X‐Rays from HH 80, HH 81, and the Central Region

We report detections of X-rays from HH 80 and HH 81 with the ACIS instrumenton the Chandra X-ray Observatory. These are among the most luminous HH sourcesin the optical and they are now the most luminous known in X-rays. These X-raysarise from the strong shocks that occur when the southern extension of thisbipolar outflow slams into the ambient material. There is a one-to-onecorrespondence between regions of high X-ray emission and high H? emission. TheX-ray luminosities of HH 80 and HH 81 are 4.5 and 4.3 x 1031 erg s-1,respectively, assuming the measured low-energy absorption is not in thesources. The measured temperature of the HH plasma is not as large as thatexpected from the maximum velocities seen in the extended tails of the opticalemission lines. Rather it is consistent with the ~106 K temperature of the?narrow? core of the optical lines. There is no observed emission from HH 80North, the northern extension of the bipolar flow, based upon a measurement oflower sensitivity. We imaged the central region of the bipolar flow revealing acomplex of X-ray sources including one near, but not coincident with theputative power source in the radio and infrared. This source, CXOPTMJ181912.4-204733, has no counterparts at other wavelengths and is consistent inluminosity and spectrum with a massive star with AV ~ 90 mag. It may contributesignificantly to the power input to the complex. Alternatively, this emissionmight be extended X-rays from outflows close to the power source. We detect 94X-ray sources overall in this area of star formation.Comment: 30 pages, 11 figures, PDF format, ApJ April 2004, in pres