scholarly journals Advances in Infrared Observations of Planetary Nebulae

1978 ◽  
Vol 76 ◽  
pp. 103-110 ◽  
Author(s):  
David M Rank
Keyword(s):  
Thermal Emission ◽  
Line Emission ◽  
Planetary Nebulae ◽  
Far Infrared ◽  
Infrared Emission ◽  
Continuum Emission ◽  
Infrared Observations ◽  
Ngc 7027 ◽  
Structure Line ◽  
Middle Infrared

The discovery of infrared continuum emission from NGC 7027 by Gillett, Low, and Stein in 1967 marked the beginning of far infrared observations of planetary nebulae. These early observations verified the predictions (Delmer, Gould, and Ramsey 1967) of infrared fine structure line emission from the SIV ion and also provided a surprise; namely, that the continuum radiation from planetary nebulae was not free-free emission from the gas, but rather that it was thermal emission from heated dust grains. In the ten years which have elapsed since 1967, numerous infrared emission lines have been observed and interpreted in many of the brighter planetary nebulae. In the middle infrared these lines were principally Ne II at 12.8μ, Gillett et al. (1969); SIV at 10.5μ, Holtz, et al. (1971), Gillett, et al. (1972), Aitken and Jones (1973); and AIII at 9.0μ Geballe and Rank (1973) and Gillett and Forrest (1973).

scholarly journals Infrared Observations of the Galactic Nucleus

1980 ◽  
Vol 5 ◽  
pp. 163-169 ◽  
Author(s):  
J. H. Lacy
Keyword(s):  
Stellar Population ◽  
Near Infrared ◽  
Line Emission ◽  
Far Infrared ◽  
Infrared Emission ◽  
Ionized Gas ◽  
Infrared Observations ◽  
Cool Stars ◽  
Infrared Sources ◽  
Near Infrared Emission

AbstractInfrared observations of the galactic nucleus and conclusions regarding the nature of the objects present there are reviewed. Observations of three sources of infrared radiation are discussed: near-infrared emission from cool stars, mid- and far-infrared emission from dust, and line emission from ionized gas. These observations provide information about the mass distribution, the stellar population, and the origin and ionization of the compact mid-infrared sources. The possibility of the existence of a massive central black hole is discussed.

scholarly journals Ionization of the Galactic Center Arched Filaments

1989 ◽  
Vol 120 ◽  
pp. 132-133
Author(s):  
R. Rubin ◽  
M. Morris ◽  
E.F. Erickson ◽  
S. Colgan ◽  
J. Simpson
Keyword(s):  
Fine Structure ◽  
Radio Emission ◽  
Galactic Center ◽  
Galactic Plane ◽  
Line Emission ◽  
Far Infrared ◽  
Thin Filaments ◽  
Ob Stars ◽  
Structure Line ◽  
Photoionization Model

The remarkable filament system seen in radio observations in the vicinity of the galactic center includes two thin filaments which arch away from the galactic plane (E.G. Yusef-Zadem et al 1984). The brightest part of each of these thermal structures is located at GO.10+0.02 and GO.07+0.04. Morris and Yusef-Zadem (1989) reason that photoionization by OB stars is unlikely on geometrical and morphological grounds. They suggest a magnetohydrodynamic mechanism to account for the radio emission and ionization. Erickson et al. (1968) were able to explain most of their observations of the far infrared (FIR) fine structure line emission from these locations in terms of a photoionization model.

scholarly journals Radio properties of the OH megamaser galaxy IRAS 02524+2046

2020 ◽  
Vol 638 ◽  
pp. A78
Author(s):  
Hao Peng ◽  
Zhongzu Wu ◽  
Bo Zhang ◽  
Yongjun Chen ◽  
Xingwu Zheng ◽  
...  
Keyword(s):  
Flux Density ◽  
Spectral Index ◽  
Line Emission ◽  
Far Infrared ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Starburst Galaxy ◽  
Radio Flux ◽  
Vlbi Observations

We present results from VLBI observations of continuum and OH line emission in IRAS 02524+2046 as well as arcsecond-scale radio properties of this galaxy using VLA archive data. We found that there is no significant detection of radio continuum emission from VLBI observations. The arcsecond-scale radio images of this source show no clear extended emission. The total radio flux density at L and C bands are approximately 2.9 mJy and 1.0 mJy, respectively, which indicates a steep radio spectral index between the two bands. A steep spectral index, low brightness temperature, and high q-ratio (i.e., the far-infrared to the radio flux density), which are three critical indicators in the classification of radio activity in the nuclei of galaxies, are all consistent with the classification of this source as a starburst galaxy from its optical spectrum. The high-resolution line profile reveals that we detected both the 1665 MHz and 1667 MHz OH maser lines, which show two and three clear components, respectively. The channel maps show that the maser emission are distributed in a region of ∼210 pc × 90 pc. The detected maser components in different regions indicate similar double spectral features, which might be evidence that this galaxy is at a stage of major merger as seen from the optical morphology.

scholarly journals Far-infrared spectroscopy of Planetary Nebulae with the KAO

1997 ◽  
Vol 180 ◽  
pp. 278-278
Author(s):  
R. H. Rubin ◽  
S.W.J. Colgan ◽  
M.R. Haas ◽  
S. D. Lord ◽  
J. P. Simpson
Keyword(s):  
Infrared Spectroscopy ◽  
Ionizing Radiation ◽  
Radiation Field ◽  
Electron Density ◽  
Flux Ratio ◽  
Planetary Nebulae ◽  
Far Infrared ◽  
Far Infrared Spectroscopy ◽  
Ionic Ratio ◽  
Ngc 7027

We present new far-infrared line observations of the planetary nebulae (PNs) NGC 7027, NGC 7009, NGC 6210, NGC 6543, and IC 4997 obtained with the Kuiper Airborne Observatory (KAO). The bulk of our data are for NGC 7027 and NGC 7009, including [Ne V] 24 μm, [O IV] 26 μm, [O III] (52, 88μm), and [Nm] 57 μm. Our data for [O III] (52, 88) and [N III] 57 in NGC 7027 represent the first measurements of these lines in this source. The large [O III] 52/88 flux ratio implies an electron density (cm–3) of log Ne[O III] = 4.19, the largest Ne ever inferred from these lines. We derive N++/O++ = 0.394±0.062 for NGC 7027 and 0.179±0.043 for NGC 6210. We are able to infer the O+3/O++ ionic ratio from our data. As gauged by this ionic ratio, NGC 7027 is substantially higher ionization than is NGC 7009 – consistent with our observation that the former produces copious [Ne V] emission while the latter does not. These data help characterize the stellar ionizing radiation field.

Far-infrared observations of NGC 7027

1977 ◽  
Vol 211 ◽  
pp. 475 ◽  
Author(s):  
C. M. Telesco ◽  
D. A. Harper
Keyword(s):  
Far Infrared ◽  
Infrared Observations ◽  
Ngc 7027

Far-infrared emission line and continuum observations of NGC 7027

1981 ◽  
Vol 243 ◽  
pp. 170 ◽  
Author(s):  
G. Melnick ◽  
R. W. Russell ◽  
G. E. Gull ◽  
M. Harwit
Keyword(s):  
Emission Line ◽  
Far Infrared ◽  
Infrared Emission ◽  
Ngc 7027

The Orion Molecular Clouds OMC‐1 and OMC‐2 Mapped in the Far‐Infrared Fine‐Structure Line Emission of C+and O0

1997 ◽  
Vol 481 (1) ◽  
pp. 343-354 ◽  
Author(s):  
F. Herrmann ◽  
S. C. Madden ◽  
T. Nikola ◽  
A. Poglitsch ◽  
R. Timmermann ◽  
...  
Keyword(s):  
Fine Structure ◽  
Molecular Clouds ◽  
Line Emission ◽  
Far Infrared ◽  
Structure Line

scholarly journals PAH features in Infrared Luminous Galaxies: Results from Michelle

2004 ◽  
Vol 217 ◽  
pp. 216-217
Author(s):  
M. S. Clemens ◽  
B. Nikolic ◽  
P. Alexander ◽  
G. Cotter ◽  
M. S. Longair
Keyword(s):  
Narrow Band Imaging ◽  
Far Infrared ◽  
Infrared Emission ◽  
Radio Continuum ◽  
Energy Output ◽  
Mid Infrared ◽  
Infrared Observations ◽  
Relative Contribution ◽  
Polycyclic Aromatic ◽  
Continuum Data

We present recent results from mid-infrared observations of a sample of nearby, infrared luminous starbursts and AGN made with the new mid-infrared instrument, “Michelle”, on UKIRT. Narrow band imaging in the 7-13 micron range with sub-arcsec resolution has been used to study the spatial distribution of polycyclic aromatic hydrocarbon (PAH) features. The comparison of these sub-arcsecond resolution data with radio continuum data at similar resolution can be used to determine, 1) the sources of excitation required for PAH emission, and 2) whether PAH features are a measure of the relative contribution of star formation and AGN to the bolometric energy output of a galaxy. Unlike the far-infrared emission from dust, that in the mid-infrared can be used to discriminate between different heating sources.

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