RZ Piscium Hosts a Compact and Highly Perturbed Debris Disk

Abstract

RZ Piscium (RZ Psc) is well-known in the variable star field because of its numerous, irregular optical dips in the past five decades, but the nature of the system is heavily debated in the literature. We present multiyear infrared monitoring data from Spitzer and WISE to track the activities of the inner debris production, revealing stochastic infrared variability as short as weekly timescales that is consistent with destroying a 90-km-size asteroid every year. ALMA 1.3 mm data combined with spectral energy distribution modeling show that the disk is compact ($\sim$0.1--13 au radially) and lacks cold gas. The disk is found to be highly inclined and has a significant vertical scale height. These observations confirm that RZ Psc hosts a close to edge-on, highly perturbed debris disk possibly due to migration of recently formed giant planets which might be triggered by the low-mass companion RZ Psc B if the planets formed well beyond the snowlines.Comment: 16 pages, 5 figures, accepted for publication in Ap