T CrB是一颗共生的复发新星,已知表现出活跃的阶段,其特征是热成分温度的明显增加和闪烁的出现,即在分钟的时间尺度上观察到的通量的变化。历史上的紫外线观测已经排除了轨道可变性作为闪烁的解释,而是建议闪烁是由可变的质量转移引起的。我们已经分析了光学和X射线观测调查的闪烁的性质,以及在T CrB的活动阶段。分光光度观测证实,活动期有~ 1000 d和~ 5000 d两个周期。X射线中的闪烁被检测到,并且遵循与光学中观察到的类似的振幅-通量关系。闪烁在较硬的X射线能量下最为突出,这表明它起源于吸积盘和白矮星之间的边界层。来自边界层的X射线辐射然后被厚的吸积盘或星云再处理成紫外线辐射。更详细的了解闪烁将受益于长期同步X射线和光学监测的现象,在共生复发新星和相关的系统,如Z和型共生星。
英文摘要:
T CrB is a symbiotic recurrent nova known to exhibit active phases, characterised by apparent increases in the hot component temperature and the appearance of flickering, i.e. changes in the observed flux on the time-scale of minutes. Historical UV observations have ruled out orbital variability as an explanation for flickering and instead suggest flickering is caused by variable mass transfer. We have analysed optical and X-ray observations to investigate the nature of the flickering as well as the active phases in T CrB. The spectroscopic and photometric observations confirm that the active phases follow two periods of ~1000d and ~5000d. Flickering in the X-rays is detected and follows an amplitude-flux relationship similar to that observed in the optical. The flickering is most prominent at harder X-ray energies, suggesting that it originates in the boundary layer between the accretion disc and the white dwarf. The X-ray radiation from the boundary layer is then reprocessed by a thick accretion disc or a nebula into UV radiation. A more detailed understanding of flickering would benefit from long-term simultaneous X-ray and optical monitoring of the phenomena in symbiotic recurrent novae and related systems such as Z And type symbiotic stars.
Dissecting a disk-instability outburst in a symbiotic star: $NuSTAR$, and $Swift$ observations of T Coronae Borealis during the rise to the "super-active" state
The quiescent states of V745 Sco and V3890 Sgr: VLT/X-shooter and Swift/XRT+UVOT observations
Faculty of Mathematics and Physics, University of Ljubljana(卢布尔雅那大学数学与物理学院);INAF National Institute of Astrophysics, Astronomical Observatory of Padova(意大利国家天体物理研究所帕多瓦天文台);INAF – Osservatorio di Astrofisica e Scienza dello Spazio(意大利国家天体物理研究所天文与空间科学观测站);Instituto de Astrofisica, Depto. de Ciencias Fisicas, Facultad de Ciencias Exactas, Universidad Andres Bello(安德烈斯贝略大学精确科学学院物理科学系天体物理研究所)
Pre-nova Observations of T CrB: A view from the CHARA Array
New Mexico Institute of Mining and Technology(新墨西哥矿业与技术学院);The CHARA Array of Georgia State University(佐治亚州立大学CHARA阵列);Mount Wilson Observatory(威尔逊山天文台);Department of Astronomy and Astrophysics, The Pennsylvania State University(宾夕法尼亚州立大学天文学与天体物理学系);Astronomical Observatory Institute, Faculty of Physics and Astronomy, Adam Mickiewicz University(亚当·密茨凯维奇大学物理与天文学院天文台研究所)
利用 CHARA 阵列的 MIRC-X 和 MYSTIC 干涉测量,精确测定了共生再发新星 T CrB 红巨星的前新星角直径和半径,支持其充满洛希瓣。
The pre-eruption state of T CrB as observed with ALMA in 2024
European Southern Observatory(欧洲南方天文台);Universitat Politècnica de Catalunya(加泰罗尼亚理工大学);Institut d'Estudis Espacials de Catalunya (IEEC)(加泰罗尼亚空间研究所);Universidad de Santiago de Chile(智利圣地亚哥大学);Center for Interdisciplinary Research in Astrophysics and Space Exploration (CIRAS), USACH(美国智利圣地亚哥大学天体物理与太空探索跨学科研究中心);Max-Planck Institut für extraterrestrische Physik (MPE)(马克斯·普朗克地外物理学研究所)
An extreme case of X-ray reflection in the symbiotic V648 Car
Universidade Federal de Sergipe(塞尔希培联邦大学);Observatório Nacional(国家天文台);NASA/GSFC(美国国家航空航天局戈达德太空飞行中心);University of Maryland, Baltimore County(马里兰大学巴尔的摩县分校)
Regulation of accretion by its outflow in a symbiotic star: the 2016 outflow fast state of MWC 560
吸积盘是如何受到其外流的影响?为了解决从冷巨星吸积的白矮星的这个问题,我们在其2016年光学高态期间对流出驱动共生星MWC 560(=V694 Mon)进行了光学,无线电,X射线和紫外线观测。我们跟踪了多波长的变化,这些变化表明,在长达数月的外流快态开始时,外流功率突然增加,就像光通量达到峰值一样:(1)巴耳末吸收速度突然加倍;(2)射电通量出现$20$ $μ$ Jy/月的增加;(3)软X射线通量出现数量级的增加。并置到以前的X射线观测和他们的同时代的光谱,我们推断,高速和低速的光学外流组件必须同时存在,以产生一个大的软X射线通量,这可能源于这些快速和缓慢的吸收碰撞的冲击。我们的光学和紫外光谱表明,宽吸收线气体在整个2016年流出快速状态中是快速,稳定和致密的($\gtrsim10^{6.5}$ cm $^{-3}$),稳定地供给低密度($\lesssim10^{5.5}$ cm $^{-3}$)区域的放射性气体。持续的光学和紫外线闪烁表明吸积盘保持完整。这些性质在2016年的稳定性与MWC 560在1990年爆发时的不稳定性形成对比,尽管圆盘达到了类似的吸积率。我们认为,2016年稳定的快速外流的自我调节效应阻止了内盘的灾难性弹射。这种行为在一个共生的二类似盘/流出的关系,在X射线双星吸积状态的变化。
The accretion-driven eruption of the recurrent nova T Corona Borealis
Universidade Federal de Santa Catarina(圣卡塔琳娜联邦大学);Instituto Nacional de Pesquisas Espaciais - INPE(国家空间研究所);Universidade Estadual de Maringá - UEM(马林加州立大学);Universidad Nacional de Hurlingham (UNAHUR)(乌尔希纳姆国立大学);Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)(国家科学研究委员会)
Multi-wavelength study of the pre-eruption dip in the recurrent nova T Coronae Borealis preceding imminent nova eruption
Liupanshui Normal University(六盘水师范学院);Shanghai Astronomical Observatory, Chinese Academy of Sciences(中国科学院上海天文台);Yunnan Observatories, Chinese Academy of Sciences(中国科学院云南天文台);Tsung-Dao Lee Institute, Shanghai Jiao Tong University(上海交通大学李政道研究所);Qiannan Normal University for Nationalities(黔南民族师范学院)