2016A&A...586A..59G


C.D.S. - SIMBAD4 rel 1.7 - 2019.12.06CET15:31:49

2016A&A...586A..59G - Astronomy and Astrophysics, volume 586A, 59-59 (2016/2-1)

The planetary nebulae and HII regions in NGC 6822 revisited. Clues to AGB nucleosynthesis.

GARCIA-ROJAS J., PENA M., FLORES-DURAN S. and HERNANDEZ-MARTINEZ L.

Abstract (from CDS):

The chemical behaviour of an ample sample of planetary nebulae (PNe) in NGC6822 is analysed. Spectrophotometric data of 11 PNe and two HII regions were obtained with the OSIRIS spectrograph attached to the Gran Telescopio Canarias. Data for other 13 PNe and three HII regions were retrieved from the literature. Physical conditions and chemical abundances of O, N, Ne, Ar, and S were derived in a consistent way for 19 PNe and 4 HII regions. Abundances in the PNe sample are widely distributed showing 12+log(O/H) from 7.4 to 8.2 and 12+log(Ar/H) from 4.97 to 5.80. Two groups of PNe can be differentiated: one old with low metallicity (12+log(O/H)<8.0 and 12+log(Ar/H)<5.7) and another younger one with metallicities similar to the values for HII regions. The old objects are distributed in a larger volume than the young ones. An important fraction of PNe (over 30%) was found to be highly N-rich (Peimbert Type I PNe). Such PNe occur at any metallicity. In addition, about 60% of the sample presents high ionization (He++/He≥0.1), possessing a central star with effective temperature higher than 100000K. Possible biases in the sample are discussed. From comparison with stellar evolution models by Karakas (2010MNRAS.403.1413K) and Fishlock et al. (2014ApJ...797...44F) of the observed N/O abundance ratios, our PNe should have had initial masses that are lower than 4M, although if the comparison is made with Ne vs. O abundances, the initial masses should have been lower than 2M. It appears that these models of stars of 2-3M are producing too much 22Ne in the stellar surface at the end of the AGB. On the other hand, the comparison with another set of stellar evolution models with a different treatment of convection and on the assumptions about the overshoot of the convective core during the core H-burning phase, provided there is reasonable agreement between the observed and predicted N/O and Ne/H ratios if initial masses of more massive stars are about 4M.

Abstract Copyright:

Journal keyword(s): ISM: abundances - HII regions - planetary nebulae: general - galaxies: abundances - galaxies: dwarf - stars: AGB and post-AGB

CDS comments: In ref list HERNANDEZ-MARTINEZ 2009, A&A, 505, 102 is a misprint for HERNANDEZ-MARTINEZ 2009, A&A, 505, 1027.

Simbad objects: 33

goto Full paper

goto View the reference in ADS

Number of rows : 33

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 10604 1
2 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9131 1
3 NGC 300 GiG 00 54 53.4460065856 -37 41 03.182962667 8.83 8.69 8.13 7.46   ~ 1272 2
4 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 5398 1
5 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14374 1
6 NGC 3109 G 10 03 06.877 -26 09 34.46 11.10 10.42 10.04 9.91   ~ 682 2
7 Ross 640 WD* 16 28 25.0030292072 +36 46 15.849157470   14.01   13.9   DZA5.5 162 0
8 [HP2009] PN 6 PN 19 44 02.29 -14 42 43.3           ~ 7 0
9 [HP2009] PN 13 PN 19 44 31.27 -14 47 14.9           ~ 3 0
10 [HP2009] PN 23 PN 19 44 44.22 -14 50 46.4           ~ 5 0
11 [HP2009] PN 24 PN 19 44 45.59 -14 52 37.0           ~ 3 0
12 [HP2009] PN 7 PN 19 44 49.11 -14 43 00.6           ~ 5 0
13 [HP2009] PN 16 PN 19 44 49.52 -14 48 03.5           ~ 12 0
14 [LCM2005] PN 14 PN? 19 44 49.59 -14 46 31.3           ~ 7 0
15 [HP2009] PN 21 PN 19 44 50.90 -14 49 13.8           ~ 6 0
16 [HP2009] PN 18 PN 19 44 51.79 -14 48 15.7           ~ 4 0
17 [HP2009] PN 5 PN 19 44 52.02 -14 42 18.0           ~ 4 0
18 NGC 6822 G 19 44 56.199 -14 47 51.29   18 8.1     ~ 1408 0
19 [HP2009] PN 10 PN 19 44 56.93 -14 45 18.6           ~ 8 0
20 [HP2009] PN 9 PN? 19 44 58.77 -14 44 14.7           ~ 2 0
21 [HP2009] PN 22 PN? 19 44 58.90 -14 49 31.0           ~ 2 0
22 [HP2009] PN 17 PN 19 44 59.73 -14 48 07.2           ~ 5 0
23 [HP2009] PN 15 PN? 19 45 00.59 -14 48 04.6           ~ 2 0
24 [HP2009] PN 11 PN? 19 45 00.74 -14 46 28.9           ~ 2 0
25 [LCM2005] PN 4 PN? 19 45 01.53 -14 41 36.3           ~ 8 0
26 [HP2009] PN 19 PN 19 45 06.44 -14 48 39.5   24.730 23.968     ~ 5 0
27 [HP2009] PN 14 PN 19 45 07.15 -14 47 31.4           ~ 14 0
28 [HP2009] PN 26 PN? 19 45 07.84 -14 55 50.3           ~ 2 0
29 [HP2009] PN 20 PN 19 45 11.50 -14 48 53.6           ~ 5 0
30 [HP2009] PN 25 PN? 19 45 13.36 -14 54 48.6           ~ 2 0
31 [HP2009] PN 2 PN 19 45 56.38 -14 40 50.5           ~ 4 0
32 [HP2009] PN 8 PN 19 46 02.22 -14 43 42.2           ~ 4 0
33 NAME Local Group GrG ~ ~           ~ 6696 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2016A&A...586A..59G and select 'bookmark this link' or equivalent in the popup menu


2019.12.06-15:31:49

© Université de Strasbourg/CNRS

    • Contact