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.
|
