相关论文: A Numerical Model for the Multi-wavelength Lightcu…
Recent modeling of NICER observations of thermal X-ray pulsations from the surface of the isolated millisecond pulsar PSR J0030+0451 suggests that the hot emitting regions on the pulsar's surface are far from antipodal, which is at odds…
Modeling of the NICER X-ray waveform of the pulsar PSR J0030+0451, aimed to constrain the neutron star mass and radius, has inferred surface hot-spots (the magnetic polar caps) that imply significantly non-dipolar magnetic fields. To this…
NICER has observed a few millisecond pulsars where the geometry of the X-ray emitting hotspots on the neutron star is analyzed in order to constrain the mass and radius from X-ray light curve modeling. One example, PSR J0030+0451, is shown…
The diversity of pulsar light-curves and radio polarisation properties originates in the structure of the magnetic field close to the stellar surface. For millisecond pulsars, this complexity is particularly puzzling. Fortunately, some…
Modeling of the NICER X-ray light curves of millisecond pulsars PSR J0030+0451 provides a strong evidence for the existence of non-dipole magnetic fields. We study the X-ray and $\gamma$-ray emission of PSR J0030+0451 in the dissipative…
Recently, it was proposed that an off-center dipole magnetic configuration, together with a non-trivial temperature profile, may be the best model to explain the X-ray light curve of PSR J0030+0451 observed by the Neutron Star Interior…
With the advent of multi-wavelength electromagnetic observations of neutron stars, spanning many decades in photon energies, from radio wavelengths up to X-rays and $\gamma$-rays, it becomes possible to significantly constrain the geometry…
Millisecond pulsars are known to show complex radio pulse profiles and polarisation position angle evolution with rotational phase. Small scale surface magnetic fields and multipolar components are believed to be responsible for this…
NICER observations of millisecond pulsars (MSPs) suggest that non-dipolar magnetic fields are required to explain their surface X-ray hotspots. C. Kalapotharakos et al. (2021) modeled the NICER light curve of MSP J0030+0451 (J0030) using a…
Neutron star Interior Composition Explorer (NICER) data have been used to estimate the masses and radii of the rotation-powered millisecond pulsars PSR J0030$+$0451, PSR J0740$+$6620, PSR J0437$-$4715, PSR J1231$-$1411, and PSR…
Multi-wavelength observations of pulsar emission properties are powerful means to constrain their magnetospheric activity and magnetic topology. Usually a star centred magnetic dipole model is invoked to explain the main characteristics of…
The evolution of the multipolar structure of the magnetic field of isolated neutron stars is studied assuming the currents to be confined to the crust. Lower orders ($\le 25$) of multipole are seen to evolve in a manner similar to the…
We report on Bayesian parameter estimation of the mass and equatorial radius of the millisecond pulsar PSR J0030$+$0451, conditional on pulse-profile modeling of Neutron Star Interior Composition Explorer (NICER) X-ray spectral-timing event…
Several important properties of rotation-powered millisecond pulsars (MSPs), such as their mass-radius ratio, equation of state and magnetic field topology, can be inferred from precise observations and modelling of their X-ray light…
PSR J0108$-$1431 is an old pulsar where the X-ray emission is expected to have a thermal component from the polar cap and a non-thermal component from the magnetosphere. Although the phase-integrated spectra are fit best with a single…
The NASA Neutron star Interior Composition Explorer (\emph{NICER}) mission measures the X-ray pulse profiles of select millisecond pulsars and uses sophisticated pulse profile modeling (PPM) techniques to constrain their masses ($M$) and…
Thermal X-ray emission from rotation-powered pulsars is believed to originate from localized "hotspots" on the stellar surface occurring where large-scale currents from the magnetosphere return to heat the atmosphere. Lightcurve modeling…
We present observations of fields containing eight recently discovered binary millisecond pulsars using the telescopes at MDM Observatory. Optical counterparts to four of these systems are detected, one of which, PSR J2214+3000, is a novel…
The Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for exploring the modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute event time…
NICER observed several rotation-powered millisecond pulsars to search for or confirm the presence of X-ray pulsations. When broad and sine-like, these pulsations may indicate thermal emission from hot polar caps at the magnetic poles on the…