MeerKAT radio telescope captures a “little mouse” in the sky

Using the MeerKAT radio telescope, European astronomers serendipitously discovered a new radio nebula during observations of the binary black hole GRS 1915 + 105. The newly discovered object, nicknamed “Little Mouse”, is a pulsar radio star that escapes from its birth site, thus creating a radio nebula with a shape like comets. The discovery was reported in a paper published May 10 on arXiv Prepress server.

Pulsars are highly magnetized and rotate Neutron stars It emits a beam of electromagnetic radiation. They are usually detected in short bursts of radio emission; However, some of them have also been observed via optical, X-ray, and gamma-ray telescopes.

A team of astronomers led by Sara Elisa Motta of the Brera Observatory in Italy recently conducted Meerkat observations of the black hole binary system known as GRS 1915+105 and its surroundings. during the monitoring campaignconducted as part of the ThunderKAT large survey program, they accidentally discovered a feature very similar to a “mouse” – a radio nebula It was discovered in 1987.

“Based on the similarity to a mouse, we named the newly identified feature in GRS 1915+105’s field ‘the little mouse,'” the researchers explained.

Observations find that the miniaturized radio nebula is produced by pulsar PSR J1914+1054g (or J1914 for short), recently discovered by MeerKAT, evading its birth site. The nebula points back toward previously unknown, faint supernova remnant (SNR) candidate G45.24+0.18. The geometric center of G45.24+0.18 is located within 30 arcseconds of the extension of the axis of miniature symmetry, and 12 arcminutes away from the head of the nebula.

The J1914 pulsar has a rotation period of about 138.9 ms and a measured scattering of about 418.9 pcs/cm.³. Observations show that J1914 has a rolling luminosity at 400 dc erg/s and a characteristic age of about 82,000 years. The distance to the pulsar has been estimated to be about 26,700 light-years.

The astronomers note that if J1914’s characteristic age is close to its actual age, then the pulsar’s velocity should be between 320 and 360 km/s. This would be within the kick velocity distribution of isolated young pulsars, centered at about 300 km/s, with a dispersion of about 190 km/s.

“If the connection between J1914 and the faint SNR is correct, we may have a small, dim, rapidly rotating, distant pulsar with a high kick velocity, a member of a low population sample, which could help extrapolate the local velocity distribution of the young pulsar to the wider galaxy.”

Summarizing the results, the paper’s authors confirm that Mini Mouse is the fourth case of bow shock associated with a runaway pulsar, pulsar The signal and SNR associated with her birth were noted.

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