To TDE or not to TDE: the luminous transient ASASSN-18jd with TDE-like and AGN-like qualities
Published in MNRAS, 2020
Check out the paper here!
Abstract: We present the discovery of ASASSN-18jd (AT 2018bcb), a luminous optical/ultraviolet(UV)/X-ray transient located in the nucleus of the galaxy 2MASX J22434289-1659083 at z = 0.1192. Over the year after discovery, Swift UltraViolet and Optical Telescope (UVOT) photometry shows the UV spectral energy distribution of the transient to be well modelled by a slowly shrinking blackbody with temperature T ∼ 2.5×10^4 K, a maximum observed luminosity of L_max = 4.5(+0.6,−0.3)×10^44 erg s^−1, and a radiated energy of E = 9.6(+1.1,−0.6)×10^51 erg. X-ray data from Swift X-Ray Telescope (XRT) and XMM-Newton show a transient, variable X-ray flux with blackbody and power-law components that fade by nearly an order of magnitude over the following year. Optical spectra show strong, roughly constant broad Balmer emission and transient features attributable to He II, N III-V, O III, and coronal Fe. While ASASSN-18jd shares similarities with tidal disruption events (TDEs), it is also similar to the newly discovered nuclear transients seen in quiescent galaxies and faint active galactic nuclei (AGNs).