Astronomers have detected a periodic signal in the radio light curve of the blazar J1043+2408. The finding came as a result of over 10 years of observations of J1043+2408 with Owens Valley Radio Observatory's 40-metre telescope.
A blazar is a feeding super-massive black-hole sitting in the centre of a distant galaxy, which generates a high-energy jet pointed almost exactly toward the Earth. These radio-loud active galactic nuclei are most energetic and luminous objects in the known universe. They are powerful sources of emission across the electromagnetic spectrum and also generate high-energy gamma ray photons.
BL Lacertae objects (BL Lacs) and optically violently variable (OVV) quasars are two classes of blazers. OVV quasars are intrinsically powerful radio-loud quasars, while BL Lacs exhibit higher Doppler factors and lower-power jets than other blazars. J1043+2408 is a member of BL Lacs class of blazers and is frequently observed by astronomers using ground-based observatories and space telescopes.
The current study was led by Gopal Bhatta of Jagiellonian University in Kraków, Poland. Bhatta and his team observed J1043+2408 for about 10.5 years and found a radio signal which repeats itself in about 563 days.
Astronomer say they used several methods of time series analysis, including Lomb-Scargle periodogram, epoch folding, and discrete auto-correlation function in their study, and each method revealed a repeating signal.
The research team believes that such a periodic signal could be a result of a binary supermassive black hole system, Lense-Thirring precession or jet precession. In this particular case, they consider gravitational perturbation in a binary supermassive black hole as the most reasonable explanation.
"We conclude that while other above-discussed scenarios can't be completely ruled out, periodic modulations induced by gravitational perturbation in binary SMBH [supermassive black hole] system seems a more plausible mechanism at the root of the observed periodic radio signal," researchers wrote in their paper.
Such observations could help improve current understanding about the processes happening in the innermost regions of blazars, according to astronomers.
The findings of the study are published in a paper available on arXiv.org.
Warming was most pronounced in Siberia region
The tank will be subjected to high stresses and loads via dozens of hydraulic cylinders during testing
'Sunlit wet sidewalk' provides evidence of methane rainfall on the north pole of Saturn's moon Titan
Methane rainfall indicates the start of the summer season in Titan's northern hemisphere
Scientists believe there could be other hydrides or superhydrides with super conducting properties