XMM Observations of Two Quadrupolar Outflows
Abstract
X-ray images of two small dark clouds, L1455 and L723, have been obtained with the EPIC cameras on board the XMM-Newton telescope. Both regions contain multiple independent but overlapping bipolar flows in high-velocity CO, a collection of Herbig-Haro objects, and a number of filaments and knots of H2 emission. The field of view in each cloud was centered on the confluence of the nearly orthogonal CO flows. More than three dozen compact X-ray sources were detected. However, the Class 0/I protostars thought to be the driving sources of the flows in both clouds were not detected. Strong emission was observed from RNO 15, an optically visible, nebulous T Tauri star in the dense core of L1455. A thermal plasma model for the X-ray spectrum of RNO 15 gave a luminosity of L X ~ 1031.2 erg s-1. The heavily reddened Class II star L1455 IRS 5 in the same region was detected as a weak X-ray source. No emission was detected from IRS 1 or IRS 4, which have been suggested as the launch sites for separate outflows in L1455. X-ray emission was observed from IRAS 19156+1906 in L723. The thermal radio source VLA 2, which is offset ~10'' east of the IRAS position and is considered the most likely energy source for the strong east-west flow in L723, was not detected. The source of the more narrowly collimated north-south flow in L723 is unknown but may be an embedded infrared object at the X-ray and IRAS position.
- Publication:
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The Astrophysical Journal
- Pub Date:
- March 2009
- DOI:
- 10.1088/0004-637X/693/2/1803
- Bibcode:
- 2009ApJ...693.1803S
- Keywords:
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- ISM: Herbig-Haro objects;
- ISM: individual: L1455 L723;
- stars: formation;
- stars: pre-main sequence;
- X-rays: stars