Infrared and Millimetric Study of the Young Outflow Cepheus E

by

A. Moro-Martin(1), A. Noriega-Crespo(2), S. Molinari (3), L. Testi (4), J. Chernicharo (5), A. Sargent (6)

(1) Steward Observatory, University of Arizona, Tucson, Az 85721

(2) SIRTF Science Center, Caltech, MS 100-22, Pasadena, CA 91125

(3) Infrared Processing and Analysis Center, Caltech MS 100-22, Pasadena, CA 91125

(4) Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze, Italy

(5) Instituto de Estructura de la Materia, CSIC, Calle Serrano 40, Madrid, Spain

(6) Department of Mathematics, Physics and Astronomy, California Institute of Technology, MS105-24, Pasadena, CA 91125

Abstract:

The Cepheus E outflow has been studied in the mid and far infrared using the ISO CAM and LWS instruments, and at millimetric wavelengths using OVRO. In the near and mid-IR, its morphology is similar to that expected for a jet driven outflow, where the leading bow shocks entrain and accelerate the surrounding molecular gas. As expected, fine structure atomic/ionic emission lines arise from the bow shocks, at both the Mach Disk and the stagnation tip, where J-shocks are dominant. The H$_2$, H$_2$O and CO molecular emission could arise further `downstream' at the bow shock wings where the shocks (v = $8 - 35$ \kms) are oblique and more likely to be C-type. The $^{13}$CO emission arises from entrained molecular gas and a compact high velocity emission is observed, together with an extended low velocity component that {\it almost} coincides spatially with the H$_2$ near-IR emission. The millimetric continuum emission shows two sources. We identify one of them with IRAS 23011+6126, postulating is the driver of the Cepheus E outflow; the other, also an embedded source, is likely to be driving one of other outflows observed in the region. Finally, we suggest that the strong [C~II] 158~\mum~emission must originate from an extended photo-dissociation region, very likely excited by the nearby Cepheus OB3 association.

Mantained by: Leonardo Testi