Jorissen, A. ; Mayer, A. ; van Eck, S. ; Ottensamer, R. ; Kerschbaum, F. ; Ueta, T. ; Blommaert, J. A. D. L. ; Groenewegen, M. A. T. ; Hron, J. ; Nowotny, W. ; Olofsson, H. ; Posch, T. ; Waelkens, C.

published in Why Galaxies Care about AGB Stars II: Shining Examples and Common Inhabitants, 445, pp. 595 (2011)

Abstract: The Asymptotic Giant Branch (AGB) stars X Her and TX Psc have been imaged at 70 and 160 µm with the PACS instrument on-board the Herschel satellite, as part of the large MESS (Mass loss of Evolved StarS) Guaranteed Time Key Program. The images reveal axisymmetric extended structures with their axes oriented along the stars’ space motion. This extended structure very likely originates in the interaction of the wind ejected by the AGB star with the surrounding interstellar medium (ISM). As predicted by former numerical simulations, the detailed structure of the wind-ISM interface depends upon the relative velocity between star+wind and the ISM, which is large for these two stars (56 and 108 km s-1 for TX Psc and X Her, respectively). In both cases, there is a compact blob upstream whose origin is not fully elucidated.

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