Follow-up on the Supermassive Black Hole Binary Candidate J1048+7143: Successful Prediction of the Next Gamma-Ray Flare and Refined Binary Parameters in the Framework of the Jet Precession Model

• Published in: Astrophysical journal. Letters 2024-03, Vol.963 (1), p.L16
• Main Authors: Kun, Emma, Jaroschewski, Ilja, Tjus, Julia Becker, Britzen, Silke, Frey, Sándor, Gabányi, Krisztina Éva, Cui, Lang, Wang, Xin, Shen, Yuling
• Format: Article
• Language: English
• Subjects: Active galactic nuclei; Black holes; Blazars; Gamma rays; Interferometry; Light curve; Parameters; Precession; Sheaths; Spine; Supermassive black holes; Very long base interferometry
• ISSN: 2041-8205; 2041-8213; 2041-8213
• DOI: 10.3847/2041-8213/ad2767

Analyzing single-dish and very long baseline interferometry radio, as well as Fermi Large Area Telescope γ -ray observations, we explained the three major flares in the γ -ray light curve of FSRQ J1048+7143 with the spin–orbit precession of the dominant mass black hole in a supermassive black hole binary system. Here, we report on the detection of a fourth γ -ray flare from J1048+7143, appearing in the time interval that was predicted in our previous work. Including this new flare, we constrained the mass ratio into a narrow range of 0.062 < q < 0.088, and consequently we were able to further constrain the parameters of the hypothetical supermassive binary black hole at the heart of J1048+7143. We predict the occurrence of the fifth major γ -ray flare that would appear only if the jet will still lay close to our line of sight. The fourth major γ -ray flare also shows the two-subflare structure, further strengthening our scenario in which the occurrence of the subflares is the signature of the precession of a spine–sheath jet structure that quasiperiodically interacts with a proton target, e.g., clouds in the broad-line region.