1. Specview Tutorial for the Line Identification Tool I. Busko Space Telescope Science Institute March, 2010

2. In this tutorial we will learn how to display and manipulate spectral line identifications: Read spectrum, Display line identifications from a line catalog, Modify the display in a variety of ways, Add lines from other catalogs, Select subsets of lines from line catalogs, Save result to file.

3. NOTICE: Specview works either as a desktop application, or an applet. This tutorial is designed for use by either, but the applet version has been tested and runs only on certain platform/browser combinations: OS Browser Mac OS X 10.6 Safari 4.0.3. (6531.9) Windows XP Pro 2002 Internet Explorer 7 Windows XP Pro 2002 Firefox 3.5.8 For better performance, we strongly suggest that you install the desktop application version of Specview.

4. Click on Run link at: http://www.stsci.edu/r esources/software_har dware/specview/apple t_demo …or… Start the Specview desktop application. First, get into Specview: (spectrum plotting window) Version 2.14

5. Section 1a: Read data and select spectrum of interest: Read spectrum from VO spectral services: next slide. Read file in your own computer disk: go to Section 1b (slide 11).

6. Read in spectrum using VO services: Open Read from VO window from File menu…

7. Set up VO search query: Enter object name and either hit the Return/Enter key, or click on Resolve to let the resolver fill up the R.A. and Dec. fields. Enter the desired search radius. Click now on Search and wait a minute or so until all data is downloaded from the VO services.

8. Were you patient?! If so, tables of available spectra appear on the Search Results pane. Click on the Servers table to select a particular VO service and have its table of available spectra appear on the Search Results pane.

9. Select (click on) the spectra you want to download and then click on Download. Observe the download status column; when YES appears, the spectrum has been downloaded and is in memory. Downloading spectra:

10. The download actions explained before bring your spectra into the Spectrograms in Memory window: Confirm contents, then select the spectrum you want to work with. Then click on Plot/Coplot button to display the spectrum in the main display window.

11. To read in a data file from your computer, click on File menu and then Read from File menu entry, and …… …select and open file to display the spectrum in the main display window. Section 1b: Reading files from your computer

12. The spectrum just read is displayed in the main display window. Section 2: Display line identifications To start the Line ID Tool, click on the Line IDs button.

13. The Line Identification Tool will show up on screen: A number of line catalogs can be selected via tab selection. Keep the default “Stellar” catalog, and click on the Select all button. This will select all lines in the Stellar table. Then click on the Draw button.

14. Line identifications for all selected lines will be plotted on the display window:

15. Lets zoom on the region around 5000 Å (notice te object's redshift): Section 3: Modifying the display

16. Now place the cursor over one of the line identifiers. The cross hair cursor changes to a little hand. Click the cursor there and a window shows up that enable the line identifier to be edited. Experiment with changing the text of the identifier, as well as flipping it in between a vertical and horizontal orientation.

17. Line identifiers can be repositioned (in the Y-direction only) by just dragging them with the cursor. Experiment with any one being displayed. Also, try experimenting window resizing (application version only) and the zoom/pan controls, to have a feeling on how these line identifiers behave.

18. Line identifiers can be made to approximately follow the spectrum local slope. First, click on the Erase all button to clean up the display. Then change the plot mode from Constant height to Follow spectrogram. …and click on the Draw button again.

19. Here is the zoomed central region of the spectrum, with line identifiers following the spectrogram local slope.

20. Select the “Nebular” line catalog. Click on Select all, and then pick a different color on the color selector… … and click Draw again. Section 4: Adding lines from other catalogs color selector

21. Line identifications from the Nebular catalog will be plotted with their assigned color:

22. Section 5: Selecting subsets of lines The line tables displayed by the Line Identification Tool can be sorted based on column contents. To sort a column, just click on the column header. The first click sorts the column in increasing order, the second in decreasing, and the third places the column back at its original ordering. Columns can be sorted in hierarchical order. Click on the column header while holding the Ctrl key pressed. This will sort the column, preserving the sorting status of previously sorted columns.

23. Lets try this with the Reader-Corliss catalog. After selecting it, click on the “Element” column to group lines of the same element / ionization state together. Scroll down to, say, the element S, like in the picture below. Now hold the Ctrl key down while clicking on the “Int” column. Notice how the rows are re-sorted but preserving the existing sort state of the “Element” column. In this way, specific subsets of lines can be grouped together to ease their selection for further plotting.

24. One can also use the Add set button to create multiple copies of the same line catalog. In that way, different selection criteria, and also different display parameters can be used with each set. Lets plot the SI lines from Reader-Corliss in black, and the SIV lines in red. First, select the SI lines as show in the picture. Then click on the Add set button.

25. Notice how a second set of Reader-Corliss spectral lines appears. In this set, sort rows by the “Element” column, and scroll down to the SIV rows. Select the table rows corresponding to the SIV element… … then select the red color on the color selector. Click on Draw to plot the line identifiers thus selected. color selector

26. The SI and SIV lines, all coming from the same catalog, are painted with different colors:

27. Section 6: Saving results to file Use the Specview File menu, options Print to JPEG file or Print main display, to save a hardcopy of the plot: