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38th International Cosmic Ray Conference, ICRC 2023

作者： Zhiyong, You Shoushan, Zhang Liqiao, Yin Lingling, Ma Zhen, Cao Yudong, Wang Cao, Zhen Aharonian, F. An, Q. Axikegu Bai, L.X. Bai, Y.X. Bai, L.X. Bai, Y.X. Bao, Y.W. Bastieri, D. Bi, X.J. Bi, Y.J. Cai, H. Cai, J.T. Cao, Zhe Chang, J. Chang, J.F. Chen, B.M. Chen, E.S. Chen, J. Chen, Liang Chen, Liang Chen, Long Chen, M.J. Chen, M.L. Chen, Q.H. Chen, S.H. Chen, S.Z. Chen, T.L. Chen, X.L. Chen, Y. Cheng, N. Cheng, Y.D. Cui, S.W. Cui, X.H. Cui, Y.D. D’Ettorre Piazzoli, B. Dai, B.Z. Dai, H.L. Dai, Z.G. Danzengluobu della Volpe, D. Dong, X.J. Duan, K.K. Fan, J.H. Fan, Y.Z. Fan, Z.X. Fang, J. Fang, K. Feng, C.F. Feng, L. Feng, S.H. Feng, Y.L. Gao, B. Gao, C.D. Gao, L.Q. Gao, Q. Gao, W. Ge, M.M. Geng, L.S. Gong, G.H. Gou, Q.B. Gu, M.H. Guo, F.L. Guo, J.G. Guo, X.L. Guo, Y.Q. Guo, Y.Y. Han, Y.A. He, H.H. He, H.N. He, J.C. He, S.L. He, X.B. He, Y. Heller, M. Hor, Y.K. Hou, C. Hu, H.B. Hu, S. Hu, S.C. Hu, X.J. Huang, D.H. Huang, Q.L. Huang, W.H. Huang, X.T. Huang, X.Y. Huang, Z.C. Ji, F. Ji, X.L. Jia, H.Y. Jiang, K. Jiang, Z.J. Jin, C. Ke, T. Kuleshov, D. Levochkin, K. Li, B.B. Li, Cheng Li, Cong Li, F. Li, H.B. Li, H.C. Li, H.Y. Li, J. Li, K. Li, W.L. Li, X.R. Li, Xin Li, Xin Li, Y. Li, Y.Z. Li, Zhe Li, Zhuo Liang, E.W. Liang, Y.F. Lin, S.J. Liu, B. Liu, C. Liu, D. Liu, H. Liu, H.D. Liu, J. Liu, J.L. Liu, J.S. Liu, J.Y. Liu, M.Y. Liu, R.Y. Liu, S.M. Liu, W. Liu, Y. Liu, Y.N. Liu, Z.X. Long, W.J. Lu, R. Lv, H.K. Ma, B.Q. Ma, L.L. Ma, X.H. Mao, J.R. Masood, A. Min, Z. Mitthumsiri, W. Montaruli, T. Nan, Y.C. Pang, B.Y. Pattarakijwanich, P. Pei, Z.Y. Qi, M.Y. Qi, Y.Q. Qiao, B.Q. Qin, J.J. Ruffolo, D. Rulev, V. Sáiz, A. Shao, L. Shchegolev, O. Sheng, X.D. Shi, J.Y. Song, H.C. Stenkin, Yu.V. Stepanov, V. Su, Y. Sun, Q.N. The Institute of High Energy Physics The Chinese Academy of Sciences YuQuan Road.19B shijingshan district Beijing China University of Chinese Academy of Sciences Department YuQuan Road.19A shijingshan district Beijing100049 China TIANFU Cosmic Ray Research Center Sichuan Chengdu China Key Laboratory of Particle Astrophyics & Experimental Physics Division & Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Dublin Institute for Advanced Studies 31 Fitzwilliam Place Dublin 2 Ireland Max-Planck-Institut for Nuclear Physics P.O. Box 103980 Heidelberg69029 Germany State Key Laboratory of Particle Detection and Electronics China University of Science and Technology of China Anhui Hefei230026 China School of Physical Science and Technology School of Information Science and Technology Southwest Jiaotong University Sichuan Chengdu610031 China College of Physics Sichuan University Sichuan Chengdu610065 China School of Astronomy and Space Science Nanjing University Jiangsu Nanjing210023 China Center for Astrophysics Guangzhou University Guangdong Guangzhou510006 China School of Physics and Technology Wuhan University Hubei Wuhan430072 China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Jiangsu Nanjing210023 China Hebei Normal University Hebei Shijiazhuang050024 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai200030 China Ministry of Education Tibet Lhasa850000 China National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Sun Yat-sen University Guangdong Zhuhai519000 China Dipartimento di Fisica dell’Università di Napoli ‘Federico II" Complesso Universitario di Monte Sant’Angelo via Cinthia Napoli80126 Italy School of Physics and Astronomy Yunnan University Yunnan Kunming650091 China Departement de Physique Nucleair

One of the main scientific aims of LHAASO is to measure the energy spectra of cosmic rays for individual mass compositions. LHAASO is made up of three detector arrays, which are WFCTA, KM2A, and WCDA. The three detector arrays can achieve hybrid observation, so several extensive air shower observables that are sensitive to mass compositions can be measured simultaneously. ROOT-TMVA package is used to combine these component-sensitive parameters for selecting proton events. The selected proton events have a purity of over 90%. In this paper, we have selected simulated events with shower cores located in the KM2A array to investigate the feasibility of the analysis method for studying the proton energy spectrum. We have also studied the associated systematic uncertainties, including those introduced by the composition models, proton selection, energy reconstruction method, and hadronic interaction models. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： Cosmic rays

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On the effects of parameters on galaxy properties in CAMELS and the predictability of Ωm

arXiv

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arXiv 2025年

作者： Contardo, Gabriella Trotta, Roberto Gioia, Serafina Di Hogg, David W. Villaescusa-Navarro, Francisco Center for Astrophysics and Cosmology University of Nova Gorica Ajdovščina Slovenia Trieste Italy ICSC - Centro Nazionale di Ricerca in High Performance Computing Big Data e Quantum Computing Via Magnanelli 2 Bologna Italy Astrophysics Group Physics Department Blackett Lab Imperial College London Prince Consort Road LondonSW7 2AZ United Kingdom INAF – Osservatorio Astronomico di Trieste Via G. B. Tiepolo 11 TriesteI-34143 Italy Trieste Italy Center for Cosmology and Particle Physics Department of Physics New York University New YorkNY United States Max-Planck-Institut für Astronomie Heidelberg Germany Center for Computational Astrophysics Flatiron Institute New YorkNY United States Department of Astrophysical Sciences Peyton Hall Princeton University NJ08544-0010 United States

Recent analyses of cosmological hydrodynamic simulations from CAMELS have shown that machine learning models can predict the parameter describing the total matter content of the universe, Ωm, from the features of a single galaxy. We investigate the statistical properties of two of these simulation suites, IllustrisTNG and ASTRID, confirming that Ωm induces a strong displacement on the distribution of galaxy features. We also observe that most other parameters have little to no effect on the distribution, except for the stellar-feedback parameter ASN1, which introduces some near-degeneracies that can be broken with specific features. These two properties explain the predictability of Ωm. We use Optimal Transport to further measure the effect of parameters on the distribution of galaxy properties, which is found to be consistent with physical expectations. However, we observe discrepancies between the two simulation suites, both in the effect of Ωm on the galaxy properties and in the distributions themselves at identical parameter values. Thus, although Ωm’s signature can be easily detected within a given simulation suite using just a single galaxy, applying this result to real observational data may prove significantly more challenging. © 2025, CC BY.

关键词： Galaxies

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Phase-resolved Spectroscopy of Low-frequency Quasi-periodic Oscillations from the Newly Discovered Black Hole X-ray Binary Swift J1727.8–1613

arXiv

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arXiv 2024年

作者： Shui, Qing-Cang Zhang, Shu Peng, Jing-Qiang Zhang, Shuang-Nan Chen, Yu-Peng Ji, Long Kong, Ling-Da Feng, Hua Yu, Zhuo-Li Wang, Peng-Ju Chang, Zhi Yin, Hong-Xing Qu, Jin-Lu Tao, Lian Ge, Ming-Yu Zhang, Liang Li, Jian Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing100049 China School of Physics and Astronomy Sun Yat-Sen University Zhuhai519082 China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle Physics Eberhard Karls Universität Sand 1 TübingenD-72076 Germany Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Institute of Space Sciences Shandong University Shandong Weihai264209 China CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Hefei230026 China School of Astronomy and Space Science University of Science and Technology of China Hefei230026 China

Low-frequency quasi-periodic oscillations (LFQPOs) are commonly observed in X-ray light curves of black hole X-ray binaries (BHXRBs);however, their origin remains a topic of debate. In order to thoroughly investigate variations in spectral properties on the QPO timescale, we utilized the Hilbert-Huang transform technique to conduct phase-resolved spectroscopy across a broad energy band for LFQPOs in the newly discovered BHXRB Swift J1727.8–1613. This is achieved through quasi-simultaneous observations from Neutron star Interior Composition ExploreR (NICER), Nuclear Spectroscopic Telescope ARray (NuSTAR), and Hard X-ray Modulation Telescope (Insight-HXMT). Our analysis reveals that both the non-thermal and disk-blackbody components exhibit variations on the QPO timescale, with the former dominating the QPO variability. For the spectral parameters, we observe modulation of the disk temperature, spectral indices, and reflection fraction with the QPO phase with high statistical significance ( 5σ). Notably, the variation in the disk temperature is found to precede the variations in the non-thermal and disk fluxes by ∼ 0.4 − 0.5 QPO cycles. We suggest that these findings offer further evidence that the type-C QPO variability is a result of geometric effects of the accretion flow. © 2024, CC BY.

关键词： Hilbert-Huang transform

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GalSBI: Phenomenological galaxy population model for cosmology using simulation-based inference

arXiv

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arXiv 2024年

作者： Fischbacher, Silvan Kacprzak, Tomasz Tortorelli, Luca Moser, Beatrice Refregier, Alexandre Gebhardt, Patrick Gruen, Daniel Institute for Particle Physics and Astrophysics ETH Zurich Wolfgang-Pauli-Strasse 27 ZurichCH-8093 Switzerland Swiss Data Science Center Paul Scherrer Institute Forschungsstrasse 111 Villigen5232 Switzerland University Observatory Faculty of Physics Ludwig-Maximilian-Universität München Scheinerstrasse 1 Munich81679 Germany Excellence Cluster ORIGINS Boltzmannstr. 2 Garching85748 Germany

We present GalSBI, a phenomenological model of the galaxy population for cosmological applications using simulation-based inference. The model is based on analytical parametrizations of galaxy luminosity functions, morphologies and spectral energy distributions. Model constraints are derived through iterative Approximate Bayesian Computation, by comparing Hyper Suprime-Cam deep field images with simulations which include a forward model of instrumental, observational and source extraction effects. We developed an emulator trained on image simulations using a normalizing flow. We use it to accelerate the inference by predicting detection probabilities, including blending effects and photometric properties of each object, while accounting for background and PSF variations. This enables robustness tests for all elements of the forward model and the inference. The model demonstrates excellent performance when comparing photometric properties from simulations with observed imaging data for key parameters such as magnitudes, colors and sizes. The redshift distribution of simulated galaxies agrees well with high-precision photometric redshifts in the COSMOS field within 1.5σ for all magnitude cuts. Additionally, we demonstrate how GalSBI’s redshifts can be utilized for splitting galaxy catalogs into tomographic bins, highlighting its potential for current and upcoming surveys. GalSBI is fully open-source, with the accompanying Python package, galsbi1, offering an easy interface to quickly generate realistic, survey-independent galaxy catalogs. © 2024, CC BY.

关键词： cosmology

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Global analysis of fragmentation functions to charged hadrons with high-precision data from the LHC

arXiv

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arXiv 2024年

作者： Gao, Jun Liu, ChongYang Shen, XiaoMin Xing, Hongxi Zhao, Yuxiang INPAC Shanghai Key Laboratory for Particle Physics and Cosmology School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Shanghai200240 China Deutsches Elektronen-Synchrotron DESY Notkestr. 85 Hamburg22607 Germany Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter Institute of Quantum Matter South China Normal University Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Guangdong Provincial Key Laboratory of Nuclear Science Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China Institute of Modern Physics Chinese Academy of Sciences Huizhou516000 China Institute of Modern Physics Chinese Academy of Sciences Gansu Lanzhou730000 China University of Chinese Academy of Sciences Beijing100049 China Institute of Particle Physics Central China Normal University Wuhan430079 China

Fragmentation functions (FFs) are essential non-perturbative QCD inputs for predicting hadron production cross sections in high energy scatterings. In this study, we present a joint determination of FFs for light charged hadrons through a global analysis at next-to-leading order (NLO) in QCD. Our analysis incorporates a wide range of precision measurements from the LHC, as well as data from electron-positron collisions and semi-inclusive deep inelastic scatterings. By including measurements of jet fragmentation at the LHC in our global analysis, we are able to impose strong constraints on the gluon FFs. A careful selection of hadron kinematics is applied to ensure the validity of factorization and perturbative calculations of QCD. In addition, we introduce several methodological advances in fitting, resulting in a flexible parametrization form and the inclusion of theoretical uncertainties from perturbative calculations. Our best-fit predictions show very good agreement with the global data, with χ2/Npt ∼ 0.90. We also generate a large number of Hessian error sets to estimate uncertainties and correlations of the extracted FFs. FFs to charged pions (kaons and protons) are well constrained for momentum fractions down to 0.01 (0.1). Total momentum of partons carried by light charged hadrons are determined precisely. Their values for u, d quarks and gluon saturate at about 50% for a lower cut of the momentum fraction of 0.01. Comparing our determinations to results from other groups, we find significant discrepancies, particularly for the proton fragmentation functions, as well as for gluon and unfavored quarks to pions and kaons. Pulls from individual datasets and impact of various choices of the analysis are also studied in details. Our analysis raises questions concerning existing and future experimental measurements, including the need for clarifications on the definitions of various hadron final states and the necessity of further measurements on fragmentation fro

关键词： Hadrons

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A Phase-resolved View of "Heartbeat"-like variability in IGR J17091-3624 During the 2022 Outburst

arXiv

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arXiv 2024年

作者： Shui, Qing-Cang Zhang, Shu Peng, Jing-Qiang Zhang, Shuang-Nan Chen, Yu-Peng Kong, Ling-Da Yu, Zhuo-Li Ji, Long Wang, Peng-Ju Chang, Zhi Yin, Hong-Xing Li, Jian Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing100049 China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle Physics Eberhard Karls Universität Sand 1 TübingenD-72076 Germany School of Physics and Astronomy Sun Yat-Sen University Zhuhai519082 China Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Institute of Space Sciences Shandong University Shandong Weihai264209 China CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Hefei230026 China School of Astronomy and Space Science University of Science and Technology of China Hefei230026 China

IGR J17091–3624, in addition to GRS 1915+105, is the only black hole X-ray binary that displays "heartbeat"-like variability characterized by structured flares with high amplitudes. In this study, we conduct a detailed phase-resolved analysis of the recently identified "heartbeat"-like Class X variability in IGR J17091–3624 during its 2022 outburst, utilizing data from NICER and NuSTAR observations. A shortage in the high-energy (>20 keV) X-ray flux is detected at peak phases of the soft X-ray flare at a ∼ 15σ confidence level from the phase-folded light curves. Furthermore, our phase-resolved spectral analysis reveals variations in the spectral shape, particularly showing significant synchronous variations in the disk temperature and flux with the count rate. These findings imply that the flare is primarily driven by instabilities within the accretion disk, consistent with previous studies on the well-known Class ρ variability in GRS 1915+105. However, we also observe a positive correlation between the disk temperature and flux over the flare cycle, which differs from a loop relation between the two parameters found in the Class ρ variability. This could suggest differences in underlying physical processes between the two variability classes. Variations in the Componization component during flares are also observed: the electron temperature and covering fraction show anti-correlations with the disk flux, revealing potential interactions between the accretion disk and the corona during these flares. © 2024, CC BY.

关键词： Stars

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Finite Bubble Statistics Constrain Late Cosmological Phase Transitions

arXiv

引用

arXiv 2023年

作者： Elor, Gilly Jinno, Ryusuke Kumar, Soubhik McGehee, Robert Tsai, Yuhsin Weinberg Institute Department of Physics University of Texas at Austin AustinTX78712 United States Graduate School of Science The University of Tokyo Tokyo113-0033 Japan Center for Cosmology and Particle Physics Department of Physics New York University New YorkNY10003 United States Berkeley Center for Theoretical Physics Department of Physics University of California BerkeleyCA94720 United States Theoretical Physics Group Lawrence Berkeley National Laboratory BerkeleyCA94720 United States William I. Fine Theoretical Physics Institute School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Leinweber Center for Theoretical Physics Department of Physics University of Michigan Ann ArborMI48109 United States Department of Physics University of Notre Dame IN46556 United States

We consider first order cosmological phase transitions (PT) happening at late times, below Standard Model (SM) temperatures TPT GeV. The inherently stochastic nature of bubble nucleation and the finite number of bubbles associated with a late-time PT lead to superhorizon fluctuations in the PT completion time. We compute how such fluctuations eventually source curvature fluctuations with universal properties, independent of the microphysics of the PT dynamics. Using Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) measurements, we constrain the energy released in a dark-sector PT. For 0.1 eV TPT keV this constraint is stronger than both the current bound from additional neutrino species ∆Neff, and in some cases, even CMB-S4 projections. Future measurements of CMB spectral distortions and pulsar timing arrays will also provide competitive sensitivity for keV TPT GeV. © 2023, CC BY.

关键词： cosmology

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Investigation of the Ultra-High-Energy gamma-ray emission from the Northern Fermi Bubble with LHAASO-KM2A

Investigation of the Ultra-High-Energy gamma-ray emission fr...

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38th International Cosmic Ray Conference, ICRC 2023

作者： Zhang, Yi He, Jiayin Zhang, Rui Zhao, Shiping Cao, Zhen Aharonian, F. An, Q. Axikegu Bai, Y.X. Bao, Y.W. Bastieri, D. Bi, X.J. Bi, Y.J. Cai, J.T. Cao, Q. Cao, W.Y. Cao, Zhe Chang, J. Chang, J.F. Chen, A.M. Chen, E.S. Chen, Liang Chen, Lin Chen, Long Chen, M.J. Chen, M.L. Chen, Q.H. Chen, S.H. Chen, S.Z. Chen, T.L. Chen, Y. Cheng, N. Cheng, Y.D. Cui, M.Y. Cui, S.W. Cui, X.H. Cui, Y.D. Dai, B.Z. Dai, H.L. Dai, Z.G. Danzengluobu della Volpe, D. Dong, X.Q. Duan, K.K. Fan, J.H. Fan, Y.Z. Fang, J. Fang, K. Feng, C.F. Feng, L. Feng, S.H. Feng, X.T. Feng, Y.L. Gabici, S. Gao, B. Gao, C.D. Gao, L.Q. Gao, Q. Gao, W. Gao, W.K. Ge, M.M. Geng, L.S. Giacinti, G. Gong, G.H. Gou, Q.B. Gu, M.H. Guo, F.L. Guo, X.L. Guo, Y.Q. Guo, Y.Y. Han, Y.A. He, H.H. He, H.N. He, J.Y. He, X.B. He, Y. Heller, M. Hor, Y.K. Hou, B.W. Hou, C. Hou, X. Hu, H.B. Hu, Q. Hu, S.C. Huang, D.H. Huang, T.Q. Huang, W.J. Huang, X.T. Huang, X.Y. Huang, Y. Huang, Z.C. Ji, X.L. Jia, H.Y. Jia, K. Jiang, K. Jiang, X.W. Jiang, Z.J. Jin, M. Kang, M.M. Ke, T. Kuleshov, D. Kurinov, K. Li, B.B. Li, Cheng Li, Cong Li, D. Li, F. Li, H.B. Li, H.C. Li, H.Y. Li, J. Li, Jian Li, Jie Li, K. Li, W.L. Li, W.L. Li, X.R. Li, Xin Li, Y.Z. Li, Zhe Li, Zhuo Liang, E.W. Liang, Y.F. Lin, S.J. Liu, B. Liu, C. Liu, D. Liu, H. Liu, H.D. Liu, J. Liu, J.L. Liu, J.Y. Liu, M.Y. Liu, R.Y. Liu, S.M. Liu, W. Liu, Y. Liu, Y.N. Lu, R. Luo, Q. Lv, H.K. Ma, B.Q. Ma, L.L. Ma, X.H. Mao, J.R. Min, Z. Mitthumsiri, W. Mu, H.J. Nan, Y.C. Neronov, A. Ou, Z.W. Pang, B.Y. Pattarakijwanich, P. Pei, Z.Y. Qi, M.Y. Qi, Y.Q. Qiao, B.Q. Qin, J.J. Ruffolo, D. Sáiz, A. Semikoz, D. Shao, C.Y. Shao, L. Shchegolev, O. Sheng, X.D. Shu, F.W. Song, H.C. Stenkin, Yu.V. Stepanov, V. Su, Y. Sun, Q.N. Sun, X.N. Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences 9 Jiangsu Nanjing210023 China University of Science and Technology of China Anhui Hefei230026 China Institute of Frontier and Interdisciplinary Science Shandong University Shandong Qingdao266237 China Key Laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China University of Chinese Academy of Sciences Beijing100049 China TIANFU Cosmic Ray Research Center Sichuan Chengdu China Dublin Institute for Advanced Studies 31 Fitzwilliam Place Dublin 2 Ireland Max-Planck-Institut for Nuclear Physics P.O. Box 103980 Heidelberg69029 Germany State Key Laboratory of Particle Detection and Electronics China School of Physical Science and Technology School of Information Science and Technology Southwest Jiaotong University Sichuan Chengdu610031 China School of Astronomy and Space Science Nanjing University Jiangsu Nanjing210023 China Center for Astrophysics Guangzhou University Guangdong Guangzhou510006 China Hebei Normal University Hebei Shijiazhuang050024 China Key Laboratory of Dark Matter and Space Astronomy Key Laboratory of Radio Astronomy Purple Mountain Observatory Chinese Academy of Sciences Jiangsu Nanjing210023 China Tsung-Dao Lee Institute School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai200030 China Key Laboratory of Cosmic Rays [Tibet University Ministry of Education Tibet Lhasa850000 China National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Sun Yat-sen University 519000 Zhuhai Guangdong Guangzhou510275 China School of Physics and Astronomy Yunnan University Yunnan Kunming650091 China Département de Physique Nucléaire et Cor

We analyze gamma-ray emission from the Northern Fermi bubble region at the ultra-high-energy range, using the data collected by LHAASO-KM2A from December 2019 to September 2022. Employing an improved gamma/hadron separation method, the median energy of the gamma rays is above 25 TeV. We perform the "direct integral method" in the background estimation;however, no significant excess is observed. Consequently, we present the expected upper limits for gamma-ray emissions within the Fermi bubble region at this energy range. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： Gamma rays

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Ultracool dwarfs candidates based on 6 yr of the Dark Energy Survey data

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MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2023年第2期522卷 1951-1967页

作者： dal Ponte, M. Santiago, B. Carnero Rosell, A. De Paris, L. Pace, A. B. Bechtol, K. Abbott, T. M. C. Aguena, M. Allam, S. Alves, O. Bacon, D. Bertin, E. Bocquet, S. Brooks, D. Burke, D. L. Kind, M. Carrasco Carretero, J. Conselice, C. Costanzi, M. Desai, S. De Vicente, J. Doel, P. Everett, S. Ferrero, I Flaugher, B. Frieman, J. Garcia-Bellido, J. Gerdes, D. W. Gruendl, R. A. Gruen, D. Gutierrez, G. Hinton, S. R. Hollowood, D. L. James, D. J. Kuehn, K. Kuropatkin, N. Marshall, J. L. Mena-Fernandez, J. Menanteau, F. Miquel, R. Ogando, R. L. C. Palmese, A. Paz-Chinchon, F. Pereira, M. E. S. Plazas Malagon, A. A. Pieres, A. Raveri, M. Rodriguez-Monroy, M. Sanchez, E. Scarpine, V Schubnell, M. Sevilla-Noarbe, I Smith, M. Soares-Santos, M. Suchyta, E. Swanson, M. E. C. Tarle, G. Thomas, D. To, C. Weaverdyck, N. Instituto de Física UFRGS Caixa Postal 15051 Porto Alegre RS-91501-970 Brazil Laboratório Interinstitucional de e-Astronomia - LIneA Rua Gal. José Cristino 77 Rio de Janeiro RJ-20921-400 Brazil Instituto de Astrofisica de Canarias E-38205 La Laguna Tenerife Spain Universidad de La Laguna Dpto. Astrofísica E-38206 La Laguna Tenerife Spain McWilliams Center for Cosmology Carnegie Mellon University 5000 Forbes Ave Pittsburgh PA 15213 USA Physics Department University of Wisconsin-Madison Madison WI 53706 USA Cerro Tololo Inter-American Observatory NSF’s National Optical-Infrared Astronomy Research Laboratory Casilla 603 La Serena Chile Fermi National Accelerator Laboratory PO Box 500 Batavia IL 60510 USA Department of Physics University of Michigan Ann Arbor MI 48109 USA Institute of Cosmology and Gravitation University of Portsmouth Portsmouth PO1 3FX UK CNRS UMR 7095 Institut d’Astrophysique de Paris F-75014 Paris France Sorbonne Universités UPMC Univ Paris 06 UMR 7095 Institut d’Astrophysique de Paris F-75014 Paris France University Observatory Faculty of Physics Ludwig-Maximilians-Universität Scheinerstr. 1 D-81679 Munich Germany Department of Physics & Astronomy University College London Gower Street London WC1E 6BT UK Kavli Institute for Particle Astrophysics & Cosmology PO Box 2450 Stanford University Stanford CA 94305 USA SLAC National Accelerator Laboratory Menlo Park CA 94025 USA Center for Astrophysical Surveys National Center for Supercomputing Applications 1205 West Clark St. Urbana IL 61801 USA Department of Astronomy University of Illinois at Urbana-Champaign 1002 W. Green Street Urbana IL 61801 USA Institut de Física d’Altes Energies (IFAE) The Barcelona Institute of Science and Technology Campus UAB E-08193 Bellaterra (Barcelona) Spain Jodrell Bank Center for Astrophysics School of Physics and Astronomy University of Manchester Oxford Road Manchester M13 9PL UK University of Nottingham School of Physics and Astrono

We present a sample of 19 583 ultracool dwarf candidates brighter than z <= 23 selected from the Dark Energy Survey DR2 coadd data matched to VHS DR6, VIKING DR5, and AllWISE covering similar to 480 deg(2). The ultracool candidates were first pre-selected based on their (i-z), (z-Y), and (Y-J) colours. They were further classified using a method that compares their optical, near-infrared, and mid-infrared colours against templates of M, L, and T dwarfs. 14 099 objects are presented as new L and T candidates and the remaining objects are from the literature, including 5342 candidates from our previous work. Using this new and deeper sample of ultracool dwarf candidates we also present: 20 new candidate members to nearby young moving groups and associations, variable candidate sources and four new wide binary systems composed of two ultracool dwarfs. Finally, we also show the spectra of 12 new ultracool dwarfs discovered by our group and presented here for the first time. These spectroscopically confirmed objects are a sanity check of our selection of ultracool dwarfs and photometric classification method.

关键词： surveys brown dwarfs stars: low-mass

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The end-to-end Calibration of LHAASO-WFCTA based on Nitrogen Laser System 38

The end-to-end Calibration of LHAASO-WFCTA based on Nitrogen...

引用

38th International Cosmic Ray Conference, ICRC 2023

作者： Sun, Qinning Min, Zhen Liu, Hu Chen, Long Wang, Yang Zhu, Fengrong Zhang, Shoushan Cao, Zhen Aharonian, F. An, Q. Axikegu Bai, L.X. Bai, Y.X. Bai, L.X. Bai, Y.X. Bao, Y.W. Bastieri, D. Bi, X.J. Bi, Y.J. Cai, H. Cai, J.T. Cao, Zhe Chang, J. Chang, J.F. Chen, B.M. Chen, E.S. Chen, J. Chen, Liang Chen, Liang Chen, Long Chen, M.J. Chen, M.L. Chen, Q.H. Chen, S.H. Chen, S.Z. Chen, T.L. Chen, X.L. Chen, Y. Cheng, N. Cheng, Y.D. Cui, S.W. Cui, X.H. Cui, Y.D. D’Ettorre Piazzoli, B. Dai, B.Z. Dai, H.L. Dai, Z.G. Danzengluobu della Volpe, D. Dong, X.J. Duan, K.K. Fan, J.H. Fan, Y.Z. Fan, Z.X. Fang, J. Fang, K. Feng, C.F. Feng, L. Feng, S.H. Feng, Y.L. Gao, B. Gao, C.D. Gao, L.Q. Gao, Q. Gao, W. Ge, M.M. Geng, L.S. Gong, G.H. Gou, Q.B. Gu, M.H. Guo, F.L. Guo, J.G. Guo, X.L. Guo, Y.Q. Guo, Y.Y. Han, Y.A. He, H.H. He, H.N. He, J.C. He, S.L. He, X.B. He, Y. Heller, M. Hor, Y.K. Hou, C. Hu, H.B. Hu, S. Hu, S.C. Hu, X.J. Huang, D.H. Huang, Q.L. Huang, W.H. Huang, X.T. Huang, X.Y. Huang, Z.C. Ji, F. Ji, X.L. Jia, H.Y. Jiang, K. Jiang, Z.J. Jin, C. Ke, T. Kuleshov, D. Levochkin, K. Li, B.B. Li, Cheng Li, Cong Li, F. Li, H.B. Li, H.C. Li, H.Y. Li, J. Li, K. Li, W.L. Li, X.R. Li, Xin Li, Xin Li, Y. Li, Y.Z. Li, Zhe Li, Zhuo Liang, E.W. Liang, Y.F. Lin, S.J. Liu, B. Liu, C. Liu, D. Liu, H. Liu, H.D. Liu, J. Liu, J.L. Liu, J.S. Liu, J.Y. Liu, M.Y. Liu, R.Y. Liu, S.M. Liu, W. Liu, Y. Liu, Y.N. Liu, Z.X. Long, W.J. Lu, R. Lv, H.K. Ma, B.Q. Ma, L.L. Ma, X.H. Mao, J.R. Masood, A. Min, Z. Mitthumsiri, W. Montaruli, T. Nan, Y.C. Pang, B.Y. Pattarakijwanich, P. Pei, Z.Y. Qi, M.Y. Qi, Y.Q. Qiao, B.Q. Qin, J.J. Ruffolo, D. Rulev, V. Sáiz, A. Shao, L. Shchegolev, O. Sheng, X.D. Shi, J.Y. Song, H.C. Stenkin, Yu.V. Stepanov, V. Su, Y. Sun, Q.N. Southwest Jiaotong University School of Physical Science and Technology No. 999 Xi’an Road Chengdu China Institute of High Energy Physics Chinese Academy of Sciences Key Laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center No. 19B Yuquan Road Beijing100049 China Institute of High Energy Physics Chinese Academy of Sciences TIANFU Cosmic Ray Research Center No. 1500 Kezhi Road Chengdu China University of Chinese Academy of Sciences Beijing100049 China TIANFU Cosmic Ray Research Center Sichuan Chengdu China Dublin Institute for Advanced Studies 31 Fitzwilliam Place Dublin 2 Ireland Max-Planck-Institut for Nuclear Physics P.O. Box 103980 Heidelberg69029 Germany State Key Laboratory of Particle Detection and Electronics China University of Science and Technology of China Anhui Hefei230026 China School of Physical Science and Technology School of Information Science and Technology Southwest Jiaotong University Sichuan Chengdu610031 China College of Physics Sichuan University Sichuan Chengdu610065 China School of Astronomy and Space Science Nanjing University Jiangsu Nanjing210023 China Center for Astrophysics Guangzhou University Guangdong Guangzhou510006 China School of Physics and Technology Wuhan University Hubei Wuhan430072 China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Jiangsu Nanjing210023 China Hebei Normal University Hebei Shijiazhuang050024 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai200030 China Ministry of Education Tibet Lhasa850000 China National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Sun Yat-sen University Guangdong Zhuhai519000 China Dipartimento di Fisica dell’Università di Napoli ‘Federico II" Complesso Universitario di Monte Sant’Angelo via Cinthia Napoli80126 Italy School of Physics and As

The Wide Field-of-view Cherenkov Telescope Array (WFCTA) of Large High Altitude Air Shower Observatory (LHAASO) is designed to perform nearly calorimetric measurements of extensive air showers induced by cosmic rays with energies between 1013 eV - 1018 eV. In order to achieve an end-to-end calibration of WFCTA and investigate properties of the atmospheric aerosol, five laser systems have been operated at LHAASO, including 3 nitrogen and 2 Nd:YAG laser devices. This work presents an overview of the laser signals received by the telescope and the monitoring of geometric information related to nitrogen laser events. Additionally, it introduces the simulation method for the LHAASO-WFCTA laser calibration system. Through prolonged and stable operation, a substantial amount of data has been accumulated, requiring further data analysis for the calibration of the telescope’s absolute gain and measurement of aerosol extinction coefficients. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： cosmology

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