As part of the VLA Low Band Ionospheric and Transient Experiment (VLITE), astronomers utilize Karl GThe Jansky Superarray (VLA) has discovered a millisecond pulsar in the globular cluster Glimpse-C01. This is the first pulsar detected in the cluster. The findings were published in a December 18 article on the preprint server arxiv.
Pulsars are highly magnetized rotating neutron stars that emit electromagnetic radiation from their poles, most commonly in the form of radio waves. The fastest spinning pulsar, with a rotation period of less than 30 milliseconds, is known as a millisecond pulsar (MSPS). Astronomers believe that they form in binary star systems, and when the initially larger component becomes a neutron star, the rotation accelerates due to the accretion of material from secondary stars.
Due to their huge stellar density, globular clusters (GCS) are considered an excellent site for MSPS formation. Their star density is very large, and many neutron stars can get companion stars through binary swap encounters.
That's why Amaris V. of the University of Texas at LupockMcCarver) decided to conduct a radio-imaging search for pulsars in nearly a hundred globular clusters. To do this, they analyzed images from the VLite and VLite Symbiosis Sky Survey (VCSS).
In this paper, we conducted a large-scale search for pulsar candidates in globular clusters using low-frequency continuous-wave radio imagery," the researchers wrote.
In total, the team identified 97 sources in a sample of 10 globular clusters. After that, they performed a weighted fit using archiving and new flux density measurements to determine the spectral index of each source. The strongest pulsar candidate is the source in Glimpse-C01, a dense and massive middle-aged globular cluster located about 10,760 light-years from Earth. The source has an extremely steep spectrum, and analysis of additional radio, X-ray and infrared data confirms its pulsar nature.
This newly discovered pulsar is labeled Glimpse-C01A with a spin period of 1978 milliseconds with a dispersion of 4911 pc/cm3。This pulsar has a higher hard X-ray (2-10 keV) luminosity than most globular clusters, while its rotation period is slower. This indicates that its magnetic field is high – at the level of 1 billion gauss. The characteristic age of this pulsar is estimated to be 100 million years.
Summarizing the results, the researchers noted that regular timing of Glimpse-C01A and the establishment of orbital and timing solutions are necessary to obtain more information about the properties of the pulsar. They added that their findings underscore the effectiveness of spectral exponential search for pulsars.