检索结果-内蒙古大学图书馆

ATOMS: ALMA three-millimeter observations of massive star-forming regions – XVIII. On the origin and evolution of dense gas fragments in molecular shells of compact H ii regions

arXiv

引用

arXiv 2024年

作者： Zhang, Siju Liu, Tie Wang, Ke Zavagno, Annie Garay, Guido Liu, Hongli Xu, Fengwei Liu, Xunchuan Sanhueza, Patricio Soam, Archana Zhou, Jian-Wen Li, Shanghuo Goldsmith, Paul F. Zhang, Yong Chibueze, James O. Lee, Chang Won Hwang, Jihye Bronfman, Leonardo Dewangan, Lokesh K. Kavli Institute for Astronomy and Astrophysics Peking University 5 Yiheyuan Road Haidian District Beijing100871 China Departamento de Astronomía Universidad de Chile Las Condes Santiago7591245 Chile Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China Key Laboratory for Research in Galaxies and Cosmology Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China Aix Marseille Univ CNRS CNES LAM Marseille France Institut Universitaire de France Paris 1 rue Descartes Paris75231 Cedex 05 France Chinese Academy of Sciences South America Center for Astronomy National Astronomical Observatories CAS Beijing100101 China School of Physics and Astronomy Yunnan University Kunming650091 China Department of Astronomy School of Physics Peking University Beijing100871 China National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Indian Institute of Astrophysics II Block Koramangala Bengaluru560034 India Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 Bonn53121 Germany Max Planck Institute for Astronomy Konigstuhl 17 HeidelbergD-69117 Germany Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States School of Physics and Astronomy Sun Yat-sen University 2 Daxue Road Tangjia Guangdong Province Zhuhai China Department of Mathematical Sciences University of South Africa Cnr Christian de Wet Rd and Pioneer Avenue Florida Park Roodepoort1709 South Africa Department of Physics and Astronomy Faculty of Physical Sciences University of Nigeria Carver Building 1 University Road Nsukka410001 Nigeria Korea Astronomy and Space Science Institute 776 Daedeokdaero Yuseong-gu Daejeon34055 Korea Republic of 217 Gajeong-ro Yuseong-gu Daejeon341

Fragmentation and evolution for the molecular shells of the compact H ii regions are less explored compared to their evolved counterparts. We map nine compact H ii regions with a typical diameter of 0.4 pc that are surrounded by molecular shells traced by CCH. Several to a dozen dense gas fragments probed by H13CO+ are embedded in these molecular shells. These gas fragments, strongly affected by the H ii region, have a higher surface density, mass, and turbulence than those outside the shells but within the same pc-scale natal clump. These features suggest that the shells swept up by the early H ii regions can enhance the formation of massive dense structures that may host the birth of higher-mass stars. We examine the formation of fragments and find that fragmentation of the swept-up shell is unlikely to occur in these early H ii regions, by comparing the expected time scale of shell fragmentation with the age of H ii region. We propose that the appearance of gas fragments in these shells is probably the result of sweeping up pre-existing fragments into the molecular shell that has not yet fragmented. Taken together, this work provides a basis for understanding the interplay of star-forming sites with an intricate environment containing ionization feedback such as those observed in starburst regions. © 2024, CC BY.

关键词： Giant stars

来源：评论

学校读者我要写书评

暂无评论

Forbidden hugs in pandemic times: IV. Panchromatic evolution of three luminous red novae

引用

astronomy and Astrophysics 2023年 671卷

作者： Pastorello, A. Valerin, G. Fraser, M. Reguitti, A. Elias-Rosa, N. Filippenko, A.V. Rojas-Bravo, C. Tartaglia, L. Reynolds, T.M. Valenti, S. Andrews, J.E. Ashall, C. Bostroem, K.A. Brink, T.G. Burke, J. Cai, Y.-Z. Cappellaro, E. Coulter, D.A. Dastidar, R. Davis, K.W. Dimitriadis, G. Fiore, A. Foley, R.J. Fugazza, D. Galbany, L. Gangopadhyay, A. Geier, S. Gutiérrez, C.P. Haislip, J. Hiramatsu, D. Holmbo, S. Howell, D.A. Hsiao, E.Y. Hung, T. Jha, S.W. Kankare, E. Karamehmetoglu, E. Kilpatrick, C.D. Kotak, R. Kouprianov, V. Kravtsov, T. Kumar, S. Li, Z.-T. Lundquist, M.J. Lundqvist, P. Matilainen, K. Mazzali, P.A. McCully, C. Misra, K. Morales-Garoffolo, A. Moran, S. Morrell, N. Newsome, M. Padilla Gonzalez, E. Pan, Y.-C. Pellegrino, C. Phillips, M.M. Pignata, G. Piro, A.L. Reichart, D.E. Rest, A. Salmaso, I. Sand, D.J. Siebert, M.R. Smartt, S.J. Smith, K.W. Srivastav, S. Stritzinger, M.D. Taggart, K. Tinyanont, S. Yan, S.-Y. Wang, L. Wang, X.-F. Williams, S.C. Wyatt, S. Zhang, T.-M. De Boer, T. Chambers, K. Gao, H. Magnier, E. INAF Osservatorio Astronomico di Padova Vicolo dell Osservatorio 5 Padova35122 Italy Universitá Degli Studi di Padova Dipartimento di Fisica e Astronomia Vicolo dell Osservatorio 2 Padova35122 Italy School of Physics O Brien Centre for Science North University College Dublin Dublin 4 Belfield Ireland Instituto de Astrofísica Facultad de Ciencias Exactas Universidad Andres Bello Fernández Concha 700 Las Condes Santiago Chile Nuncio Monsenor Sótero Sanz 100 Santiago Providencia8320000 Chile CSIC Campus UAB Carrer de Can Magrans s/n Barcelona08193 Spain Department of Astronomy University of California BerkeleyCA94720-3411 United States Miller Institute for Basic Research in Science University of California BerkeleyCA94720 United States Department of Astronomy and Astrophysics University of California Santa CruzCA95064 United States Tuorla Observatory Department of Physics and Astronomy University of Turku Turku20014 Finland Niels Bohr Institute University of Copenhagen Jagtvej 128 København N2200 Denmark Department of Physics and Astronomy University of California Davis 1 Shields Avenue DavisCA95616-5270 United States Gemini Observatory 670 North A ohoku Place HiloHI96720-2700 United States Department of Physics Virginia Tech 850 West Campus Drive BlacksburgVA24061 United States DIRAC Institute Department of Astronomy University of Washington 3910 15th Avenue NE SeattleWA98195-0002 United States Las Cumbres Observatory 6740 Cortona Dr. Suite 102 GoletaCA93117 United States Department of Physics University of California Santa BarbaraCA93106 United States Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Tsinghua University Beijing100084 China School of Physics Trinity College Dublin University of Dublin Dublin Ireland Fondazione Bruno Kessler Trento38123 Italy INFN-TI

We present photometric and spectroscopic data on three extragalactic luminous red novae (LRNe): AT 2018bwo, AT 2021afy, and AT 2021blu. AT 2018bwo was discovered in NGC 45 (at about 6.8 Mpc) a few weeks after the outburst onset. During the monitoring period, the transient reached a peak luminosity of 1040 erg s1. AT 2021afy, hosted by UGC 10043 (49.2 Mpc), showed a double-peaked light curve, with the two peaks reaching a similar luminosity of 2.1(±0.6) - 1041 erg s1. Finally, for AT 2021blu in UGC 5829 (∼8.6 Mpc), the pre-outburst phase was well-monitored by several photometric surveys, and the object showed a slow luminosity rise before the outburst. The light curve of AT 2021blu was sampled with an unprecedented cadence until the object disappeared behind the Sun, and it was then recovered at late phases. The light curve of LRN AT 2021blu shows a double peak, with a prominent early maximum reaching a luminosity of 6.5 - 1040 erg s1, which is half of that of AT 2021afy. The spectra of AT 2021afy and AT 2021blu display the expected evolution for LRNe: a blue continuum dominated by prominent Balmer lines in emission during the first peak, and a redder continuum consistent with that of a K-type star with narrow absorption metal lines during the second, broad maximum. The spectra of AT 2018bwo are markedly different, with a very red continuum dominated by broad molecular features in absorption. As these spectra closely resemble those of LRNe after the second peak, AT 2018bwo was probably discovered at the very late evolutionary stages. This would explain its fast evolution and the spectral properties compatible with that of an M-type star. From the analysis of deep frames of the LRN sites years before the outburst, and considerations of the light curves, the quiescent progenitor systems of the three LRNe were likely massive, with primaries ranging from about 13 M for AT 2018bwo, to 141+4 Mo for AT 2021blu, and over 40 M for AT 2021afy. © 2023 The Authors.

关键词： Luminance

来源：评论

学校读者我要写书评

暂无评论

The Extended [CII] under Construction? Observation of the brightest high-z lensed star-forming galaxy at z = 6.2

arXiv

引用

arXiv 2023年

作者： Fudamoto, Yoshinobu Inoue, Akio K. Coe, Dan Welch, Brian Acebron, Ana Ricotti, Massimo Mandelker, Nir Windhorst, Rogier A. Xu, Xinfeng Sugahara, Yuma Bauer, Franz E. Bradač, Maruša Bradley, Larry D. Diego, Jose M. Florian, Michael Frye, Brenda Fujimoto, Seiji Hashimoto, Takuya Henry, Alaina Mahler, Guillaume Oesch, Pascal A. Ravindranath, Swara Rigby, Jane Sharon, Keren Strait, Victoria Tamura, Yoichi Trenti, Michele Vanzella, Eros Zackrisson, Erik Zitrin, Adi Waseda Research Institute for Science and Engineering Faculty of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku Tokyo169-8555 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo Japan Department of Physics School of Advanced Science and Engineering Faculty of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku Tokyo169-8555 Japan 3700 San Martin Drive BaltimoreMD21218 United States STScI BaltimoreMD United States Center for Astrophysical Sciences Department of Physics and Astronomy The Johns Hopkins University 3400 N Charles St. BaltimoreMD21218 United States Department of Astronomy University of Maryland College ParkMD20742 United States Observational Cosmology Lab NASA Goddard Space Flight Center GreenbeltMD20771 United States Center for Research and Exploration in Space Science and Technology NASA/GSFC GreenbeltMD20771 United States Dipartimento di Fisica Università degli Studi di Milano Via Celoria 16 MilanoI-20133 Italy INAF - IASF Milano via A. Corti 12 MilanoI-20133 Italy Department of Astronomy University of Maryland College Park20742 United States Centre for Astrophysics and Planetary Science Racah Institute of Physics The Hebrew University Jerusalem91904 Israel School of Earth and Space Exploration Arizona State University TempeAZ85287-1404 United States Center for Astrophysical Sciences Department of Physics & Astronomy Johns Hopkins University BaltimoreMD21218 United States Instituto de Astrofísica Facultad de Física Pontificia Universidad Católica de Chile Campus San Joaquín Av. Vicuña Mackenna 4860 Macul Santiago7820436 Chile Centro de Astroingeniería Facultad de Física Pontificia Universidad Católica de Chile Campus San Joaquín Av. Vicuña Mackenna 4860 Macul Santiago7820436 Chile Millennium Institute of Astrophysics Nuncio Monseñor Sótero Sanz 100 Of 104 Providencia Santiago Chile University of Ljubljana Department of Mathematics and Physics Jad

We present results of [C ii] 158 µm emission line observations, and report the spectroscopic redshift confirmation of a strongly lensed (µ ∼ 20) star-forming galaxy, MACS0308-zD1 at z = 6.2078 ±0.0002. The [C ii] emission line is detected with a signal-to-noise ratio > 6 within the rest-frame UV bright clump of the lensed galaxy (zD1.1) and exhibits multiple velocity components;the narrow [C ii] has a velocity full-width-half-maximum (FWHM) of 110 ± 20 km/s, while broader [C ii] is seen with an FWHM of 230 ± 20 km/s. The broader [C ii] component is blueshifted (−80 ± 20 km/s) with respect to the narrow [C ii] component, and has a morphology which extends beyond the UV-bright clump. We find that while the narrow [C ii] emission is most likely associated with zD1.1, the broader component is possibly associated with outflowing gas. Based on the non-detection of λ158 µm dust continuum, we find that MACS0308-zD1’s star-formation activity occurs in a dust-free environment with the stringent upper limit of infrared luminosity . 9 × 108 L•. Targeting this strongly lensed faint galaxy for followup ALMA and JWST observations will be crucial to characterize the details of typical galaxy growth in the early Universe. © 2023, CC BY.

关键词： Galaxies

来源：评论

学校读者我要写书评

暂无评论

The magnetic field in quiescent star-forming filament G16.96+0.27

arXiv

引用

arXiv 2024年

作者： Gu, Qi-Lao Liu, Tie Shen, Zhi-Qiang Jiao, Sihan Montillaud, Julien Juvela, Mika Lu, Xing Lee, Chang Won Liu, Junhao Li, Pak Shing Liu, Xunchuan Johnstone, Doug Kwon, Woojin Kim, Kee-Tae Tatematsu, Ken’ichi Sanhueza, Patricio Ristorcelli, Isabelle Koch, Patrick Zhang, Qizhou Pattle, Kate Hirano, Naomi Alina, Dana Di Francesco, James Shanghai Astronomical Observatory Chinese Academy of Sciences No.80 Nandan Road Xuhui Shanghai200030 China National Astronomical Observatories Chinese Academy of Sciences A20 Datun Road Chaoyang Beijing100101 China Université de Franche-Comté CNRS Institut UTINAM OSU THETA BesançonF-25000 France Department of Physics University of Helsinki PO box 64 FI-00014 Finland Korea Astronomy and Space Science Institute 776 Daedeokdae-ro Yuseong-gu Daejeon34055 Korea Republic of University of Science and Technology 217 Gajeong-ro Yuseong-gu Daejeon34113 Korea Republic of National Astronomical Observatory of Japan 2-21-1 Osawa Tokyo Mitaka181-8588 Japan NRC Herzberg Astronomy and Astrophysics 5071 West Saanich Rd VictoriaBCV9E 2E7 Canada Department of Physics and Astronomy University of Victoria VictoriaBCV8P 5C2 Canada Department of Earth Science Education 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 The Center for Educational Research Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of Nobeyama Radio Observatory National Astronomical Observatory of Japan National Institutes of Natural Sciences Nobeyama Minamimaki Minamisaku Nagano384-1305 Japan Astronomical Science Program Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Tokyo Mitaka181-8588 Japan IRAP Université de Toulouse CNRS 9 avenue du Colonel Roche BP 44346 Toulouse31028 Cedex 4 France Academia Sinica Institute of Astronomy and Astrophysics No. 1 Section 4 Roosevelt Road Taipei10617 Taiwan Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Department of Physics and Astronomy University College London Gower Street LondonWC1E 6BT United Kingdom Department of Physics School of Science and Technology Nazarbayev University Astana010000 Kazakhs

We present 850 µm thermal dust polarization observations with a resolution of 14.4′′(∼ 0.13 pc) towards an infrared dark cloud G16.96+0.27 using JCMT/POL-2. The average magnetic field orientation, which roughly agrees with the larger-scale magnetic field orientation traced by the Planck 353 GHz data, is approximately perpendicular to the filament structure. The estimated plane-of-sky magnetic field strength is ∼ 96 µG and ∼ 60 µG using two variants of the Davis-Chandrasekhar-Fermi methods. We calculate the virial and magnetic critical parameters to evaluate the relative importance of gravity, the magnetic field, and turbulence. The magnetic field and turbulence are both weaker than gravity, but magnetic fields and turbulence together are equal to gravity, suggesting that G16.96+0.27 is in a quasi-equilibrium state. The cloud-magnetic-field alignment is found to have a trend moving away from perpendicularity in the dense regions, which may serve as a tracer of potential fragmentation in such quiescent filaments. © 2024, CC BY.

关键词： Stars

来源：评论

学校读者我要写书评

暂无评论

Anomalous low-frequency conductivity in easy-plane XXZ spin chains

引用

Physical Review B 2020年第22期101卷 224415-224415页

作者： Utkarsh Agrawal Sarang Gopalakrishnan Romain Vasseur Brayden Ware Department of Physics University of Massachusetts Amherst Massachusetts 01003 USA Department of Physics and Astronomy CUNY College of Staten Island Staten Island New York 10314 USA Physics Program and Initiative for the Theoretical Sciences The Graduate Center CUNY New York New York 10016 USA Rudolf Peierls Center for Theoretical Physics Clarendon Laboratory University of Oxford Oxford OX1 3PU United Kingdom

Using the framework of generalized hydrodynamics, we compute the low-frequency spin conductivity σ(ω) of XXZ spin chains with easy-plane anisotropy. We find that for almost all values of the anisotropy −1<Δ<1, the low-frequency conductivity scales anomalously with frequency, as σ(ω)∼1/ω. We interpret this anomalous response as a consequence of quasiparticles undergoing Lévy flights. For special values of the anisotropy, the divergence is cut off at low frequencies, so σ(ω) has a finite dc limit. These results reveal a hitherto unknown mechanism for anomalous response in integrable systems and also provide a physical explanation of the discontinuous behavior of the spin Drude weight. We use our approach to recover that at the isotropic point Δ=1, σ(ω)∼ω−1/3. We support our results with extensive numerical studies using matrix-product operator methods.

关键词： Anomalous diffusion Spin dynamics Integrable systems

来源：评论

学校读者我要写书评

暂无评论

Bulk passivation of perovskite films utilizing halide anion ionic liquids

引用

International Journal of Thermofluids 2023年 20卷

作者： Alashkar, Adnan Ayoub, Mohamad Ibrahim, Taleb Khamis, Mustafa Nancarrow, Paul Alami, Abdul Hai Tabet, Nouar PhD Program in Materials Science and Engineering American University of Sharjah Sharjah 26666 United Arab Emirates Sustainable and Renewable Energy Engineering Department University of Sharjah Sharjah 27272 United Arab Emirates Sustainable Energy & Power Systems Research Centre RISE University of Sharjah Sharjah 27272 United Arab Emirates Department of Chemical Engineering American University of Sharjah Sharjah 26666 United Arab Emirates Department of Biology Chemistry and Environmental Sciences College of Arts and Sciences American University of Sharjah Sharjah 26666 United Arab Emirates Center for Advanced Materials Research Research Institute of Science and Engineering University of Sharjah Sharjah 27272 United Arab Emirates Department of Applied Physics and Astronomy University of Sharjah Sharjah 27272 United Arab Emirates

Chemical additives to perovskite precursors constitute a predominant route to passivate defects in perovskite films and improve carrier charge dynamics. In this work, ionic liquids (ILs) with chloride and iodide anions are used as additives for bulk passivation of perovskite films. The ionic liquids in the form of 1‑butyl‑4-methylpyradinium iodide (IL-I) and 1-ethylimidazolium chloride (IL-Cl) are mixed individually with a precursor of Cesium Formamidinium Lead Triiodide and Methylammonium Chloride (CsFAPbI3−MACl). The decay of charge carriers within the perovskite film before and after passivation with ILs was measured by Time Resolved Photoluminescence Spectroscopy (TRPL). The effect of added ILs on the recombination rate of the photocarriers was investigated by analyzing the decay of the TRPL signal in all samples. The average lifetimes obtained within one day of preparations were 79 ns, 73 ns and 275 ns for pristine perovskite, IL-I passivated perovskite and IL-Cl passivated perovskite films, respectively. These values show that the presence of the IL with chloride anion greatly improves the average lifetime of the charge carrier by around 250%, while IL with iodide anion decreased the lifetime by 32% as compared with the pristine perovskite sample. This finding renders the IL-Cl passivated perovskite films as a valuable resource in applications ranging from photoelectric to hydrogen generation devices. © 2023

关键词： Ionic liquids

来源：评论

学校读者我要写书评

暂无评论

Nearly room temperature ferromagnetism in pressure-induced correlated metallic state of van der Waals insulator CrGeTe3

arXiv

引用

arXiv 2021年

作者： Bhoi, Dilip Gouchi, Jun Hiraoka, Naoka Zhang, Yufeng Ogita, Norio Hasegawa, Takumi Kitagawa, Kentaro Takagi, Hidenori Kim, Kee Hoon Uwatoko, Yoshiya The Institute for Solid State Physics University of Tokyo Chiba Kashiwa277-8581 Japan Department of Physics Graduate School of Sciences University of Tokyo Tokyo113-0033 Japan School of Physics Southeast University Nanjing211189 China Graduate School of Integrated Arts and Sciences Hiroshima University Hiroshima Higashi-Hiroshima739-8521 Japan Institute for Functional Matter and Quantum Technologies University of Stuttgart Stuttgart70569 Germany Max Planck Institute for Solid State Research Heisenbergstraße 1 Stuttgart70569 Germany Department of Physics and Astronomy CeNSCMR Seoul National University Seoul151-747 Korea Republic of Institute of Applied Physics Seoul National University Seoul151-747 Korea Republic of

A complex interplay of different energy scales involving Coulomb repulsion, spin-orbit coupling and Hund's coupling energy in two-dimensional (2D) van der Waals (vdW) material produces novel emerging physical state. For instance, ferromagnetism in vdW charge transfer insulator CrGeTe3, that provides a promising platform to simultaneously manipulate the magnetic and electrical proper- ties for potential device implementation using few layers thick materials. Here, we show a continuous tuning of magnetic and electrical properties of CrGeTe3single crystal using pressure. With appli- cation of pressure, CrGeTe3transforms from a FM insulator with Curie temperature, TC ∼ 66 K at ambient condition to a correlated 2D Fermi metal with TC exceeding ∼ 250 K. Notably, absence of an accompanying structural distortion across the insulator-metal transition (IMT) suggests that the pressure induced modification of electronic ground states are driven by electronic correlation furnishing a rare example of bandwidth-controlled IMT in a vdW material. © 2021, CC BY-NC-SA.

关键词： Van der Waals forces

来源：评论

学校读者我要写书评

暂无评论

NuSTAR Observations of Candidate Subparsec Binary Supermassive Black Holes

arXiv

引用

arXiv 2023年

作者： Saade, M. Lynne Brightman, Murray Stern, Daniel Connor, Thomas Djorgovski, S.G. D’Orazio, Daniel J. Ford, K.E.S. Graham, Matthew J. Haiman, Zoltán Jun, Hyunsung D. Kammoun, Elias Kraft, Ralph P. McKernan, Barry Vikhlinin, Alexei Walton, Dominic J. Department of Physics and Astronomy University of California 475 Portola Plaza Los AngelesCA90095 United States Science & Technology Institute Universities Space Research Association 320 Sparkman Drive HuntsvilleAL35805 United States Cahill Center for Astronomy and Astrophysics California Institute of Technology 1216 E. California Blvd. PasadenaCA91125 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Harvard-Smithsonian Center for Astrophysics 60 Garden Street CambridgeMA02138 United States Niels Bohr International Academy Niels Bohr Institute Blegdamsvej 17 Copenhagen2100 Denmark Department of Astrophysics American Museum of Natural History Central Park West at 79th Street New YorkNY10024 United States Department of Science Borough of Manhattan Community College City University of New York New YorkNY10007 United States Physics Program The Graduate Center City University of New York New YorkNY10016 United States Department of Astronomy Columbia University New YorkNY10027 United States SNU Astronomy Research Center Astronomy Program Dept. of Physics and Astronomy Seoul National University Seoul08826 Korea Republic of IRAP Université de Toulouse CNRS UPS CNES 9 Avenue du Colonel Roche BP 44346 ToulouseF-31028 Cedex 4 France INAF – Osservatorio Astrofisico di Arcetri Largo Enrico Fermi 5 FirenzeI-50125 Italy Centre for Astrophysics Research University of Hertfordshire College Lane HatfieldAL10 9AB United Kingdom Institute of Astronomy University of Cambridge Madingley Road CambridgeCB3 0HA United Kingdom

We present analysis of NuSTAR X-ray observations of three AGN that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey based on apparent periodicity in their optical light curves. Simulations predict that close-separation accreting SMBH binaries will have different X-ray spectra than single accreting SMBHs. We previously observed these AGN with Chandra and found no differences between their low energy X-ray properties and the larger AGN population. However some models predict differences to be more prominent at energies higher than probed by Chandra. We find that even at the higher energies probed by NuSTAR, the spectra of these AGN are indistinguishable from the larger AGN population. This could rule out models predicting large differences in the X-ray spectra in the NuSTAR bands. Alternatively, it might mean that these three AGN are not binary SMBHs. © 2023, CC BY-NC-SA.

关键词： Active Galactic Nuclei

来源：评论

学校读者我要写书评

暂无评论

Extreme blazars under the eyes of MAGIC 37

Extreme blazars under the eyes of MAGIC

引用

37th International Cosmic Ray Conference, ICRC 2021

作者： Arbet-Engels, A. Prandini, E. Ventura, S. Fallah Ramazani, V. Cerruti, M. Arcaro, C. Asano, K. Dorner, D. Manganaro, M. Bonnoli, G. D’Ammando, F. Foffano, L. Tavecchio, F. Becerra González, J. Jormanainen, J. Da Vela, P. Acciari, V.A. Ansoldi, S. Antonelli, L.A. Rugliancih, B. Artero, M. Asaoo, K. Back, D. Babić, A. Baquero, A. Barres de Almeida, U. Barrio, J.A. Batković, I. Bednarek, W. Bellizzi, L. Bernardini, E. Bernardos, M. Berti, A. Besenrieder, J. Bhattacharyya, W. Bigongiari, C. Bilaud, A. Blanch, O. Bökenkamp, H. Bonoli, G. Bošnjak, Ž. Busetto, G. Carosi, R. Ceribella, G. Ceruti, M. Chai, Y. Chilingarian, A. Cikota, S. Colak, S.M. Colombo, E. Contreras, J.L. Cortina, J. Covino, S. D’Amico, G. D’Elia, V. Da Vala, P. Dazzi, F. De Angelis, A. De Lotto, B. Delfino, M. Delgado, J. Delgado Mendez, C. Depaoli, D. Di Pierro, F. Di Venere, L. Do Souto Espiñeira, E. Dominis Prester, D. Donini, A. Doner, D. Doro, M. Elsaeser, D. Falah Ramazani, V. Fattorini, A. Fonseca, M.V. Font, L. Fruck, C. Fukami, S. Fukazawa, Y. García López, R.J. Garczarczyk, M. Gasparyan, S. Gaug, M. Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. Green, J.G. Green, D. Hadasch, D. Hahn, A. Heckmann, L. Herrera, J. Hoang, J. Hrupec, D. Hütten, M. Inada, T. Ishio, K. Iwamura, Y. Jiménez Martínez, I. Jormaninen, J. Jouvin, L. Karjalainen, M. Kerszberg, D. Kobayashi, Y. Kubo, H. Kushida, J. Lamastra, A. Lelas, D. Leone, F. Lindfors, E. Linhoff, L. Lombardi, S. Longo, F. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Machado de Oliveira Fraga, B. Maggio, C. Majumdar, P. Makariev, M. Mallamaci, M. Maneva, G. Manganro, M. Manheim, K. Maraschi, L. Mariotti, M. Martínez, M. Mazin, D. Menchiari, S. Mender, S. Mićanović, S. Miceli, D. Miener, T. Miranda, J.M. Mirzoyan, R. Molina, E. Moralejo, A. Morcuende, D. Moreno, V. Moretti, E. Nakamori, T. Nava, L. Neustroev, V. Nigro, C. Nilsson, K. Nishijima, K. Noda, K. Nozaki, S. Ohtani, Y. Oka, T. ETH Zürich ZürichCH-8093 Switzerland Università di Padova INFN PadovaI-35131 Italy Università di Siena INFN Pisa SienaI-53100 Italy Finnish Centre for Astronomy with ESO University of Turku TurkuFI-20014 Finland Universitat de Barcelona ICCUB IEEC-UB BarcelonaE-08028 Spain RomeI-00136 Italy The University of Tokyo Chiba Kashiwa277-8582 Japan Universität Würzburg WürzburgD-97074 Germany University of Rijeka Department of Physics Rijeka51000 Croatia Apartado 3004 GranadaE-18080 Spain INAF - Istituto di Radioastronomia Via Gobetti 101 BolognaI-40129 Italy University of Geneva Département de physique nucléaire et corpusculaire Genève1211 Switzerland Instituto de Astrofísica de Canarias Dpto. de Astrofísica Universidad de La Laguna La Laguna Tenerife38200 Spain University of Innsbruck Institute for Astro and Particle Physics Innsbruck6020 Austria Instituto de Astrofísica de Canarias Dpto. de Astrofísica Universidad de La Laguna La Laguna TenerifeE-38200 Spain Università di Udine INFN Trieste UdineI-33100 Italy National Institutes for Astrophysics RomeI-00136 Italy BarcelonaE-08193 Spain The University of Tokyo Chiba Kashiwa277-8582 Japan Technische Universität Dortmund DortmundD-44221 Germany Zagreb10000 Croatia IPARCOS Institute EMFTEL Department Universidad Complutense de Madrid MadridE-28040 Spain URCA RJ Rio de Janeiro22290-180 Brazil University of Lodz Faculty of Physics and Applied Informatics Department of Astrophysics Lodz90-236 Poland Universita di Siena INFN Pisa SienaI-53100 Italy ZeuthenD-15738 Germany Max-Planck-Institut für Physik MünchenD-80805 Germany Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n Granada18008 Spain Università di Pisa INFN Pisa PisaI-56126 Italy Universitat de Barcelona ICUB IEEC UB BarcelonaE-08028 Spain Armenian MAGIC Group A. Alikhanyan National Science Laboratory Yerevan0036 Armenia Centro de Investigaciones En-ergéticas Me

Extreme high-frequency-peaked BL Lac objects (EHBLs) are the most energetic persistent sources in the universe. This contribution reports on long-term observing campaigns of tens of EHBLs that have been organized by the MAGIC collaboration to enlarge their population at VHE and understand the origin of their extreme properties. EHBLs are characterized by a spectral energy distribution (SED) featuring a synchrotron peak energy above 1 keV. Several EHBLs display a hard spectral index at very high energies (VHE;E > 100 GeV), suggesting a gamma-ray SED component peaking significantly above 1 TeV. Such extreme properties are challenging current standard emission and acceleration mechanisms. Recent studies have also unveiled intriguing disparities in the temporal characteristics of EHBLs. Some sources seem to display a persistent EHBL behaviour, while others belong to the EHBL family only temporarily. Here, we present recent results of the first hard-TeV EHBL catalog. The MAGIC observations are accompanied by an extensive multiwavelength coverage to obtain an optimal determination of the SED. This allow us to investigate leptonic and hadronic scenarios for the emission. We also present the recent detection of the EHBL RX J0812.0+0237 in the VHE band by MAGIC. Finally, we discuss a broad multiwavelength campaign on the BL Lac type object 1ES 2344+514, which showed intermittent EHBL characteristics in August 2016. © Copyright owned by the author(s).

关键词： Acceleration

来源：评论

学校读者我要写书评

暂无评论

First measurement of the strange axial coupling constant using neutral-current quasielastic interactions of atmospheric neutrinos at KamLAND

arXiv

引用

arXiv 2022年

作者： Abe, S. Asami, S. Eizuka, M. Futagi, S. Gando, A. Gando, Y. Gima, T. Goto, A. Hachiya, T. Hata, K. Ichimura, K. Ieki, S. Ikeda, H. Inoue, K. Ishidoshiro, K. Kamei, Y. Kawada, N. Kishimoto, Y. Koga, M. Kurasawa, M. Mitsui, T. Miyake, H. Nakahata, T. Nakamura, K. Nakamura, R. Ozaki, H. Sakai, T. Shimizu, I. Shirai, J. Shiraishi, K. Suzuki, A. Suzuki, Y. Takeuchi, A. Tamae, K. Watanabe, H. Yoshida, Y. Obara, S. Ichikawa, A.K. Yoshida, S. Umehara, S. Fushimi, K. Kotera, K. Urano, Y. Berger, B.E. Fujikawa, B.K. Learned, J.G. Maricic, J. Axani, S.N. Fu, Z. Smolsky, J. Winslow, L.A. Efremenko, Y. Karwowski, H.J. Markoff, D.M. Tornow, W. Detwiler, J.A. Enomoto, S. Decowski, M.P. Grant, C. Li, A. Song, H. Dell’Oro, S. O’Donnell, T. Research Center for Neutrino Science Tohoku University Sendai980-8578 Japan Department of Human Science Obihiro University of Agriculture and Veterinary Medicine Obihiro080-8555 Japan The University of Tokyo Institutes for Advanced Study The University of Tokyo Chiba Kashiwa277-8583 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 Toyonaka Osaka560-0043 Japan Research Center for Nuclear Physics Osaka University Ibaraki Osaka567-0047 Japan Department of Physics Tokushima University Tokushima770-8506 Japan Graduate School of Integrated Arts and Sciences Tokushima University Tokushima770-8502 Japan Nuclear Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics and Astronomy University of Hawaii at Manoa HonoluluHI96822 United States University of Delaware NewarkDE19716 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 Physics Departments Duke University DurhamNC27708 United States North Carolina Central University DurhamNC27707 United States The University of North Carolina at Chapel Hill Chapel HillNC27599 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 State University BlacksburgVA24061 United States

We report a measurement of the strange axial coupling constant gAs using atmospheric neutrino data at KamLAND. This constant is a component of the axial form factor of the neutral-current quasielastic (NCQE) interaction. The value of gAs significantly changes the ratio of proton and neutron NCQE cross sections. KamLAND is suitable for measuring NCQE interactions as it can detect nucleon recoils with low-energy thresholds and measure neutron multiplicity with high efficiency. KamLAND data, including the information on neutron multiplicity associated with the NCQE interactions, makes it possible to measure gAs with a suppressed dependence on the axial mass MA, which has not yet been determined. For a comprehensive prediction of the neutron emission associated with neutrino interactions, we establish a simulation of particle emission via nuclear deexcitation of 12C, a process not considered in existing neutrino Monte Carlo event generators. Energy spectrum fitting for each neutron multiplicity gives gAs = −0.14+0−02526, which is the most stringent limit obtained using NCQE interactions without MA constraints. The two-body current contribution considered in this analysis relies on a theoretically effective model and electron scattering experiments and requires future verification by direct measurements and future model improvement. © 2022, CC BY.

关键词： Electron scattering

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：