Лекции - Конспект лекций по курсу Радиоастрономия
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79
. 4.5. .
1983 .
-15 16.
, ~79 . . -
30°.
1 . -
, -
.
1985 . – -
1
2, ,
. 1986 .
.
1990 .
,
1992 . .
300 , 3 15 , -
— 120 . -
. .
80
. 4.5. -
, , -
. 11.5 12–13
.
. 6°.
– ∅~100 (
). ~0.5,
~0.15. – >1000
2.5
. -
(∅~300
, 1 ), , ;
- –
(∅~300
). (∅~800 ) -
.
.
1963 . 14 . -
.
,
. 1991 .
–VLA (λ = 3.5 ) -
. Tharsis
Stealth,
(
,
~0.5
/
3
). , -
. ,
CO
2
H
2
O -
2–5 [Science, 1991, 253, 1508].
. 1964 .
λ = 12 70 . .
, , -
σ ~60%
; , -
.
-
.
. 1975–1979 .
(λ = 12.6 ).
81
x: 0.44–0.66, 0.20–0.40,
0.10.
∅ ≥ λ, ,
x
[Icarus, 1980, 44, 431].
. 1973 . λ = 12.5 .
, , σ
eff
=
= 0.6σ
.
> 8
(
, 1 ).
. ,
ε;
x ,
. –VLA (λ =
= 3.5
) ; -
,
[Science, 248, 975].
, , –
.
. 1979 . λ = 12.5
; σ
eff
= (0.2 ± 0.1)πa
2
, a =272
[Icarus, 1980, 43, 169].
.
. 4179 -
, –
1992
. d
min
= 3.6 . .
: 70
, – 100 , λ = 3.5 6 .
.
14 .
, -
. ,
2.5 1.5 ,
P ~ 7 . [ , 1995, 342, 480]. -
1620, ,
, ~2.76;
.
82
216 -
, 171 . . -
217×94 . 1880 .,
. ,
-
( . 4.6). , -
, - ,
.
, [Science, 2000, 288, 836;
http://www.jpl.nasa.gov/pictures/kleopatra].
. -
1980 . P/Encke
12.6
. ~1
2
. -
,
IRAS–Araki–Alcock, P/Halley, Hyakutake. -
, -
.
.
.
. ,
2–3
, .
. 4.6. .
83
, N -
N
τ=1
,
.
1961–1969 . λ = 7.8 .
, 4 -
. -
-
16 / . –
« », -
. -
70
. , -
300 / .
. , -
, . 1944 ., -
. – -
(§2.9) -
.
( ), -
, ,
, .
-
σ = 6.6·10
–25
N
2
2
. -
,
, .
-
.
, -
,
.
84
Гл а ва 5. Межзвёздная среда
и области звездообразования в Галактике
5.1. Фоновое радиоизлучение Галактики в континууме
. 1932 . 14.6 . 1940- . .
ν = 160
. ,
, – –
, .
-
, -
~10
16
K, -
.
,
.
-
.
. 5.1. 150 .
85
.
, . 18
2·10
5
K 7.5·10
4
K
. -
α < 2 (I
ν
∝ ν
–α
).
: T
b
(ν) ∝ ν
β
,
α = –(β + 2).
178 β = –0.4 –
0.6
.
:
1)
, -
;
2)
, -
;
3)
, -
;
4)
, -
.
,
-
,
, . -
. ,
.
20
. -
:
200 , – 400 . λ = 20
.
~1°.
, 11
NRAO c
11′,
( ) ~10′–20′. -
, –
.
86
( )
IMP 6 [Brown L.W., ApJ, 1973, 180, 359], RAE 2 [Novaco
J.C., Brown L.W., ApJ, 1978, 221, 114]
WIND [ . . .,
, 2000, 26, 643], ( -
).
I 6 91- , -
. -
,
32
0.13–2.6 .
RAE 2 (Radio Astronomy Explorer),
10 1973 .
1100 ;
-
. RAE 2 229-
V-
.
22
0.25 9.18 . -
: , -
, .
WIND
20–1040 100-
. -
( 1.4 .
),
.
WIND 26–30 1997 .
, .
3 ,
I(3
) = 10
–19
/(
2
⋅ ⋅ ).
ν < 3 I ∝ ν
–0.5
, ν > 3 I ∝ ν
1.5
. - , -
- -
-
N
e
~ 0.03
–3
, T
e
= 4000 K.
(2.30) ME ~ 25
–6
. -
87
r, - ,
1 -
(500 ), 260 r ~ 15 . -
,
. IMP 6 WIND,
30°
ν < 600
, ,
~70°, .
. -
Sgr A. . -
, ν > 1 S
ν
∝ ν
–0.7
. -
~10″.
. λ ~100 LL
7
10≈ .
: ,
. .
, Sgr B2. ,
,
.
CO, -
~270 .
,
21 -
OH λ = 18
–250 / .
. -
. –
, « » ,
l = 30°
, b = +80°. -
.
, .
~100 . , -
.
, -
88
Hα. (
. – . 5.1 ). -
, -
. H ~ 5⋅10
–5
, . .
.
.
. -
. ,
.
. -
,
. -
.
, <10
–4
( -
, , ). -
,
,
, ,
15 , 1.5 [ . ., -
. ., , 1957, 34, 145]. -
. -
l = 180°, b = ±45°. -
, l = 0°, b = ±45°
, . ,
: -
, , ( 234 T
b
< 30 K).
, -
, .
.
[34, 35]. -
, ,
. -
,
.
89
, -
8.0
2
1
=
−γ
=α
, γ = 2.6.
-
: N(E) = 126E
–2.62
/(
2
).
–
. -
.
1.
.
) -
, -
( , . 5.2). -
U << v
||
, v
||
– Hv . -
2U,
2
L
||
v
, L – .
U
L
dt
dL
L
dt
d
2
2
||||||
−=−=
vvv
. (5.1)
v
||
- χ, -
.
. 5.2. .
90
. 5.3.
-
( )
( )
.
) (
). -
, –
. -
, .
. -
-
.
.
2.
. , -
B . -
«1»,
–
«2». , -
1, -
-
-
,
-
.
,
[]
c
Bu
E
×
−=
, -
-
u ( . 5.3). -
. -
2
2
2
1
2
1
B
p
B
p
⊥⊥
==µ
, (5.2)
2
p∝
B. p
1⊥
, p
2⊥
–
91
-
,.
, -
-
.
3.
( , -
, ) [34].
« -
». « » ( ) – -
,
.
. -
,
.
, ,
, .
-
-
. ,
. -
,
, .
, ,
: . -
-
,
— .
γ = 0.93, -
γ=3.
. -
γ = 2.62 , ,
,
.
92
5.2. Межзвёздный нейтральный водород
-
21 . -
1
2
S.
, , F = S ± I, S –
, I – ; F = 0 –
(
), F = 1 – . F = 1
→ 0 –
: -
, . -
. -
-
λ = 21 .
F = 0, 1 -
ν
−=
sB
Tk
h
g
g
n
n
10
0
1
0
1
exp , (5.3)
n
1
, n
0
– F = 1, 0; g
1
, g
0
– -
, g
F
= 2F + 1;
ν
10
= 1420405752 . T
s
, . . -
. λ = 21
(1.3)
.
ν
10
hν
10
<< k
B
T
s
,
T
s
= 1 K. -
: n
1
≅ 3n
0
, n
H
≅ 4n
0
, n
0
≅ ¼n
H
.
-
()
[]
()
[]
100101H010101010H1
νρ+=νρ++ BqnnBAqnn , (5.4)
93
F = 1, 0, n
H
–
(
–3
); A
10
= 2.85⋅10
15
–1
– -
F=1→0; -
:
01
3
3
10
10
0
1
3
3
10
10
0
1
88
B
c
h
B
g
g
c
h
A
g
g
νπ
=
νπ
=
; (5.5)
q
01
q
10
– -
:
1/211
01
103.2 Tq
−
⋅=
3 –1
.,
ν
−=
10
10
01
exp3
Tk
h
q
q
B
. (5.6)
,
ν
10
,
F = 1,
(
) F = 0. -
,
F = 1 F = 0 -
, T
s
→ T – .
, T
s
, . . 21
ρ(ν
10
). T
s
= T :
).K()(1600
½3
H
Tn >
−
(5.7)
T ~ 100 K n
H
> 0.1
–3
, -
, .
21 :
T
b
(ν) = T
s
[1 – e
–τ(ν)
]. (5.8)
94
[τ(ν) << 1]
T
b
(ν) = T
s
τ(ν), -
.
N
H
1
2
(« -
» – column density). -
-
:
ν
ν−ν
−κ=κ
ν
2
10
10
0
2
exp c
Tk
M
B
. (5.9)
10
0
1
3
10
2/3
3
0
8
A
g
gc
vνπ
=κ
. (5.10)
κ
ν
:
M
Tk
c
B
D
D
2
,,
2
1
exp
10
2
10
0
=
ν
=ν∆
ν∆
ν−ν
−κ=κ
ν
v
v
. (5.11)
M – , ∆ν
D
– ,
v
– . -
[κ
0
] =
2
, . . κ
0
.
∫
νν
κκ=ντ
L
Lndxxn
0
HH
~)()( . (5.12)
,
n
H
≅ 4n
0
, -
95
:
∫∫
+∞
∞−
+∞
∞−
νν⋅=νντ⋅= dTdTN
bs
)(104)(104
1717
H
. (5.13)
.
()
σ
ν−ν
−=
νν
2
2
0
0
2
expNN
, (5.14)
s
T
N
C
H
=τ
, (5.15)
()
σ
ν−ν
−τ=ντ
2
2
0
0
2
exp)(
, (5.16)
σ –
e
–1
. ,
,
, T
b
(ν) = T
s
τ(ν). τ(ν) << 1 -
, τ(ν)
. :
.
.
M
Tk
B
2
=σ .
( T ~ 100 K, n
H
~ 0.5
–3
)
λ = 21 τ > 1 L > 800 .
,
.
« » -
λ = 21 .
96
, -
( ) -
, τ > 1.
λ
= 21 . -
,
T
0
. , (1.9),
T
b
(ν) = T
0
exp[–τ(ν)] + T
s
{1 – exp[–τ(ν)]}. (5.17)
-
∆T
b
(ν) = (T
s
– T
0
){1 – exp[–τ(ν)]}. (5.18)
:
0 < 1 – exp[–τ(ν)] < 1. (5.19)
, « » ∆T
b
(ν), -
,
(T
s
– T
0
). T
s
> T
0
( « » ) -
; T
s
< T
0
( « -
» ) – .
(
- T
s
)
, . . -
∆T
b
.
, 21
-
, . -
-
. .
97
21 . 21 -
1954–1957 . ( -
). 1960- . –
(
) , , ( ).
, -
,
.
,
−ν=ν
c
v
1
10
,
:
1)
( -
– Local Standard of Rest, LSR) –
19.5
/ ;
2)
– 30 / ;
3)
– 0.465 / ;
4)
– – 0.029 / .
:
) ;
)
;
) ;
) .
-
( ) -
V
r
( . . 5.4):
()( )
[]
blzRzRRV
r
cossin,,
00
ω−ω= , (5.20)
lRRlRr
22
0
2
0
sincos −±= . (5.21)
R
0
– , R – -
, r –
, l, b – ,
ω(R, z) –
, ,