Related papers: A model for periodic blazars

Black-hole driven relativistic astrophysical jets, such as blazars and gamma-ray bursts (GRBs), are powerful sources of electromagnetic radiation. Their emission is powered by some energy dissipation and particle acceleration mechanism…

The long-term variability of the multiwavelength blazar emission can be interpreted in terms of orientation variations of a helical, inhomogeneous, non-thermally emitting jet, possibly caused by the orbital motion of the parent black hole…

Recent observations and analysis of blazar sources provide strong evidence for (i) the presence of significant periodicities in their lightcurves and (ii) the occurrence of helical trajectories in their radio jets. In scenarios, where the…

Binary supermassive black hole (SMBH) systems result from galaxy mergers, and will eventually coalesce due to gravitational wave (GW) emission if the binary separation can be reduced to $\lesssim 0.1$ pc by other mechanisms. Here, we…

During the last 40-50 years, the TeV blazar Ton 599 has systematically experienced major outbursts detected in a wide wavelength range from radio to $\gamma$-rays. In this work, we present an analysis of Ton 599 quasi-periodic variability…

The search for periodic signals from blazars has become an actively pursued field of research in recent years. This is because periodic signals bring us information about the processes occurring near the innermost regions of blazars, which…

The precessing jet-nozzle scenario has been applied to interpret the VLBI-kinematics of twenty-seven superluminal components in blazar 3C345 measured during an about 38-yr period. The superluminal knots could be ejected from a double…

The nearby radio galaxy M87 offers a unique opportunity to explore the connections between the central supermassive black hole and relativistic jets. Previous studies of the inner region of M87 revealed a wide opening angle for the jet…

Observations of accreting black hole (BH) systems, such as microquasars and supermassive black holes, often reveal a precessing jet with changing directions, indicating a misaligned accretion flow relative to the BH spin. The precession is…

Most large galaxies host supermassive black holes in their nuclei and are subject to mergers, which can produce a supermassive black hole binary (SMBHB), and hence periodic signatures due to orbital motion. We report unique periodic radio…

The precise origin of short gamma ray bursts (SGRBs) remains an important open question in relativistic astrophysics. Increasingly, observational evidence suggests the merger of a binary compact object system as the source for most SGRBs,…

It has been observed that many relativistic jets display a kind of cork-screw-like precession. Numerical simulations has suggested that such kind of precession may originate from the precession of the disk. In this work, we introduce an…

Binary supermassive black holes (BSBHs) are expected to be a generic byproduct from hierarchical galaxy formation. The final coalescence of BSBHs is thought to be the loudest gravitational wave (GW) siren, yet no confirmed BSBH is known in…

BL Lacertae is the prototype of the BL Lac class of active galactic nuclei, exhibiting intensive activity on parsec (pc) scales, such as intense core variability and multiple ejections of jet components. In particular, in previous works the…

Relativistic jets from supermassive black holes are among the most powerful and luminous astrophysical systems in Universe. We propose that the open magnetic field lines through the black hole, which drive a strongly magnetized jet, may…

A central compact object (CCO, e.g. a black hole) with an accretion disk has been suggested as the common central engine of various astrophysical phenomena, such as gamma-ray bursts (GRBs), tidal disruption events (TDEs) and active galactic…

We try to propose a tentative relativistic jet model for explaining the entire radio-optical phenomena observed in blazar OJ287, which has been observed quasi-periodically with a cycle of about 12yr in its optical light curve. We…

Structured jets are recently invoked to explain the complex emission of gamma ray bursts, such as GW 170817. Based on the accretion simulations, the jets are expected to have a structure that is more complex than a simple top-hat. Also, the…

Galaxy mergers, each hosting a supermassive black hole (SMBH), are thought to form SMBH binaries. Motivated by recent observations from the East Asian VLBI Network (EAVN) showing periodic behavior in the M87 jet, a precession of about 11…

A repeating fast radio burst (FRB), FRB 20180916B (hereafter FRB 180916), was reported to have a 16.35-day period. This period might be related to a precession period. In this paper, we investigate two precession models to explain the…