Archival Swift Observations of the Host Galaxy of the TDE AT2025aarm
ATel #17466; J. M. Miller (Univ. of Michigan), B. Mockler (Carnegie Obs.)
on 31 Oct 2025; 20:04 UT
Credential Certification: Jon Miller (jonmm@umich.edu)
Subjects: Ultra-Violet, X-ray, Tidal Disruption Event
AT2025aarm has been classified as a tidal disruption event, at a redshift of just z = 0.01368 (Newsome et al. 2025, 2025TNSCR4734), or d ~ 59 Mpc. As such, it is unusually proximal, and now the target of
extensive follow-up efforts. The host galaxy was serendipitously observed with Swift in ObsID 03106511001, obtained on April 10, 2019. Herein, we report the properties of the host galaxy measured during that observation. The source was observed using the XRT (480 s), and UVOT U an d UW1 filters (4 mins each).
XRT (0.3-10.0 keV):
flux: < 1.6 E-11 erg/cm^2/s
(assuming a kT = 50 eV blackbody)
UVOT U band:
mag = 17.00 +/- 0.04 (stat) +/- 0.02 (sys) (AB system)
flux density = 1.44 +/- 0.05 +/- 0.02 E-15 erg/s/cm^2/A
UVOT UW1 band:
mag = 18.70 +/- 0.11 (stat) +/- 0.03 (sys) (AB system)
flux density = 5.29 +/- 0.55 (stat) +/- 0.16 (sys) E-16 erg/s/cm^2/A
