Bursting Activity of Magnetar SGR J1830–0645 Observed with AstroSat
Bursting Activity of Magnetar SGR J1830–0645 Observed with AstroSat - CityLife Astronomers from India have observed a magnetar called SGR J1830–0645 during its recent bursting activity. The findings provide more insight into the behavior and properties of this magnetar, which was discovered on October 10, 2020 by NASA’s Swift spacecraft when it emitted a soft, short gamma-ray burst. The dipole magnetic field of the magnetar has a strength of about 550 trillion Gauss, and its presence of the emission line suggests that there may be relatively cool material near the neutron star, causing the fluorescence of iron. In total, the astronomers observed 67 bursts, with an average duration of 33 milliseconds. This research provides valuable insights into the characteristics of magnetar SGRJ1830-0645 and suggests that astronomers can further understand the mechanisms behind their emissions and the dynamics of their magnetic fields.
Được phát hành : 2 năm trước qua Mampho Brescia trong Science
Astronomers have used India’s AstroSat spacecraft to observe a magnetar called SGR J1830–0645 during its recent bursting activity. The findings of the observational campaign provide more insight into the behavior and properties of this magnetar.
Magnetars are neutron stars that have incredibly powerful magnetic fields, more than a quadrillion times stronger than Earth’s magnetic field. These magnetic fields cause the emission of high-energy electromagnetic radiation as they decay. Magnetars are generally young and exhibit strong temporal variability in their magnetosphere.
SGR J1830–0645 was discovered on October 10, 2020, by NASA’s Swift spacecraft when it emitted a soft, short gamma-ray burst. It has a spin period of approximately 10.41 seconds and a spin-down age of 24,000 years. The dipole magnetic field of SGR J1830–0645 has a strength of about 550 trillion Gauss.
A team of astronomers led by Rahul Sharma from the Raman Research Institute in Bangalore, India, observed SGR J1830–0645 using AstroSat’s Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC). They conducted timing and spectral analysis, detecting short sub-second X-ray bursts, 0.9–10 keV pulsations, variation in pulse profiles with energy, significant variation in the pulsed fraction, and a 6.4 keV emission line.
The presence of the emission line suggests that there may be relatively cool material near the neutron star, causing the fluorescence of iron. In total, the astronomers observed 67 bursts, with an average duration of 33 milliseconds. The brightest burst lasted for about 90 milliseconds.
The pulsed fraction of SGR J1830–0645 showed a significant evolution with increasing energy, increasing up to about 5 keV and then dropping steeply. This behavior differs from that observed in other magnetars. The study also found that SGR J1830–0645 has spectral properties typical of most magnetars in the soft X-ray band, consisting of two thermal components and a non-thermal power-law component.
This research provides valuable insights into the characteristics of magnetar SGR J1830–0645 during its bursting activity. By studying magnetars like this, astronomers can further understand the mechanisms behind their emissions and the dynamics of their magnetic fields.
Source: Rahul Sharma et al, AstroSat observation of the magnetar SGR J1830–0645 during its first detected X-ray outburst, arXiv (2023). DOI: 10.48550/arxiv.2310.04079