2004MNRAS.351..935Z


C.D.S. - SIMBAD4 rel 1.7 - 2021.05.06CEST01:10:57

2004MNRAS.351..935Z - Mon. Not. R. Astron. Soc., 351, 935-955 (2004/July-1)

Electron temperatures and densities of planetary nebulae determined from the nebular hydrogen recombination spectrum and temperature and density variations.

ZHANG Y., LIU X.-W., WESSON R., STOREY P.J., LIU Y. and DANZIGER I.J.

Abstract (from CDS):

A method is presented to derive electron temperatures and densities of planetary nebulae (PNe) simultaneously, using the observed hydrogen recombination spectrum, which includes continuum and line emission. By matching theoretical spectra to observed spectra around the Balmer jump at about 3646 Å, we determine electron temperatures and densities for 48 Galactic PNe. The electron temperatures based on this method - hereafter Te(Bal) - are found to be systematically lower than those derived from [Oiii] λ4959/λ4363 and [Oiii] (88 µm + 52 µm)/λ4959 ratios - hereafter Te([Oiii]na) and Te([Oiii]fn). The electron densities based on this method are found to be systematically higher than those derived from [Oii] λ3729/λ3726, [Sii] λ6731/λ6716, [Cliii] λ5537/λ5517, [Ariv] λ4740/λ4711 and [Oiii] 88 µm/52 µm ratios. These results suggest that temperature and density fluctuations are generally present within nebulae. The comparison of Te([Oiii]na) and Te(Bal) suggests that the fractional mean-square temperature variation (t2) has a representative value of 0.031. A majority of temperatures derived from the Te([Oiii]fn) ratio are found to be higher than those of Te([Oiii]na), which is attributed to the existence of dense clumps in nebulae - those [Oiii] infrared fine-structure lines are suppressed by collisional de-excitation in the clumps. By comparing Te([Oiii]fn), Te([Oiii]na) and Te(Bal) and assuming a simple two-density-component model, we find that the filling factor of dense clumps has a representative value of 7x10–5. The discrepancies between Te([Oiii]na) and Te(Bal) are found to be anticorrelated with electron densities derived from various density indicators; high-density nebulae have the smallest temperature discrepancies. This suggests that temperature discrepancy is related to nebular evolution. In addition, He/H abundances of PNe are found to be positively correlated with the difference between Te([Oiii]na) and Te(Bal), suggesting that He/H abundances might have been overestimated generally because of the possible existence of H-deficient knots. Electron temperatures and densities deduced from spectra around the Paschen jump regions at 8250 Åare also obtained for four PNe: NGC 7027, NGC 6153, M 1-42 and NGC 7009. Electron densities derived from spectra around the Paschen jump regions are in good agreement with the corresponding values derived from spectra around the Balmer jump, whereas temperatures deduced from the spectra around the Paschen jump are found to be lower than the corresponding values derived from spectra around the Balmer jump for all the four cases. The reason remains unclear.

Abstract Copyright: 2004 RAS

Journal keyword(s): atomic processes - ISM: abundances - planetary nebulae: general

Simbad objects: 52

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Number of rows : 52

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NGC 40 PN 00 13 01.0170260109 +72 31 19.032886305   11.63 11.46     [WC8] 594 2
2 PN Vy 1-1 PN 00 18 42.1733129759 +53 52 19.778791084           [WC] 123 0
3 IC 2003 PN 03 56 21.9883931981 +33 52 30.752777910   13.11 11.87 13.44   [WC3?] 244 0
4 PN A66 30 PN 08 46 53.4640384491 +17 52 46.368019418   14.23 14.30 13.47   [WC5] 386 0
5 IC 3568 PN 12 33 06.8549263326 +82 33 50.203860251   11.809 10.730 12.651   ~ 391 0
6 WRAY 16-165 PN 15 06 13.7149467774 -42 59 56.513764472   13.2 13.20     ~ 71 0
7 NGC 5873 PN 15 12 50.8601856470 -38 07 31.593041989   11.6 9.7     [WC] 136 0
8 NGC 5882 PN 15 16 49.9567882973 -45 38 58.610861335   11.9 10.9     ~ 268 0
9 PN Mz 3 PN 16 17 13.3911453557 -51 59 10.706640574   10.8 14.00     O9.5 336 0
10 NGC 6153 PN 16 31 30.5709136856 -40 15 12.646146874   10.7 15.55     ~ 290 0
11 PN DdDm 1 PN 16 40 18.1519945482 +38 42 20.023281608   14.0 13.90     sd+G/K 133 0
12 NGC 6210 PN 16 44 29.5195973291 +23 47 59.491267229   12.3 11.7     Of/[WR] 576 0
13 IC 4634 PN 17 01 33.5805836298 -21 49 33.002375687   12.3 11.3     O3If 266 0
14 NGC 6302 PN 17 13 44.339 -37 06 10.95   7.1 10.10     ~ 762 1
15 PN M 1-20 PN 17 28 57.612 -19 15 53.94           ~ 120 0
16 PN H 1-35 PN 17 49 13.9251055629 -34 22 52.842287784     12.90     wels? 108 0
17 PN Cn 2-1 PN 17 54 33.010 -34 22 21.15     12.70 14.47 13.70 ~ 131 0
18 NGC 6543 PN 17 58 33.4042519454 +66 37 58.748961810   11.09 11.28     [WC] 1132 1
19 PN M 2-24 PN 18 02 02.8949286491 -34 27 47.271639687   15.62 14.60 15.29   ~ 94 0
20 PN M 3-21 PN 18 02 32.33 -36 39 11.3     12.20     ~ 104 1
21 PN H 1-50 PN 18 03 53.5070795395 -32 41 42.015753284   10 12.80     ~ 76 0
22 PN M 1-42 PN 18 11 04.99 -28 58 59.1   13.1 14.00     ~ 196 0
23 NGC 6572 PN 18 12 06.3140077888 +06 51 13.030152295   9.3 10.8     [WC] 740 0
24 NGC 6567 PN 18 13 45.1634807418 -19 04 34.069059115     10.9     [WC5/6] 261 1
25 PN M 2-36 EB* 18 17 41.43 -29 08 19.9   12.8 13.40   17.012 ~ 127 0
26 NGC 6620 PN 18 22 54.182 -26 49 17.19   12.8 13.30 14.34 14.55 ~ 135 0
27 PN Hf 2-2 PN 18 32 30.9017640192 -28 43 20.276271603     15.90     ~ 89 0
28 PN M 3-32 PN 18 44 43.03 -25 21 34.8           ~ 64 0
29 IC 4776 PN 18 45 50.705 -33 20 34.12   11.98 10.62     [WC]pec 192 1
30 PN Hu 2-1 PN 18 49 47.56755 +20 50 39.4576   12.369 11.126 12.30   ~ 266 0
31 M 57 PN 18 53 35.0969571234 +33 01 44.883146221   15.405 15.769 15.901 16.062 DA(O?) 797 2
32 NGC 6741 PN 19 02 37.10 -00 26 56.7     9.6     ~ 342 0
33 IC 1297 PN 19 17 23.4475611063 -39 36 46.255054503     10.89     [WC3/4] 154 0
34 NGC 6778 PN 19 18 25.0 -01 35 47     14.8     ~ 244 0
35 NGC 6790 PN 19 22 56.966 +01 30 46.46   12.52 10.45     wels 314 0
36 NGC 6803 PN 19 31 16.47 +10 03 21.7     15.2     ~ 244 0
37 NGC 6807 PN 19 34 33.53 +05 41 02.5     12     ~ 135 0
38 NGC 6818 PN 19 43 58.022 -14 09 13.44     9.3     ~ 339 1
39 NGC 6826 PN 19 44 48.1500835472 +50 31 30.250916761   10.21 9.6     O6fp 703 0
40 NGC 6833 PN 19 49 46.5751757576 +48 57 40.076934646           ~ 166 0
41 NGC 6884 PN 20 10 23.6401227444 +46 27 39.547818788   11.9 10.9     ~ 308 1
42 NGC 6879 PN 20 10 26.70 +16 55 21.4     14.8     O3f(He) 145 0
43 NGC 6891 PN 20 15 08.8436589777 +12 42 15.585470301   12.11 12.51     O3Ib(f*) 386 0
44 IC 4997 PN 20 20 08.7615653034 +16 43 53.993812400   11.94 11.15     [WC7/8] 530 0
45 NGC 7009 PN 21 04 10.8153350719 -11 21 48.581808296   12.48 12.07     ~ 972 1
46 NGC 7027 PN 21 07 01.571952 +42 14 10.47120   10.358 8.831 10.157   ~ 2357 1
47 PN Hu 1-2 PN 21 33 08.3071114501 +39 38 09.524664348     12.0     ~ 277 1
48 PN A66 78 PN 21 35 29.3817385380 +31 41 45.450384940   13.04 13.25     [WC5] 307 0
49 IC 5217 PN 22 23 55.7197244731 +50 58 00.461084740     15.5     [WC7] 301 0
50 NGC 7293 PN 22 29 38.5453078023 -20 50 13.746093105 11.894 13.158 13.524 13.689 13.898 DAO.5 910 0
51 PN Me 2-2 PN 22 31 43.683 +47 48 03.91   9.3       ~ 148 0
52 NGC 7662 PN 23 25 53.6 +42 32 06   9.4 12     ~ 913 0

    Equat.    Gal    SGal    Ecl

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2021.05.06-01:10:57

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