2020
DOI: 10.1093/mnras/staa515
|View full text |Cite
|
Sign up to set email alerts
|

H2 emission in the low-ionization structures of the planetary nebulae NGC 7009 and NGC 6543

Abstract: Despite the many studies in the last decades, the low-ionization structures (LISs) of planetary nebulae (PNe) still hold several mysteries. Recent imaging surveys have demonstrated that LISs are composed of molecular gas. Here, we report H 2 emission in the LISs of NGC 7009 and NGC 6543 by means of very deep narrow-band H 2 images taken with NIRI@Gemini. The surface brightness of the H 2 1-0 S(1) line is estimated to be (0.46-2.9)×10 −4 erg s −1 cm −2 sr −1 in NGC 7009 and (0.29-0.48)×10 −4 erg s −1 cm −2 sr −… Show more

Help me understand this report
View preprint versions

Search citation statements

Order By: Relevance

Paper Sections

Select...
4
1

Citation Types

1
23
0

Year Published

2020
2020
2024
2024

Publication Types

Select...
7

Relationship

2
5

Authors

Journals

citations
Cited by 19 publications
(24 citation statements)
references
References 73 publications
(137 reference statements)
1
23
0
Order By: Relevance
“…Shocks cannot be ruled out in the case of the young PN K 4-47, for which high knots' radial velocities (∼100 km s −1 ) have been measured [22]. The low line ratios (1-2 and 0.1, respectively) measured for the knots in NGC 7662 and NGC 6543 with nebular ages from 1000 to 2000 yrs, indicate UV-fluorescent H 2 emission [17].…”
Section: Molecular Hydrogen In Microstructuresmentioning
confidence: 95%
See 3 more Smart Citations
“…Shocks cannot be ruled out in the case of the young PN K 4-47, for which high knots' radial velocities (∼100 km s −1 ) have been measured [22]. The low line ratios (1-2 and 0.1, respectively) measured for the knots in NGC 7662 and NGC 6543 with nebular ages from 1000 to 2000 yrs, indicate UV-fluorescent H 2 emission [17].…”
Section: Molecular Hydrogen In Microstructuresmentioning
confidence: 95%
“…The high R(H 2 ) (∼10) and R(Brγ) (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) values found in the knots of K 4-47 as well as in the CKs of NGC 6270 and NGC 7293 show the two extreme phases (early and late phases in PN evolution), in which H 2 emission has a thermal origin (see Figure 6 in [17]). Shocks cannot be ruled out in the case of the young PN K 4-47, for which high knots' radial velocities (∼100 km s −1 ) have been measured [22].…”
Section: Molecular Hydrogen In Microstructuresmentioning
confidence: 99%
See 2 more Smart Citations
“…The pairs of knots or LISs in this nebula [17,18]) are substantially brighter in the low-ionization lines (e.g., [N II] λλ6548,6584, [S II] λλ6716,6731, [O I] λλ6300,6363, [N I] λ5200, among others) than their surrounding gas (see also, [1,19]). Moreover, the recent detection of a H 2 v = 1-0 2.12 µm S(1) ro-vibrational line emanating from the LISs in NGC 7009 [20] or generally in PNe [21,22] has shown a strong link between the emission from low-ionization lines and molecular hydrogen. Possible explanations to this link are either a low velocity shock interaction with the nebular shell or the photo-evaporation of dense molecular knots resembling the spectrum of mini-photodissociation regions (PDRs, see [23]).…”
Section: Ngc 7009mentioning
confidence: 99%