分类： 天文学 >> 天体物理学 提交时间： 2023-12-17
Yuxiao Wu
Zhichen Pan
Lei Qian
Scott Ransom
BoJun Wang
Zhen Yan
Jintao Luo
Liyun Zhang
Minghui Li
Dejiang Yin
Baoda Li
Yifeng Li
Yinfeng Dai
Yaowei Li
Xinnan Zhang
Tong Liu
Yu Pan
摘要： We present the discovery of three pulsars in Globular Cluster M15 (NGC 7078) by the Five-hundred-meter Aperture Spherical radio Telescope (FAST).In the three pulsars, PSR~J2129+1210J (M15J) is a millisecond pulsar with a spinning period of 11.84 ms and a dispersion measure of 66.68 pc cm$^{-3}$.Both PSR~J2129+1210K and L (M15K and L) are long period pulsars with spinning periods of 1928 ms and 3961 ms, respectively,while M15L is the GC pulsar with the longest spinning period till now.The discoveries of M15K and L support the theory that core-collapsed Globular Clusters may contain partially recycled long period pulsars citep{verbunt-2014-slowpulsar}.With the same dataset, the timing solutions of M15A to H were updated,and the timing parameter P1 of M15F is different from the previous results, which is approximately 0.027$ times 10^{-18} ss^{-1}$ from our work and $0.032 times 10^{-18} ss^{-1}$ from Anderson's citep{anderson-1993}.As predicted by Rodolfi et al. citep{ridolfi-2017},the luminosity of M15C kept decreasing and the latest detection in our dataset is on December 20$^{ rm th}$, 2022.We also detected M15I for one more time.The different barycentric spin periods indicate that this pulsar should locate in a binary system,manifesting itself as the exceptional one in such a core-collapsing GC.
分类： 光学 >> 量子光学 提交时间： 2023-02-19
Jianglin Guan
Chuntao Li
Renhong Gao
Haisu Zhang
Jiantian Lin
Minghui Li
Min Wang
Lingling Qiao
Li Deng
Ya Cheng
摘要： Integrated on-chip microdisk lasers have attracted great attention as a light source of compact size, low lasing threshold and narrow bandwidth. However, challenges remain unresolved in terms of single mode operation at high output power while maintaining the ultra-narrow bandwidth. In this work, we demonstrate monolithically integrated on-chip single-frequency microdisk lasers coupled with bus-waveguides fabricated by photolithography assisted chemo-mechanical etching. Owing to the high-Q factor of a polygon whispering gallery mode formed in the microdisk and long cavity lengths (e.g., 409 um and 1 mm), a microdisk laser with a narrow linewidth of 0.11 MHz and a maximum output power of 62.1 uW has been achieved at room temperature.
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