Spectral analysis of mid-IR excesses of central stars of planetary nebulae
نویسندگان
چکیده
منابع مشابه
Spectral Analysis of Central Stars of Planetary Nebulae
Spectral analysis by means of NLTE model atmospheres has presently arrived at a high level of sophistication. High-resolution spectra of central stars of planetary nebulae can be reproduced in detail from the infrared to the X-ray wavelength range. In the case of LSV+46◦21, the exciting star of Sh 2−216, we demonstrate the state-of-the-art in the determination of photospheric properties like, e...
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A radial velocity (RV) survey to detect central stars in binary systems was carried out between 2002 and 2004. [5] reported that 10 out of 11 monitored stars exhibited strong RV variability, but periods were not detected. Since other mechanisms, such as wind variability, can cause apparent RV variations, we monitored 4 of the 10 RV-variable stars at echelle resolutions to determine the origin o...
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I list the 16 planetary nebulae (PNe) known to contain closebinary nuclei, and show that the nebulae generally have axisymmetric structures, including elliptical, bipolar, or ring morphologies. The orbital periods range from 2.7 hr to 16 days, and close binaries constitute ≈10% of all central stars. Since the known binaries were found mainly from photometric variability, which depends on heatin...
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We present narrow-band images of nine planetary nebulae (PN) and a spectral analysis of four of their central stars (CSPN) by means of model atmosphere techniques based on medium-resolution optical spectra. Four of our CSPN are unambiguously identified. They are very hot (Teff > 100 kK) and have about 1 2 times solar He/H abundance ratios. (the exciting stars of PN G214.9+07.8, PN G231.8+04.1, ...
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The kinematic structure of a sample of planetary nebulae, consisting of 23 [WR] central stars, 21 weak emission line stars (wels) and 57 non-emission line central stars, is studied. The [WR] stars are shown to be surrounded by turbulent nebulae, a characteristic shared by some wels but almost completely absent from the non-emission line stars. The fraction of objects showing turbulence for non-...
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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2011
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921312011179