A5100625108- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Geophysics and Sensor Technology
- Cosmology and Gravitation Theories
- GNSS positioning and interference
- Particle accelerators and beam dynamics
- Polyomavirus and related diseases
- Computational Physics and Python Applications
- 3D Surveying and Cultural Heritage
- Geotechnical and Geomechanical Engineering
- Boron and Carbon Nanomaterials Research
- Particle Accelerators and Free-Electron Lasers
- Allergic Rhinitis and Sensitization
- Astronomical Observations and Instrumentation
- Remote Sensing and LiDAR Applications
- Earthquake Detection and Analysis
- Titanium Alloys Microstructure and Properties
- Optical measurement and interference techniques
Xinjiang Astronomical Observatory
2017-2025
Chinese Academy of Sciences
2020-2025
National Astronomical Observatories
2020-2025
Sun Yat-sen University
2025
Shanghai Jiao Tong University
2024
Tongren Hospital
2024
University of Chinese Academy of Sciences
2017
We present a new model for the distribution of free electrons in Galaxy, Magellanic Clouds and intergalactic medium (IGM) that can be used to estimate distances real or simulated pulsars fast radio bursts (FRBs) based on their dispersion measure (DM). The Galactic has an extended thick disk representing so-called warm interstellar medium, thin molecular ring, spiral arms recent fit HII regions, Center seven local features including Gum Nebula, Loop I Local Bubble. An offset Sun from plane...
The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content intergalactic medium, which is assumed dominate total extragalactic dispersion. While host galaxy contributions dispersion measure (DM) appear be small for most FRBs, in at least one case there evidence an extreme magneto-ionic local environment and a compact persistent source. Here we report detection localization repeating FRB 20190520B, co-located with compact, source associated dwarf high...
The polarization of fast radio bursts (FRBs), which are bright astronomical transient phenomena, contains information about their environments. Using wide-band observations with two telescopes, we report measurements five repeating FRBs and find a trend lower at frequencies. This behavior is modeled as multipath scattering, characterized by single parameter, σRM, the rotation measure (RM) scatter. Sources higher σRM have RM magnitude scattering time scales. sources highest FRB 20121102A...
Fast radio bursts (FRBs) are brief, intense flashes of waves from unidentified extragalactic sources. Polarized FRBs originate in highly magnetized environments. We report observations the repeating FRB 20190520B spanning 17 months, which show that FRB's Faraday rotation is variable and twice changes sign. The also depolarizes below frequencies about 1 to 3 gigahertz. interpret these properties as being due parallel component magnetic field integrated along line sight, including reversing...
We report the properties of more than 800 bursts detected from repeating fast radio burst (FRB) source FRB 20201124A with Five-hundred-meter Aperture Spherical Telescope (FAST) during an extremely active episode on UTC September 25-28, 2021 in a series four papers. In this second paper series, we mainly focus energy distribution bursts. The event rate initially increased exponentially but activity stopped within 24 hours after 4th day. detection 542 one hour fourth day marked highest single...
Abstract The repeating fast radio burst FRB 20190520B is localized to a galaxy at z = 0.241, much closer than expected given its dispersion measure DM 1205 ± 4 pc cm −3 . Here we assess implications of the large and scattering observed from for host galaxy’s plasma properties. A sample 75 bursts detected with Five-hundred-meter Aperture Spherical Telescope shows on two scales: mean temporal delay τ (1.41 GHz) 10.9 1.5 ms, which attributed galaxy, scintillation bandwidth Δ ν d 0.21 0.01 MHz,...
Abstract As the third paper in multiple-part series, we report statistical properties of radio bursts detected from repeating fast burst (FRB) source FRB 20201124A with Five-hundred-meter Aperture Spherical Telescope during an extremely active episode between 25th and 28th September 2021 (UT). We focus on polarization 536 bright S/N > 50. found that Faraday rotation measures (RMs) monotonically dropped −579 to −605 rad m −2 4 day window. The RM values were compatible (−300 −900 ) reported...
The origin of fast radio bursts (FRBs), the brightest cosmic explosion in bands, remains unknown. We introduce here a novel method for comprehensive analysis active FRBs' behaviors time-energy domain. Using "Pincus Index" and "Maximum Lyapunov Exponent", we were able to quantify randomness chaoticity, respectively, bursting events put FRBs context common transient physical phenomena, such as pulsar, earthquakes, solar flares. In bivariate domain, repeated FRB bursts' deviate significantly...
Abstract Fast radio bursts (FRBs) are signals that last milliseconds. They originate from cosmological distances and have relatively high dispersion measures (DMs), making them excellent distance indicators. However, the origins of FRB remain to be resolved. With its wide field view sensitivity, CHIME/FRB has discovered more than half all known FRBs. As FRBs located within or connected with their host galaxies, study progenitors is becoming important. In this work, we collect currently...
Abstract Fast radio bursts (FRBs) are bright originating at cosmological distances. Only three repeating FRBs FRB 20121102A, 20190520B, and 20201124A among ∼60 known have circular polarization. We observed the 20220912A with Robert C. Byrd Green Bank Telescope (GBT) L -band on 2022 October 24 detected 128 in 1.4 hr, corresponding to a burst rate of about 90 hr −1 , which is highest yet for by GBT. The average rotation measure (RM) was −0.4 ± 0.3 rad m −2 negligible intraday RM change,...
Fast radio bursts (FRBs) are bright millisecond at cosmological distances. Only a small fraction of FRBs apparently repeat. Polarization, fundamental property electromagnetic signals, often carries critical information about the radiation processes, environment, and intervening medium FRBs. Here we report circular polarization detections two active repeating FRBs, namely 20121102A 20190520B, with Five-hundred-meter Aperture Spherical Telescope. We detect in both which increases number to...
We derive the Sun's offset from local mean Galactic plane($z_\odot$) using observed $z$ distribution of young pulsars. Pulsar distances are obtained measurements annual parallax, HI absorption spectra or associations where available and otherwise pulsar dispersion a model for free electrons in Galaxy. fit cumulative function ${\rm sech}^2(z)$ function, representing an isothermal self-gravitating disk, with uncertainties being estimated bootstrap method. take pulsars having characteristic age...
Abstract We report the timing analysis of PSR J1846−0513, a pulsar discovered by Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. The possesses spin period 23.36 ms and spin-down rate ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mo>̇</mml:mo> </mml:mover> </mml:math> ) 1.0106(3) × 10 −18 s −1 , it is located an eccentric orbit e...
ABSTRACT We report the phase-connected timing ephemeris, polarization pulse profiles, Faraday rotation measurements, and Rotating-Vector-Model (RVM) fitting results of 12 millisecond pulsars (MSPs) discovered with Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST survey (CRAFTS). The campaigns were carried out Arecibo over 3 yr. 11 are neutron star–white dwarf binary systems, orbital periods between 2.4 100 d. 10 them have spin periods, companion...
<title>Abstract</title> The origin of fast radio bursts (FRBs), the brightest cosmic explosions, is still unknown<sup>1–3</sup> . Bearing critical clues to FRBs’ origin, long-term evolution FRBs has yet be con- firmed, since field young and most were seen only once. Here we report clear evidence decadal FRB 20121102A, first precisely localized repeater. In conjunction with archival data, our FAST GBT monitoring campaign 2020 reveals a significant ∼7% decline local dispersion measure (DM)....
<title>Abstract</title> Active repeating Fast Radio Bursts (FRBs), with their large number of bursts, burst energy distribution, and potential evolution, offer critical insights into the FRBs emission mechanisms. Traditional pipelines search for bursts through conducting dedispersion trials looking signals above certain fluence thresholds, both which could result in missing weak narrow-band bursts. In order to improve completeness set, we develop an End-to-end DedispersE-agnostic...
Abstract The combined timing analysis of data from the Five-hundred-meter Aperture Spherical radio Telescope (FAST) and Fermi Large Area confirmed that PSR J0002+6216 is not a hyper-velocity (exceeding 1000 km s −1 ) pulsar. From this analysis, we determined total proper motion to be μ tot = 39.05 ± 15.79 mas yr , which consistent with Very Long Baseline Interferometry (VLBI) measurements within 0.24 σ . Moreover, two glitches were detected for first time, occurred on MJD 58850(17) 60421(6),...
Periodontitis is a chronic inflammatory condition affecting the structures supporting teeth, primarily induced by bacteria. Plaque control and maintenance of local periodontal immune homeostasis are crucial for treating periodontitis achieving bone regeneration. In this study, we prepared pH/ROS dual-responsive hydrogel system (CDFBCS@SA) composed modified carboxymethyl cellulose (CMCDA) chitosan (CCS) through dynamic chemical crosslinking to load sinapic acid (SA), natural phenolic with...
ABSTRACT The follow-up timing observations were carried out for 24 pulsars discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. We report their phase-connected ephemeris, polarization pulse profiles, and Faraday rotation measurements. With spin periods spanning from 2.995 ms to 4.34 s, period derivatives determined spread between 7.996(8) × 10−21 9.83(3) 10−15 s s−1, which imply that they have characteristic ages 1.97 106...
We report on an {unusually} bright observation of PSR J1720$-$0533 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulsar is in a black widow system that {was discovered by Commensal Radio Astronomy FAST Survey (CRAFTS). By coincidence, scintillation maximum was simultaneous with eclipse our which allowed for precise measurements flux density variations, as well dispersion measure (DM) and polarization.} found there are quasi-periodic pulse emission variations...
Abstract We present Arecibo 327 MHz confirmation and follow-up studies of seven new pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These are in a pilot program Commensal Radio Astronomy FAST Survey (CRAFTS) with ultra-wide-bandwidth commissioning receiver. Five them normal two extreme nulling slow pulsars. PSR J2111+2132’s dispersion measure(DM: 78.5 pc cm −3 ) is above upper limits Galactic free electron density models, NE2001 YMW16, J2057+2133’s...