MHRS
Millimetron High Resolution Spectrometer
Frequency Coverage
1-2 THz continuous coverage (Red shifts) >2 THz Spot frequencies with continuous as a goal
Frequency |
Feature name |
Resolution |
Remark |
557 GHz |
Water Ground State |
|
|
1110 GHz |
Water Ground State |
|
|
1.9 THz |
C+ |
500 km/s - 3 GHz |
Mapping important (FPA) |
112 micron 2.7 THz |
HD |
|
|
63 micron, 4.7 THz |
OI |
|
|
Continuus coverage |
CO lines |
|
|
88 micron |
OIII |
|
High exitation line |
122 micron |
N+ |
|
|
205 micron 1.4 THz |
N+ |
|
|
Add others here |
... |
|
Types of observations
Main challenges
- Standing waves. May require delay line in the beam path or quarter wave plate.
- Stability requirements
- Polarization sensitivity
- Dual LO frequency obervations (may be coutered by stability and repeatability)
- 2SB --- for spectral line surveys ?
Point source observations
What absolute flux accuracy is really required?
Mapping
Small focal plane arrays at higher frequencies (C+) 1deg x 1deg
Position swithcing
Impossible dut to high mass of the telescope.
General specifications
Sensitivity |
2 quanta hf/2k |
|
Instantaneous IF bandwidth |
8 GHz (1000 km/s) |
|
Velocity Resolution |
0.1..0.3 km/s |
Trade off with bandwidth |
Total flux calibration accuracy |
1% to be studied |
|
Stability Total power |
10^{-8} @ 10 s |
|
Spectroscopic Allen variance |
200 s |
|
This is derivative from total flux calibration accuracy || Beam Absolute Pointing accuracy || 0.3 " ||
Beam Relating Pointing staility |
0.3 " |
Scanning mechanizm ?