OM Tool for Planning User Defined Science Windows

* NEW * Prime Instrument Option

Information about the OM Tool

Below is a interactive mouse tool to aid in planning User Defined Science Windows (3.5.10.1 of the XMM-Newton Users' Handbook ) for the Optical Monitor (OM). This tool will enable you to produce your own set of Science Windows (encompassing image and fast mode) that follow all the rules set down in the technical note on Constraints on the OM Window Configuration and Definition of the OM Default Configurations and the XMM-Newton Users' Handbook . The tool also allows you to map out the dispersion direction of the optical and UV grisms. The interactive input required to complete these calculations are set out in four panels in the tool below,

1. Loading Image Background into the tool.
2. Drawing Science Windows.
3. Sky Field of View.
4. Final Results.

On submission the tool outputs your specified science windows in Right Ascension and Declination coordinates, and also Detector coordinates. Both of these coordinates are suitable for input into the remote proposal handling tool. The Detector coordinates only apply to the specified position angle input into the tool.

Please note that this tool should be used to help you plan your OM observations. Although this tool does check the position and sizes of output windows, the final and definitive check is given by the Remote Proposal Submission System. The Vilspa SOC will not accept any claim based on this web tool.

This tool has been tested in the web browser Mozilla 1.2b and Mozilla 1.5, and runs with no initialisation problems or panel layout problems. This tool also runs in Windows XP, using Microsoft Internet Explorer Version 6.0.2600.0000. If you do notice any problems then please contact us.

IMPORTANT - please read the User Instructions below, before using this tool.

You have a choice between three background options for the sky field of view (or sky FOV),

• Star Field Background - an arbitrary star field background.
• Black Background - a black background.
• Grey Background - a gray background; this is the default background.

The LOAD button loads the chosen background into the sky FOV in panel 3.

If you want to be able to load your own images into this tool then please go to the section titled Using Your Own Images, after reading how to use the tool. You can use this web version of the tool to become accustomed with the tool.

This panel sets up the user defined science windows and allows you to draw, reset and check these science windows.

Before drawing any window you need to set the following:-

• Right Ascension - the sign and coordinate for the centre of the OM FOV in hours, minutes and seconds (hh, mm, ss.s) in J2000.
• Declination - the sign and coordinate for the centre of the OM FOV in degrees, arcminutes and arcseconds (dd, mm, ss.s) in J2000.
• Position Angle - the position angle of XMM-Newton in degrees (dd.d). You can change this to see how position angle effects the dispersion angle for the visible and UV grisms. To compute possible position angles click here to use the visibility checker on the XMM SOC web.
• Number of Fast Mode Science Windows - you can chose up to 2 fast mode windows.
• Number of Image Mode Science Windows - you can chose up to 5 image mode windows.
• Image Mode Science Window Resolution - you can set the image mode windows to low (default) or high resolution, which effects the allowed size of these windows. (NOTE - different image mode windows can have different resolutions).

NOTE: If the total number of science windows (image + fast) exceeds 5, then a warning message will appear on the screen and you should adjust the number of science windows chosen accordingly.

You can use the Load Coordinates button to load the Right Ascension, Declination and Position Angle coordinates entered in this panel.

This panel also contains the following buttons which enable you to draw your fast and image mode science windows onto the sky FOV (in panel 3);

• Add Fast Window - allows you to add a fast mode window.
• Add Image Window - allows you to add an image mode window.
• Add V-G - allows you to add the spectral dispersion direction of the visible grism.
• Add UV-G - allows you to add the spectral dispersion direction of the ultraviolet grism.
• Reset Windows - allows you to reset the sky FOV (panel 3) at any time.
• Check Windows - allows you to check that the science windows lie within the specifications set down in the technical note on Constraints on the OM Window Configuration and Definition of the OM Default Configurations.
• Replace Window - allows you to replace a window that you have already saved.

This panel represents the sky FOV, and allows you to draw science windows using the mouse.

A red colored box is automatically drawn on the sky FOV, and this represent the Optical Monitor field of view (or OM FOV), anything outside this red box will not be observable by the Optical Monitor. The tool has been set up in this way to enable you to see if any bright stars outside the OM FOV will contaminate your data. For this reason you can apply an optical or ultraviolet grism spectral dispersion direction to any star outside the OM FOV.

A red cross hair is automatically drawn on the OM FOV; this cross hair represent the centre of the OM FOV. A cream North-East coordinate direction is also automatically drawn, and rotates with position angle, along with the image.

To draw a fast mode science window, click either mouse button to produce a small orange box that indicates the position in which you want the fast mode window to be centered. Once you are satisfied with the position, click the Add Fast Window in the Drawing Science Windows panel (panel 2), and further adjust the Right Ascension and Declination using the Java Applet Window to centre your fast mode window. Once the window has been saved it becomes light green. If your fast mode window falls outside the OM FOV, you will be warned and the tool will be automatically reset.

To draw an image mode science window, first choose the resolution of the image window by using the buttons in panel 2, then hold down either mouse button and drag the mouse to form an orange rectangle, releasing the button to drop the window. If the rectangle you have drawn is to large for an image mode science window, a warning will appear on the screen. You can redraw the orange rectangle as many times as you want. Once you are satisfied with the window, click the Add Image Window in the Drawing Science Windows panel (panel 2), and the image mode window will be saved. If your image mode window falls outside the OM FOV, you will be warned.

If you try to add more windows then you have specified, a warning message will appear on the screen indicating that there are no more windows to add.

To draw the dispersion direction for a star's spectrum, click either mouse button on the centre of the star in question, then use the Add V-G or Add UV-G buttons in the Drawing Science Windows panel (panel 2), respectively (you may click on any star within the sky FOV). A yellow (Visible grism) or violet (UV grism) line indicating the dispersion direction will then be drawn in the sky FOV. By varying the Position Angle of the telescope you can investigate possible problems of bright star interference with your target object spectrum, and also the effects of non-square windows. You may add up to 20 lines for each grism.

Once you have saved all of your science windows, you can use the Check Windows button in the Drawing Science Windows panel (panel 2), to check your windows lie within the specifications set down in the technical note on Constraints on the OM Window Configuration and Definition of the OM Default Configurations. After clicking the Check Windows button, you will be given the option to either,

• check the window, in which case any problems will be highlighted and suggested alternatives for problem windows will be drawn in the OM FOV in blue, or
• the sky FOV can be reset.

You can replace a saved image window (i.e. green image window) by clicking the image resolution required using the buttons in panel 2, and then drawing the replacement window in the OM FOV. Once you are happy with your replacement window, press the Replace Window button on panel 2. After pressing this button a Java Applet Window will appear giving you the choice of which window you wish to replace. If you request an image window that does not exist you will receive an error message. Please note,

• you may see an error message about windows overlapping or exceeding the total number of pixels allowed, please ignore these error messages and proceed with the Replace Window button.
• you must always re-check your windows using the Check button (panel 2) if you have replaced the windows in any way.

After you have,

• checked your science windows using the Check Windows in the Drawing Science Windows panel (panel 2), and
• you are happy with the returned results that will be drawn as blue science windows in the OM FOV (panel 3),

On submission a new Java window will be opened containing information about your input values and your user defined science windows. X0 and Y0 for each window are given in,

• Right Ascension and Declination coordinates for the central position of the window.
• Detector coordinates (pixels) for the lower left corner of the window.

Avoiding Problems when setting up your Science Windows

There are a set of constraints for User defined science windows set down in the XMM-Newton Users' Handbook ; these constraints are summarised below. This tool will either warn you of any violations, or slightly adjust window size to comply with the constraints.

1. A total of 5 science windows (with up to 2 fast mode windows) are allowed.
2. Science windows must start at an even pixel number, and their size must be a multiple of 16 pixels.
3. Due to a strong change of sky coverage for elongated windows (due to the roll angle of the telescope), you are strongly recommended to use square windows.
4. The total number of pixels that can be used for science windows during one exposure is 432698.
5. Science windows must overlap entirely for all satellite positions, or not overlap at all.

For Right Ascension, Declination and Position angle values to be entred into the tool, you must either,

• press the RETURN key after typing in each number, or
• press the Load Coordinates button in the Drawing Science Windows panel (panel 2).

If you find that the tool has crashed then reload the web page to restart the tool.

We suggest that you place any fast mode windows on the OM FOV first, and once you are happy with these positions, then add your image mode windows. We also suggest that any objects that you wish to observe using fast mode windows, be positioned toward the centre of the OM FOV, because if your fast mode window falls on the edge or outside the OM FOV, the tool will be automatically reset.

NOTE: Please pay attention to any warnings. To highlight a problem, the tool will beep and a dialog box will appear explaining the violation. After clicking the OK button, you should adjust your input values accordingly.

Return to tool

The above tool gives you a choice of only three backgrounds. If you require a specific star field to be loaded into this tool then you will need to do a number of things,

1. Download the Application - outlined below.
2. Download a suitable image - outlined below.
3. Check with your systems manager that you are able to run Java 1.4.0 (or above). Available here.

This tool allows you to load JPEG and FITS files.

To download the Application Clicking Here . The file size is 190KB, and the file name is omTool_rv7.jar.

Once downloaded go to the directory in which you saved the application, and type the following command into the command line to run the application,

java -jar omTool_rv7.jar

if you have any problems in running this application then please contact us.

You need to put you image into the same directory as the downloadable Application. The downloadable tool can load JPEG and FITS formated images, using the Load JPEG Image or Load FITS Image button in panel 1 respectively. You can also load a black or grey background for the OM FOV using the Load Black Background or Load Grey Background in panel 1 respectively.

JPEG Images

Your JPEG images must cover 25x25 arcmins of sky, and should be 600x600 pixels in size. This is important, if the size of the image is not correct then the OM FOV set up in this tool will not give you a true representation of what you see in the OM FOV.

Use the Load JPEG Image button in panel 1 to load the image into the application .

FITS Images

Your FITS images should follow the basic FITS standard, must cover 25x25 arcmins of sky, and should be 600x600 pixels in size. As with JPEG images, if the size of the image is not correct then the OM FOV set up in this tool will not give you a true representation of what you see in the OM FOV.

Here are the steps you need to take to produce a suitable FITS image that can be loaded into the downloadable Application.

1. Load up the Leicester Database and Archive Service web page by Clicking Here !! This page provides access to the digitized optical Schmidt plates forming the STScI Digitized Sky Survey, and will bring up a LEDAS Digitized Sky Survey request form.
2. Either entre the Object name and click Resolve name button, or entre RA and Dec for the centre of your OM FOV.
3. Set the Field size to 25 arcmin. This is important, if the size of the image is not correct then the OM FOV set up in this tool will not give you a true representation of what you see in the OM FOV.
4. Set the Pixel size to 2.5 arcsec (this will give you a 600x600 pixel image).
5. Submit the form by pressing the Submit button.
6. Once the GIF image has been loaded, click on the FITS format option under the Science images heading, and save the file.

The image can then be loaded into the application using the Load FITS Image button in panel 1.