JWST MIRI-MRS observations of the Red Rectangle: AIB class transformation in the outer nebula
/ Authors
A. Ebenbichler, P. Baez, A. Candian, E. Peeters, J. Cami, P. Sarre, A. N. Witt, I. Argyriou, B. Vandenbussche, H. V. Winckel
and 1 more author
/ Abstract
Aims: We characterize the mid-infrared spectrum of the outer regions of the Red Rectangle nebula to probe the carbonaceous dust and molecular content beyond the circumbinary disk. Methods: We present JWST MIRI-MRS observations of the SW whisker, extracted from three distinct environments: the biconical outflow, the whisker itself, and the shadow region outside the outflow. We compare these with an archival ISO-SWS observation of the inner nebula. Results: The JWST spectra display only classical AIB emission on a weak dust continuum, with no signatures of the oxygen-rich circumbinary disk mineralogy nor of the rich molecular emission seen at optical wavelengths. The AIBs are predominantly Class A - in marked contrast to the exclusively Class B profiles previously reported for the inner regions - with systematic differences between the outflow and shadow regions pointing to environmentally driven PAH processing.