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Diffusive transport in a quasiperiodic Fibonacci chain: Absence of many-body localization at weak interactions

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Physical Review B 2019年第8期100卷 085105-085105页

作者： Vipin Kerala Varma Marko Žnidarič Department of Physics and Astronomy College of Staten Island CUNY Staten Island New York 10314 USA Physics program and Initiative for the Theoretical Sciences The Graduate Center CUNY New York New York 10016 USA Department of Physics and Astronomy University of Pittsburgh Pittsburgh Pennsylvania 15260 USA Physics Department Faculty of Mathematics and Physics University of Ljubljana Jadranska 19 SI-1000 Ljubljana Slovenia

We study high-temperature magnetization transport in a many-body spin-1/2 chain with on-site quasiperiodic potential governed by the Fibonacci rule. In the absence of interactions it is known that the system is critical with the transport described by a continuously varying dynamical exponent (from ballistic to localized) as a function of the on-site potential strength. Upon introducing weak interactions, we find that an anomalous noninteracting dynamical exponent becomes diffusive for any potential strength. This is borne out by a boundary-driven Lindblad dynamics as well as unitary dynamics, with agreeing diffusion constants. This must be contrasted to a random potential where transport is subdiffusive at such small interactions. Mean-field treatment of the dynamics for small U always slows down the noninteracting dynamics to subdiffusion, and is therefore unable to describe diffusion in an interacting quasiperiodic system. Finally, briefly exploring larger interactions we find a regime of interaction-induced subdiffusive dynamics, despite the on-site potential itself having no “rare regions.”

关键词： Many-body localization Quantum transport 1-dimensional spin chains Strongly correlated systems Spin lattice models

Cosmic-Ray Boron Flux Measured from 8.4 GeV/n to 3.8 TeV/n with the Calorimetric Electron Telescope on the International Space Station

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Physical Review Letters 2022年第25期129卷 251103-251103页

作者： O. Adriani Y. Akaike K. Asano Y. Asaoka E. Berti G. Bigongiari W. R. Binns M. Bongi P. Brogi A. Bruno J. H. Buckley N. Cannady G. Castellini C. Checchia M. L. Cherry G. Collazuol G. A. de Nolfo K. Ebisawa A. W. Ficklin H. Fuke S. Gonzi T. G. Guzik T. Hams K. Hibino M. Ichimura K. Ioka W. Ishizaki M. H. Israel K. Kasahara J. Kataoka R. Kataoka Y. Katayose C. Kato N. Kawanaka Y. Kawakubo K. Kobayashi K. Kohri H. S. Krawczynski J. F. Krizmanic P. Maestro P. S. Marrocchesi A. M. Messineo J. W. Mitchell S. Miyake A. A. Moiseev M. Mori N. Mori H. M. Motz K. Munakata S. Nakahira J. Nishimura S. Okuno J. F. Ormes S. Ozawa L. Pacini P. Papini B. F. Rauch S. B. Ricciarini K. Sakai T. Sakamoto M. Sasaki Y. Shimizu A. Shiomi P. Spillantini F. Stolzi S. Sugita A. Sulaj M. Takita T. Tamura T. Terasawa S. Torii Y. Tsunesada Y. Uchihori E. Vannuccini J. P. Wefel K. Yamaoka S. Yanagita A. Yoshida K. Yoshida W. V. Zober Department of Physics Department of Physics University of Florence Via Sansone 1–50019 Sesto Fiorentino Italy INFN Sezione di Florence Via Sansone 1–50019 Sesto Fiorentino Italy Waseda Research Institute for Science and Engineering Waseda University 17 Kikuicho Shinjuku Tokyo 162-0044 Japan JEM Utilization Center Human Spaceflight Technology Directorate Japan Aerospace Exploration Agency 2-1-1 Sengen Tsukuba Ibaraki 305-8505 Japan Institute for Cosmic Ray Research The University of Tokyo 5-1-5 Kashiwa-no-Ha Kashiwa Chiba 277-8582 Japan Department of Physical Sciences Earth and Environment University of Siena via Roma 56 53100 Siena Italy INFN Sezione di Pisa Polo Fibonacci Largo B. Pontecorvo 3–56127 Pisa Italy Department of Physics and McDonnell Center for the Space Sciences Washington University One Brookings Drive St. Louis Missouri 63130-4899 USA Heliospheric Physics Laboratory NASA/GSFC Greenbelt Maryland 20771 USA Center for Space Sciences and Technology University of Maryland Baltimore County 1000 Hilltop Circle Baltimore Maryland 21250 USA Astroparticle Physics Laboratory NASA/GSFC Greenbelt Maryland 20771 USA Center for Research and Exploration in Space Sciences and Technology NASA/GSFC Greenbelt Maryland 20771 USA Institute of Applied Physics (IFAC) National Research Council (CNR) Via Madonna del Piano 10 50019 Sesto Fiorentino Italy Department of Physics and Astronomy Louisiana State University 202 Nicholson Hall Baton Rouge Louisiana 70803 USA Department of Physics and Astronomy University of Padova Via Marzolo 8 35131 Padova Italy INFN Sezione di Padova Via Marzolo 8 35131 Padova Italy Institute of Space and Astronautical Science Japan Aerospace Exploration Agency 3-1-1 Yoshinodai Chuo Sagamihara Kanagawa 252-5210 Japan Kanagawa University 3-27-1 Rokkakubashi Kanagawa Yokohama Kanagawa 221-8686 Japan Faculty of Science and Technology Graduate School of Science and Technology Hirosaki University 3 Bunkyo Hiros

We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from 8.4 GeV/n to 3.8 TeV/n based on the data collected by the Calorimetric Electron Telescope (CALET) during ∼6.4 yr of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy E0∼200 GeV/n of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be γ=−3.047±0.024 in the interval 25

关键词： Cosmic ray & astroparticle detectors Cosmic ray acceleration Cosmic ray composition & spectra Cosmic ray propagation Cosmic ray sources Cosmic rays & astroparticles

TOI-2458 b: A mini-Neptune consistent with in situ hot Jupiter formation

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arXiv 2024年

作者： Šubjak, Jan Gandolfi, Davide Goffo, Elisa Rapetti, David Jankowski, Dawid Mizuki, Toshiyuki Dai, Fei Serrano, Luisa M. Wilson, Thomas G. Goździewski, Krzysztof Nowak, Grzegorz Jenkins, Jon M. Twicken, Joseph D. Winn, Joshua N. Bieryla, Allyson Ciardi, David R. Cochran, William D. Collins, Karen A. Deeg, Hans J. Garcia, Rafael A. Guenther, Eike W. Hatzes, Artie P. Kabath, Petr Korth, Judith Latham, David W. Livingston, John H. Lund, Michael B. Mathur, Savita Narita, Norio Orell-Miquel, Jaume Palle, Enric Persson, Carina M. Redfield, Seth Schwarz, Richard P. Watanabe, David Ziegler, Carl Astronomical Institute Czech Academy of Sciences Fričova 298 Ondřejov251 65 Czech Republic Center for Astrophysics | Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Dipartimento di Fisica Universita degli Studi di Torino via Pietro Giuria 1 TorinoI-10125 Italy Thuringer Landessternwarte Tautenburg Sternwarte 5 Tautenburg07778 Germany NASA Ames Research Center Moffett FieldCA94035 United States Research Institute for Advanced Computer Science Universities Space Research Association WashingtonDC20024 United States Institute of Astronomy Faculty of Physics Astronomy and Informatics Nicolaus Copernicus University Grudziadzka 5 Toruń87-100 Poland Astrobiology Center of NINS 2-21-1 Osawa Mitaka Tokyo181-8588 Japan National Astronomical Observatory of Japan 2-21-2 Osawa Mitaka Tokyo181-8588 Japan Institute for Astronomy University of Hawai'i 2680 Woodlawn Drive HonoluluHI96822 United States Department of Physics University of Warwick Gibbet Hill Road CoventryCV4 7AL United Kingdom SETI Institute Mountain ViewCA94043 United States Department of Astrophysical Sciences Princeton University PrincetonNJ08544 United States NASA Exoplanet Science Institute-Caltech/IPAC PasadenaCA91125 United States McDonald Observatory The University of Texas AustinTX United States Center for Planetary Systems Habitability The University of Texas AustinTX United States C. Via Lactea S/N Tenerife La LagunaE-38205 Spain Dept. de Astrofisica Tenerife La LagunaE-38206 Spain Universite Paris-Saclay Universite Paris Cite CEA CNRS AIM Gif-sur-Yvette91191 France Lund Observatory Division of Astrophysics Department of Physics Lund University Box 118 Lund22100 Sweden Astronomical Science Program Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Komaba Institute for Science The University of Tokyo 3-8-1 Komaba Meguro Tokyo153-8902 Japan Chalmers University of Technology Departmen

We report on the discovery and spectroscopic confirmation of TOI-2458 b, a transiting mini-Neptune around an F-type star leaving the mainsequence with a mass of M*= 1.05 ± 0.03Mo, a radius of R*= 1.31 ± 0.03 Ro, an effective temperature of Teff = 6005 ± 50 K, and a metallicity of -0.10 ± 0.05 dex. By combining TESS photometry with high-resolution spectra acquired with the HARPS spectrograph, we found that the transiting planet has an orbital period of ∼3.74 days, a mass of Mp = 13.31±0.99M⊕ and a radius of Rp = 2.83±0.20 R⊕. The host star TOI-2458 shows a short activity cycle of ∼54 days revealed in the HARPS S-index and Hα times series. We took the opportunity to investigate other F stars showing activity cycle periods comparable to that of TOI-2458 and found that they have shorter rotation periods than would be expected based on the gyrochronology predictions. In addition, we determined TOI-2458's stellar inclination angle to be i*= 10.6+13.3 -10.6 degrees. We discuss that both phenomena (fast stellar rotation and planet orbit inclination) could be explained by in situ formation of a hot Jupiter interior to TOI-2458 b. It is plausible that this hot Jupiter was recently engulfed by the star. Analysis of HARPS spectra has identified the presence of another planet with a period of P = 16.55 ± 0.06 days and a minimum mass of Mp sin i = 10.22 ± 1.90M⊕. Using dynamical stability analysis, we constrained the mass of this planet to the range Mc (10, 25)M⊕. © 2024, CC BY.

关键词： Stars

Search for solar flare neutrinos with the KamLAND detector

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arXiv 2021年

作者： Abe, S. Asami, S. Gando, A. Gando, Y. Gima, T. Goto, A. Hachiya, T. Hata, K. Hayashida, S. Hosokawa, K. Ichimura, K. Ieki, S. Ikeda, H. Inoue, K. Ishidoshiro, K. Kamei, Y. Kawada, N. Kishimoto, Y. Kinoshita, T. Koga, M. Maemura, N. Mitsui, T. Miyake, H. Nakamura, K. Nakamura, K. Nakamura, R. Ozaki, H. Sakai, T. Sambonsugi, H. Shimizu, I. Shirai, J. Shiraishi, K. Suzuki, A. Suzuki, Y. Takeuchi, A. Tamae, K. Ueshima, K. Wada, Y. Watanabe, H. Yoshida, Y. Obara, S. Ichikawa, A.K. Kozlov, A. Chernyak, D. Takemoto, Y. Yoshida, S. Umehara, S. Fushimi, K. Nakamura, K.Z. Yoshida, M. Berger, B.E. Fujikawa, B.K. Learned, J.G. Maricic, J. Axani, S.N. Winslow, L.A. Fu, Z. Ouellet, J. Efremenko, Y. Karwowski, H.J. Markoff, D.M. Tornow, W. Li, A. Detwiler, J.A. Enomoto, S. Decowski, M.P. Grant, C. O’Donnell, T. Dell’Oro, S. Research Center for Neutrino Science Tohoku University Sendai980-8578 Japan Institute for the Physics and Mathematics of the Universe The University of Tokyo Kashiwa277-8568 Japan Graduate Program on Physics for the Universe Tohoku University Sendai980-8578 Japan Frontier Research Institute for Interdisciplinary Sciences Tohoku University Sendai980-8578 Japan Department of Physics Tohoku University Sendai980-8578 Japan Graduate School of Science Osaka University Osaka Toyonaka560-0043 Japan Osaka University Osaka Ibaraki567-0047 Japan Graduate School of Advanced Technology and Science Tokushima University Tokushima770-8506 Japan Department of Physics Kyoto University Kyoto606-8502 Japan Nuclear Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics and Astronomy University of Hawaii at Manoa HonoluluHI96822 United States Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics and Astronomy University of Tennessee KnoxvilleTN37996 United States Triangle Universities Nuclear Laboratory DurhamNC27708 United States The University of North Carolina at Chapel Hill Chapel HillNC27599 United States North Carolina Central University DurhamNC27701 United States Physics Department Duke University DurhamNC27705 United States Center for Experimental Nuclear Physics and Astrophysics University of Washington SeattleWA98195 United States Nikhef The University of Amsterdam Science Park Amsterdam Netherlands Boston University BostonMA02215 United States Center for Neutrino Physics Virginia Polytechnic Institute and State University BlacksburgVA24061 United States

We report the result of a search for neutrinos in coincidence with solar flares from the GOES flare database. The search was performed on a 10.8 kton-year exposure of KamLAND collected from 2002 to 2019. This large exposure allows us to explore previously unconstrained parameter space for solar flare neutrinos. We found no statistical excess of neutrinos and established 90% confidence level upper limits of 8.4 × 107 cm−2 (3.0×109 cm−2) on electron anti-neutrino (electron neutrino) fluence at 20 MeV normalized to the X12 flare, assuming that the neutrino fluence is proportional to the X-ray intensity. © 2021, CC BY-NC-ND.

关键词： Neutrons

Time-series and phasecurve photometry of episodically-active asteroid (6478) gault in a quiescent state using APO, GROWTH, P200 and ZTF

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arXiv 2021年

作者： Purdum, Josiah N. Lin, Zhong-Yi Bolin, Bryce T. Sharma, Kritti Choi, Philip I. Bhalerao, Varun Hanuš, Josef Kumar, Harsh Quimby, Robert van Roestel, Joannes C. Zhai, Chengxing Fernandez, Yanga R. Lisse, Carey M. Bodewits, Dennis Fremling, Christoffer Golovich, Nathan Ryan Hsu, Chen-Yen Ip, Wing-Huen Ngeow, Chow-Choong Saini, Navtej S. Shao, Michael Yao, Yuhan Ahumada, Tomás Anand, Shreya Andreoni, Igor Burdge, Kevin B. Burruss, Rick Chang, Chan-Kao Copperwheat, Chris M. Coughlin, Michael De, Kishalay Dekany, Richard Delacroix, Alexandre Drake, Andrew Duev, Dmitry Graham, Matthew Hale, David Kool, Erik C. Kasliwal, Mansi M. Kostadinova, Iva S. Kulkarni, Shrinivas R. Laher, Russ R. Mahabal, Ashish Masci, Frank J. Mróz, Przemyslaw J. Neill, James D. Riddle, Reed Rodriguez, Hector Smith, Roger M. Walters, Richard Yan, Lin Zolkower, Jeffry Department of Astronomy San Diego State University 5500 Campanile Dr San DiegoCA92182 United States Institute of Astronomy National Central University Taoyuan32001 Taiwan IPAC Mail Code 100-22 Caltech 1200 E. California Blvd. PasadenaCA91125 United States Department of Mechanical Engineering Indian Institute of Technology Bombay Powai Mumbai400076 India Physics and Astronomy Department Pomona College 333 N. College Way ClaremontCA91711 United States Department of Physics Indian Institute of Technology Bombay Powai Mumbai400076 India Institute of Astronomy Faculty of Mathematics and Physics Charles University V Holešovičkách 2 Prague18000 Czech Republic LSSTC Data Science The University of Tokyo Institutes for Advanced Study The University of Tokyo Kashiwa Chiba277-8583 Japan Division of Physics Mathematics and Astronomy California Institute of Technology PasadenaCA91125 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Dept. of Physics and Florida Space Inst. Univ. of Central Florida 4000 Central Florida Boulevard OrlandoFL32816-2385 United States Johns Hopkins University Applied Physics Laboratory LaurelMD20723 United States Physics Department Leach Science Center Auburn University AuburnAL36832 United States Lawrence Livermore National Laboratory 7000 East Avenue LivermoreCA94550 United States Graduate Institute of Astronomy National Central University 32001 Taiwan Institute of Astronomy National Central University 32001 Taiwan Department of Astronomy University of Maryland College ParkMD20742 United States Caltech Optical Observatories California Institute of Technology PasadenaCA91125 United States Astrophysics Research Institute Liverpool John Moores University 146 Brownlow Hill LiverpoolL3 5RF United Kingdom School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Division of Physics Mathematics

We observed Episodically Active Asteroid (6478) Gault in 2020 with multiple telescopes in Asia and North America and have found that it is no longer active after its recent outbursts at the end of 2018 and start of 2019. The inactivity during this apparation allowed us to measure the absolute magnitude of Gault of Hr = 14.63±0.02, Gr = 0.21±0.02 from our secular phasecurve observations. In addition, we were able to constrain Gault's rotation period using time-series photometric lightcurves taken over 17 h on multiple days in 2020 August, September and October. The photometric lightcurves have a repeating.0.05 magnitude feature suggesting that (6478) Gault has a rotation period of ∼2.5 hours and may have a semi-spherical or top-like shape, much like Near-Earth Asteroids Ryugu and Bennu. The rotation period of ∼2.5 hours is near to the expected critical rotation period for an asteroid with the physical properties of (6478) Gault suggesting that its activity observed over multiple epochs is due to surface mass shedding from its fast rotation spun up by the Yarkovsky-O'Keefe-Radzievskii-Paddack effect. © 2021, CC BY.

关键词： Asteroids

EMPRESS. V. Metallicity Diagnostics of Galaxies over 12 + log(O/H) 6.9-8.9 Established by a Local Galaxy Census: Preparing for JWST Spectroscopy

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arXiv 2022年

作者： Nakajima, Kimihiko Ouchi, Masami Xu, Yi Rauch, Michael Harikane, Yuichi Nishigaki, Moka Isobe, Yuki Kusakabe, Haruka Nagao, Tohru Ono, Yoshiaki Onodera, Masato Sugahara, Yuma Kim, Ji Hoon Komiyama, Yutaka Lee, Chien-Hsiu Zahedy, Fakhri S. National Astronomical Observatory of Japan 2-21-1 Osawa Tokyo Mitaka181-8588 Japan Institute for Cosmic Ray Research The University of Tokyo 5-1-5 Kashiwanoha Chiba Kashiwa277-8582 Japan University of Tokyo Chiba Kashiwa277-8583 Japan Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongo Tokyo Bunkyo113-0033 Japan Observatories of the Carnegie Institution for Science 813 Santa Barbara St. PasadenaCA91101 United States Department of Physics and Astronomy University College London Gower Street LondonWC1E 6BT United Kingdom Department of Astronomical Science The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Tokyo Mitaka181-8588 Japan Department of Physics Graduate School of Science The University of Tokyo 7-3-1 Hongo Tokyo Bunkyo113-0033 Japan Observatoire de Genève Université de Genève 51 Chemin de Pégase Versoix1290 Switzerland Research Center for Space and Cosmic Evolution Ehime University Ehime Matsuyama790-8577 Japan 650 North Aohoku Place HiloHI96720 United States Waseda Research Institute for Science and Engineering Faculty of Science and Engineering Waseda University 3-4-1 Okubo Tokyo Shinjuku169-8555 Japan Metaspace 36 Nonhyeon-ro Gangnam-gu Seoul06312 Korea Republic of Astronomy Program Department of Physics and Astronomy Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of SNU Astronomy Research Center Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of NSF's National Optical-Infrared Astronomy Research Laboratory 950 N Cherry Ave. TucsonAZ86719 United States

We present optical-line gas metallicity diagnostics established by the combination of local SDSS galaxies and the largest compilation of extremely metal-poor galaxies (EMPGs) including new EMPGs identified by the Subaru EMPRESS survey. A total of 103 EMPGs are included that cover a large parameter space of magnitude (Mi=-19 to-7) and Hβ equivalent width (10-600Å), i.e., wide ranges of stellar mass and star-formation rate. Using reliable metallicity measurements of the direct method for these galaxies, we derive the relationships between strong optical-line ratios and gas-phase metallicity over the range of 12+log(O/H) 6.9-8.9 corresponding to 0.02-2 solar metallicity Zo. We confirm that R23-index, ([O iii]+[O ii])/Hβ, is the most accurate metallicity indicator with the metallicity uncertainty of 0.14 dex over the range among various popular metallicity indicators. The other metallicity indicators show large scatters in the metal-poor range (. 0.1Zo). It is explained by our CLOUDY photoionization modeling that, unlike R23-index, the other metallicity indicators do not use a sum of singly and doubly ionized lines and cannot trace both low and high ionization gas. We find that the accuracy of the metallicity indicators is significantly improved, if one uses Hβ equivalent width measurements that tightly correlate with ionization states. In this work, we also present the relation of physical properties with UV-continuum slope β and ionization production rate ξionderived with GALEX data for the EMPGs, and provide local anchors of galaxy properties together with the optical-line metallicity indicators that are available in the form of ASCII table and useful for forthcoming JWST spectroscopic studies. Copyright © 2022, The Authors. All rights reserved.

关键词： Galaxies

A spectacular galactic scale magnetohydrodynamic powered wind in ESO 320-G030

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arXiv 2024年

作者： Gorski, M.D. Aalto, S. König, S. Wethers, C.F. Yang, C. Muller, S. Onishi, K. Sato, M. Falstad, N. Mangum, Jeffrey G. Linden, S.T. Combes, F. Martín, S. Imanishi, M. Wada, Keiichi Barcos-Muñoz, L. Stanley, F. García-Burillo, S. van der Werf, P.P. Evans, A.S. Henkel, C. Viti, S. Harada, N. Díaz-Santos, T. Gallagher, J.S. González-Alfonso, E. Department of Space Earth and Environment Chalmers University of Technology Onsala Space Observatory Onsala439 92 Sweden National Radio Astronomy Observatory 520 Edgemont Road CharlottesvilleVA22903-2475 United States Department of Astronomy University of Massachusetts at Amherst AmherstMA01003 United States Observatoire de Paris LERMA Collège de France PSL University CNRS Sorbonne University ParisF-75014 France European Southern Observatory Alonso de Córdova 3107 Vitacura Santiago763-0355 Chile Joint ALMA Observatory Alonso de Córdova 3107 Vitacura Santiago763-0355 Chile National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Kagoshima University 1-21-35 Kagoshima890-0065 Japan Department of Astronomy University of Virginia 530 McCormick Road CharlottesvilleVA22903 United States 300 Rue de la Piscine Saint-Martin-d’Hères38400 France Observatorio de Madrid Alfonso XII 3 Madrid28014 Spain Leiden Observatory Leiden University PO Box 9513 Leiden2300 RA Netherlands Max-Planck-Institut für Radioastronomie Auf-dem-Hügel 69 Bonn53121 Germany Xinjiang Astronomical Observatory Chinese Academy of Sciences Urumqi830011 China Astron. Dept. Faculty of Science King Abdulaziz University P.O. Box 80203 Jeddah21589 Saudi Arabia Department of Physics and Astronomy University College London Gower Street LondonWC1E 6BT United Kingdom Astronomical Science Program Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-1855 Japan Heraklion70013 Greece School of Sciences European University Cyprus Diogenes street Engomi Nicosia1516 Cyprus Department of Astronomy University of Wisconsin 475 North Charter St. MadisonWI53706 United States Universidad de Alcalá Departamento de Física y Matemáticas Campus Universitario Madrid Alcalá de HenaresE-28871 Spain Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States

How galaxies regulate nuclear growth through gas accretion by supermassive black holes (SMBHs) is one of the most fundamental questions in galaxy evolution. One potential way to regulate nuclear growth is through a galactic wind that removes gas from the nucleus. It is unclear whether galactic winds are powered by jets, mechanical winds, radiation, or via magnetohydrodynamic (MHD) processes. Compact obscured nuclei (CONs) represent a significant phase of galactic nuclear growth. These galaxies hide growing SMBHs or unusual starbursts in their very opaque, extremely compact (r © 2024, CC BY.

关键词： Magnetohydrodynamics

Magnetic Control of Soft Chiral Phonons in PbTe

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arXiv 2021年

作者： Baydin, Andrey Hernandez, Felix G.G. Rodriguez-Vega, Martin Okazaki, Anderson K. Tay, Fuyang Timothy Noe, G. Katayama, Ikufumi Takeda, Jun Nojiri, Hiroyuki Rappl, Paulo H.O. Abramof, Eduardo Fiete, Gregory A. Kono, Junichiro Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Smalley-Curl Institute Rice University HoustonTX77005 United States Instituto de Física Universidade de São Paulo SP São Paulo05508-090 Brazil Theoretical Division Los Alamos National Laboratory Los AlamosNM87545 United States Laboratório Associado de Sensores e Materiais Instituto Nacional de Pesquisas Espaciais SP São José dos Campos12201-970 Brazil Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Physics Graduate School of Engineering Science Yokohama National University Yokohama240-8501 Japan Institute for Materials Research Tohoku University Sendai980-8577 Japan Department of Physics Northeastern University BostonMA02115 United States Department of Physics Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics and Astronomy Rice University HoustonTX77005 United States Department of Material Science and NanoEngineering Rice University HoustonTX77005 United States

PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this phonon via polarization-dependent terahertz spectroscopy. We observed softening of this mode with decreasing temperature, indicative of incipient ferroelectricity, which we explain through a model including strong anharmonicity with a quartic displacement term. In magnetic fields up to 25 T, the phonon mode splits into two modes with opposite handedness, exhibiting circular dichroism. Their frequencies display Zeeman splitting together with an overall diamagnetic shift with increasing magnetic field. Using a group-theoretical approach, we demonstrate that these observations are the result of magnetic field-induced morphic changes in the crystal symmetries through the Lorentz force exerted on the lattice ions. Thus, our study reveals a novel process of controlling phonon properties in a soft ionic lattice by a strong magnetic field. Copyright © 2021, The Authors. All rights reserved.

关键词： Magnetic fields

ACA CO(J = 2 − 1) Mapping of the Nearest Spiral Galaxy M33. I. Initial Results and Identification of Molecular Clouds

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arXiv 2023年

作者： Muraoka, Kazuyuki Konishi, Ayu Tokuda, Kazuki Kondo, Hiroshi Miura, Rie E. Tosaki, Tomoka Onodera, Sachiko Kuno, Nario Kobayashi, Masato I.N. Tsuge, Kisetsu Sano, Hidetoshi Kitano, Naoya Fujita, Shinji Nishimura, Atsushi Onishi, Toshikazu Saigo, Kazuya Yamada, Rin I. Demachi, Fumika Tachihara, Kengo Fukui, Yasuo Kawamura, Akiko Department of Physics Graduate School of Science Osaka Metropolitan University 1-1 Gakuen-cho Naka-ku Osaka Sakai599-8531 Japan Department of Earth and Planetary Sciences Faculty of Science Kyushu University Nishi-ku Fukuoka819-0395 Japan National Astronomical Observatory of Japan National Institutes of Natural Science 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Departamento de Fisica Teorica y del Cosmos Universidad de Granada Campus de Fuentenueva GranadaE18071 Spain Joetsu University of Education Yamayashiki-machi Niigata Joetsu943-8512 Japan Meisei University 2-1-1 Hodokubo Hino Tokyo191-0042 Japan Division of Physics Faculty of Pure and Applied Sciences University of Tsukuba 1-1-1 Tennodai Ibaraki Tsukuba305-8577 Japan Tomonaga Center for the History of the Universe University of Tsukuba Ibaraki Tsukuba305-8571 Japan I. Physikalisches Institut Universität zu Köln Zülpicher Str 77 KölnD-50937 Germany Department of Physics The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Faculty of Engineering Gifu University 1-1 Yanagido Gifu501-1193 Japan Institute of Astronomy The University of Tokyo 2-21-1 Osawa Mitaka Tokyo181-0015 Japan Graduate School of Science and Engineering Kagoshima University 1-21-40 Korimoto Kagoshima Kagoshima890-0065 Japan Department of Physics Nagoya University Chikusa-ku Nagoya464-8602 Japan Institute for Advanced Research Nagoya University Furo-cho Chikusa-ku Nagoya464-8601 Japan

We present the results of ALMA-ACA 7 m-array observations in 12CO(J = 2 − 1), 13CO(J = 2 − 1), and C18O(J = 2 − 1) line emission toward the molecular-gas disk in the Local Group spiral galaxy M33 at an angular resolution of 7′′ . 31 × 6′′ . 50 (30 pc × 26 pc). We combined the ACA 7 m-array 12CO(J = 2 − 1) data with the IRAM 30 m data to compensate for emission from diffuse molecular-gas components. The ACA+IRAM combined 12CO(J = 2 − 1) map clearly depicts the cloud-scale molecular-gas structure over the M33 disk. Based on the ACA+IRAM 12CO(J = 2 − 1) cube data, we cataloged 848 molecular clouds with a mass range from 103 M☉ to 106 M☉. We found that high-mass clouds (≥ 105 M☉) tend to associate with the 8 µm-bright sources in the spiral arm region, while low-mass clouds (5 M☉) tend to be apart from such 8 µm-bright sources and to exist in the inter-arm region. We compared the cataloged clouds with GMCs observed by the IRAM 30 m telescope at 49 pc resolution (IRAM GMC: Corbelli et al. 2017), and found that a small IRAM GMC is likely to be identified as a single molecular cloud even in ACA+IRAM CO data, while a large IRAM GMC can be resolved into multiple ACA+IRAM clouds. The velocity dispersion of a large IRAM GMC is mainly dominated by the line-of-sight velocity difference between small clouds inside the GMC rather than the internal cloud velocity broadening. © 2023, CC BY-NC-ND.

关键词： Clouds