Electron temperature and electron concentration of the planetary nebula IC 4997

Astrophysics ◽  
1966 ◽  
Vol 1 (2) ◽  
pp. 126-127
Author(s):  
G. A. Gurzadyan
Keyword(s):  
Electron Temperature ◽  
Electron Concentration ◽  
Planetary Nebula

scholarly journals Echelle measurements of the electron temperature of the giant halo of the planetary nebula NGC 6543

1991 ◽  
Vol 252 (4) ◽  
pp. 535-542 ◽  
Author(s):  
J. Meaburn ◽  
R. Nicholson ◽  
M. Bryce ◽  
J. E. Dyson ◽  
J. R. Walsh
Keyword(s):  
Electron Temperature ◽  
Planetary Nebula

The Electron Temperature of the Planetary Nebula IC 418

1969 ◽  
Vol 1 (5) ◽  
pp. 216-217
Author(s):  
A. E. Le Marne ◽  
P. A. Shaver
Keyword(s):  
High Resolution ◽  
Electron Temperature ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Pencil Beam ◽  
Radio Observatory ◽  
A Current

In a current programme at the Molonglo Radio Observatory using the high-resolution pencil beam of the instrument (∼3′ arc) an attempt is being made to extend the measured spectra of known planetary nebulae down to 408 MHz. Of 23 such planetaries already investigated, 14 have been detected. The main results will be given elsewhere; here it is proposed to discuss in detail only the well-known planetary nebula IC 418.

Numerical Calculation of Sub-Micron Hot Spot in Si Devices

2003 ◽  
Author(s):  
Kazuyoshi Fushinobu ◽  
Hirohisa Maruyama
Keyword(s):  
Numerical Calculation ◽  
Electron Temperature ◽  
Electron Concentration ◽  
Hot Spot ◽  
Lattice Temperature ◽  
Device Modeling ◽  
Electrical Behavior

Numerical calculation of silicon MOSFET is performed. Conjugate nature of the thermal and electrical behavior in the device is considered, and the lattice temperatures is solved as well as the electron concentration and the electron temperature. The calculated results shows the importance of considering both the electron and lattice temperatures for device modeling; the electron temperature has a significant impact on the calculated electron concentration and the lattice temperature. Submicron local hot spot is observed in the device, and its characteristics are discussed.

scholarly journals SOFIA observations of the planetary nebula NGC 7009

2011 ◽  
Vol 7 (S283) ◽  
pp. 67-70
Author(s):  
R. H. Rubin ◽  
S. W. J. Colgan ◽  
R. L. M. Corradi ◽  
R. Sankrit ◽  
A. G. G. M. Tielens ◽  
...  
Keyword(s):  
Fine Structure ◽  
Electron Temperature ◽  
Planetary Nebula ◽  
Central Star ◽  
Optical Measurements ◽  
Optical Line

AbstractWe report spectrophotometric observations made with SOFIA/FORCAST on 2011 June 2 UT. Optical measurements have previously shown that the abundance discrepancy factor (adf) varies with position in several high-adf PNe, and is highest close to the central star. The very low electron temperature inclusions postulated to explain the abundance discrepancy, must be cooled predominantly by fine structure IR lines. These SOFIA data will map mid-IR FS lines (and our related Herschel program will add several far-IR FS lines) in the bright, well-characterized, high-adf PN NGC 7009. We will compare these IR results with FS optical line measurements in order to correlate ratios of IR to optical fluxes with position, and thus correlate with where the adf peaks.

scholarly journals Параметры микроканальной структуры в начальной фазе искрового разряда в воздухе атмосферного давления в промежутке острие-плоскость

2021 ◽  
Vol 47 (2) ◽  
pp. 24
Author(s):  
К.И. Алмазова ◽  
А.А. Амирова ◽  
А.Н. Белоногов ◽  
В.В. Боровков ◽  
Г.Б. Рагимханов ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Electric Field ◽  
Electron Temperature ◽  
Electron Concentration ◽  
Initial Phase ◽  
Spark Discharge ◽  
Degree Of Ionization ◽  
Average Electron ◽  
High Degree

The results of investigations of the microstructure in the initial phase of a spark discharge in air in the 1.5 mm long gap between a tip and a plane are presented. Measurements show that, within 15 ns after breakdown, the channel is a set of a large number of microchannels, the current in the channel grows almost linearly up to 1 kA, and the electron concentration reaches the value of 2 • 10^19 cm^(−3). Kinetic processes in a separate microchannel were calculated based on the experimental data. It was found that the average electron temperature is in the range of 4-8 eV, the electric field is ~ 300 kV/cm, and the electrical conductivity is ∼10 Ω^(−1)•cm^(−1). The obtained results indicate that it is just the microstructure of the discharge determines the relatively high values of the average electron temperature in combination with a sufficiently high degree of ionization.

scholarly journals The Proto-Planetary Nebula Vy 2-2

1989 ◽  
Vol 131 ◽  
pp. 443-443 ◽  
Author(s):  
R. E. S. Clegg ◽  
M. G. Hoare ◽  
J. R. Walsh
Keyword(s):  
Ir Spectroscopy ◽  
Electron Temperature ◽  
Empirical Analysis ◽  
Planetary Nebula ◽  
Black Body ◽  
Central Star ◽  
Speckle Interferometry ◽  
Maser Emission ◽  
Near Ir ◽  
Carbon Abundance

High and low-resolution optical and near-IR spectroscopy of the candidate proto-planetary (or very young PN) Vy 2-2 (P-K 45 - 2°1) is reported. This object has associated OH maser emission and an angular diameter of only 0.4 arcsec, found from VLA and optical speckle interferometry. Empirical analysis gives the values Ne ≈3 × 105 cm−3, Te=11000(±1500)K. The electron temperature is quite uncertain because of the high density. Abundances of He, C, N, O, Ne and Ar are reported; the carbon abundance is uncertain as it relies on the C II λ4267Å line, since the object is too highly-reddened (c=1.8 ± 0.2) to be observed with IUE. We find He/H=0.10, O/H=4 × 10−4 and C/O=0.8. The HI Zanstra temperature is 38 000 K (for black-body). The spectrum shows broad stellar lines of He II λ4686, C III λ4647 and N III λ4640; the central star may be of type Of.

scholarly journals Temperature Variations from HST Imagery and Spectroscopy of NGC 7009

2003 ◽  
Vol 209 ◽  
pp. 361-362
Author(s):  
R. H. Rubin ◽  
N. J. Bhatt ◽  
R. J. Dufour ◽  
B. A. Buckalew ◽  
M. J. Barlow ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Spatial Resolution ◽  
Planetary Nebula ◽  
Heavy Element ◽  
High Spatial Resolution ◽  
Flux Ratio ◽  
Mean Square ◽  
Temperature Variations ◽  
Element Abundances ◽  
Intrinsic Flux

We obtained new HST/STIS long-slit spectra and WFPC2 imagery of the planetary nebula NGC 7009 in order to obtain high spatial resolution of the intrinsic flux ratio [O III] 4364/5008, which is a well-known diagnostic for electron temperature (Te). Our primary purpose was to quantify Te variations across the nebula. We address whether the observational data support the possibility that the [fractional] mean-square Te variation (t2) (Peimbert 1967) in NGC 7009 may be as large as ~0.1. Such large values are required to reconcile the “abundance dichotomy” by Te variations alone. The abundance dichotomy (discussed by Liu at greater length elsewhere in this volume) refers to the significantly higher heavy element abundances derived from optical recombination lines (e.g., a factor of ~5 for NGC 7009, Liu et al. 1995) compared with the corresponding values deduced from collisionally-excited lines.

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