Serendipitous Chandra X-ray Detection of a Hot Bubble within the Planetary Nebula NGC 5315

Joel H. Kastner, Rochester Institute of Technology
Rodolfo Montez Jr, Rochester Institute of Technology
Bruce Balick, University of Washington
Orsola De Marco, American Museum of Natural History

This is the pre-print of an article published by the American Astronomical Society. The final, published version is available here:

© 2007 The American Astronomical Society.

Also archived in: arXiv:0709.4139v1 [astro-ph]

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.


We report the serendipitous detection of the planetary nebula NGC 5315 by the Chandra X-ray Observatory. The Chandra imaging spectroscopy results indicate that the X-rays from this PN, which harbors a Wolf-Rayet (WR) central star, emanate from a TX 2.5 × 106 K plasma generated via the same wind collisions that have cleared a compact ( 8000 AU radius) central cavity within the nebula. The inferred X-ray luminosity of NGC 5315 is 2.5 × 1032 erg s−1 (0.3-2.0 keV), placing this object among the most luminous such “hot bubble” X-ray sources yet detected within PNe. With the X-ray detection of NGC 5315, objects with WR-type central stars now constitute a clear majority – 2 – of known examples of diffuse X-ray sources among PNe; all such “hot bubble” PN X-ray sources display well-defined, quasi-continuous optical rims. We therefore assert that X-ray-luminous hot bubbles are characteristic of young PNe with large central star wind kinetic energies and closed bubble morphologies. However, the evidence at hand also suggests that processes such as wind and bubble temporal evolution, as well as heat conduction and/or mixing of hot bubble and nebular gas, ultimately govern the luminosity and temperature of superheated plasma within PNe.