Early emission characterization of TDE 2025aarm

TL;DR

This paper presents early multi-wavelength observations of the nearby TDE 2025aarm, revealing optical, UV, and X-ray data that shed light on its emission mechanisms and properties.

Contribution

First detailed early emission analysis of TDE 2025aarm, including optical, UV, and X-ray data, providing insights into its physical characteristics and emission processes.

Findings

Optical spectra show blue continuum with helium, hydrogen, and Bowen lines.

Optical light curves peak at M_g ~ -18.68 mag, consistent with fallback of a 0.16 M_sun star.

Swift-XRT detects soft X-ray emission fitted by a black-body with k_BT ~ 0.39 keV.

Abstract

In this Letter, we present early emission data analysis of the tidal disruption event TDE 2025aarm, including optical, UV and X-ray data. At a redshift of z = 0.01368, TDE 2025aarm is the second closest TDE ever discovered, offering an unprecedented opportunity to study such phenomena in great details. We observed TDE 2025aarm in optical with the Liverpool Telescope for a total of three epochs, and complemented our dataset with ancillary spectroscopic and photometric data. The early optical spectra are characterized by a blue-continuum and helium, hydrogen and possibly Bowen lines typical of H+He events. The optical light curves peak at M_g ~ -18.68 mag and are well described by fallback of a M_star ~ 0.16 M_sun star onto a M_BH ~ 2x10^{7}M_sun black hole. We report Swift-XRT detection in the 0.3-10 keV range, with a total flux of F_X ~ 1.42x10^{-14} erg cm^{-2} s^{-1}, fitted by a black-body with k_BT ~ 0.39 keV. This makes TDE~2025aarm a new event among optical/UV bright TDEs detected in soft X-rays. Our analysis suggests that the early emission from TDE 2025aarm is powered by circularization shocks, and that the delayed accretion scenario best describes the observed features.