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A “strange” unit radio astronomy
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I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:
Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$
I'm guessing it's "Watts per square meter per something
per second", but I'm not sure what the something
is.
A similar unit appears in this paper on the first line on page 364:
The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.
Again, this looks to me like megasomething
. Can anyone shed some light on this?
On page 362 of the second paper, the unit appears as $(Watts/M^2
)/(C/S)$ as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.
radio-astronomy units
$endgroup$
add a comment |
$begingroup$
I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:
Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$
I'm guessing it's "Watts per square meter per something
per second", but I'm not sure what the something
is.
A similar unit appears in this paper on the first line on page 364:
The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.
Again, this looks to me like megasomething
. Can anyone shed some light on this?
On page 362 of the second paper, the unit appears as $(Watts/M^2
)/(C/S)$ as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.
radio-astronomy units
$endgroup$
add a comment |
$begingroup$
I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:
Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$
I'm guessing it's "Watts per square meter per something
per second", but I'm not sure what the something
is.
A similar unit appears in this paper on the first line on page 364:
The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.
Again, this looks to me like megasomething
. Can anyone shed some light on this?
On page 362 of the second paper, the unit appears as $(Watts/M^2
)/(C/S)$ as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.
radio-astronomy units
$endgroup$
I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:
Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$
I'm guessing it's "Watts per square meter per something
per second", but I'm not sure what the something
is.
A similar unit appears in this paper on the first line on page 364:
The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.
Again, this looks to me like megasomething
. Can anyone shed some light on this?
On page 362 of the second paper, the unit appears as $(Watts/M^2
)/(C/S)$ as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.
radio-astronomy units
radio-astronomy units
edited 4 hours ago
Jim421616
asked 4 hours ago
Jim421616Jim421616
569211
569211
add a comment |
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1 Answer
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I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
$$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.
$endgroup$
1
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
add a comment |
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1 Answer
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1 Answer
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active
oldest
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$begingroup$
I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
$$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.
$endgroup$
1
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
add a comment |
$begingroup$
I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
$$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.
$endgroup$
1
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
add a comment |
$begingroup$
I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
$$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.
$endgroup$
I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
$$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.
answered 4 hours ago
HDE 226868♦HDE 226868
20k265125
20k265125
1
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
add a comment |
1
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
1
1
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
$begingroup$
The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
$endgroup$
– Jim421616
4 hours ago
add a comment |
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