JWST detection of extremely excited outflowing CO and H_2O in VV 114 E SW: A possible rapidly accreting IMBH

Abstract

Mid-infrared (mid-IR) gas-phase molecular bands are powerful diagnostics of the warm interstellar medium. We report the James Webb Space Telescope detection of the CO $v=1-0$ ($4.4-5.0$\,mu m) and H$_2$O $ ($5.0-7.8$\,mu m) ro-vibrational bands, both in absorption, toward the ``s2'' core in the southwest nucleus of the merging galaxy VV 114 E. All ro-vibrational CO lines up to low =33$ ($E_ low are detected, as well as a forest of H$_2$O lines up to $ ($E_ low The highest-excitation lines are blueshifted by $ $ relative to the extended molecular cloud, which is traced by the rotational CO\,($J=3-2$) 346\,GHz line observed with the Atacama Large Millimeter/submillimeter Array. The bands also show absorption in a low-velocity component (blueshifted by $ $) with lower excitation. The analysis shows that the bands are observed against a continuum with an effective temperature of $T_ bck extinguished with $ m ext 2.5-3$ ($A_k The high-excitation CO and H$_2$O lines are consistent with $v=0$ thermalization with rot and column densities of CO $ and $N_ H_2O $. Thermalization of the $v=0$ levels of H$_2$O requires either an extreme density of $n_ H_2 $, or radiative excitation by the mid-IR field in a very compact ($<1$\,pc) optically thick source emitting $ odot $. The latter alternative is favored, implying that the observed absorption probes the very early stages of a fully enshrouded active black hole (BH). On the basis of a simple model for BH growth and applying a lifetime constraint to the s2 core, an intermediate-mass BH (IMBH, $M_ BH odot $) accreting at super-Eddington rates is suggested, where the observed feedback has not yet been able to break through the natal cocoon.