Last Update: 8th November, 2016

Pointing Observation with Continuum Sources

If there is no strong SiO maser source near your target or the maser source reachs elevation limit (El > 80 deg. or 12 deg. <. El) during allocated observing time, you can do pointing observation with continuum emitted from quasers. This often happens when your target is apart from the Galactic Plane (~9 hr < LST < ~15 hr), since most of SiO maser sources are the late-type star belonging to Our Galaxy. It will be explained how you can do pointing observation with a continuum source in following sections.

How to Use the Obstable

For continuum observation, you should make observing scripts not with the Obstable Z but with an Obstable (an older one).

  1. You can not use the Obstable from outside of the observatory like the Obstable Z.
  2. Login to ut12x1 (or obstable1) from any machine.
    > ssh -X (YOUR ACCOUNT ID)
    > ssh -X -l (YOUR ACCOUNT ID)
  3. After login to ut12x1, type the following command at the prompt.
    > obs
  4. You will see a window like this. Enter your project name (i.e., proj1, proj2, and so on) in the box. You may leave "Observer" blank.

  5. After a successful login, you should have the following window on your screen.

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Creating Observing Scripts

The basic framework of Observe Table is as same as the Obstable Z: Source Table, Scan Table and Device Table. Adding to this, naming rule also holds:

As long as making observing scripts for pointing with continuum sources, it will be much easier than making other observing scripts.

Source Table

By clicking the "(RA, DEC) (L, B)" button, you should have a following window.

"Cont List" button provides a list of continuum sources observable from the 45-m telescope. If you intend to perform pointing observation with continuum sources, all you need is just choose the target from the list and save with "Save" button.

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Scan Table

With the "Scan : Cont" window accessible from pushing the "Cont" button in the Scan Table row, you can make the Scan Table for continuum observation. Two sample files are already prepared for pointing observation with continuum sources: point2 and point4. The difference of the two is the length of the cross scan: point2 is 2 arcminutes while point4 is 4 arcminutes. In general, point2 suits for the aim. Choose "point2" from "Sample List" and save with "Save" button.

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Device Table

Like other tables, Device Table can easily made with "Device : Cont" window which can be used by clicking the "Cont" button in the Device Table row.

If you ignore this instruction, OPERATIONS OF THE 45-M TELESCOPE (not only your observations!!) might be stopped.

Beam switching system has a trouble. In order to avoid the trouble, please modify the sample file. Push the "beam switch" button at the bottom of the Device Table window, you will find a new window. Rotation speed is the one to modify. Change the value from the default (465 rpm) to 300 rpm and then, save the Device Table. With this procedure, you will be able to perform pointing observation without a critical trouble.

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Observe Table

The last procedure is to make Observe Table and generate the observing scripts. Go back to the main window and fill the text boxes with the name of Source Table, Scan Table and Device Table which you have made and name the observe table within seven charactors. And then, push the "Save & Send" button to send it to COSMOS.

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