Accretion from Winds of Red Giant Branch Stars May Reveal the Supermassive Black Hole in Leo I

A supermassive black hole (SMBH) of 3× 10⁶ M_⊙ was recently detected via dynamical measurements at the center of the dwarf galaxy Leo I. Standing 2 orders of magnitude above standard scaling relations, this SMBH is hosted by a galaxy devoid of gas and with no significant star formation in the last 1 Gyr. This detection can profoundly impact the formation models for black holes and their hosts. We propose that winds from a population of 100 evolved stars within the Bondi radius of the SMBH produce a sizable accretion rate, with Eddington ratios between 9×10^-8 and 9×10^-7, depending on the value of the stellar mass loss. These rates are typical of SMBHs accreting in advection-dominated accretion flow (ADAF) mode. The predicted spectrum peaks in the microwaves at 0.1-1 THz (300-3000 μm) and exhibits significant variations at higher energies depending on the accretion rate. We predict a radio flux of 0.1 mJy at 6 GHz, mildly dependent on the accretion properties. Deep imaging with Chandra, VLA, and ALMA can confirm the presence of this SMBH and constrain its accretion flow. In this talk, we will provide an update on our Chandra and VLA DDT observations targeting Leo I.