Detection of Tidal Disruption Events around Direct-collapse Black Holes at High Redshifts with the James Webb Space Telescope

Abstract

Abstract This is the third sequel in a series discussing the discovery of various types of extragalactic transients with the James Webb Space Telescope (JWST) in a narrow-field (∼0.1 deg2), moderately deep (m AB ∼ 27 mag) survey. In this part we focus on the detectability and observational characteristics of direct-collapse black holes (DCBHs) and tidal disruption events (TDEs) around them. We use existing models for DCBH accretion luminosities and spectra, as well as for TDE light curves, and find that accreting DCBH seeds may be bright enough for detection up to z ∼ 7 with JWST NIRCam imaging. TDEs of massive (M ≳ 50 M ⊙) stars around them can enhance the chance for discovering them as transient objects, although the rate of such events is low, a few per survey time. TDEs around nonaccreting black holes of M ∼ 106 M ⊙ may also be detected at z < 7 redshifts in the redder NIRCam bands between 3 and 5 μs. It is also shown that accreting DCBHs appear separate from supernovae on the NIRCam color–color plot, but TDEs from quiescent black holes fall in nearly the same color range as superluminous supernovae, which makes them more difficult to identify.