@article{14800, abstract = {Research on two-dimensional (2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief background introduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials (PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field. }, author = {Chang, Cheng and Chen, Wei and Chen, Ye and Chen, Yonghua and Chen, Yu and Ding, Feng and Fan, Chunhai and Fan, Hong Jin and Fan, Zhanxi and Gong, Cheng and Gong, Yongji and He, Qiyuan and Hong, Xun and Hu, Sheng and Hu, Weida and Huang, Wei and Huang, Yuan and Ji, Wei and Li, Dehui and Li, Lain Jong and Li, Qiang and Lin, Li and Ling, Chongyi and Liu, Minghua and Liu, Nan and Liu, Zhuang and Loh, Kian Ping and Ma, Jianmin and Miao, Feng and Peng, Hailin and Shao, Mingfei and Song, Li and Su, Shao and Sun, Shuo and Tan, Chaoliang and Tang, Zhiyong and Wang, Dingsheng and Wang, Huan and Wang, Jinlan and Wang, Xin and Wang, Xinran and Wee, Andrew T.S. and Wei, Zhongming and Wu, Yuen and Wu, Zhong Shuai and Xiong, Jie and Xiong, Qihua and Xu, Weigao and Yin, Peng and Zeng, Haibo and Zeng, Zhiyuan and Zhai, Tianyou and Zhang, Han and Zhang, Hui and Zhang, Qichun and Zhang, Tierui and Zhang, Xiang and Zhao, Li Dong and Zhao, Meiting and Zhao, Weijie and Zhao, Yunxuan and Zhou, Kai Ge and Zhou, Xing and Zhou, Yu and Zhu, Hongwei and Zhang, Hua and Liu, Zhongfan}, issn = {1001-4861}, journal = {Acta Physico-Chimica Sinica}, number = {12}, publisher = {Peking University}, title = {{Recent progress on two-dimensional materials}}, doi = {10.3866/PKU.WHXB202108017}, volume = {37}, year = {2021}, } @article{14889, abstract = {We consider the Fröhlich Hamiltonian with large coupling constant α. For initial data of Pekar product form with coherent phonon field and with the electron minimizing the corresponding energy, we provide a norm approximation of the evolution, valid up to times of order α2. The approximation is given in terms of a Pekar product state, evolved through the Landau-Pekar equations, corrected by a Bogoliubov dynamics taking quantum fluctuations into account. This allows us to show that the Landau-Pekar equations approximately describe the evolution of the electron- and one-phonon reduced density matrices under the Fröhlich dynamics up to times of order α2.}, author = {Leopold, Nikolai K and Mitrouskas, David Johannes and Rademacher, Simone Anna Elvira and Schlein, Benjamin and Seiringer, Robert}, issn = {2578-5885}, journal = {Pure and Applied Analysis}, number = {4}, pages = {653--676}, publisher = {Mathematical Sciences Publishers}, title = {{Landau–Pekar equations and quantum fluctuations for the dynamics of a strongly coupled polaron}}, doi = {10.2140/paa.2021.3.653}, volume = {3}, year = {2021}, } @article{14890, abstract = {We consider a system of N interacting bosons in the mean-field scaling regime and construct corrections to the Bogoliubov dynamics that approximate the true N-body dynamics in norm to arbitrary precision. The N-independent corrections are given in terms of the solutions of the Bogoliubov and Hartree equations and satisfy a generalized form of Wick's theorem. We determine the n-point correlation functions of the excitations around the condensate, as well as the reduced densities of the N-body system, to arbitrary accuracy, given only the knowledge of the two-point functions of a quasi-free state and the solution of the Hartree equation. In this way, the complex problem of computing all n-point correlation functions for an interacting N-body system is essentially reduced to the problem of solving the Hartree equation and the PDEs for the Bogoliubov two-point functions.}, author = {Bossmann, Lea and Petrat, Sören P and Pickl, Peter and Soffer, Avy}, issn = {2578-5885}, journal = {Pure and Applied Analysis}, number = {4}, pages = {677--726}, publisher = {Mathematical Sciences Publishers}, title = {{Beyond Bogoliubov dynamics}}, doi = {10.2140/paa.2021.3.677}, volume = {3}, year = {2021}, } @inbook{14984, abstract = {Hybrid zones are narrow geographic regions where different populations, races or interbreeding species meet and mate, producing mixed ‘hybrid’ offspring. They are relatively common and can be found in a diverse range of organisms and environments. The study of hybrid zones has played an important role in our understanding of the origin of species, with hybrid zones having been described as ‘natural laboratories’. This is because they allow us to study,in situ, the conditions and evolutionary forces that enable divergent taxa to remain distinct despite some ongoing gene exchange between them.}, author = {Stankowski, Sean and Shipilina, Daria and Westram, Anja M}, booktitle = {Encyclopedia of Life Sciences}, isbn = {9780470016176}, publisher = {Wiley}, title = {{Hybrid Zones}}, doi = {10.1002/9780470015902.a0029355}, volume = {2}, year = {2021}, } @inbook{14987, abstract = {The goal of zero-shot learning is to construct a classifier that can identify object classes for which no training examples are available. When training data for some of the object classes is available but not for others, the name generalized zero-shot learning is commonly used. In a wider sense, the phrase zero-shot is also used to describe other machine learning-based approaches that require no training data from the problem of interest, such as zero-shot action recognition or zero-shot machine translation.}, author = {Lampert, Christoph}, booktitle = {Computer Vision}, editor = {Ikeuchi, Katsushi}, isbn = {9783030634155}, pages = {1395--1397}, publisher = {Springer}, title = {{Zero-Shot Learning}}, doi = {10.1007/978-3-030-63416-2_874}, year = {2021}, } @misc{14988, abstract = {Raw data generated from the publication - The TPLATE complex mediates membrane bending during plant clathrin-mediated endocytosis by Johnson et al., 2021 In PNAS}, author = {Johnson, Alexander J}, publisher = {Zenodo}, title = {{Raw data from Johnson et al, PNAS, 2021}}, doi = {10.5281/ZENODO.5747100}, year = {2021}, } @article{15013, abstract = {We consider random n×n matrices X with independent and centered entries and a general variance profile. We show that the spectral radius of X converges with very high probability to the square root of the spectral radius of the variance matrix of X when n tends to infinity. We also establish the optimal rate of convergence, that is a new result even for general i.i.d. matrices beyond the explicitly solvable Gaussian cases. The main ingredient is the proof of the local inhomogeneous circular law [arXiv:1612.07776] at the spectral edge.}, author = {Alt, Johannes and Erdös, László and Krüger, Torben H}, issn = {2690-1005}, journal = {Probability and Mathematical Physics}, number = {2}, pages = {221--280}, publisher = {Mathematical Sciences Publishers}, title = {{Spectral radius of random matrices with independent entries}}, doi = {10.2140/pmp.2021.2.221}, volume = {2}, year = {2021}, } @article{13356, abstract = {Self-assembly of nanoparticles can be mediated by polymers, but has so far led almost exclusively to nanoparticle aggregates that are amorphous. Here, we employed Coulombic interactions to generate a range of composite materials from mixtures of charged nanoparticles and oppositely charged polymers. The assembly behavior of these nanoparticle/polymer composites depends on their order of addition: polymers added to nanoparticles give rise to stable aggregates, but nanoparticles added to polymers disassemble the initially formed aggregates. The amorphous aggregates were transformed into crystalline ones by transiently increasing the ionic strength of the solution. The morphology of the resulting crystals depended on the length of the polymer: short polymer chains mediated the self-assembly of nanoparticles into strongly faceted crystals, whereas long chains led to pseudospherical nanoparticle/polymer assemblies, within which the crystalline order of nanoparticles was retained.}, author = {Bian, Tong and Klajn, Rafal}, issn = {1749-6632}, journal = {Annals of the New York Academy of Sciences}, keywords = {History and Philosophy of Science, General Biochemistry, Genetics and Molecular Biology, General Neuroscience}, number = {1}, pages = {191--201}, publisher = {Wiley}, title = {{Morphology control in crystalline nanoparticle–polymer aggregates}}, doi = {10.1111/nyas.14674}, volume = {1505}, year = {2021}, } @article{13357, abstract = {Coulombic interactions can be used to assemble charged nanoparticles into higher-order structures, but the process requires oppositely charged partners that are similarly sized. The ability to mediate the assembly of such charged nanoparticles using structurally simple small molecules would greatly facilitate the fabrication of nanostructured materials and harnessing their applications in catalysis, sensing and photonics. Here we show that small molecules with as few as three electric charges can effectively induce attractive interactions between oppositely charged nanoparticles in water. These interactions can guide the assembly of charged nanoparticles into colloidal crystals of a quality previously only thought to result from their co-crystallization with oppositely charged nanoparticles of a similar size. Transient nanoparticle assemblies can be generated using positively charged nanoparticles and multiply charged anions that are enzymatically hydrolysed into mono- and/or dianions. Our findings demonstrate an approach for the facile fabrication, manipulation and further investigation of static and dynamic nanostructured materials in aqueous environments.}, author = {Bian, Tong and Gardin, Andrea and Gemen, Julius and Houben, Lothar and Perego, Claudio and Lee, Byeongdu and Elad, Nadav and Chu, Zonglin and Pavan, Giovanni M. and Klajn, Rafal}, issn = {1755-4349}, journal = {Nature Chemistry}, keywords = {General Chemical Engineering, General Chemistry}, number = {10}, pages = {940--949}, publisher = {Springer Nature}, title = {{Electrostatic co-assembly of nanoparticles with oppositely charged small molecules into static and dynamic superstructures}}, doi = {10.1038/s41557-021-00752-9}, volume = {13}, year = {2021}, } @article{13358, abstract = {DNA nanotechnology offers a versatile toolbox for precise spatial and temporal manipulation of matter on the nanoscale. However, rendering DNA-based systems responsive to light has remained challenging. Herein, we describe the remote manipulation of native (non-photoresponsive) chiral plasmonic molecules (CPMs) using light. Our strategy is based on the use of a photoresponsive medium comprising a merocyanine-based photoacid. Upon exposure to visible light, the medium decreases its pH, inducing the formation of DNA triplex links, leading to a spatial reconfiguration of the CPMs. The process can be reversed simply by turning the light off and it can be repeated for multiple cycles. The degree of the overall chirality change in an ensemble of CPMs depends on the CPM fraction undergoing reconfiguration, which, remarkably, depends on and can be tuned by the intensity of incident light. Such a dynamic, remotely controlled system could aid in further advancing DNA-based devices and nanomaterials.}, author = {Ryssy, Joonas and Natarajan, Ashwin K. and Wang, Jinhua and Lehtonen, Arttu J. and Nguyen, Minh‐Kha and Klajn, Rafal and Kuzyk, Anton}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, keywords = {General Chemistry, Catalysis}, number = {11}, pages = {5859--5863}, publisher = {Wiley}, title = {{Light‐responsive dynamic DNA‐origami‐based plasmonic assemblies}}, doi = {10.1002/anie.202014963}, volume = {60}, year = {2021}, } @article{13359, abstract = {Dissipative self-assembly is ubiquitous in nature, where it gives rise to complex structures and functions such as self-healing, homeostasis, and camouflage. These phenomena are enabled by the continuous conversion of energy stored in chemical fuels, such as ATP. Over the past decade, an increasing number of synthetic chemically driven systems have been reported that mimic the features of their natural counterparts. At the same time, it has been shown that dissipative self-assembly can also be fueled by light; these optically fueled systems have been developed in parallel to the chemically fueled ones. In this perspective, we critically compare these two classes of systems. Despite the complementarity and fundamental differences between these two modes of dissipative self-assembly, our analysis reveals that multiple analogies exist between chemically and light-fueled systems. We hope that these considerations will facilitate further development of the field of dissipative self-assembly.}, author = {Weißenfels, Maren and Gemen, Julius and Klajn, Rafal}, issn = {2451-9294}, journal = {Chem}, keywords = {Materials Chemistry, Biochemistry (medical), General Chemical Engineering, Environmental Chemistry, Biochemistry, General Chemistry}, number = {1}, pages = {23--37}, publisher = {Elsevier}, title = {{Dissipative self-assembly: Fueling with chemicals versus light}}, doi = {10.1016/j.chempr.2020.11.025}, volume = {7}, year = {2021}, } @inbook{13360, abstract = {Inorganic nanoparticles (NPs) exhibit a wide range of fascinating physicochemical properties, many of which can be controlled by modulating the NP–NP coupling. Controlling the self-assembly of NPs using light has traditionally been achieved by functionalizing their surfaces with monolayers of photoswitchable molecules, which can be reversibly isomerized between two or more states upon exposure to different wavelengths of light. NPs whose assembly can be controlled by light in a reversible fashion can find interesting applications. The chapter deals with systems comprising mixtures of non-photoswitchable NPs and small-molecule photoacids and photobases. Examples of light-controlled self-assembly of NPs hitherto reported have been categorized into six distinct approaches. These are: functionalizing NPs with monolayers of photoswitchable molecules, light-controlled adsorption/desorption of photoswitchable molecules onto NPs, and light-induced electron transfer between the particle's inorganic core and the NP-bound ligands.}, author = {Bian, Tong and Chu, Zonglin and Klajn, Rafal}, booktitle = {Out‐of‐Equilibrium (Supra)molecular Systems and Materials}, editor = {Giuseppone, Nicolas and Walther, Andreas}, isbn = {9783527346158}, pages = {241--273}, publisher = {Wiley}, title = {{Controlling Self‐Assembly of Nanoparticles Using Light}}, doi = {10.1002/9783527821990.ch9}, year = {2021}, } @article{13453, abstract = {Most massive stars are born in binaries close enough for mass transfer episodes. These modify the appearance, structure, and future evolution of both stars. We compute the evolution of a 100-day-period binary, consisting initially of a 25 M⊙ star and a 17 M⊙ star, which experiences stable mass transfer. We focus on the impact of mass accretion on the surface composition, internal rotation, and structure of the accretor. To anchor our models, we show that our accretor broadly reproduces the properties of ζ Ophiuchi, which has long been proposed to have accreted mass before being ejected as a runaway star when the companion exploded. We compare our accretor to models of single rotating stars and find that the later and stronger spin-up provided by mass accretion produces significant differences. Specifically, the core of the accretor retains higher spin at the end of the main sequence, and a convective layer develops that changes its density profile. Moreover, the surface of the accretor star is polluted by CNO-processed material donated by the companion. Our models show effects of mass accretion in binaries that are not captured in single rotating stellar models. This possibly impacts the further evolution (either in a binary or as single stars), the final collapse, and the resulting spin of the compact object.}, author = {Renzo, M. and Götberg, Ylva Louise Linsdotter}, issn = {1538-4357}, journal = {The Astrophysical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, publisher = {American Astronomical Society}, title = {{Evolution of accretor stars in massive binaries: Broader implications from modeling ζ Ophiuchi}}, doi = {10.3847/1538-4357/ac29c5}, volume = {923}, year = {2021}, } @article{13454, abstract = {Helium star–carbon-oxygen white dwarf (CO WD) binaries are potential single-degenerate progenitor systems of thermonuclear supernovae. Revisiting a set of binary evolution calculations using the stellar evolution code MESA, we refine our previous predictions about which systems can lead to a thermonuclear supernova and then characterize the properties of the helium star donor at the time of explosion. We convert these model properties to near-UV/optical magnitudes assuming a blackbody spectrum and support this approach using a matched stellar atmosphere model. These models will be valuable to compare with pre-explosion imaging for future supernovae, though we emphasize the observational difficulty of detecting extremely blue companions. The pre-explosion source detected in association with SN 2012Z has been interpreted as a helium star binary containing an initially ultra-massive WD in a multiday orbit. However, extending our binary models to initial CO WD masses of up to 1.2 M⊙, we find that these systems undergo off-center carbon ignitions and thus are not expected to produce thermonuclear supernovae. This tension suggests that, if SN 2012Z is associated with a helium star–WD binary, then the pre-explosion optical light from the system must be significantly modified by the binary environment and/or the WD does not have a carbon-rich interior composition.}, author = {Wong, Tin Long Sunny and Schwab, Josiah and Götberg, Ylva Louise Linsdotter}, issn = {1538-4357}, journal = {The Astrophysical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, publisher = {American Astronomical Society}, title = {{Pre-explosion properties of Helium star donors to thermonuclear supernovae}}, doi = {10.3847/1538-4357/ac27ae}, volume = {922}, year = {2021}, } @article{13455, abstract = {The majority of massive stars live in binary or multiple systems and will interact with a companion during their lifetimes, which helps to explain the observed diversity of core-collapse supernovae. Donor stars in binary systems can lose most of their hydrogen-rich envelopes through mass transfer. As a result, not only are the surface properties affected, but so is the core structure. However, most calculations of the core-collapse properties of massive stars rely on single-star models. We present a systematic study of the difference between the pre-supernova structures of single stars and stars of the same initial mass (11–21 M⊙) that have been stripped due to stable post-main-sequence mass transfer at solar metallicity. We present the pre-supernova core composition with novel diagrams that give an intuitive representation of the isotope distribution. As shown in previous studies, at the edge of the carbon-oxygen core, the binary-stripped star models contain an extended gradient of carbon, oxygen, and neon. This layer remains until core collapse and is more extended in mass for higher initial stellar masses. It originates from the receding of the convective helium core during core helium burning in binary-stripped stars, which does not occur in single-star models. We find that this same evolutionary phase leads to systematic differences in the final density and nuclear energy generation profiles. Binary-stripped star models have systematically higher total masses of carbon at the moment of core collapse compared to single-star models, which likely results in systematically different supernova yields. In about half of our models, the silicon-burning and oxygen-rich layers merge after core silicon burning. We discuss the implications of our findings for the “explodability”, supernova observations, and nucleosynthesis of these stars. Our models are publicly available and can be readily used as input for detailed supernova simulations.}, author = {Laplace, E. and Justham, S. and Renzo, M. and Götberg, Ylva Louise Linsdotter and Farmer, R. and Vartanyan, D. and de Mink, S. E.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, publisher = {EDP Sciences}, title = {{Different to the core: The pre-supernova structures of massive single and binary-stripped stars}}, doi = {10.1051/0004-6361/202140506}, volume = {656}, year = {2021}, } @article{13456, abstract = {While most simulations of the epoch of reionization have focused on single-stellar populations in star-forming dwarf galaxies, products of binary evolution are expected to significantly contribute to emissions of hydrogen-ionizing photons. Among these products are stripped stars (or helium stars), which have their envelopes stripped from interactions with binary companions, leaving an exposed helium core. Previous work has suggested these stripped stars can dominate the Lyman Continuum (LyC) photon output of high-redshift, low-luminosity galaxies post-starburst. Other sources of hard radiation in the early universe include zero-metallicity Population iii stars, which may have similar spectral energy distribution (SED) properties to galaxies with radiation dominated by stripped-star emissions. Here, we use four metrics (the power-law exponent over wavelength intervals 240–500 Å, 600–900 Å, and 1200–2000 Å, and the ratio of total luminosity in FUV wavelengths to LyC wavelengths) to compare the SEDs of simulated galaxies with only single-stellar evolution, galaxies containing stripped stars, and galaxies containing Population iii stars, with four different initial mass functions (IMFs). We find that stripped stars significantly alter SEDs in the LyC range of galaxies at the epoch of reionization. SEDs in galaxies with stripped stars have lower power-law indices in the LyC range and lower FUV to LyC luminosity ratios. These differences in SEDs are present at all considered luminosities (${M}_{\mathrm{UV}}\gt -15$, AB system), and are most pronounced for lower-luminosity galaxies. Intrinsic SEDs as well as those with interstellar medium absorption of galaxies with stripped stars and Population iii stars are found to be distinct for all tested Population iii IMFs.}, author = {Berzin, Elizabeth and Secunda, Amy and Cen, Renyue and Menegas, Alexander and Götberg, Ylva Louise Linsdotter}, issn = {1538-4357}, journal = {The Astrophysical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {1}, publisher = {American Astronomical Society}, title = {{Spectral signatures of population III and envelope-stripped stars in galaxies at the epoch of reionization}}, doi = {10.3847/1538-4357/ac0af6}, volume = {918}, year = {2021}, } @article{13457, abstract = {Context. Observations of massive stars in open clusters younger than ∼8 Myr have shown that a majority of them are in binary systems, most of which will interact during their life. While these can be used as a proxy of the initial multiplicity properties, studying populations of massive stars older than ∼20 Myr allows us to probe the outcome of these interactions after a significant number of systems have experienced mass and angular momentum transfer and may even have merged. Aims. Using multi-epoch integral-field spectroscopy, we aim to investigate the multiplicity properties of the massive-star population in the dense core of the ∼40 Myr old cluster NGC 330 in the Small Magellanic Cloud in order to search for possible imprints of stellar evolution on the multiplicity properties. Methods. We obtained six epochs of VLT/MUSE observations operated in wide-field mode with the extended wavelength setup and supported by adaptive optics. We extracted spectra and measured radial velocities for stars brighter than mF814W = 19. We identified single-lined spectroscopic binaries through significant RV variability with a peak-to-peak amplitude larger than 20 km s−1. We also identified double-lined spectroscopic binaries, and quantified the observational biases for binary detection. In particular, we took into account that binary systems with similar line strengths are difficult to detect in our data set. Results. The observed spectroscopic binary fraction among stars brighter than mF814W = 19 (approximately 5.5 M⊙ on the main sequence) is fSBobs = 13.2 ± 2.0%. Considering period and mass ratio ranges from log(P) = 0.15−3.5 (about 1.4 to 3160 d), q = 0.1−1.0, and a representative set of orbital parameter distributions, we find a bias-corrected close binary fraction of fcl = 34−7+8%. This fraction seems to decline for the fainter stars, which indicates either that the close binary fraction drops in the B-type domain, or that the period distribution becomes more heavily weighted toward longer orbital periods. We further find that both fractions vary strongly in different regions of the color-magnitude diagram, which corresponds to different evolutionary stages. This probably reveals the imprint of the binary history of different groups of stars. In particular, we find that the observed spectroscopic binary fraction of Be stars (fSBobs = 2 ± 2%) is significantly lower than that of B-type stars (fSBobs = 9 ± 2%). Conclusions. We provide the first homogeneous radial velocity study of a large sample of B-type stars at a low metallicity ([Fe/H] ≲ −1.0). The overall bias-corrected close binary fraction (log(P) < 3.5 d) of the B-star population in NGC 330 is lower than the fraction reported for younger Galactic and Large Magellanic Cloud clusters in previous works. More data are needed, however, to establish whether the observed differences are caused by an age or a metallicity effect.}, author = {Bodensteiner, J. and Sana, H. and Wang, C. and Langer, N. and Mahy, L. and Banyard, G. and de Koter, A. and de Mink, S. E. and Evans, C. J. and Götberg, Ylva Louise Linsdotter and Patrick, L. R. and Schneider, F. R. N. and Tramper, F.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, publisher = {EDP Sciences}, title = {{The young massive SMC cluster NGC 330 seen by MUSE. II. Multiplicity properties of the massive-star population}}, doi = {10.1051/0004-6361/202140507}, volume = {652}, year = {2021}, } @article{13458, abstract = {Most massive stars experience binary interactions in their lifetimes that can alter both the surface and core structure of the stripped star with significant effects on their ultimate fate as core-collapse supernovae. However, core-collapse supernovae simulations to date have focused almost exclusively on the evolution of single stars. We present a systematic simulation study of single and binary-stripped stars with the same initial mass as candidates for core-collapse supernovae (11–21 M⊙). Generally, we find that binary-stripped stars core tend to have a smaller compactness parameter, with a more prominent, deeper silicon/oxygen interface, and explode preferentially to the corresponding single stars of the same initial mass. Such a dichotomy of behavior between these two modes of evolution would have important implications for supernovae statistics, including the final neutron star masses, explosion energies, and nucleosynthetic yields. Binary-stripped remnants are also well poised to populate the possible mass gap between the heaviest neutron stars and the lightest black holes. Our work presents an improvement along two fronts, as we self-consistently account for the pre-collapse stellar evolution and the subsequent explosion outcome. Even so, our results emphasize the need for more detailed stellar evolutionary models to capture the sensitive nature of explosion outcome.}, author = {Vartanyan, David and Laplace, Eva and Renzo, Mathieu and Götberg, Ylva Louise Linsdotter and Burrows, Adam and de Mink, Selma E.}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {1}, publisher = {American Astronomical Society}, title = {{Binary-stripped stars as core-collapse supernovae progenitors}}, doi = {10.3847/2041-8213/ac0b42}, volume = {916}, year = {2021}, } @article{13459, abstract = {The B emission-line stars are rapid rotators that were probably spun up by mass and angular momentum accretion through mass transfer in an interacting binary. Mass transfer will strip the donor star of its envelope to create a small and hot subdwarf remnant. Here we report on Hubble Space Telescope/STIS far-ultraviolet spectroscopy of a sample of Be stars that reveals the presence of the hot sdO companion through the calculation of cross-correlation functions of the observed and model spectra. We clearly detect the spectral signature of the sdO star in 10 of the 13 stars in the sample, and the spectral signals indicate that the sdO stars are hot, relatively faint, and slowly rotating as predicted by models. A comparison of their temperatures and radii with evolutionary tracks indicates that the sdO stars occupy the relatively long-lived, He-core burning stage. Only 1 of the 10 detections was a known binary prior to this investigation, which emphasizes the difficulty of finding such Be+sdO binaries through optical spectroscopy. However, these results and others indicate that many Be stars probably host hot subdwarf companions.}, author = {Wang, Luqian and Gies, Douglas R. and Peters, Geraldine J. and Götberg, Ylva Louise Linsdotter and Chojnowski, S. Drew and Lester, Kathryn V. and Howell, Steve B.}, issn = {1538-3881}, journal = {The Astronomical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {5}, publisher = {American Astronomical Society}, title = {{The detection and characterization of Be+sdO binaries from HST/STIS FUV spectroscopy}}, doi = {10.3847/1538-3881/abf144}, volume = {161}, year = {2021}, } @article{13995, abstract = {Shape resonances play a central role in many areas of science, but the real-time measurement of the associated many-body dynamics remains challenging. Here, we present measurements of recoil frame angle-resolved photoionization delays in the vicinity of shape resonances of CF4. This technique provides insights into the spatiotemporal photoionization dynamics of molecular shape resonances. We find delays of up to ∼600 as in the ionization out of the highest occupied molecular orbital (HOMO) with a strong dependence on the emission direction and a pronounced asymmetry along the dissociation axis. Comparison with quantum-scattering calculations traces the asymmetries to the interference of a small subset of partial waves at low kinetic energies and, additionally, to the interference of two overlapping shape resonances in the HOMO-1 channel. Our experimental and theoretical results establish a broadly applicable approach to space- and time-resolved photoionization dynamics in the molecular frame.}, author = {Heck, Saijoscha and Baykusheva, Denitsa Rangelova and Han, Meng and Ji, Jia-Bao and Perry, Conaill and Gong, Xiaochun and Wörner, Hans Jakob}, issn = {2375-2548}, journal = {Science Advances}, keywords = {Multidisciplinary}, number = {49}, publisher = {American Association for the Advancement of Science}, title = {{Attosecond interferometry of shape resonances in the recoil frame of CF4}}, doi = {10.1126/sciadv.abj8121}, volume = {7}, year = {2021}, }