• SUSHAN KONAR

Articles written in Journal of Astrophysics and Astronomy

• Neutron Star Physics in the Square Kilometre Array Era: An Indian Perspective

It is an exceptionally opportune time for astrophysics when a number of next-generation mega-instruments are poised to observe the Universe across the entire electromagnetic spectrum with unprecedented data quality. The Square Kilometre Array (SKA) is undoubtedly one of the major components of this scenario. In particular, the SKA is expected to discover tens of thousands of new neutron stars giving a major fillip to a wide range of scientific investigations. India has a sizeable community of scientists working on different aspects of neutron star physics with immediate access to both the uGMRT (an SKA pathfinder) and the recently launched X-ray observatory Astrosat. The current interests of the community largely centre around studies of (a) the generation of neutron stars and the SNe connection, (b) the neutron star population and evolutionary pathways, (c) the evolution of neutron stars in binaries and the magnetic fields, (d) the neutron star equation of state, (e) the radio pulsar emission mechanism, and (f) the radio pulsars as probes of gravitational physics. Most of these studies are the main goals of the SKA first phase, which is likely to be operational in the next four years. This article summarizes the science goals of the Indian neutron star community in the SKA era, with significant focus on coordinated efforts among the SKA and other existing/upcoming instruments.

• Editorial

• Magnetic Fields of Neutron Stars

This article briefly reviews our current understanding of the evolution of magnetic fields in neutron stars, which basically defines the evolutionary pathways between different observational classes of neutron stars. The emphasis here is on the evolution in binary systems and the newly emergent classes of millisecond pulsars.

• Radio pulsar sub-populations (I): The curious case of nulling pulsars

About $\sim$200 radio pulsars have been observed to exhibit nulling episodes – short and long. We find that the nulling fraction of a pulsar does not have any obvious correlation with any of the intrinsic pulsar parameters. It also appears that the phenomenon of nulling may be preferentially experienced by pulsars withemission coming predominantly from the polar cap region, and also having extremely curved magnetic fields.

• Radio pulsar sub-populations (II): The mysterious RRATs

Several conjectures have been put forward to explain rotating radio transients (RRATs), the newest subclass of neutron stars, and their connections to other radio pulsars. This work discusses these conjectures in the context of the characteristic properties of the RRAT population. Contrary to expectations, it is seen that: (a) the RRAT population is statistically un-correlated with the nulling pulsars and (b) theRRAT phenomenon is unlikely to be related to old age or death-line proximity. It is perhaps more likely that the special emission property of RRATs is a signature of them being later evolutionary phases of other types of neutron stars which may have resulted in restructuring their magnetic fields.

• Enigma of GLEAM-X J162759.5–523504.3

It is proposed that GLEAM-X J162759.5−523504.3, the newly discovered radio transient with an unusually long spin-period ($P_s = 1091$.1690s), can be identified to be a radio magnetar, which has a dipolar surface magnetic field of $2.5 \times 10^{16}$ G. It is shown that: (a) it is possible to anchor such a strong field at the core–crust boundary of a neutron star and (b) the energy of field dissipation can explain the observed luminosity (radio and X-ray) of this source.

• # Journal of Astrophysics and Astronomy

Volume 44, 2023
All articles
Continuous Article Publishing mode

• # Continuous Article Publication

Posted on January 27, 2016

Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019