We have discovered a triple-peaked X-ray burst from the low-mass X-ray binary (LMXB) 4U 1636-53 with the Rossi X-ray Timing Explorer (RXTE). This is the first triple-peaked burst reported from any LMXB using RXTE, and it is only the second burst of this kind observed from any source. (The previous one was also from 4U 1636-53, and was observed with EXOSAT.) From fits to time-resolved spectra, we find that this is not a radius-expansion burst, and that the same triple-peaked pattern seen in the X-ray light curve is also present in the bolometric light curve of the burst. Similar to what was previously observed in double-peaked bursts from this source, the radius of the emitting area increases steadily during the burst, with short periods in between during which the radius remains more or less constant. The temperature first increases steeply, and then decreases across the burst also showing three peaks. The first and last peak in the temperature profile occur, respectively, significantly before and significantly after the first and last peaks in the X-ray and bolometric light curves. We found no significant oscillations during this burst. This triple-peaked burst, as well as the one observed with EXOSAT and the double-peak bursts in this source, all took place when 4U 1636-53 occupied a relatively narrow region in the colour-colour diagram, corresponding to a relatively high (inferred) mass-accretion rate. No model presently available is able to explain the multiple-peaked bursts.
Hunting for extreme high-energy-peaked BL Lacs: Rare to find and difficult to classify
INAF – Osservatorio di Astrofisica e Scienza dello Spazio(国家天体物理研究所空间科学与天体物理观测台);Instituto de Astrofisica, Universidad Andres Bello(安第斯贝尔托大学 Astrophysics 研究所)
High-Synchrotron-Peaked BL Lacs as Multi-Messenger Sources: Connecting Ultra-High-Energy Cosmic Rays and Neutrinos
Unidade Acadêmica de Física, Universidade Federal de Campina Grande (UAF-UFCG)(坎皮纳格兰德联邦大学物理学术单位);Instituto de Física, Universidade de São Paulo (IFUSP)(圣保罗大学物理研究所);Departamento de Engenharias e Exatas, Universidade Federal do Paraná (UFPR)(巴拉那联邦大学工程与理学院);Programa de Pós-Graduação em Física, Departamento de Física, Universidade Estadual de Londrina (UEL)(隆德里纳州立大学物理系物理学研究生项目);Programa de Pós-Graduação em Física e Astronomia, Universidade Tecnológica Federal do Paraná (UTFPR)(巴拉那联邦技术大学物理与天文学研究生项目);Programa de Pós-Graduação em Física Aplicada, Universidade Federal da Integração Latino-Americana(拉丁美洲一体化联邦大学应用物理学研究生项目);Departamento de Física, Universidade Federal do Espírito Santo, Núcleo de Astrofísica e Cosmologia (Cosmo-Ufes)(圣埃斯皮里图联邦大学物理系天体物理与宇宙学中心)
A Parsec-Scale Transient High-Frequency-Peaked Radio Source in the Very Large Array Sky Survey Brightening and Fading over a Decadal Timescale
David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto(多伦多大学戴维·A·邓普天文学与天体物理学系);Dunlap Institute for Astronomy & Astrophysics, University of Toronto(多伦多大学邓普天文学与天体物理学研究所);Department of Astronomy and Astrophysics, University of California, Santa Cruz(加州大学圣克鲁兹分校天文学与天体物理学系);National Radio Astronomy Observatory(美国国家射电天文台)
An Enhanced Formation Channel for Galactic Dual-Line Gravitational-Wave Sources: von Zeipel-Lidov-Kozai Effect in Triples Involving Sgr A*
Kavli Institute for Astronomy and Astrophysics, Peking University(北京大学科维理天文与天体物理研究所);School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences(中国科学院大学杭州高等研究院基础物理与数学学院);School of Physical Sciences, University of Chinese Academy of Sciences(中国科学院大学物理科学学院);Institute of Fundamental Physics and Quantum Technology, Ningbo University(宁波大学基础物理与量子技术研究所);School of Physical Science and Technology, Ningbo University(宁波大学物理科学与技术学院);Department of Astronomy, School of Physics, Peking University(北京大学物理学院天文学系);Institute for Astronomy, School of Physics, Zhejiang University(浙江大学物理学院天体物理研究所);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台)