths than at lower frequencies. We present a search for pulsars close to Sgr A* using the data from the three most-sensitive stations in the EHT 2017 campaign: the Atacama Large Millimeter/submillimeter Array, the Large Millimeter Telescope and the IRAM 30 m Telescope. We apply three detection methods based on Fourier-domain analysis, the Fast-Folding-Algorithm and single pulse search targeting both pulsars and burst-like transient emission; using the simultaneity of the observations to confirm potential candidates. No new pulsars or significant bursts were found. Being the first pulsar search ever carried out at such high radio frequencies, we detail our analysis methods and give a detailed estimation of the sensitivity of the search. We conclude that the EHT 2017 observations are only sensitive to a small fraction ($\lesssim$2.2%) of the pulsars that may exist close to Sgr A*, motivating further searches for fainter pulsars in the region., Comment: 33 pages, 7 figures, 6 Tables. Accepted for publication in ApJ

Published
2023

22. A Measurement of Gravitational Lensing of the Cosmic Microwave Background Using SPT-3G 2018 Data

Author

Pan, Z., Bianchini, F., Wu, W. L. K., Ade, P. A. R., Ahmed, Z., Anderes, E., Anderson, A. J., Ansarinejad, B., Archipley, M., Aylor, K., Balkenhol, L., Barry, P. S., Thakur, R. Basu, Benabed, K., Bender, A. N., Benson, B. A., Bleem, L. E., Bouchet, F. R., Bryant, L., Byrum, K., Camphuis, E., Carlstrom, J. E., Carter, F. W., Cecil, T. W., Chang, C. L., Chaubal, P., Chen, G., Chichura, P. M., Cho, H. -M., Chou, T. -L., Cliche, J. -F., Coerver, A., Crawford, T. M., Cukierman, A., Daley, C., de Haan, T., Denison, E. V., Dibert, K. R., Ding, J., Dobbs, M. A., Doussot, A., Dutcher, D., Everett, W., Feng, C., Ferguson, K. R., Fichman, K., Foster, A., Fu, J., Galli, S., Gambrel, A. E., Gardner, R. W., Ge, F., Goeckner-Wald, N., Gualtieri, R., Guidi, F., Guns, S., Gupta, N., Halverson, N. W., Harke-Hosemann, A. H., Harrington, N. L., Henning, J. W., Hilton, G. C., Hivon, E., Holder, G. P., Holzapfel, W. L., Hood, J. C., Howe, D., Huang, N., Irwin, K. D., Jeong, O., Jonas, M., Jones, A., Kéruzoré, F., Khaire, T. S., Knox, L., Kofman, A. M., Korman, M., Kubik, D. L., Kuhlmann, S., Kuo, C. -L., Lee, A. T., Leitch, E. M., Levy, K., Lowitz, A. E., Lu, C., Maniyar, A., Menanteau, F., Meyer, S. S., Michalik, D., Millea, M., Montgomery, J., Nadolski, A., Nakato, Y., Natoli, T., Nguyen, H., Noble, G. I., Novosad, V., Omori, Y., Padin, S., Paschos, P., Pearson, J., Posada, C. M., Prabhu, K., Quan, W., Raghunathan, S., Rahimi, M., Rahlin, A., Reichardt, C. L., Riebel, D., Riedel, B., Ruhl, J. E., Sayre, J. T., Schiappucci, E., Shirokoff, E., Smecher, G., Sobrin, J. A., Stark, A. A., Stephen, J., Story, K. T., Suzuki, A., Takakura, S., Tandoi, C., Thompson, K. L., Thorne, B., Trendafilova, C., Tucker, C., Umilta, C., Vale, L. R., Vanderlinde, K., Vieira, J. D., Wang, G., Whitehorn, N., Yefremenko, V., Yoon, K. W., Young, M. R., and Zebrowski, J. A.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present a measurement of gravitational lensing over 1500 deg$^2$ of the Southern sky using SPT-3G temperature data at 95 and 150 GHz taken in 2018. The lensing amplitude relative to a fiducial Planck 2018 $\Lambda$CDM cosmology is found to be $1.020\pm0.060$, excluding instrumental and astrophysical systematic uncertainties. We conduct extensive systematic and null tests to check the robustness of the lensing measurements, and report a minimum-variance combined lensing power spectrum over angular multipoles of $50

Published
2023
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23. Registration between DCT and EBSD datasets for multiphase microstructures

Author

Ball, James A. D., Oddershede, Jette, Davis, Claire, Slater, Carl, Said, Mohammed, Vashishtha, Himanshu, Michalik, Stefan, and Collins, David M.

Subjects
Condensed Matter - Materials Science
Abstract

The ability to characterise the three-dimensional microstructure of multiphase materials is essential for understanding the interaction between phases and associated materials properties. Here, laboratory-based diffraction-contrast tomography (DCT), a recently-established materials characterization technique that can determine grain phases, morphologies, positions and orientations in a voxel-based reconstruction method, was used to map part of a dual-phase steel alloy sample. To assess the resulting microstructures that were produced by the DCT technique, an EBSD map was collected within the same sample volume. To identify the 2D slice of the 3D DCT reconstruction that best corresponded to the EBSD map, a novel registration technique based solely on grain-averaged orientations was developed -- this registration technique requires very little a priori knowledge of dataset alignment and can be extended to other techniques that only recover grain-averaged orientation data such as far-field 3D X-ray diffraction microscopy. Once the corresponding 2D slice was identified in the DCT dataset, comparisons of phase balance, grain size, shape and texture were performed between DCT and EBSD techniques. More complicated aspects of the microstructural morphology such as grain boundary shape and grains less than a critical size were poorly reproduced by the DCT reconstruction, primarily due to the difference in resolutions of the technique compared with EBSD. However, lab-based DCT is shown to accurately determine the centre-of-mass position, orientation, and size of the large grains for each phase present, austenite and martensitic ferrite. The results reveals a complex ferrite grain network of similar crystal orientations that are absent from the EBSD dataset. Such detail demonstrates that lab-based DCT, as a technique, shows great promise in the field of multi-phase material characterization., Comment: 15 pages, 11 figures. Preprint submitted to Materials Characterization

Published
2023
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24. On the characterization of formal automorphisms of integro-differential operators

Author

Lastra, Alberto, Michalik, Sławomir, and Suwińska, Maria

Subjects
Mathematics - Complex Variables, Mathematics - Analysis of PDEs, 35C10, 35G10
Abstract

Necessary and sufficient conditions on a family of integro-differential operators to determine a formal automorphism are established. Equivalently, the problem can be read in terms of existence and uniqueness of formal solutions of Cauchy problems in different settings. The main results provide a characterization not only in the framework of general formal power series, but also on subspaces appearing in applications such as Gevrey settings and moment differential operators.

Published
2023

25. Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances

Author

Kahil, F., Gandorfer, A., Hirzberger, J., Calchetti, D., Sinjan, J., Valori, G., Solanki, S. K., Van Noort, M., Albert, K., Jorge, N. Albelo, Alvarez-Herrero, A., Appourchaux, T., Rubio, L. R. Bellot, guez, J. Blanco Rodrí, Feller, A., Fiethe, B., Germerott, D., Gizon, L., Guerrero, L., Gutierrez-Marques, P., Kolleck, M., Korpi-Lagg, A., Michalik, H., Vacas, A. Moreno, arez, D. Orozco Su\', erez-Grande, I. P\', Kilders, E. Sanchis, Schou, J., uhle, U. Sch\", Staub, J., Strecker, H., iniesta, J. C. del Toro, Volkmer, R., and Woch, J.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO) nominal mission phase. Our ultimate aims are to reconstruct the HRT data by deconvolving with the HRT point spread function (PSF) and to correct for the effects of optical aberrations on the data. We use a pair of focused--defocused images to compute the wavefront error and derive the PSF of HRT by means of a phase diversity (PD) analysis. The wavefront error of HRT depends on the orbital distance of SO to the Sun. At distances $>0.5$\,au, the wavefront error is small, and stems dominantly from the inherent optical properties of HRT. At distances $<0.5$\,au, the thermo-optical effect of the Heat Rejection Entrance Window (HREW) becomes noticeable. We develop an interpolation scheme for the wavefront error that depends on the thermal variation of the HREW with the distance of SO to the Sun. We also introduce a new level of image reconstruction, termed `aberration correction', which is designed to reduce the noise caused by image deconvolution while removing the aberrations caused by the HREW. The computed PSF via phase diversity significantly reduces the degradation caused by the HREW in the near-perihelion HRT data. In addition, the aberration correction increases the noise by a factor of only $1.45$ compared to the factor of $3$ increase that results from the usual PD reconstructions.

Published
2023
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26. Accuracy analysis of the on-board data reduction pipeline for the Polarimetric and Helioseismic Imager on the Solar Orbiter mission

Author

Albert, Kinga, Hirzberger, Johann, Durán, J. Sebastián Castellanos, Suárez, David Orozco, Woch, Joachim, Michalik, Harald, and Solanki, Sami K.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Scientific data reduction on-board deep space missions is a powerful approach to maximise science return, in the absence of wide telemetry bandwidths. The Polarimetric and Helioseismic Imager (PHI) on-board the Solar Orbiter (SO) is the first solar spectropolarimeter that opted for this solution, and provides the scientific community with science-ready data directly from orbit. This is the first instance of full solar spectropolarimetric data reduction on a spacecraft. In this paper, we analyse the accuracy achieved by the on-board data reduction, which is determined by the trade-offs taken to reduce computational demands and to ensure the autonomous operation of the instrument during the data reduction process. We look at the magnitude and nature of errors introduced in the different pipeline steps of the processing. We use an MHD sunspot simulation to isolate the data processing from other sources of inaccuracy. We process the data set with calibration data obtained from SO/PHI in orbit, and compare results calculated on a representative SO/PHI model on ground with a reference implementation of the same pipeline, without the on-board processing trade-offs. Our investigation shows that the accuracy in the Stokes vectors, achieved by the data processing, is at least two orders of magnitude better than what the instrument was designed to achieve. We also found that the errors in the physical parameters are within the accuracy of typical RTE inversions with Milne-Eddington approximation of the atmosphere. This paper demonstrates that the on-board data reduction of the data from SO/PHI does not compromise the accuracy of the processing. This places on-board data processing as a viable alternative for future scientific instruments that would need more telemetry than many missions are able to provide, in particular those in deep space.

Published
2023
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34. On sequences preserving q-Gevrey asymptotic expansions

Author

Lastra, Alberto and Michalik, Sławomir

Subjects
Mathematics - Complex Variables, Mathematics - Analysis of PDEs, Mathematics - Functional Analysis
Abstract

The modification of the coefficients of formal power series is analyzed in order that such variation preserves q-Gevrey asymptotic properties, in particular q-Gevrey asymptotic expansions. A characterization of such sequences is determined, providing a handy tool in practice. The sequence of q-factorials is proved to preserve q-Gevrey asymptotic expansions.

Published
2023

35. Magnetic fields inferred by Solar Orbiter: A comparison between SO/PHI-HRT and SDO/HMI

Author

Sinjan, J., Calchetti, D., Hirzberger, J., Kahil, F., Valori, G., Solanki, S. K., Albert, K., Jorge, N. Albelo, Alvarez-Herrero, A., Appourchaux, T., Rubio, L. R. Bellot, Rodríguez, J. Blanco, Feller, A., Gandorfer, A., Germerott, D., Gizon, L., Cama, J. M. Gómez, Guerrero, L., Gutierrez-Marques, P., Kolleck, M., Korpi-Lagg, A., Michalik, H., Vacas, A. Moreno, Suárez, D. Orozco, Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Schou, J., Schühle, U., Staub, J., Strecker, H., Iniesta, J. C. del Toro, Volkmer, R., and Woch, J.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Physics - Space Physics
Abstract

The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager on board the Solar Orbiter spacecraft (SO/PHI) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) both infer the photospheric magnetic field from polarised light images. SO/PHI is the first magnetograph to move out of the Sun--Earth line and will provide unprecedented access to the Sun's poles. This provides excellent opportunities for new research wherein the magnetic field maps from both instruments are used simultaneously. We aim to compare the magnetic field maps from these two instruments and discuss any possible differences between them. We used data from both instruments obtained during Solar Orbiter's inferior conjunction on 7 March 2022. The HRT data were additionally treated for geometric distortion and degraded to the same resolution as HMI. The HMI data were re-projected to correct for the $3^{\circ}$ separation between the two observatories. SO/PHI-HRT and HMI produce remarkably similar line-of-sight magnetograms, with a slope coefficient of $0.97$, an offset below $1$ G, and a Pearson correlation coefficient of $0.97$. However, SO/PHI-HRT infers weaker line-of-sight fields for the strongest fields. As for the vector magnetic field, SO/PHI-HRT was compared to both the $720$-second and $90$-second HMI vector magnetic field: SO/PHI-HRT has a closer alignment with the $90$-second HMI vector. In the weak signal regime ($< 600$ G), SO/PHI-HRT measures stronger and more horizontal fields than HMI, very likely due to the greater noise in the SO/PHI-HRT data. In the strong field regime ($\gtrsim 600$ G), HRT infers lower field strengths but with similar inclinations (a slope of $0.92$) and azimuths (a slope of $1.02$). The slope values are from the comparison with the HMI $90$-second vector., Comment: 10 pages, 5 figures, accepted for publication in A&A; manuscript is a part of Astronomy & Astrophysics special issue: Solar Orbiter First Results (Nominal Mission Phase)

Published
2023
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36. Comparison of Polarized Radiative Transfer Codes used by the EHT Collaboration

Author

Prather, Ben S., Dexter, Jason, Moscibrodzka, Monika, Pu, Hung-Yi, Bronzwaer, Thomas, Davelaar, Jordy, Younsi, Ziri, Gammie, Charles F., Gold, Roman, Wong, George N., Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Baloković, Mislav, Barrett, John, Bauböck, Michi, Benson, Bradford A., Bintley, Dan, Blackburn, Lindy, Blundell, Raymond, Bouman, Katherine L., Bower, Geoffrey C., Boyce, Hope, Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Broguiere, Dominique, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E., Ceccobello, Chiara, Chael, Andrew, Chan, Chi-kwan, Chang, Dominic O., Chatterjee, Koushik, Chatterjee, Shami, Chen, Ming-Tang, Chen, Yongjun, Cheng, Xiaopeng, Cho, Ilje, Christian, Pierre, Conroy, Nicholas S., Conway, John E., Cordes, James M., Crawford, Thomas M., Crew, Geoffrey B., Cruz-Osorio, Alejandro, Cui, Yuzhu, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dhruv, Vedant, Doeleman, Sheperd S., Dougal, Sean, Dzib, Sergio A., Eatough, Ralph P., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Ford, H. Alyson, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, García, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gómez-Ruiz, Arturo I., Gómez, José L., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Haworth, Kari, Hecht, Michael H., Hesper, Ronald, Heumann, Dirk, Ho, Luis C., Ho, Paul, Honma, Mareki, Huang, Chih-Wei L., Huang, Lei, Hughes, David H., Ikeda, Shiro, Impellizzeri, C. M. Violette, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, Jiménez-Rosales, Alejandra, Johnson, Michael D., Jorstad, Svetlana, Joshi, Abhishek V., Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofuji, Yutaro, Koyama, Shoko, Kramer, Carsten, Kramer, Michael, Krichbaum, Thomas P., Kuo, Cheng-Yu, La Bella, Noemi, Lauer, Tod R., Lee, Daeyoung, Lee, Sang-Sung, Leung, Po Kin, Levis, Aviad, Li, Zhiyuan, Lico, Rocco, Lindahl, Greg, Lindqvist, Michael, Lisakov, Mikhail, Liu, Jun, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin J., Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Martí-Vidal, Iván, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Michalik, Daniel, Mizuno, Izumi, Mizuno, Yosuke, Moran, James M., Moriyama, Kotaro, Müller, Cornelia, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Fuentes, Santiago Navarro, Neilsen, Joey, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A., Oh, Junghwan, Okino, Hiroki, Olivares, Héctor, Ortiz-León, Gisela N., Oyama, Tomoaki, Özel, Feryal, Palumbo, Daniel C. M., Paraschos, Georgios Filippos, Park, Jongho, Parsons, Harriet, Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Piétu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Pötzl, Felix M., Preciado-López, Jorge A., Psaltis, Dimitrios, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Raymond, Alexander W., Rezzolla, Luciano, Ricarte, Angelo, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, Ros, Eduardo, Romero-Cañizales, Cristina, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L., Ruiz, Ignacio, Ruszczyk, Chet, Rygl, Kazi L. J., Sánchez, Salvador, Sánchez-Argüelles, David, Sánchez-Portal, Miguel, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfeld, Jonathan, Schuster, Karl-Friedrich, Shao, Lijing, Shen, Zhiqiang, Small, Des, Sohn, Bong Won, SooHoo, Jason, Souccar, Kamal, Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Torne, Pablo, Traianou, Efthalia, Trent, Tyler, Trippe, Sascha, Turk, Matthew, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Vos, Jesse, Wagner, Jan, Ward-Thompson, Derek, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wielgus, Maciek, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wu, Qingwen, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, André, Young, Ken, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Interpretation of resolved polarized images of black holes by the Event Horizon Telescope (EHT) requires predictions of the polarized emission observable by an Earth-based instrument for a particular model of the black hole accretion system. Such predictions are generated by general relativistic radiative transfer (GRRT) codes, which integrate the equations of polarized radiative transfer in curved spacetime. A selection of ray-tracing GRRT codes used within the EHT collaboration is evaluated for accuracy and consistency in producing a selection of test images, demonstrating that the various methods and implementations of radiative transfer calculations are highly consistent. When imaging an analytic accretion model, we find that all codes produce images similar within a pixel-wise normalized mean squared error (NMSE) of 0.012 in the worst case. When imaging a snapshot from a cell-based magnetohydrodynamic simulation, we find all test images to be similar within NMSEs of 0.02, 0.04, 0.04, and 0.12 in Stokes I, Q, U , and V respectively. We additionally find the values of several image metrics relevant to published EHT results to be in agreement to much better precision than measurement uncertainties., Comment: Accepted for publication in ApJ

Published
2023
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37. Per-grain and neighbourhood stress interactions during deformation of a ferritic steel obtained using three-dimensional X-ray diffraction

Author

Ball, James A. D., Kareer, Anna, Magdysyuk, Oxana V., Michalik, Stefan, Connolley, Thomas, and Collins, David M.

Subjects
Condensed Matter - Materials Science
Abstract

Three-dimensional X-ray diffraction (3DXRD) has been used to measure, in-situ, the evolution of $\sim 1800$ grains in a single phase low carbon ferritic steel sample during uniaxial deformation. The distribution of initial residual grain stresses in the material was observed to prevail as plasticity builds, though became less pronounced, and therefore less influential as strain increased. The initial Schmid factor of a grain was found to be strongly correlated to the intergranular stress change and the range of stresses that are permissible; a grain well aligned for easy slip is more likely to exhibit a range of stresses than those orientated poorly for dislocation motion. The orientation path of a grain, however, is not only dependent on its initial orientation, but hypothesised to be influenced by its stress state and the stress state of its grain environment. A grain neighbourhood effect is observed: the Schmid factor of serial adjoining grains influences the stress state of a grain of interest, whereas parallel neighbours are much less influential. This phenomenon is strongest at low plastic strains only, with the effect diminishing as plasticity builds. The influence of initial residual stresses becomes less evident, and grains rotate to eliminate any orientation dependent load shedding. The ability of the BCC ferrite to exhaust such neighbourhood interactions, which would otherwise be detrimental in crystal structures with lower symmetric and fewer slip systems, is considered key to the high ductility possessed by these materials., Comment: 17 pages (+2 supplementary pages), 13 figures (+3 supplementary figures). Preprint submitted to Acta Materialia

Published
2023
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38. Genome Comparison Reveals Inversions and Alternative Evolutionary History of Nutritional Endosymbionts in Planthoppers (Hemiptera: Fulgoromorpha).

Author

Deng, Junchen, Bennett, Gordon, Franco, Diego, Prus-Frankowska, Monika, Stroiński, Adam, Michalik, Anna, and Łukasik, Piotr

Subjects
betaproteobacteria, diversity and origin, endosymbiosis, genome inversion, planthopper, Animals, Hemiptera, Phylogeny, Symbiosis, Bacteria, Insecta, Betaproteobacteria
Abstract

The evolutionary success of sap-feeding hemipteran insects in the suborder Auchenorrhyncha was enabled by nutritional contributions from their heritable endosymbiotic bacteria. However, the symbiont diversity, functions, and evolutionary origins in this large insect group have not been broadly characterized using genomic tools. In particular, the origins and relationships among ancient betaproteobacterial symbionts Vidania (in Fulgoromorpha) and Nasuia/Zinderia (in Cicadomorpha) are uncertain. Here, we characterized the genomes of Vidania and Sulcia from three Pyrops planthoppers (family Fulgoridae) to understand their metabolic functions and evolutionary histories. We find that, like in previously characterized planthoppers, these symbionts share nutritional responsibilities, with Vidania providing seven out of ten essential amino acids. Sulcia lineages across the Auchenorrhyncha have a highly conserved genome but with multiple independent rearrangements occurring in an early ancestor of Cicadomorpha or Fulgoromorpha and in a few succeeding lineages. Genomic synteny was also observed within each of the betaproteobacterial symbiont genera Nasuia, Zinderia, and Vidania, but not across them, which challenges the expectation of a shared ancestry for these symbionts. The further comparison of other biological traits strongly suggests an independent origin of Vidania early in the planthopper evolution and possibly of Nasuia and Zinderia in their respective host lineages. This hypothesis further links the potential acquisition of novel nutritional endosymbiont lineages with the emergence of auchenorrhynchan superfamilies.

Published
2023

39. On the summability and convergence of formal solutions of linear $q$-difference-differential equations with constant coefficients

Author

Ichinobe, Kunio and Michalik, Sławomir

Subjects
Mathematics - Analysis of PDEs, Mathematics - Classical Analysis and ODEs, Mathematics - Complex Variables, 35C10, 35E15, 39A13, 40G10
Abstract

We consider the Cauchy problem for homogeneous linear $q$-difference-differential equations with constant coefficients. We characterise convergent, $k$-summable and multisummable formal power series solutions in terms of analytic continuation properties and growth estimates of the Cauchy data. We also introduce and characterise sequences preserving summability, which make a very useful tool, especially in the context of moment differential equations., Comment: 22 pages

Published
2023

40. Diagonals separating the square of a continuum

Author

Illanes, Alejandro, Martínez-de-la-Vega, Verónica, Martínez-Montejano, Jorge M., and Michalik, Daria

Subjects
Mathematics - General Topology, Mathematics - Dynamical Systems
Abstract

A metric continuum $X$ is indecomposable if it cannot be put as the union of two of its proper subcontinua. A subset $R$ of $X$ is said to be continuumwise connected provided that for each pair of points $p,q\in R$, there exists a subcontinuum $M$ of $X$ such that $\{p,q\}\subset M\subset R$. Let $X^{2}$ denote the Cartesian square of $X$ and $\Delta$ the diagonal of $X^{2}$. In \cite{ka} it was asked if for a continuum $X$, distinct from the arc, $X^{2}\setminus \Delta$ is continuumwise connected if and only if $X$ is decomposable. In this paper we show that no implication in this question holds. For the proof of the non-necessity, we use the dynamic properties of a suitable homeomorphism of the Cantor set onto itself to construct an appropriate indecomposable continuum $X$.

Published
2022

41. Brain volume, energy balance, and cardiovascular health in two nonindustrial South American populations.

Author

Kaplan, Hillard, Hooper, Paul, Gatz, Margaret, Mack, Wendy, Law, E, Chui, Helena, Sutherland, M, Sutherland, James, Rowan, Christopher, Wann, L, Allam, Adel, Thompson, Randall, Michalik, David, Lombardi, Guido, Miyamoto, Michael, Eid Rodriguez, Daniel, Copajira Adrian, Juan, Quispe Gutierrez, Raul, Beheim, Bret, Cummings, Daniel, Seabright, Edmond, Alami, Sarah, R Garcia, Angela, Buetow, Kenneth, Thomas, Gregory, Finch, Caleb, Stieglitz, Jonathan, Trumble, Benjamin, Irimia, Andrei, and Gurven, Michael

Subjects
Tsimane, brain volume, evolutionary medicine, mismatch, Humans, United States, Cross-Sectional Studies, Aging, Cardiovascular System, Brain, South America
Abstract

Little is known about brain aging or dementia in nonindustrialized environments that are similar to how humans lived throughout evolutionary history. This paper examines brain volume (BV) in middle and old age among two indigenous South American populations, the Tsimane and Moseten, whose lifestyles and environments diverge from those in high-income nations. With a sample of 1,165 individuals aged 40 to 94, we analyze population differences in cross-sectional rates of decline in BV with age. We also assess the relationships of BV with energy biomarkers and arterial disease and compare them against findings in industrialized contexts. The analyses test three hypotheses derived from an evolutionary model of brain health, which we call the embarrassment of riches (EOR). The model hypothesizes that food energy was positively associated with late life BV in the physically active, food-limited past, but excess body mass and adiposity are now associated with reduced BV in industrialized societies in middle and older ages. We find that the relationship of BV with both non-HDL cholesterol and body mass index is curvilinear, positive from the lowest values to 1.4 to 1.6 SDs above the mean, and negative from that value to the highest values. The more acculturated Moseten exhibit a steeper decrease in BV with age than Tsimane, but still shallower than US and European populations. Lastly, aortic arteriosclerosis is associated with lower BV. Complemented by findings from the United States and Europe, our results are consistent with the EOR model, with implications for interventions to improve brain health.

Published
2023

42. A Wave Packet Approach to Resonant Scattering

Author

Michalik, A. M. and Marsiglio, F.

Subjects
Quantum Physics, Condensed Matter - Other Condensed Matter
Abstract

Resonant transmission occurs when constructive interference results in the complete passage of an incoming wave through an array of barriers. In this paper we explore such a scenario with one dimensional models. We adopt wave packets with finite width to illustrate the deterioration of resonance with decreasing wave packet width, and suggest an approximate wave function for the transmitted and reflected components, derived from aspects of both the wave packet and plane wave approaches. A comparison with exact numerical calculations shows excellent agreement, and provides insight into the scattering process., Comment: 15 pages, 6 figures

Published
2022
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43. Short range order and topology of binary Ge-S glasses

Author

Pethes, Ildikó, Jóvári, Pál, Michalik, Stefan, Wagner, Tomas, Prokop, Vit, Kaban, Ivan, Száraz, Dániel, Hannon, Alex, and Krbal, Milos

Subjects
Physics - Chemical Physics, Condensed Matter - Materials Science
Abstract

Short range order and topology of Ge$_x$S$_{100-x}$ glasses over a broad composition range (20 $\le$ x $\le$ 42 in at%) was investigated by neutron diffraction, X-ray diffraction, and Ge K-edge extended X-ray absorption fine structure (EXAFS) measurements. The experimental data sets were fitted simultaneously in the framework of the reverse Monte Carlo simulation method. It was found that both constituents (Ge and S) satisfy the Mott-rule in all investigated glasses: Ge and S atoms have 4 and 2 neighbours, respectively. The structure of these glasses can be described with the chemically ordered network model: Ge-S bonds are preferred, S-S bonds are present only in S-rich glasses. Dedicated simulations showed that Ge-Ge bonds are necessary in Ge-rich glasses. Connections between Ge atoms (such as edge-sharing GeS$_{4/2}$ tetrahedra) in stoichiometric and S-rich glasses were analysed. The frequency of primitive rings was also calculated., Comment: published in Journal of Alloys and Compounds

Published
2022
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44. The on-ground data reduction and calibration pipeline for SO/PHI-HRT

Author

Sinjan, J., Calchetti, D., Hirzberger, J., Suárez, D. Orozco, Albert, K., Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Germerott, D., Guerrero, L., Marquez, P. Gutierrez, Kahil, F., Kolleck, M., Solanki, S. K., Iniesta, J. C. del Toro, Volkmer, R., Woch, J., Fiethe, B., Cama, J. M. Gómez, Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Carmona, M., Deutsch, W., Fernandez-Rico, G., Fernández-Medina, A., Parejo, P. García, Blesa, J. L. Gasent, Gizon, L., Grauf, B., Heerlein, K., Korpi-Lagg, A., Lange, T., Jiménez, A. López, Maue, T., Meller, R., Michalik, H., Vacas, A. Moreno, Müller, R., Nakai, E., Schmidt, W., Schou, J., Schühle, U., Staub, J., Strecker, H., Torralbo, I., and Valori, G.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The ESA/NASA Solar Orbiter space mission has been successfully launched in February 2020. Onboard is the Polarimetric and Helioseismic Imager (SO/PHI), which has two telescopes, a High Resolution Telescope (HRT) and the Full Disc Telescope (FDT). The instrument is designed to infer the photospheric magnetic field and line-of-sight velocity through differential imaging of the polarised light emitted by the Sun. It calculates the full Stokes vector at 6 wavelength positions at the Fe I 617.3 nm absorption line. Due to telemetry constraints, the instrument nominally processes these Stokes profiles onboard, however when telemetry is available, the raw images are downlinked and reduced on ground. Here the architecture of the on-ground pipeline for HRT is presented, which also offers additional corrections not currently available on board the instrument. The pipeline can reduce raw images to the full Stokes vector with a polarimetric sensitivity of $10^{-3}\cdot I_{c}$ or better.

Published
2022
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48. Micropulse laser therapy in chronic idiopathic central serous chorioretinopathy in right eye of 38-year-old patient – case report

Author

Maciej Michalik, Krzysztof Marcinkowski, Dominika Hennik, and Sebastian Sirek

Subjects
micropulse laser, central serous chorioretinopathy, retinal macula, Pharmacy and materia medica, RS1-441, Dentistry, RK1-715
Abstract

INTRODUCTION: Central serous chorioretinopathy (CSC) is a disease characterized by idiopathic serous elevation of the sensory layer of the retina in the proximity of the macula. This phenomenon predominantly manifests unilaterally, particularly in young males who exhibit increased susceptibility to stress. The optimal treatment strategy for CSC remains questionable due to a diverse range of symptoms, variable clinical courses, an overall limited understanding of CSC’s pathophysiology and a lack of consensus on classification systems. Recently, there has been growing adoption of micropulse laser therapy in CSC treatment, allowing targeted action on retinal pigment epithelium, without causing damage to nearby photoreceptors. The aim was to evaluate the use of micropulse laser therapy in chronic CSC. DESCRIPTION AND RESULTS: A 38-year-old patient with recurrent CSC in the right eye, previously treated locally with eye drops and oral medication for over a year, underwent evaluation. At the time of diagnosis, the patient exhibited a visual acuity of 0.63, intraocular pressure of 19 mmHg, and a central retinal thickness of 530 µm, as measured by optical coherence tomography (OCT). Fluorescein angiography (FA) confirmed the diagnosis, leading to the qualification for retinal micropulse laser therapy. Following the treatment, a subsequent FA test revealed improvement in the patient’s clinical condition, with a vision acuity of 1.0 and intraocular pressure reduced to 17 mmHg. Additionally, the central retinal thickness measured by OCT decreased to 299 µm. CONCLUSIONS: The use of micropulse laser therapy demonstrates the potential to achieve sustainable clinical effects in patients with recurrent CSC.

Published
2024
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49. The association between physical activity and quality of life among people aged 60–89 living in own homes and nursing homes

Author

Aleksandra Kiełtyka-Słowik, Urszula Michalik-Marcinkowska, and Bożena Zawadzka

Subjects
Physical activity, Quality of life, Older people, IPAQ, WHOQOL-AGE, Nursing home, Geriatrics, RC952-954.6
Abstract

Abstract Background The aim of the study was to obtain a response to the question of whether and how physical activity (PA) among people aged 60–89 years impacts quality of life and other sociodemographic characteristics (sex, age and place of living). Methods Among 341 respondents aged 60 to 89, including 273 women (80%) and 68 men (20%) successfully completed IPAQ and WHOQOL AGE questionnaires. In the study were used International Physical Activity Questionnaire – IPAQ and World Health Organization Quality Of Life - Age – WHOQOL-AGE in Polish version. Results The average total physical activity, including vigorous-intensity physical effort, moderate-intensity physical effort and walking amounts to 1381.87 ± 1978.60 MET-min/week. The average quality of life for the whole group of older people as evaluated with WHOQOL AGE scale was 64.79 (SD = 14.76; min:18.77-max: 98.07). Statistical analysis between physical activity and life quality proved significant dependence for the global life quality rating (p

Published
2024
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50. Revealing per-grain and neighbourhood stress interactions of a deforming ferritic steel via three-dimensional X-ray diffraction

Author

James A. D. Ball, Anna Kareer, Oxana V. Magdysyuk, Stefan Michalik, Thomas Connolley, and David M. Collins

Subjects
Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

Abstract The structural performance of polycrystalline alloys is strongly controlled by the characteristics of individual grains and their interactions, motivating this study to understand the dynamic micromechanical response within the microstructure. Here, a high ductility single-phase ferritic steel during uniaxial deformation is explored using three-dimensional X-ray diffraction. Grains well aligned for dislocation slip are shown to possess a wide intergranular stress range, controlled by per-grain dependent hardening activity. Contrariwise, grains orientated poorly for slip have a narrow stress range. A grain neighbourhood effect is observed of statistical significance: the Schmid factor of serial adjoining grains influences the stress state of a grain of interest, whereas parallel neighbours are less influential. This phenomenon is strongest at low plastic strains, with the effect diminishing as grains rotate during plasticity to eliminate any orientation dependent load shedding. The ability of the ferrite to eliminate such neighbourhood interactions is considered key to the high ductility possessed by these materials.

Published
2024
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