@article{18656, abstract = {We consider the time evolution of the out-of-time-ordered correlator (OTOC) of two general observables and in a mean field chaotic quantum system described by a random Wigner matrix as its Hamiltonian. We rigorously identify three time regimes separated by the physically relevant scrambling and relaxation times. The main feature of our analysis is that we express the error terms in the optimal Schatten (tracial) norms of the observables, allowing us to track the exact dependence of the errors on their rank. In particular, for significantly overlapping observables with low rank the OTOC is shown to exhibit a significant local maximum at the scrambling time, a feature that may not have been noticed in the physics literature before. Our main tool is a novel multi-resolvent local law with Schatten norms that unifies and improves previous local laws involving either the much cruder operator norm (cf. [10]) or the Hilbert-Schmidt norm (cf. [11]).}, author = {Cipolloni, Giorgio and Erdös, László and Henheik, Sven Joscha}, issn = {1095-0753}, journal = {Advances in Theoretical and Mathematical Physics}, number = {6}, pages = {2025--2083}, publisher = {International Press of Boston}, title = {{Out-of-time-ordered correlators for Wigner matrices}}, doi = {10.4310/ATMP.241031013250}, volume = {28}, year = {2024}, } @article{17292, abstract = {The Gibbons-Hawking ansatz provides a large family of circle-invariant hyperkähler 4-manifolds, and thus Calabi-Yau 2-folds. In this setting, we prove versions of the Thomas conjecture on existence of special Lagrangian representatives of Hamiltonian isotopy classes of Lagrangians, and the Thomas-Yau conjecture on longtime existence of the Lagrangian mean curvature ow. We also make observations concerning closed geodesics, curve shortening flow and minimal surfaces.}, author = {Lotay, Jason D. and Oliveira, Goncalo}, issn = {0022-040X}, journal = {Journal of Differential Geometry}, number = {3}, pages = {1121--1184}, publisher = {International Press of Boston}, title = {{Special Lagrangians, Lagrangian mean curvature flow and the Gibbons-Hawking ansatz}}, doi = {10.4310/jdg/1717348872}, volume = {126}, year = {2024}, } @inproceedings{17053, abstract = {We introduce a formalization of ternary simulation as abstract interpretation along with a widening operator to speed up convergence. With the same goal, we present a subsumption algorithm that can determine termination earlier than the usual approach using hash sets. Additionally, we introduce a narrowing operator that utilizes recent advances in backbone extraction, allowing to increase the overapproximation precision in simulation at any time. The experiments evaluate the presented techniques in the context of hardware model checking.}, author = {Froleyks, Nils and Yu, Zhengqi and Biere, Armin}, booktitle = {27th Workshop on Methods and Description Languages for Modeling and Verification of Circuits and Systems}, isbn = {9783800762682}, location = {Kaiserslautern, Germany}, pages = {148--151}, publisher = {VDE Verlag}, title = {{Ternary simulation as abstract interpretation (Work in Progress)}}, year = {2024}, } @phdthesis{17485, abstract = {Large language models (LLMs) have made tremendous progress in the past few years, from being able to generate coherent text to matching or surpassing humans in a wide variety of creative, knowledge or reasoning tasks. Much of this can be attributed to massively increased scale, both in the size of the model as well as the amount of training data, from 100s of millions to 100s of billions, or even trillions. This trend is expected to continue, which, although exciting, also raises major practical concerns. Already today's 100+ billion parameter LLMs require top-of-the-line hardware just to run. Hence, it is clear that sustaining these developments will require significant efficiency advances. Historically, one of the most practical ways of improving model efficiency has been compression, especially in the form of sparsity or quantization. While this has been studied extensively in the past, existing accurate methods are all designed for models around 100 million parameters; scaling them up to ones literally 1000x larger is highly challenging. In this thesis, we introduce a new unified sparsification and quantization approach OBC, which through additional algorithmic enhancements leads to GPTQ and SparseGPT, the first techniques fast and accurate enough to compress 100+ billion parameter models to 4- or even 3-bit precision and 50% weight-sparsity, respectively. Additionally, we show how weight-only quantizion does not just bring space savings but also up to 4.5x faster generation speed, via custom GPU kernels. In fact, we show for the first time that it is possible to develop an FP16 times INT4 mixed-precision matrix multiplication kernel, called Marlin, which comes close to simultaneously maximizing both memory and compute utilization, making weight-only quantization highly practical even for multi-user serving. Further, we demonstrate that GPTQ can be scaled to widely overparametrized trillion-parameter models, where extreme sub-1-bit compression rates can be achieved without any inference slow-down, by co-designing a bespoke entropy coding scheme together with an efficient kernel. Finally, we also study compression from the perspective of someone with access to massive amounts of compute resources for training large models completely from scratch. Here the key questions evolve around the joint scaling behavior between compression, model size, and amount of training data used. Based on extensive experimental results for both vision and text models, we introduce the first scaling law which accurately captures the relationship between weight-sparsity, number of non-zero weights and data. This further allows us to characterize the optimal sparsity, which we find to increase the longer a fixed cost model is being trained. Overall, this thesis presents contributions to three different angles of large model efficiency: affordable but accurate algorithms, highly efficient systems implementations, and fundamental scaling laws for compressed training.}, author = {Frantar, Elias}, issn = {2663-337X}, pages = {129}, publisher = {Institute of Science and Technology Austria}, title = {{Compressing large neural networks : Algorithms, systems and scaling laws}}, doi = {10.15479/at:ista:17485}, year = {2024}, } @inproceedings{17328, abstract = {We study selfish mining attacks in longest-chain blockchains like Bitcoin, but where the proof of work is replaced with efficient proof systems - like proofs of stake or proofs of space - and consider the problem of computing an optimal selfish mining attack which maximizes expected relative revenue of the adversary, thus minimizing the chain quality. To this end, we propose a novel selfish mining attack that aims to maximize this objective and formally model the attack as a Markov decision process (MDP). We then present a formal analysis procedure which computes an ϵ-tight lower bound on the optimal expected relative revenue in the MDP and a strategy that achieves this ϵ-tight lower bound, where ϵ > 0 may be any specified precision. Our analysis is fully automated and provides formal guarantees on the correctness. We evaluate our selfish mining attack and observe that it achieves superior expected relative revenue compared to two considered baselines. In concurrent work [Sarenche FC'24] does an automated analysis on selfish mining in predictable longest-chain blockchains based on efficient proof systems. Predictable means the randomness for the challenges is fixed for many blocks (as used e.g., in Ouroboros), while we consider unpredictable (Bitcoin-like) chains where the challenge is derived from the previous block.}, author = {Chatterjee, Krishnendu and Ebrahimzadeh, Amirali and Karrabi, Mehrdad and Pietrzak, Krzysztof Z and Yeo, Michelle X and Zikelic, Dorde}, booktitle = {Proceedings of the 43rd Annual ACM Symposium on Principles of Distributed Computing}, isbn = {9798400706684}, location = {Nantes, France}, pages = {268--278}, publisher = {Association for Computing Machinery}, title = {{Fully automated selfish mining analysis in efficient proof systems blockchains}}, doi = {10.1145/3662158.3662769}, year = {2024}, } @inproceedings{18061, abstract = {Mixture-of-Experts (MoE) architectures offer a general solution to the high inference costs of large language models (LLMs) via sparse routing, bringing faster and more accurate models, at the cost of massive parameter counts. For example, the SwitchTransformer-c2048 model has 1.6 trillion parameters, requiring 3.2TB of accelerator memory to run efficiently, which makes practical deployment challenging and expensive. In this paper, we present a solution to this memory problem, in form of a new compression and execution framework called QMoE. Specifically, QMoE consists of a scalable algorithm which accurately compresses trillion-parameter MoEs to less than 1 bit per parameter, in a custom format co-designed with bespoke GPU decoding kernels to facilitate efficient end-to-end compressed inference, with minor runtime overheads relative to uncompressed execution. Concretely, QMoE can compress the 1.6 trillion parameter SwitchTransformer-c2048 model to less than 160GB (20x compression, 0.8 bits per parameter) at only minor accuracy loss, in less than a day on a single GPU. This enables, for the first time, the execution of a trillion-parameter model on affordable commodity hardware, like a single server with 4x NVIDIA A6000 or 8x NVIDIA 3090 GPUs, at less than 5% runtime overhead relative to ideal uncompressed inference. The anonymized code is available at: github.com/mlsys24-qmoe/qmoe.}, author = {Frantar, Elias and Alistarh, Dan-Adrian}, booktitle = {Proceedings of Machine Learning and Systems}, location = {Santa Clara, CA, United States}, title = {{QMoE: Sub-1-bit compression of trillion parameter models}}, volume = {6}, year = {2024}, } @article{18530, abstract = {We explore the notion of history-determinism in the context of timed automata (TA) over infinite timed words. History-deterministic (HD) automata are those in which nondeterminism can be resolved on the fly, based on the run constructed thus far. History-determinism is a robust property that admits different game-based characterisations, and HD specifications allow for game-based verification without an expensive determinization step. We show that the class of timed ω -languages recognized by HD timed automata strictly extends that of deterministic ones, and is strictly included in those recognised by fully non-deterministic TA. For non-deterministic timed automata it is known that universality is already undecidable for safety/reachability TA. For history-deterministic TA with arbitrary parity acceptance, we show that timed universality, inclusion, and synthesis all remain decidable and are EXPTIME-complete. For the subclass of TA with safety or reachability acceptance, one can decide (in EXPTIME) whether such an automaton is history-deterministic. If so, it can effectively determinized without introducing new automaton states.}, author = {Bose, Sougata and Henzinger, Thomas A and Lehtinen, Karoliina and Schewe, Sven and Totzke, Patrick}, issn = {1860-5974}, journal = {Logical Methods in Computer Science}, number = {4}, pages = {1--28}, publisher = {EPI Sciences}, title = {{History-deterministic timed automata}}, doi = {10.46298/lmcs-20(4:1)2024}, volume = {20}, year = {2024}, } @phdthesis{18667, abstract = {Many chemical and physical properties of materials are determined by the material’s shape, for example the size of its pores and the width of its tunnels. This makes materials science a prime application area for geometrical and topological methods. Nevertheless many methods in topological data analysis have not been satisfyingly extended to the needs of materials science. This thesis provides new methods and new mathematical theorems targeted at those specific needs by answering four different research questions. While the motivation for each of the research questions arises from materials science, the methods are versatile and can be applied in different areas as well. The first research question is concerned with image data, for example a three-dimensional computed tomography (CT) scan of a material, like sand or stone. There are two commonly used topologies for digital images and depending on the application either of them might be required. However, software for computing the topological data analysis method persistence homology, usually supports only one of the two topologies. We answer the question how to compute persistent homology of an image with respect to one of the two topologies using software that is intended for the other topology. The second research question is concerned with image data as well, and asks how much of the topological information of an image is lost when the resolution is coarsened. As computer tomography scanners are more expensive the higher the resolution, it is an important question in materials science to know which resolution is enough to get satisfying persistent homology. We give theoretical bounds on the information loss based on different geometrical properties of the object to be scanned. In addition, we conduct experiments on sand and stone CT image data. The third research question is motivated by comparing crystalline materials efficiently. As the atoms within a crystal repeat periodically, crystalline materials are either modeled by unmanageable infinite periodic point sets, or by one of their fundamental domains, which is unstable under perturbation. Therefore a fingerprint of crystalline materials is needed, with appropriate properties such that comparing the crystals can be eased by comparing the fingerprints instead. We define the density fingerprint and prove the necessary properties. The fourth research question is motivated by studying the hole-structure or connectedness, i.e. persistent homology or merge trees, of crystalline materials. A common way to deal with periodicity is to take a fundamental domain and identify opposite boundaries to form a torus. However, computing persistent homology or merge trees on that torus loses some of the information materials scientists are interested in and is additionally not stable under certain noise. We therefore decorate the merge tree stemming from the torus with additional information describing the density and growth rate of the periodic copies of a component within a growing spherical window. We prove all desired properties, like stability and efficient computability.}, author = {Heiss, Teresa}, isbn = {978-3-99078-052-7}, issn = {2663-337X}, keywords = {persistent homology, topological data analysis, periodic, crystalline materials, images, fingerprint}, pages = {111}, publisher = {Institute of Science and Technology Austria}, title = {{New methods for applying topological data analysis to materials science}}, doi = {10.15479/at:ista:18667}, year = {2024}, } @article{18952, abstract = {A seventh blind test of crystal structure prediction was organized by the Cambridge Crystallographic Data Centre featuring seven target systems of varying complexity: a silicon and iodine-containing molecule, a copper coordination complex, a near-rigid molecule, a cocrystal, a polymorphic small agrochemical, a highly flexible polymorphic drug candidate, and a polymorphic morpholine salt. In this first of two parts focusing on structure generation methods, many crystal structure prediction (CSP) methods performed well for the small but flexible agrochemical compound, successfully reproducing the experimentally observed crystal structures, while few groups were successful for the systems of higher complexity. A powder X-ray diffraction (PXRD) assisted exercise demonstrated the use of CSP in successfully determining a crystal structure from a low-quality PXRD pattern. The use of CSP in the prediction of likely cocrystal stoichiometry was also explored, demonstrating multiple possible approaches. Crystallographic disorder emerged as an important theme throughout the test as both a challenge for analysis and a major achievement where two groups blindly predicted the existence of disorder for the first time. Additionally, large-scale comparisons of the sets of predicted crystal structures also showed that some methods yield sets that largely contain the same crystal structures.}, author = {Hunnisett, Lily M. and Nyman, Jonas and Francia, Nicholas and Abraham, Nathan S. and Adjiman, Claire S. and Aitipamula, Srinivasulu and Alkhidir, Tamador and Almehairbi, Mubarak and Anelli, Andrea and Anstine, Dylan M. and Anthony, John E. and Arnold, Joseph E. and Bahrami, Faezeh and Bellucci, Michael A. and Bhardwaj, Rajni M. and Bier, Imanuel and Bis, Joanna A. and Boese, A. Daniel and Bowskill, David H. and Bramley, James and Brandenburg, Jan Gerit and Braun, Doris E. and Butler, Patrick W. V. and Cadden, Joseph and Carino, Stephen and Chan, Eric J. and Chang, Chao and Cheng, Bingqing and Clarke, Sarah M. and Coles, Simon J. and Cooper, Richard I. and Couch, Ricky and Cuadrado, Ramon and Darden, Tom and Day, Graeme M. and Dietrich, Hanno and Ding, Yiming and DiPasquale, Antonio and Dhokale, Bhausaheb and van Eijck, Bouke P. and Elsegood, Mark R. J. and Firaha, Dzmitry and Fu, Wenbo and Fukuzawa, Kaori and Glover, Joseph and Goto, Hitoshi and Greenwell, Chandler and Guo, Rui and Harter, Jürgen and Helfferich, Julian and Hofmann, Detlef W. M. and Hoja, Johannes and Hone, John and Hong, Richard and Hutchison, Geoffrey and Ikabata, Yasuhiro and Isayev, Olexandr and Ishaque, Ommair and Jain, Varsha and Jin, Yingdi and Jing, Aling and Johnson, Erin R. and Jones, Ian and Jose, K. V. Jovan and Kabova, Elena A. and Keates, Adam and Kelly, Paul F. and Khakimov, Dmitry and Konstantinopoulos, Stefanos and Kuleshova, Liudmila N. and Li, He and Lin, Xiaolu and List, Alexander and Liu, Congcong and Liu, Yifei Michelle and Liu, Zenghui and Liu, Zhi-Pan and Lubach, Joseph W. and Marom, Noa and Maryewski, Alexander A. and Matsui, Hiroyuki and Mattei, Alessandra and Mayo, R. Alex and Melkumov, John W. and Mohamed, Sharmarke and Momenzadeh Abardeh, Zahrasadat and Muddana, Hari S. and Nakayama, Naofumi and Nayal, Kamal Singh and Neumann, Marcus A. and Nikhar, Rahul and Obata, Shigeaki and O'Connor, Dana and Oganov, Artem R. and Okuwaki, Koji and Otero-de-la-Roza, Alberto and Pantelides, Constantinos C. and Parkin, Sean and Pickard, Chris J. and Pilia, Luca and Pivina, Tatyana and Podeszwa, Rafał and Price, Alastair J. A. and Price, Louise S. and Price, Sarah L. and Probert, Michael R. and Pulido, Angeles and Ramteke, Gunjan Rajendra and Rehman, Atta Ur and Reutzel-Edens, Susan M. and Rogal, Jutta and Ross, Marta J. and Rumson, Adrian F. and Sadiq, Ghazala and Saeed, Zeinab M. and Salimi, Alireza and Salvalaglio, Matteo and Sanders de Almada, Leticia and Sasikumar, Kiran and Sekharan, Sivakumar and Shang, Cheng and Shankland, Kenneth and Shinohara, Kotaro and Shi, Baimei and Shi, Xuekun and Skillman, A. Geoffrey and Song, Hongxing and Strasser, Nina and van de Streek, Jacco and Sugden, Isaac J. and Sun, Guangxu and Szalewicz, Krzysztof and Tan, Benjamin I. and Tan, Lu and Tarczynski, Frank and Taylor, Christopher R. and Tkatchenko, Alexandre and Tom, Rithwik and Tuckerman, Mark E. and Utsumi, Yohei and Vogt-Maranto, Leslie and Weatherston, Jake and Wilkinson, Luke J. and Willacy, Robert D. and Wojtas, Lukasz and Woollam, Grahame R. and Yang, Zhuocen and Yonemochi, Etsuo and Yue, Xin and Zeng, Qun and Zhang, Yizu and Zhou, Tian and Zhou, Yunfei and Zubatyuk, Roman and Cole, Jason C.}, issn = {2052-5206}, journal = {Acta Crystallographica Section B}, number = {6}, pages = {517--547}, publisher = {International Union of Crystallography}, title = {{The seventh blind test of crystal structure prediction: Structure generation methods}}, doi = {10.1107/s2052520624007492}, volume = {80}, year = {2024}, } @article{17052, abstract = {Production of thermoelectric materials from solution-processed particles involves the synthesis of particles, their purification and densification into pelletized material. Chemical changes that occur during each one of these steps render them performance determining. Particularly the purification steps, bypassed in conventional solid-state synthesis, are the cause for large discrepancies among similar solution-processed materials. In present work, the investigation focuses on a water-based surfactant free solution synthesis of SnSe, a highly relevant thermoelectric material. We show and rationalize that the number of leaching steps, purification solvent, annealing, and annealing atmosphere have significant influence on the Sn : Se ratio and impurity content in the powder. Such compositional changes that are undetectable by conventional characterization techniques lead to distinct consolidated materials with different types and concentration of defects. Additionally, the profound effect on their transport properties is demonstrated. We emphasize that understanding the chemistry and identifying key chemical species and their role throughout the process is paramount for optimizing material performance. Furthermore, we aim to demonstrate the necessity of comprehensive reporting of these steps as a standard practice to ensure material reproducibility.}, author = {Fiedler, Christine and Calcabrini, Mariano and Liu, Yu and Ibáñez, Maria}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, number = {25}, publisher = {Wiley}, title = {{Unveiling crucial chemical processing parameters influencing the performance of solution-processed inorganic thermoelectric materials}}, doi = {10.1002/anie.202402628}, volume = {63}, year = {2024}, } @article{15119, abstract = {In this paper we consider an SPDE where the leading term is a second order operator with periodic boundary conditions, coefficients which are measurable in (t,ω) , and Hölder continuous in space. Assuming stochastic parabolicity conditions, we prove Lp((0,T)×Ω,tκdt;Hσ,q(Td)) -estimates. The main novelty is that we do not require p=q . Moreover, we allow arbitrary σ∈R and weights in time. Such mixed regularity estimates play a crucial role in applications to nonlinear SPDEs which is clear from our previous work. To prove our main results we develop a general perturbation theory for SPDEs. Moreover, we prove a new result on pointwise multiplication in spaces with fractional smoothness.}, author = {Agresti, Antonio and Veraar, Mark}, issn = {0246-0203}, journal = {Annales de l'Institut Henri Poincaré, Probabilités et Statistiques}, number = {1}, pages = {413--430}, publisher = {Institute of Mathematical Statistics}, title = {{Stochastic maximal Lp(Lq)-regularity for second order systems with periodic boundary conditions}}, doi = {10.1214/22-AIHP1333}, volume = {60}, year = {2024}, } @article{18492, abstract = {Surveys in the Milky Way and Large Magellanic Cloud have revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary properties of massive stars at low metallicity, and therefore in conditions approaching those of the Early Universe, remain sparse. We present the Binarity at LOw Metallicity (BLOeM) campaign, an ESO large programme designed to obtain 25 epochs of spectroscopy for 929 massive stars in the Small Magellanic Cloud, allowing us to probe multiplicity in the lowest-metallicity conditions to date (Z = 0.2 Z⊙). BLOeM will provide (i) the binary fraction, (ii) the orbital configurations of systems with periods of P ≲ 3 yr, (iii) dormant black-hole binary candidates (OB+BH), and (iv) a legacy database of physical parameters of massive stars at low metallicity. Main sequence (OB-type) and evolved (OBAF-type) massive stars are observed with the LR02 setup of the GIRAFFE instrument of the Very Large Telescope (3960–4570 Å resolving power R = 6200; typical signal-to-noise ratio(S/N) ≈70–100). This paper utilises the first nine epochs obtained over a three-month time period. We describe the survey and data reduction, perform a spectral classification of the stacked spectra, and construct a Hertzsprung-Russell diagram of the sample via spectral-type and photometric calibrations. Our detailed classification reveals that the sample covers spectral types from O4 to F5, spanning the effective temperature and luminosity ranges 6.5 ≲ Teff/kK ≲ 45 and 3.7 < log L/L⊙ < 6.1 and initial masses of 8 ≲ Mini ≲ 80 M⊙. The sample comprises 159 O-type stars, 331 early B-type (B0–3) dwarfs and giants (luminosity classes V–III), 303 early B-type supergiants (II–I), and 136 late-type BAF supergiants. At least 82 stars are OBe stars: 20 O-type and 62 B-type (13% and 11% of the respective samples). In addition, the sample includes 4 high-mass X-ray binaries, 3 stars resembling luminous blue variables, 2 bloated stripped-star candidates, 2 candidate magnetic stars, and 74 eclipsing binaries.}, author = {Shenar, T. and Bodensteiner, J. and Sana, H. and Crowther, P. A. and Lennon, D. J. and Abdul-Masih, M. and Almeida, L. A. and Backs, F. and Berlanas, S. R. and Bernini-Peron, M. and Bestenlehner, J. M. and Bowman, D. M. and Bronner, V. A. and Britavskiy, N. and De Koter, A. and De Mink, S. E. and Deshmukh, K. and Evans, C. J. and Fabry, M. and Gieles, M. and Gilkis, A. and González-Torà, G. and Gräfener, G. and Götberg, Ylva Louise Linsdotter and Hawcroft, C. and Hénault-Brunet, V. and Herrero, A. and Holgado, G. and Janssens, S. and Johnston, C. and Josiek, J. and Justham, S. and Kalari, V. M. and Katabi, Z. Z. and Keszthelyi, Z. and Klencki, J. and Kubát, J. and Kubátová, B. and Langer, N. and Lefever, R. R. and Ludwig, B. and Mackey, J. and Mahy, L. and Maíz Apellániz, J. and Mandel, I. and Maravelias, G. and Marchant, P. and Menon, A. and Najarro, F. and Oskinova, L. M. and O'Grady, A. J.G. and Ovadia, R. and Patrick, L. R. and Pauli, D. and Pawlak, M. and Ramachandran, V. and Renzo, M. and Rocha, D. F. and Sander, A. A.C. and Sayada, T. and Schneider, F. R.N. and Schootemeijer, A. and Schösser, E. C. and Schürmann, C. and Sen, K. and Shahaf, S. and Simón-Díaz, S. and Stoop, M. and Toonen, S. and Tramper, F. and Van Loon, J. Th and Valli, R. and Van Son, L. A.C. and Vigna-Gómez, A. and Villaseñor, J. I. and Vink, J. S. and Wang, C. and Willcox, R.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Binarity at LOw Metallicity (BLOeM): A spectroscopic VLT monitoring survey of massive stars in the SMC}}, doi = {10.1051/0004-6361/202451586}, volume = {690}, year = {2024}, } @article{18448, abstract = {Aims. This paper utilises the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) to extend the observational studies of dust and polycyclic aromatic hydrocarbon (PAH) emission to a new mass and star formation rate (SFR) parameter space beyond our local Universe. The combination of fully sampled spectral energy distributions (SEDs) with multiple mid-infrared (mid-IR) bands and the unprecedented sensitivity of MIRI allows us to investigate dust obscuration and PAH behaviour from z = 0.7 up to z = 2 in typical main-sequence galaxies. Our focus is on constraining the evolution of PAH strength and the dust-obscured luminosity fraction before and during cosmic noon, the epoch of peak star formation activity in the Universe. Methods. In this study, we utilise MIRI multi-band imaging data from the SMILES survey (5 to 25 μm), complemented with NIRCam photometry from the JADES survey (1 to 5 μm), available HST photometry (0.4 to 0.9 μm), and spectroscopic redshifts from the FRESCO and JADES surveys in GOODS-S for 443 star-forming (without dominant active galactic nucleus (AGN)) galaxies at z = 0.7 − 2.0. This redshift range was chosen to ensure that the MIRI data cover mid-IR dust emission. Our methodology involved employing ultraviolet (UV) to IR energy balance SED fitting to robustly constrain the fraction of dust mass in PAHs and dust-obscured luminosity. Additionally, we inferred dust sizes from MIRI 15 μm imaging data, enhancing our understanding of the physical characteristics of dust within these galaxies. Results. We find a strong correlation between the fraction of dust in PAHs (PAH fraction, qPAH) with stellar mass. Moreover, the sub-sample with robust qPAH measurements (N = 216) shows a similar behaviour between qPAH and gas-phase metallicity to that at z ∼ 0, suggesting a universal relation: qPAH is constant (∼3.4%) above a metallicity of Z ∼ 0.5 Z⊙ and decreases to < 1% at metallicities ≲0.3 Z⊙. This indicates that metallicity is a good indicator of the interstellar medium properties that affect the balance between the formation and destruction of PAHs. The lack of a redshift evolution from z ∼ 0 − 2 also implies that above Z ∼ 0.5 Z⊙ the PAH emission effectively traces obscured luminosity and the previous locally calibrated PAH-SFR calibrations remain applicable in this metallicity regime. We observe a strong correlation between the obscured UV luminosity fraction (ratio of obscured to total luminosity) and stellar mass. Above the stellar mass of M* > 5 × 109 M⊙, on average, more than half of the emitted luminosity is obscured, while there exists a non-negligible population of lower-mass galaxies with > 50% obscured fractions. At a fixed mass, the obscured fraction correlates with SFR surface density. This is a result of higher dust covering fractions in galaxies with more compact star-forming regions. Similarly, galaxies with high IRX (IR to UV luminosity) at a given mass or UV continuum slope (β) tend to have higher ΣSFR and shallower attenuation curves, owing to their higher effective dust optical depths and more compact star-forming regions.}, author = {Shivaei, Irene and Alberts, Stacey and Florian, Michael and Rieke, George and Wuyts, Stijn and Bodansky, Sarah and Bunker, Andrew J. and Cameron, Alex J. and Curti, Mirko and Da'Eugenio, Francesco and Dudzevičiūte, Ugne and Ji, Zhiyuan and Johnson, Benjamin D. and Kramarenko, Ivan and Lyu, Jianwei and Matthee, Jorryt J and Morrison, Jane and Naidu, Rohan and Pérez-González, Pablo G. and Reddy, Naveen and Robertson, Brant and Sun, Yang and Tacchella, Sandro and Whitaker, Katherine and Williams, Christina C. and Willmer, Christopher N.A. and Witstok, Joris and Xiao, Mengyuan and Zhu, Yongda}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{A new census of dust and polycyclic aromatic hydrocarbons at z = 0.7-2 with JWST MIRI}}, doi = {10.1051/0004-6361/202449579}, volume = {690}, year = {2024}, } @article{17889, abstract = {The increasingly neutral intergalactic gas at z > 6 impacts the Lyman-α (Lyα) flux observed from galaxies. One luminous galaxy, COLA1, stands out because of its unique double-peaked Lyα line at z = 6.6, unseen in any simulation of reionization. Here, we present JWST/NIRCam wide-field slitless spectroscopy in a 21 arcmin2 field centered on COLA1. We find 141 galaxies spectroscopically selected through the [O III] doublet at 5.35 < z < 6.95, with 40 of these sources showing Hβ. For COLA1, we additionally detect [O III]4363 as well as Hγ. We measure a systemic redshift of z = 6.5917 for COLA1, confirming the classical double-peak nature of the Lyα profile. This implies that it resides in a highly ionized bubble and that it is leaking ionizing photons with a high escape fraction of fesc(LyC) = 20–50%, making it a prime laboratory to study Lyman continuum escape in the Epoch of Reionization. COLA1 shows all the signs of a prolific ionizer with a Lyα escape fraction of 81 ± 5%, Balmer decrement indicating no dust, a steep UV slope (βUV = −3.2 ± 0.4), and a star-formation surface density ≳10× that of typical galaxies at similar redshift. We detect five galaxies in COLA1’s close environment (Δz < 0.02). Exploiting the high spectroscopic completeness inherent to grism surveys, and using mock simulations that fully mimic the selection function, we show that the number of detected companions is very typical for a normal similarly UV-bright (MUV ∼ −21.3) galaxy – that is, the ionized bubble around COLA1 is unlikely to be due to an excessively large over-density. Instead, the measured ionizing properties suggest that COLA1 by itself might be powering the bubble required to explain its double-peaked Lyα profile (Rion ≈ 0.7 pMpc), with only minor contributions from detected neighbors (−19.5 ≲ MUV ≲ −17.5).}, author = {Torralba-Torregrosa, Alberto and Matthee, Jorryt J and Naidu, Rohan P. and Mackenzie, Ruari and Pezzulli, Gabriele and Hutter, Anne and Arnalte-Mur, Pablo and Gurung-López, Siddhartha and Tacchella, Sandro and Oesch, Pascal and Kashino, Daichi and Conroy, Charlie and Sobral, David}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Anatomy of an ionized bubble: NIRCam grism spectroscopy of the z = 6.6 double-peaked Lyman- α emitter COLA1 and its environment}}, doi = {10.1051/0004-6361/202450318}, volume = {689}, year = {2024}, } @article{18904, abstract = {The Planetary Transits and Oscillations of stars mission (PLATO) will allow us to measure surface rotation and monitor photometric activity of tens of thousands of main sequence solar-type and subgiant stars. This paper is the first of a series dedicated to the preparation of the analysis of stellar surface rotation and photospheric activity with the near-future PLATO data. We describe in this work the strategy that will be implemented in the PLATO pipeline to measure stellar surface rotation, photometric activity, and long-term modulations. The algorithms are applied on both noise-free and noisy simulations of solar-type stars, which include activity cycles, latitudinal differential rotation, and spot evolution. PLATO simulated systematics are included in the noisy light curves. We show that surface rotation periods can be recovered with confidence for most of the stars with only six months of observations and that the recovery rate of the analysis significantly improves as additional observations are collected. This means that the first PLATO data release will already provide a substantial set of measurements for this quantity, with a significant refinement on their quality as the instrument obtains longer light curves. Measuring the Schwabe-like magnetic activity cycle during the mission will require that the same field be observed over a significant timescale (more than four years). Nevertheless, PLATO will provide a vast and robust sample of solar-type stars with constraints on the activity-cycle length. Such a sample is lacking from previous missions dedicated to space photometry.}, author = {Breton, S. N. and Lanza, A. F. and Messina, S. and Pagano, I. and Bugnet, Lisa Annabelle and Corsaro, E. and García, R. A. and Mathur, S. and Santos, A. R. G. and Aigrain, S. and Amard, L. and Brun, A. S. and Degott, L. and Noraz, Q. and Palakkatharappil, D. B. and Panetier, E. and Strugarek, A. and Belkacem, K. and Goupil, M.-J and Ouazzani, R. M. and Philidet, J. and Renié, C. and Roth, O.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Measuring stellar surface rotation and activity with the PLATO mission. I. Strategy and application to simulated light curves}}, doi = {10.1051/0004-6361/202449893}, volume = {689}, year = {2024}, } @article{18447, abstract = {We present the first results on the spatial distribution of star formation in 454 star-forming galaxies just after the epoch of reionisation (4.8 < z < 6.5) using Hα emission-line maps and F444W imaging that traces the stellar continuum from the JWST FRESCO NIRCam Slitless Spectroscopy Survey. The Hα equivalent width profiles of star-forming galaxies across the main sequence at z ∼ 5.3 with stellar masses 6.8≤ log(M*/M⊙) < 11.1 increase with radius, which provides direct evidence for the inside-out growth of star-forming galaxies just after the epoch of reionisation. GALFIT was used to calculate half-light radii, Reff, and central surface densities within 1 kiloparsec, Σ1kpc of Hα and the continuum. At a fixed stellar mass of Log(M*/M⊙) = 9.5, Σ1kpc, Hα is 1.04 ± 0.05 times higher than Σ1kpc, C, Reff, Hα is 1.18 ± 0.03 times larger than Reff, C and both Reff measurements are smaller than 1 kiloparsec. These measurements suggest the rapid build-up of compact bulges via star formation just after the epoch of reionisation. By comparison to analogous work done at lower redshifts with Hubble Space Telescope WFC3 slitless spectroscopy as part of the 3D-HST (z ∼ 1) and CLEAR (z ∼ 0.5) surveys, we find that Reff(z) evolves at the same pace for Hα and the continuum, but Σ1kpc(z) evolves faster for Hα than the stellar continuum. As a function of the Hubble parameter, Reff, Hα/Reff,C = 1.1h(z) and Σ1 kpc, Hα/Σ1 kpc,C = h(z)1.3. These parametrisations suggest that the inside-out growth of the disk starts to dominate the inside-out growth of the bulge towards lower redshifts. This is supported by the redshift evolution in the EW(Hα) profiles from FRESCO, 3D-HST, and CLEAR at fixed stellar mass and when star-forming progenitors are traced, in which in EW(Hα) rapidly increases with radius within the half-light radius at z ∼ 5.3, but EW(Hα) increases only significantly with radius in the outer disk at z ∼ 0.5.}, author = {Matharu, Jasleen and Nelson, Erica J. and Brammer, Gabriel and Oesch, Pascal A. and Allen, Natalie and Shivaei, Irene and Naidu, Rohan P. and Chisholm, John and Covelo-Paz, Alba and Fudamoto, Yoshinobu and Giovinazzo, Emma and Herard-Demanche, Thomas and Kerutt, Josephine and Kramarenko, Ivan and Marchesini, Danilo and Meyer, Romain A. and Prieto-Lyon, Gonzalo and Reddy, Naveen and Shuntov, Marko and Weibel, Andrea and Wuyts, Stijn and Xiao, Mengyuan}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{A first look at spatially resolved star formation at 4.8 < z < 6.5 with JWST FRESCO NIRCam slitless spectroscopy}}, doi = {10.1051/0004-6361/202450522}, volume = {690}, year = {2024}, } @article{18493, abstract = {Context. The escape of Lyman-α photons at redshifts greater than two is an ongoing subject of study and an important quantity to further understanding of Lyman-α emitters (LAEs), the transmission of Lyman-α photons through the interstellar medium and intergalactic medium, and the impact these LAEs have on cosmic reionisation. Aims. This study aims to assess the Lyman-α escape fraction, fesc, Lyα, over the redshift range 2.9 < z < 6.7, focusing on Very Large Telescope/Multi Unit Spectroscopic Explorer (VLT/MUSE) selected, gravitationally lensed, intrinsically faint LAEs. These galaxies are of particular interest as the potential drivers of cosmic reionisation. Methods. We assessed fesc, Lyα in two ways: through an individual study of 96 LAEs behind the A2744 lensing cluster, with James Webb Space Telescope/Near-Infrared Camera (JWST/NIRCam) and HST data, and through a study of the global evolution of fesc, Lyα using the state-of-the-art luminosity functions for LAEs and the UV-selected ‘parent’ population (dust-corrected). We compared these studies to those in the literature based on brighter samples. Results. We find a negligible redshift evolution of fesc, Lyα for our individual galaxies; it is likely that it was washed out by significant intrinsic scatter. We observed a more significant evolution towards higher escape fractions with decreasing UV magnitude and fit this relation. When comparing the two luminosity functions to derive fesc, Lyα in a global sense, we saw agreement with previous literature when integrating the luminosity functions to a bright limit. However, when integrating using a faint limit equivalent to the observational limits of our samples, we observed enhanced values of fesc, Lyα, particularly around z ∼ 6, where fesc, Lyα becomes consistent with 100% escape. This indicates for the faint regimes we sampled that galaxies towards reionisation tend to allow very large fractions of Lyman-α photons to escape. We interpret this as evidence of a lack of any significant dust in these populations; our sample is likely dominated by young, highly star-forming chemically unevolved galaxies. Finally, we assessed the contribution of the LAE population to reionisation using our latest values for fesc, Lyα and the LAE luminosity density. The dependence on the escape fraction of Lyman continuum photons is strong, but for values similar to those observed recently in z ∼ 3 LAEs and high-redshift analogues, LAEs could provide all the ionising emissivity necessary for reionisation.}, author = {Goovaerts, I. and Thai, T. T. and Pello, R. and Tuan-Anh, P. and Laporte, N. and Matthee, Jorryt J and Nanayakkara, T. and Pharo, J.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Charting the Lyman-α escape fraction in the range 2.9 < z < 6.7 and consequences for the LAE reionisation contribution}}, doi = {10.1051/0004-6361/202451432}, volume = {690}, year = {2024}, } @article{18528, abstract = {The recent measurement of magnetic field strength inside the radiative interior of red giant stars has opened the way toward full 3D characterization of the geometry of stable large-scale magnetic fields. However, current measurements, which are limited to dipolar (ℓ = 1) mixed modes, do not properly constrain the topology of magnetic fields due to degeneracies on the observed magnetic field signature on such ℓ = 1 mode frequencies. Efforts focused toward unambiguous detections of magnetic field configurations are now key to better understand angular momentum transport in stars. We investigated the detectability of complex magnetic field topologies (such as the ones observed at the surface of stars with a radiative envelope with spectropolarimetry) inside the radiative interior of red giants. We focused on a field composed of a combination of a dipole and a quadrupole (quadrudipole) and on an offset field. We explored the potential of probing such magnetic field topologies from a combined measurement of magnetic signatures on ℓ = 1 and quadrupolar (ℓ = 2) mixed mode oscillation frequencies. We first derived the asymptotic theoretical formalism for computing the asymmetric signature in the frequency pattern for ℓ = 2 modes due to a quadrudipole magnetic field. To access asymmetry parameters for more complex magnetic field topologies, we numerically performed a grid search over the parameter space to map the degeneracy of the signatures of given topologies. We demonstrate the crucial role played by ℓ = 2 mixed modes in accessing internal magnetic fields with a quadrupolar component. The degeneracy of the quadrudipole compared to pure dipolar fields is lifted when considering magnetic asymmetries in both ℓ = 1 and ℓ = 2 mode frequencies. In addition to the analytical derivation for the quadrudipole, we present the prospect for complex magnetic field inversions using magnetic sensitivity kernels from standard perturbation analysis for forward modeling. Using this method, we explored the detectability of offset magnetic fields from ℓ = 1 and ℓ = 2 frequencies and demonstrate that offset fields may be mistaken for weak and centered magnetic fields, resulting in underestimating the magnetic field strength in stellar cores. We emphasize the need to characterize ℓ = 2 mixed-mode frequencies, (along with the currently characterized ℓ = 1 mixed modes), to unveil the higher-order components of the geometry of buried magnetic fields and to better constrain angular momentum transport inside stars.}, author = {Das, Srijan B and Einramhof, Lukas and Bugnet, Lisa Annabelle}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Unveiling complex magnetic field configurations in red giant stars}}, doi = {10.1051/0004-6361/202450918}, volume = {690}, year = {2024}, } @article{15336, abstract = {Submillimeter surveys toward overdense regions in the early Universe are essential for uncovering the obscured star formation and the cold gas content of assembling galaxies within massive dark matter halos. In this work, we present deep ALMA mosaic observations covering an area of ∼2′×2′ around MUSE Quasar Nebula 01 (MQN01), one of the largest and brightest Ly-α emitting nebulae discovered thus far; it surrounds a radio-quiet quasar at z ≃ 3.25. Our observations target the 1.2 and the 3 mm dust continuum as well as the carbon monoxide CO(4–3) transition in galaxies in the vicinity of the quasar. We identify a robust sample of 11 CO-line-emitting galaxies (including a closely separated quasar companion) that lie within ±4000 km s−1 of the quasar systemic redshift. A fraction of these objects were missed in previous deep rest-frame optical/UV surveys, which highlights the critical role of (sub)millimeter imaging. We also detect a total of 11 sources revealed in the dust continuum at 1.2 mm; six of them have either high-fidelity spectroscopic redshift information from rest-frame UV metal absorptions or the CO(4–3) line that places them in the same narrow redshift range. A comparison of the CO luminosity function and 1.2 mm number count density with those of the general fields points to a galaxy overdensity of δ > 10. We find evidence of a systematic flattening at the bright end of the CO luminosity function with respect to the trend measured in blank fields. Our findings reveal that galaxies in dense regions at z ∼ 3 are more massive and significantly richer in molecular gas than galaxies in fields, which enables a faster and accelerated assembly. This is the first in a series of studies aimed at characterizing one of the densest regions of the Universe found so far at z > 3.}, author = {Pensabene, A. and Cantalupo, S. and Cicone, C. and Decarli, R. and Galbiati, M. and Ginolfi, M. and De Beer, S. and Fossati, M. and Fumagalli, M. and Lazeyras, T. and Pezzulli, G. and Travascio, A. and Wang, W. and Matthee, Jorryt J and Maseda, M. V.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{ALMA survey of a massive node of the Cosmic Web at z ∼ 3: I. Discovery of a large overdensity of CO emitters}}, doi = {10.1051/0004-6361/202348659}, volume = {684}, year = {2024}, } @article{18527, abstract = {Context. Galaxies evolve through a dynamic exchange of material with their immediate surrounding environment, the so-called circumgalactic medium (CGM). Understanding the physics of gas flows and the nature of the CGM is fundamental to studying galaxy evolution, especially at 4 ≤ z ≤ 6 (i.e., after the Epoch of Reionization) when galaxies rapidly assembled their masses and reached their chemical maturity. Galactic outflows are predicted to enrich the CGM with metals, although it has also been suggested that gas stripping in systems undergoing a major merger may play a role. Aims. In this work, we explore the metal enrichment of the medium around merging galaxies at z ∼ 4.5, observed by the ALMA Large Program to INvestigate [CII] at Early times (ALPINE). To do so, we study the nature of the [CII] 158 μm emission in the CGM around these systems, using simulations to help disentangle the mechanisms contributing to the CGM metal pollution. Methods. By adopting an updated classification of major merger systems in the ALPINE survey, we selected and analyzed merging galaxies whose components can be spatially and/or spectrally resolved in a robust way. This makes it possible to distinguish between the [CII] emission coming from the single components of the system and that coming from the system as a whole. We also made use of the dustyGadget cosmological simulation to select synthetic analogs of observed galaxies and guide the interpretation of the observational results. Results. We find a large diffuse [CII] envelope (≳20 kpc) embedding all the merging systems, with at least 25% of the total [CII] emission coming from the medium between the galaxies. Using predictions from dustyGadget, we suggest that this emission has a multi-fold nature, with dynamical interactions between galaxies playing a major role in stripping the gas and enriching the medium with heavy elements.}, author = {Di Cesare, Claudia and Ginolfi, M. and Graziani, L. and Schneider, R. and Romano, M. and Popping, G.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Carbon envelopes around merging galaxies at z ~ 4.5}}, doi = {10.1051/0004-6361/202449164}, volume = {690}, year = {2024}, }