Chandra observations of the planetary nebula IC 4593

DOI: 
10.1093/mnras/staa1024
Publication date: 
01/04/2020
Main author: 
Toalá, J. A.
IAA authors: 
Guerrero, M. A.
Authors: 
Toalá, J. A.;Guerrero, M. A.;Bianchi, L.;Chu, Y. -H.;De Marco, O.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Volume: 
494
Pages: 
3784
Abstract: 
The Advanced CCD Imaging Spectrometer (ACIS-S) camera on board the Chandra X-ray Observatory has been used to discover a hot bubble in the planetary nebula (PN) IC 4593, the most distant PN detected by Chandra so far. The data are used to study the distribution of the X-ray-emitting gas in IC 4593 and to estimate its physical properties. The hot bubble has a radius of ∼2 arcsec and is found to be confined inside the optically bright innermost cavity of IC 4593. The X-ray emission is mostly consistent with that of an optically thin plasma with temperature kT ≍ 0.15 keV (or T<SUB>X</SUB> ≍ 1.7 × 10<SUP>6</SUP> K), electron density n<SUB>e</SUB> ≍ 15 cm<SUP>-3</SUP>, and intrinsic X-ray luminosity in the 0.3-1.5 keV energy range L<SUB>X</SUB> = 3.4 × 10<SUP>30</SUP> erg s<SUP>-1</SUP>. A careful analysis of the distribution of hard (E &gt;0.8 keV) photons in IC 4593 suggests the presence of X-ray emission from a point source likely associated with its central star (CSPN). If this was the case, its estimated X-ray luminosity would be L<SUB>X, CSPN</SUB> = 7 × 10<SUP>29</SUP> erg s<SUP>-1</SUP>, fulfilling the log(L<SUB>X, CSPN</SUB>/L<SUB>bol</SUB>) ≍ -7 relation for self-shocking winds in hot stars. The X-ray detection of the CSPN helps explain the presence of high-ionization species detected in the ultraviolet spectra as predicted by stellar atmosphere models.
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2020MNRAS.494.3784T/abstract
ADS Bibcode: 
2020MNRAS.494.3784T
Keywords: 
stars: low-mass;stars: winds;outflows;planetary nebulae: general;planetary nebulae: IC 4593;X-rays: general;Astrophysics - Solar and Stellar Astrophysics;Astrophysics - Astrophysics of Galaxies