Detalles de publicación

PP 017069

The planetary nebula IC 4776 and its post-common-envelope binary central star

Paulina Sowicka (1), David Jones (2,3), Romano L. M. Corradi (4,2), Roger Wesson (5), Jorge García-Rojas (2,3), Miguel Santander-García (6), Henri M. J. Boffin (7), Pablo Rodríguez-Gil (2,3)
(1) NCAC, (2) IAC, (3) ULL, (4) GTC, (5) UCL, (6) OAN-IGN, (7) ESO
We present a detailed analysis of IC 4776, a planetary nebula displaying a morphology believed to be typical of central star binarity. The nebula is shown to comprise a compact hourglass-shaped central region and a pair of precessing jet-like structures. Time-resolved spectroscopy of its central star reveals periodic radial velocity variability consistent with a binary system. While the data are insufficient to accurately determine the parameters of the binary, the most likely solutions indicate that the secondary is probably a low-mass main sequence star. An empirical analysis of the chemical abundances in IC 4776 indicates that the common-envelope phase may have cut short the AGB evolution of the progenitor. Abundances calculated from recombination lines are found to be discrepant by a factor of approximately two relative to those calculated using collisionally excited lines, suggesting a possible correlation between low abundance discrepancy factors and intermediate-period post-common-envelope central stars and/or Wolf-Rayet central stars. The detection of a radial velocity variability associated with binarity in the central star of IC 4776 may be indicative of a significant population of (intermediate-period) post-common-envelope binary central stars which would be undetected by classic photometric monitoring techniques.

 
Aceptado para publicación en MNRAS | Enviado el 2017-06-29 | Proyecto P/308613