Discovery of a red quasar with recurrent activity

TL;DR

This paper reports the discovery of a double-double radio quasar with episodic activity, characterized by a smaller black hole mass and high obscuration, suggesting dust and gas influence recurrent jet activity.

Contribution

It identifies a new double-double radio quasar with evidence of recurrent activity and analyzes its black hole properties and obscuration, providing insights into jet triggering mechanisms.

Findings

Confirmed episodic radio activity through radio observations

Estimated black hole mass as 8.2×10^7 solar masses

Detected high obscuration indicating significant dust and gas presence

Abstract

We report a new double-double radio quasar, DDRQ, J0746$+$4526 which exhibits two cycles of episodic activity. From radio continuum observations at 607 MHz using the GMRT and 1400 MHz from the FIRST survey we confirm its episodic nature. We examine the SDSS optical spectrum and estimate the black hole mass to be (8.2$\pm$0.3)$\times$10$^7$M$_\odot$ from its observed MgII emission line, and the Eddington ratio to be 0.03. The black hole mass is significantly smaller than for the other reported DDRQ, J0935+0204, while the Eddington ratios are comparable. The SDSS spectrum is significantly red continuum dominated suggesting that it is highly obscured with ${E(B-V)}_{host}=0.70\pm0.16$ mag. This high obscuration further indicates the existence of a large quantity of dust and gas along the line of sight, which may have a key role in triggering the recurrent jet activity in such objects.