1999A&A...342..823V -
Astronomy and Astrophysics, volume 342, 823-830 (1999/2-3)
A near-infrared study of the planetary nebula NGC 2346.
VICINI B., NATTA A., MARCONI A., TESTI L., HOLLENBACH D. and DRAINE B.T.
Abstract (from CDS):
This paper presents new near-infrared observations of the planetary nebula NGC 2346. The data include a broad K-band image, an image in the H2 vibrationally excited 1-0S(1) line and K band slit spectra at three positions in the nebula. In the H2 1-0S(1) line, the nebula is characterized by a central, bright torus, surrounded by weaker emission with a typical butterfly shape, as seen in Hα and CO lines. The K band spectra show 11 H2 lines with excitation energies from 6150 to 12552K. The H2 data have been compared to the predictions of models which follow the evolution with time of the H2 emission in PNe of different core mass and shell properties (Natta & Hollenbach, 1998A&A...337..517N). These models compute the emission originating in the photodissociation region (PDR) created at the inner edge of the neutral shell by the UV radiation of the central core, as well as the emission in the shock associated with the expansion of the shell inside the precursor red-giant wind. In NGC 2346, a PDR origin of the H2 emission in a low-density molecular shell (n≲104cm–3) is indicated. At these low densities, time-dependent H2 chemistry and X-ray heating of the neutral gas enhance the predicted PDR H2 line intensity by large factors.
Abstract Copyright:
∼
Journal keyword(s):
shock waves - ISM: molecules - ISM: planetary nebulae: individual: NGC 2346 - infrared: ISM: lines and bands
(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases
Other object types:
*
(AG,CSI,...),
PN
(2013MNRAS,PK,...),
IR
(IRAS,PSCz,...),
V*
(V*,AAVSO),
NIR
(2MASS)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
Syntax of radial velocity (or/and redshift) is : "value [error] (wavelength) quality bibcode"
value : radial velocity or/and redshift (Heliocentric frame) according to your Output Options
(redshift may be not displayed if the data value is <0 and the database inside value is a radial velocity)
[error] : error of the corresponding value displayed before
(wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or '∼'(unknown)
quality : flag of quality ( A=best quality -> E=worst quality, ∼=unknown quality)
References (573 between 1850 and 2024) (Total 573)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
Follow
new references on this object
Annotations :
Annotations allow a user to add a note or report an error concerning the astronomical object and its data. It requires registration to post a note. See description . Please, have a look at Best practices. The list of all annotations to SIMBAD objects can be found here .
To bookmark this query, right click on this link: simbad:objects in 1999A&A...342..823V and select 'bookmark this link' or equivalent in the popup menu