Intranight optical variability of radio-loud broad absorption line quasars

TL;DR

This study monitored 10 radio-loud broad absorption line quasars and found a low intranight optical variability duty cycle, similar to radio-quiet BALQSOs, suggesting variability depends on viewing angles or disk proximity.

Contribution

First optical monitoring of highly radio-loud BALQSOs revealing their intranight variability characteristics and duty cycle.

Findings

Detected variability in 1 of 10 quasars during 3.5-6.5 hours.

Duty cycle of clear variability is 5.1%, increasing to 35.1% including probable cases.

Variability patterns are similar to radio-quiet BALQSOs, indicating viewing angle effects.

Abstract

We present the results of an optical photometric monitoring program of 10 extremely radio loud broad absorption line quasars (RL-BALQSOs) with radio-loudness parameter, R, greater than 100 and magnitude g_i < 19. Over an observing run of about 3.5-6.5 hour we found a clear detection of variability for one of our 10 radio-loud BALQSOs with the INOV duty cycle of 5.1 per cent, while on including the probable variable cases, a higher duty cycle of 35.1 per cent is found; which are very similar to the duty cycle of radio quiet broad absorption line quasars (RQ-BALQSOs). This low duty cycle of clear variability per cent in radio-loud sub-class of BALQSOs can be understood under the premise where BALs outflow may arise from large variety of viewing angles from the jet axis or perhaps being closer to the disc plane.