New features of the pulsar B0950+08 radiation at the frequency of 111 MHz

Results of long time observations of the pulsar B0950+08 are given. These observations were carried out at the LPA radio telescope at the frequency of 111 MHz from January of 2016 to May of 2019 (450 days). A strong variability in emission of this pulsar has been detected with changes of signal to noise ratios hundreds of times. Part of long-time flux density variability can be explained by the refractive scintillations in the interstellar medium. The existence of radiation between the interpulse (IP) and main pulse (MP) was confirmed. It was more powerful than at high frequencies. We detected the unusual interpulse and precursor (Pr) radiation on August 1, 2017. On the base of strong 65 interpulses we found the correlations between energies of IP and Pr and between the phase of IP and the distance Pr-IP. It is shown that the observed peculiarities of this pulsar can be explained in the frame of the aligned rotator model. We estimated distances of radiation levels from the center of the neutron star. The calculated value of the initial period of 0.2 sec means that not all pulsars are born with millisecond periods. The large age of the pulsar (6.8 millions of years) and the small angle between its magnetic moment and the rotation axis (less than 20°) confirm the suggestion on the pulsar evolution to an alignment.

Orthogonal pulsars as a key test for pulsar evolution

ABSTRACT At present, there is no direct information about evolution of inclination angle χ between magnetic and rotational axes in radio pulsars. As to theoretical models of pulsar evolution, they predict both the alignment, i.e. evolution of inclination angle χ to 0°, and its counter-alignment, i.e. evolution to 90°. In this paper, we demonstrate that the statistics of interpulse pulsars can give us the key test to solve the alignment/counter-alignment problem as the number of orthogonal interpulse pulsars (χ ≈ 90°) drastically depends on the evolution trajectory.

Predictive and Characterized Pulsar Evolution From its Optical Pulsation

The measured and predicted variables of pulsar PSR B1937+21 were explored from the energetics obtained from the previous observation made. The target parameters such as the brightness, luminosities, and optical efficiency. A series of observations were analysed to determine the individual values of the parameters chosen. Within the extended area of optical pulsation, the values were plotted to determine the relation of it to synchrotron emission. The results were presented graphically to see whether PSR B1937+21 will remain consistent with the expected pulsar model. The researcher suggests that simulation and correlation of previous observation made together with a new one to explore the cause of optical pulsation from mass transfer and spectral evolution.

A Study of a Cavity Nearby a Pulsar at -60º Latitude in the Far Infrared Map

<p>We present physical properties of a region in the interstellar medium where the past evolutionary remnant of pulsar evolution is observed. For this, a systematic search of dust structure in the far infrared (100 μm and 60 μm) IRAS (Infrared Astronomical Satellite) survey was performed using Sky View Observatory. Our selection criteria are as follows: (a) Cavity should be greater than 0.25 degree in diameter and (b) the cavity should have 3-fold minima in flux density. In the 100 micron infrared map, a new cavity-like isolated far infrared dust structure (size ~ 1.62 pc x 0.98 pc) is found at R.A. (J2000) 18h 33m 14.8s and Dec. (J2000) -60° 23' 24". We have studied flux density variation and temperature variation within the structure. We found that the dust color temperature varies from 22.78 K to 24.78 K, with offset of 2 K. The dust mass of each pixel of the region of interest was calculated using their dust color temperature. The excess mass in the region was found to be 1.62 x 10²³ Kg. The energy required to create that inhomogeneity in the structure is calculated to be 3.24 x10³⁵ J.</p><p><strong>Journal of Nepal Physical Society</strong><em><br /></em>Volume 4, Issue 1, February 2017, Page: 33-41</p>

Binary pulsar evolution: unveiled links and new species

In the last years a series of blind and/or targeted pulsar searches led to almost triple the number of known binary pulsars in the galactic field with respect to a decade ago. The focus will be on few outliers, which are emerging from the average properties of the enlarged binary pulsar population. Some of them may represent the long sought missing links between two kinds of neutron star binaries, while others could represent the stereotype of new groups of binaries, resulting from an evolutionary path which is more exotic than those considered until recently. In particular, a new class of binaries, which can be dubbed Ultra Low Mass Binary Pulsars (ULMBPs), is emerging from recent data.

Probing fundamental physics with pulsars

Pulsars provide a wealth of information about General Relativity, the equation of state of superdense matter, relativistic particle acceleration in high magnetic fields, the Galaxy's interstellar medium and magnetic field, stellar and binary evolution, celestial mechanics, planetary physics and even cosmology. The wide variety of physical applications currently being investigated through studies of radio pulsars rely on: (i) finding interesting objects to study via large-scale and targeted surveys; (ii) high-precision timing measurements which exploit their remarkable clock-like stability. We review current surveys and the principles of pulsar timing and highlight progress made in the rotating radio transients, intermittent pulsars, tests of relativity, understanding pulsar evolution, measuring neutron star masses and the pulsar timing array

Pulsar Spin-Down by 3P2 Superfluid Neutrons

To describe pulsar spin-down, a simple combined torque model, that takes into account both the standard magnetic dipole radiation and the electromagnetic radiation from the 3P2 superfluid vortex neutrons inside neutron star, is presented. Using an ordinary exponential model for the magnetic field decay, we investigate pulsar evolution tracks on the diagram, which is quite different from that of the standard magnetic dipole radiation model, especially when the superfluid torque or field decay become dominate.