Backends
A digital spectrometer of four XF
auto-correlator is current available to the community. The 4
units can be used in the low resolution mode (512 MHz bandwidth)
and high resolution mode (128 MHz bandwidth). Each unit has
1024 channels. With the current setting multi-lines observations
are possible. A wide bandwidth mode is now currently available.
Instrument
|
Bandwidth
per unit
|
# of channels per unit
|
channel separation
|
# of unit available
|
MAC Digital Spectrometer 4-XF
|
|
|
|
4
|
WHFS Spectrometer
|
|
|
|
|
Some
suggested multi-lines observation setups can be found as follow
|
Line 1
|
Frequency Line 1 [MHz]
|
Line 2
|
Frequency Line 2 [MHz]
|
|
CO(3-2)
|
345795.991
|
HCO+(4-3)
|
356734.25
|
|
CS(7-6)
|
342882.95
|
13CO(3-2)
|
330587.957
|
|
SiO(8-7)
|
347330.58
|
CH3OH
4(1)-3(0)E
|
358605.80
|
|
CH3OH 4(0)-3(1)
|
350687.73
|
CH3OH 1(1)-1(0)
|
350905.119
|
|
HC18O+(4-3)
|
340630.7
|
C18O(3-2)
|
329330.546
|
H13CO+(4-3)
|
346.99854
|
DCO+(5-4)
|
360.169830
|
Observing Modes
AzTEC: The bolometer camera will be using only the raster scan
mode, no chopping mode will be implemented. Therefore, it becomes
very inefficient to make small size maps, so it is recommended
make large maps, with sizes bigger than 15'x15'.
It is recommended to observe point sources.
The reduction procedure for diffuse, extended sources is not
established yet. So, if you want to map extended structure,
you are encouraged to join the software developing team of AzTEC
to develop the software.
CATS345:
Currently , ASTE is only working with spectral line observations,
under position switching mode.
Currently, ASTE allows to do single-point
observations, 5-9 points cross maps, and raster maps observations.
On-the fly mapping is currently under testing and will be available
to the community in the near future. The currently available
observing modes are:
Single-point observation:
the observer can specify the on - position in
RA and DEC as GAL longitude and GAL latitude (both
B1950 or J2000). Off-position can
be specified as absolute coordinates or as
an offset with respect to the on-position. Until 4
off-positions can be specified.
5-9 point cross maps:
the observer specifies the center position of the map, the spacing
between
the points, and the position angle of the cross map. Off-position
can be specified as absolute coordinates or as an offset
with respect to the center position. Until 4 off-positions
can be specified.
Raster map: the observer specifies the center
position of the map, the size and spacing of the grid, and
the position angle of the grid. The center of the grid
can be specified in RA and DEC as GAL longitude and
GAL latitude (both B1950 or J2000). Off-position
can be specified as absolute coordinates or as offset
with respect to the center position. Until
4 off-positions can be specified.
On-the-fly
map: This observing technique efficiently generate
images over large fields with respect to the resolution of the
detector. The efficiency is gained by reducing the overhead
as the telescope is no longer required to start and stop to
discrete points to accumulate integration time. In this mode,
the observer specifies the coordinate of the star point of a
map, the direction of the scan, lenght of main scan path, spacing
between scan, position angle, the acceleration time, scan time
of main scan path, transit time, and return time.
Observing
tables are prepared in ASTE control room in San Pedro.
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