A Compilation of
the Spectral Sensitivities
of the MPIfR
Bolometers
J. Gromke and E.
Kreysa
Max-Planck-Institut
für Radioastronomie, Bonn, Germany
An
important property of a bolometer receiver is its spectral response.
Only if this function and the atmospheric
transmission are known the effective
observing frequency for radio sources of given emissivity index can be
calculated (see for example in the NIC-manual p. 63).
Furthermore this information is essential in order to estimate the line
contribution to the bolometer signal.
The spectral response of a bolometer receiver is a function of many
parameters.
Unfortunately some of them are difficult to determine and a
direct measurement of
the complete bolometer system is very desirable.
This can be done by using the receiver to take a spectrum of a source
of
known emissivity (a black body) with a spectrometer of known
efficiency
(a Martin-Puplett-interferometer).
The spectral response is then obtained by dividing the measured
spectrum by the
source spectrum and the spectrometer's efficiency curve. A relative
spectral calibration
of this kind is usually done before a new bolometer system
is shipped to the telescope.
The variation of the shape of the spectral sensitivities of different
channels of a
bolometer array is typically below 5 % so that
the curve of the central channel is
a good estimate
for all channels of a bolometer
array.
We present a compilation of the spectral sensitivities of bolometer
receivers
used in the last years at the IRAM 30 m MRT, the HHT and the SEST.
Please note: According to ongoing improvements of the bolometers the
spectral
response ofa receiver may depend on the year it was used.
| bolometer |
telescope |
period used |
| 1.2
mm, 19 channel |
MRT |
04/94 - 05/96 |
| 1.2
mm, 19 channel |
MRT |
winter 97 |
| 1.2
mm, 37 channel |
MRT |
04/97 |
| 1.2
mm, 37 channel |
MRT |
winter 97/98 |
| 1.2
mm, 37 channel, "MAMBO" |
MRT |
winter 98/99 |
| 1.2
mm, 37 channel, "MAMBO" |
MRT |
winter 99/00 -today |
| 4
color |
HHT |
03/96 - today |
| 0.87
mm, 19 channel |
HHT |
02/00 - today |
| polarimeter |
MRT |
to be installed |
|
1.2 mm, 117
channel, "MAMBO-2" |
MRT
|
11/2001 -today
|
1.2
mm SEST single beam
|
SEST
|
until 03/2001
|
1.2
mm, 37 channel, "SIMBA"
|
SEST
|
03/2001 - -3/2002
|
1.2
mm, 37 channel, "SIMBA"
|
SEST
|
04/2004 -today
|
page created on
June, 30, 2000 by J. Gromke
last modified on Jan, 20, 2004 by J. Gromke