LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G....
-
Upload
tamsyn-robertson -
Category
Documents
-
view
213 -
download
0
Transcript of LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G....
![Page 1: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/1.jpg)
LIMITING REGIMES OF THE SOLAR WIND/COMETARY
OUTFLOW INTERACTION AT LOW COMET GAS
PRODUCTIONSM.G. Lebedev
Moscow State University
![Page 2: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/2.jpg)
The relevant parameters of the interaction are as follows:
Q, W, μ,
τ;
and the parameters characterizing other physical and chemical processes, such as charge exchange, ion-neutral friction, etc.
It is convenient to solve the interaction problem using dimensionless variables and dimensionless governing parameters, which can be introduced in different fashion
,,,, BnV
![Page 3: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/3.jpg)
We will determine the scale length as follows:
Then the problem is governed by the following dimensionless parameters:
and, if the magnetic field is taken into account,
The parameter ζ is the rate of the solar wind mass loading by cometary ions via gas outflow from the comet surface (parameter Q) and their subsequent photoionization (parameter τ)
WVn
QL
4
V
W
WV
Q
W
L
,
4 22
,2V
B
![Page 4: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/4.jpg)
The characteristic values of the relevant parameters for )400/1(km/s1 km/s,400 WV
Case Q, s-1 n, cm-3 τ, s L zeta
CG(a) 1 * 1024 0.9 1.1 * 107 0.34 3 * 10-8
CG(b) 8 * 1025 1.4 7.3 * 106 27 3.6 * 10-6
CG(c) 8 * 1026 2.5 4 * 106 270 7 * 10-5
CG(d) 5 * 1027 6.0 1.7 * 106 1660 10-3
GS 8 * 1027 6 106 3560 3.6 * 10-3
Halley 5 * 1029 6 106 0.4 * 106 0.4
HB 1 * 1031 6 106 7.3 * 106 7.3
![Page 5: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/5.jpg)
Since the gas production of the CG comet is very low, it is believed that only in cases c and d the gasdynamic interaction model will be adequate, whereas at greater spacings between the CG comet and the Sun hybrid and kinetic models should be invoked to accurately describe the interaction process.
The purpose of this study is to establish certain limiting laws governing, as the main dimensionless parameter zeta vanishes and to determine a zeta interval on which these laws hold true
The results of numerical simulations show that in the dimensionless variables presented above the dependence of the cometocentric bow shock stand-off distance on the solar-wind mass-loading rate is as follows:
10
![Page 6: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/6.jpg)
![Page 7: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/7.jpg)
Thus, we obtain
The dependence derived by Biermann, Brosowski, and Schmidt in their pioneer study (1967) is similar in form:
The shape of the bow shock between the comet-Sun axis and the terminator is well approximated by the paraboloid
nWV
Qkk
L BSBS
4,8.2:0 0,
0,
]1)ˆˆ[(40,
cBS unWV
Q
8.2,07.0, 0
2
0
LL
y
L
x
![Page 8: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/8.jpg)
Zeta-dependence of the cometocentric distances of the contact discontinuity and the inner shock at the comet-Sun axis for different cometary-outflow—to—solar-wind velocity
ratios
![Page 9: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/9.jpg)
The solar wind mass densities of nucleons (a) and protons (c) and Mach number (b) (a) (b) (c)
![Page 10: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/10.jpg)
Profiles of the proton, water-group-ion, and nucleon densities along the comet-Sun axis
![Page 11: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/11.jpg)
IMF effect on the parameter distributions for the CG comet in positions c and d
![Page 12: LIMITING REGIMES OF THE SOLAR WIND/COMETARY OUTFLOW INTERACTION AT LOW COMET GAS PRODUCTIONS M.G. Lebedev Moscow State University.](https://reader035.fdocuments.in/reader035/viewer/2022062720/56649f0a5503460f94c1e67a/html5/thumbnails/12.jpg)