A5100403220- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Astro and Planetary Science
- Geophysics and Sensor Technology
- Advanced Frequency and Time Standards
- Astrophysics and Star Formation Studies
- GaN-based semiconductor devices and materials
- Ionosphere and magnetosphere dynamics
- Terahertz technology and applications
- Semiconductor Lasers and Optical Devices
- Plasmonic and Surface Plasmon Research
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Nonlinear Photonic Systems
- Dark Matter and Cosmic Phenomena
- Solid State Laser Technologies
- Magnetic confinement fusion research
Kavli Institute for Theoretical Sciences
2024
Peking University
2024
University of Groningen
2023
Space Research Organisation Netherlands
2016-2023
National Astronomical Observatories
1994-2022
Chinese Academy of Sciences
2005-2022
University of Manchester
1993-2022
University of Chinese Academy of Sciences
2017-2022
Durham University
2013-2016
Shanghai Institute of Microsystem and Information Technology
2015
We present results from the search for a stochastic gravitational-wave background (GWB) as predicted by theory of General Relativity using six radio millisecond pulsars Data Release 2 (DR2) European Pulsar Timing Array (EPTA) covering timespan up to 24 years. A GWB manifests itself long-term low-frequency signal common all pulsars, red (CRS), with characteristic Hellings-Downs (HD) spatial correlation. Our analysis is performed two independent pipelines, \eprise{} and \tn{}+\ftwo{}, which...
We present the discovery of 24 pulsars in 15 Globular Clusters (GCs) using Five-hundred-meter Aperture Spherical radio Telescope (FAST). These include first pulsar discoveries M2, M10, and M14. Most new systems are either confirmed or likely members binary systems. M53C, NGC6517H I only three to be isolated. M14A is a black widow with an orbital period 5.5 hours minimum companion mass 0.016 \Ms. M14E eclipsing 20.3 hours. With other 8 that have been reported elsewhere, total 32 GC discovered...
We present the results of search for an isotropic stochastic gravitational wave background (GWB) at nanohertz frequencies using second data release European Pulsar Timing Array (EPTA) 25 millisecond pulsars and a combination with first Indian (InPTA). analysed (i) full 24.7-year EPTA set, (ii) its 10.3-year subset based on modern observing systems, (iii) set InPTA ten commonly timed pulsars, (iv) data. These combinations allowed us to probe contributions instrumental noise interstellar...
Selecting sources with rising flux densities towards longer wavelengths from Herschel/SPIRE maps is an efficient way to produce a catalogue rich in high-redshift (z > 4) dusty star-forming galaxies. The effectiveness of this approach has already been confirmed by spectroscopic follow-up observations, but the previously available catalogues made are limited small survey areas. Here we apply map-based search method 274 deg$^2$ HerMES Large Mode Survey (HeLMS) and create 477 objects SPIRE...
An easily-integrated compact graphene-based waveguide structure is proposed to achieve an analogue of electromagnetically induced transparency (EIT) effect at terahertz frequencies. The composed a graphene and two identical-shape ribbons located parallel on the same side different distances, in which closer farther behave as bright dark resonators, respectively. EIT-like caused by destructive interference resonators. By shifting Fermi energy levels ribbons, window can be dynamically tuned....
ABSTRACT The European Pulsar Timing Array (EPTA) collaboration has recently released an extended data set for six pulsars (DR2) and reported evidence a common red noise signal. Here we present analysis each of the pulsars. We consider several types noise: (i) radio frequency independent, ‘achromatic’, time-correlated noise; (ii) variations dispersion measure scattering; (iii) system band (iv) deterministic signals (other than gravitational waves) that could be in PTA data. perform Bayesian...
ABSTRACT In this work, we study variations in the parabolic scintillation arcs of binary millisecond pulsar PSR J1643−1224 over five years using Large European Array for Pulsars (LEAP). The two-dimensional (2D) power spectrum scintillation, called secondary spectrum, often shows a distribution power, where arc curvature encodes relative velocities and distances pulsar, ionized interstellar medium, Earth. We observe clear arc, which varies throughout year. spectra is inconsistent with single...
We search for a stochastic gravitational wave background (SGWB) generated by network of cosmic strings using six millisecond pulsars from Data Release 2 (DR2) the European Pulsar Timing Array (EPTA). perform Bayesian analysis considering two models string loops, and compare it to simple power-law model which is expected population supermassive black hole binaries. Our main strong assumption that previously reported common red noise process SGWB. find one-parameter slightly favored over...
We investigate the multi-wavelength properties of a sample 450-\mu m selected sources from SCUBA-2 Cosmology Legacy Survey (S2CLS). A total 69 were identified above 4\sigma\ in deep observations overlapping UDS and COSMOS fields covering 210 sq. arcmin to typical depth \sigma 450=1.5 mJy. Reliable cross identification are found for 58 (84 per cent) Spitzer Hubble Space Telescope WFC3/IR data. The photometric redshift distribution (dN/dz) 450\mu m-selected is presented, showing broad peak...
We report a new giant planet orbiting the K HD 155233, as well four stellar-mass companions from Pan–Pacific Planet Search, Southern hemisphere radial velocity survey for planets nearby giants and sub-giants. also present updated velocities refined orbit 47205b (7 CMa b), first discovered by this survey. 155233b has period of 885 ± 63 d, eccentricity e = 0.03 0.20, m sin i 2.0 0.5 MJup. The range in 0.066 to 0.33 M⊙. Whilst 104358B falls slightly below traditional 0.08 M⊙ hydrogen-burning...
Using data from the Large European Array for Pulsars (LEAP), and Effelsberg telescope, we study scintillation parameters of millisecond pulsar J0613-0200 over a 7 year timespan. The "secondary spectrum" -- 2D power spectrum presents scattered as function time delay, contains relative velocities pulsar, observer, scattering material. We detect persistent parabolic arc, suggesting is dominated by thin, anisotropic region. poorly described simple exponential tail, with excess at high delays;...
Pulsar polarization profiles are critical for understanding their magnetospheric structures and radiation mechanisms. We present profile measurements 25 pulsars in globular clusters (GCs) from the observation of Five-hundred-meter Aperture Spherical radio Telescope (FAST). The diversity shows complex magnetic structure emission pattern pulsars. Among these, 15 were firstly measured. M53A a 57\% linear ratio, being highest among these GC M15H 42\% circular which is average ratios absolute...
We have studied 4265 giant pulses (GPs) from the millisecond pulsar B1937+21; largest-ever sample gathered for this pulsar, in observations made with Large European Array Pulsars. The pulse energy distribution of GPs associated interpulse are well-described by a power law, index α = −3.99 ± 0.04, while those main best-described broken break occurring at ∼7 Jy |$\mu$|s, power-law indices αlow −3.48 0.04 and αhigh −2.10 0.09. modulation GP emission measured, which found to vary ∼0.5 phases...
We report the discovery of an eclipsing binary millisecond pulsar in globular cluster M92 (NGC6341) with Five-hundred-meter Aperture Spherical radio Telescope (FAST). PSR J1717+4308A, or M92A, has a pulse frequency 316.5~Hz (3.16~ms) and dispersion measure 35.45 pc cm$^{-3}$. The is member system orbital period 0.20~days around low-mass companion which median mass $\sim$0.18~\Ms. From observations so far, at least two events have been observed each orbit. longer one lasted for ~5000~s phase...
Abstract We present a polarization study of 25 globular cluster (GC) pulsars observed with FAST, including 15 profiles measured for the first time. The pulse width-period relationships MSPs in GCs follow power-law indices -0.268 (W10) and -0.330 (W50), consistent normal pulsars. Only 20% sample exhibit clear S-shaped position angle (PA) curves—significantly fewer than pulsar population. RMs these suggest that near Galactic plane show higher RMs, agreement former studies.
Polarization...
We have investigated the plasmonic oscillations in GaN double-channel (DC) high electron mobility transistors (HEMTs). It is shown that absorption peaks of DC-HEMT can exist wider frequency regions than single channel HEMT. These appear as a result excitation elementary plasmon modes supported by separate channels and be tuned for entire terahertz domain. Significant resonant enhancement also observed after varying two-dimensional gas density DC-HEMTs. promising properties indicate DC-HEMTs...
We present complete characterizations of multimode GaAs photodetectors for high-speed VCSEL-based optical links and compare SiGe receiver IC performances in a 62Gbps back-to-back link different photodiode designs.
In this work we report an ab initio intermolecular potential energy surface and theoretical spectroscopic studies for Xe-H(2)O complex. The energies are calculated with CCSD(T) method large basis sets (aug-cc-pVQZ H O aug-cc-pVQZ-PP Xe) augmented by a {3s3p2d2f1g} set of bond functions. This has global minimum corresponding to planar nearly linear hydrogen bonded configuration well depth 192.5 cm(-1) at distance 4.0 A, which is consistent the previous determined Wen Jager [J. Phys. Chem. A...
ABSTRACT We have carried out Hubble Space Telescope (HST) snapshot observations at 1.1 μm of 281 candidate strongly lensed galaxies identified in the wide-area extragalactic surveys conducted with Herschel Observatory. Our candidates comprise systems flux densities $500\, \mu$m, S500 ≥ 80 mJy. model and subtract surface brightness distribution for 130 systems, where we identify a foreground lens candidate. After combining visual inspection, archival high-resolution observations, subtraction,...
Abstract We present a detailed single-pulse analysis for PSR B1929+10 based on observations with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The main pulse (MP) and interpulse (IP) are found to be modulated periodicity of ∼12 times pulsar’s rotational period ( P ). modulation is confirmed as periodic amplitude instead systematic drifting. in IP anti-correlated that weak preceding component MP (MP_ i ), but correlated first two components ii which implies patterns...
We report the discovery of three new pulsars in Globular Cluster (GC) NGC6517, namely NGC 6517 E, F, and G, made with Five-hundred-meter Aperture Spherical radio Telescope (FAST). The spin periods G are 7.60~ms, 24.89~ms, 51.59~ms, respectively. Their dispersion measures 183.29, 183.713, 185.3~pc~cm$^{-3}$, respectively, all slightly larger than those previously known this cluster. period derivatives at level 1$\times$10$^{-18}$~s~s$^{-1}$, which suggests these recycled pulsars. In addition...
The nanohertz gravitational wave background (GWB) is expected to be an aggregate signal of ensemble waves emitted predominantly by a large population coalescing supermassive black hole binaries in the centres merging galaxies. Pulsar timing arrays, ensembles extremely stable pulsars, are most precise experiments capable detecting this background. However, subtle imprints that GWB induces on pulsar data obscured many sources noise. These must carefully characterized increase sensitivity GWB....
ABSTRACT We report on the detection of quasi-periodic micro-structure in three millisecond pulsars (MSPs), PSRs J1022+1001, J2145−0750, and J1744−1134, using high time resolution data acquired with Large European Array for Pulsars at a radio frequency 1.4 GHz. The occurrence rate is consistent among pulses different peak flux densities. Using an auto-correlation analysis, we measure periodicity width these pulsars. detected from J1022+1001 J1744−1134 often highly linearly polarized. In PSR...