摘要
We report detections of scintillation arcs for pulsars in globular clusters M5,M13 and M15 for the first time using the Fivehundred-meter Aperture Spherical radio Telescope(FAST).From observations of these arcs at multiple epochs,we infer that screen-like scattering medium exists at distances 4.1_(-0.3)^(+0.2),6.7_(-0.2)^(+0.2)and 1.3_(-1.0)^(+0.7) kpc from Earth in the directions of M5,M13 and M15,respectively.This means M5's and M13's scattering screens are located at 3.0_(-0.2)^(+0.1) and 4.4_(-0.1)^(+0.1) kpc above the galactic plane,whereas,M15's is at 0.6_(-0.5)^(+0.3) kpc below the plane.We estimate the scintillation timescale and decorrelation bandwidth for each pulsar at each epoch using the one-dimensional auto-correlation in frequency and time of the dynamic spectra.We found that the boundary of the Local Bubble may have caused the scattering of M15,and detected the most distant off-plane scattering screens to date through pulsar scintillation,which provides evidence for understanding the medium circulation in the Milky Way.
基金
supported by the National SKA Program of China (Grant Nos. 2020SKA0120200, 2022SKA0130100, and 2022SKA0130104)
the National Nature Science Foundation of China (Grant Nos. 12273008, 11873067, 12041303, 12041304, 61875087, U1831120, U1838106, 61803373, 11303069, 11373011, 11873080, U2031117, and 12103069)
the Natural Science and Technology Foundation of Guizhou Province (Grant No. [2023]024)
the National Key R&D Program of China (Grant No. 2017YFB0503300)
the Guizhou Provincial Science and Technology Foundation (Grant Nos. ZK[2023]024, ZK[2022]304, [2017]5726-37, and [2018]5769-02)
the Major Science and Technology Program of Xinjiang Uygur Autonomous Region (Grant Nos. 2022A03013-4, and 2022A030132)
the Scientific Research Project of the Guizhou Provincial Education (Grant Nos. KY[2022]132, and KY[2022]137)
the Guizhou Province Science and Technology Support Program (General Project) (Grant No. Qianhe Support [2023] General 333)
the Foundation of Guizhou Provincial Education Department (Grant No. KY (2020) 003)
the Natural Science Foundation of Xinjiiang Uygur Autonomous Region (Grant No. 2022D01D85)
the Youth Innovation Promotion Association CAS (Grant No. 2021055)
the CAS Project for Young Scientists in Basic Research (Grant No. YSBR-006)
the Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CAS and ACAMAR Postdoctoral Fellowship。
