Envelope masses and distances to planetary nebulae: IC 5117 and NGC 7293

1Melekh, BY, 1Demchyna, AV, 1Holovatyi, VV
1Ivan Franko National University of Lviv, Lviv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2015, 31(2):34-46
Start Page: Structure and Dynamics of the Galaxy
Language: Russian

Self-consistent method to determine the masses Mi of the ionized gas in envelopes of planetary nebulae (PNe) and the distances D to those ones is developed. The method is based on the calculation of optimized photoionization model (OPhM) of a planetary nebula envelope. Models of the «young» nebula IC5117 and «old» one NGC7293 are calculated. Correspondingly, the values of Mi and D for IC5117 (Mi = 0.0056M☉, D = 1287 pc) and NGC7293 (Mi= 0.681M☉, D = 201 pc) are determined. The radial gas density distribution in a PN envelope was defined using approximation expression that is close to the normal one and derived by us on the basis of an analysis of isophotoe maps of 12 PNe [Astron. Zhurn.—1992.—69.—P. 1166—1178]. The mass of the ionized gas was determined during OPhM calculation through the integration of the gas radial distribution over nebula volume. The distance to the PN was determined through the OPhM calculation as one of OPhM free parameters from the comparison of the modelling radiation flux in H β line at the distance to the Earth which is assumed by optimizer with the observed one. The values D determined by this means are compared with corresponding results of other investigators.

Keywords: IC 5117, NGC 7293, Planetary Nebula

1.N. V. Gavrilova, Candidate’s Dissertation in Mathematics and Physics (L’vov’s Univ., L’vov, 2005).

2.V. V. Golovatii and A. V. Demchina, “Masses of ionised gas envelopes in galactic planetary nebulae,” Zh. Fiz. Dosl. 17, 1902.1–1902.12 (2013).

3.V. V. Golovatyi and A. V. Demchyna, “Evolution of planetary-nebula envelopes and determination of their distances,” Astron. Rep. 58, 692–701 (2014).

4.V. V. Golovatyi and Yu. F. Mal’kov, “Evolution of planetary-nebula envelopes: empiric approach,” Astron. Zh. 69, 1166–1178 (1992).

5.V. V. Golovatyi and Yu. F. Mal’kov, “Planetary nebulae: photoionization models of the glow and physical specifications,” Astron. Zh. 68, 1197–1210 (1991).

6.S. R. Pottasch, Planetary Nebulae. A Study of Late Stages of Stellar Evolution (Kluwer, Dordrecht, 1983; Mir, Moscow, 1987).

7.J. H. Cahn, J. B. Kaler, and L. Stanghellini, “A catalogue of absolute fluxes and distances of planetaty nebulae,” Astron. Astrophys., Suppl. Ser. 94, 399 (1992).

8.R. E. S. Clegg, J. P. Harrington, M. J. Barlow, and J. R. Walsh, “The planetary nebula NGC 3918,” Astrophys. J. 314, 551–571 (1987).

9.G. J. Ferland, Hazy, a Brief Introduction to Cloudy. Int. Report No. 200 (Univ. Kentucky, 2005); http://www.nublado.org

10.J. P. Harrington and W. A. Feibelman, “The planetary nebula IC 3568 — A model based on IUE observations,” Astrophys. J. 265, 258–271 (1983).

11.S. Hyung, L. H. Aller, W. A. Feibelman, and S. J. Lee, “Optical spectrum of the compact planetary nebula IC 5117,” Astrophys. J. 563, 889–902 (2001).

12.J. B. Kaler, “A catalog of relative emission line intensities observed in planetary and diffuse nebulae,” Astrophys. J., Suppl. Ser. 31, 517–688 (1976).

13.A. Karska, Comparison of properties reddish planetary nebulae in the Milky Way and Big Magelan Cloud (Mikolaja Kopernik Univ., Torun, 2009), Vol. 118 [in Polish].

14.B. Ya. Melekh, V. V. Holovatyy, and Yu. I. Izotov, “Determination of the physical parameters, Lyman continua, and chemical compositions of H II regions in blue compact dwarf galaxies,” Astron. Rep. 52, 184–200 (2008).

15.M. Peimbert and S. Torres-Peimbert, “Chemical composition of type I planetary nebulae — Collisional excitation effects on He I line intensities,” Rev. Mex. Astron. Astrofis. 14, 540–558 (1987).

16.J. P. Phillips, “Density gradients in Galactic planetary nebulae,” Mon. Not. R. Astron. Soc. 378, 231–238 (2007).

17.T. Rauch, “A grid of synthetic ionizing spectra for very hot compact stars from NLTE model atmospheres,” Astron. Astrophys. 403, 709–714 (2003).

18.O. I. Sharova, “Determination of the parameters of central star from the radio flux of a planetary nebulae,” Sov. Astron. 69, 38–51 (1992).

19.A. R. Taylor, S. R. Pottasch, and C. Zhang, “Radio continuum spectra of compact planetary nebulae. A windshell model,” Astron. Astrophys. 171, 178 (1987).

20.C. Y. Zhang, “A statistical distance scale for Galactic planetary nebulae,” Astrophys. J., Suppl. Ser. 98, 659–678 (1995).