Extragalactic 2
Tutors: Mark ALLEN, Eduardo GONZALEZ SOLARES
Participants
Baldi (Linux), Bonchi (Windows), Cassara' (Windows), Chon (Mac OS X), Finet (Windows/Linux), Fritz (Mac OS X), Guelbenzu (Linux), Leitet (Mac OS X), Messias (Mac OS X), Tepper-Garcia (Mac OS X), Vulcani (Mac OS X)
Schedule Tues March 31.
0900 - 1015
Intrduction: Use cases and participants' (group) projects
Extragalactic 2: use case 3: Searching for Data available for the bright galaxy M51. (Aladin, SIMBAD,
VizieR , Topcat, VOSpec)
1045 - 1230
VODesktop
1400 - 1530
Extragalactic 1: use case 1: Confirming a supernova candidate (Aladin, Topcat)
option: Extragalactic 1: use case 2: Search for ULX sources and X-ray binaries in nearby (e.g. D<10 Mpc) galaxies (uses TOPCAT, Aladin).
1600 - 1730
CDS Training Materials
SIMBAD :
http://cdsweb.u-strasbg.fr/~allen/AIDA/Simbad.html
VIZIER :
Basic:
http://cdsweb.u-strasbg.fr/~allen/AIDA/VizierBasic.html
Advanced:
http://cdsweb.u-strasbg.fr/~allen/AIDA/VizierAdvanced.html
ALADIN:
Manual:
http://cdsweb.u-strasbg.fr/~allen/AIDA/AladinManual.pdf
AstroGrid Python Scripting Information and worked examples
http://www.astrogrid.org/wiki/Help/IntroScripting/AstrogridPython
USE CASES
Use Case 1
_Based on Eduardo Gonzalez Solare case from the VO Info Day in Lisbon
http://www.sim.ul.pt/WorkshopVO-pt2008/talks/files/eglez_tools.pdf
Use Case 2
Finet Francois
- search for existing quasars (ra. and decl., z, mag., etc.) in the narrow (+- 30')strip of sky visible at zenith from the Devasthal observatory (lat. +29°22') in order to calibrate astrometrically all objects that will be detected with the International Liquid Mirror Telescope.
- search for photometric standards in the r', g', i' systems in that same narrow strip of sky
- identification of high proper motion objects and stars with known trigonometric parallaxes in that band of sky
- production of long images at different wavelengths of that strip of sky based upon existing space and ground based observations
Use Case3: Searching for Data available for the bright galaxy M51. (Aladin, SIMBAD, VizieR , Topcat, VOSpec)
Mark Allen
- Search for images of the bright galaxy M51 in Aladin.
- Try the various image servers: The Aladin image server, Skyview and Sloan Digitial Sky Survey
- Try the 'all VO' access (selecting image servers) - Note the method for selecting images at a given sky location. Clicking in the image puts a tick in the selection boxes of the available data.
- Make a colour composite image using the RGB tool.
- Use the multi-view windows to manage the various images you have in the 'stack'
- Try the 'match' button at the bottom of the image window to align the image for synchronized zooming
- Try the transparency control for viewing images overlaid on each other
- Overlay as SIMBAD identifications using the SIMBAD link in the Server selector window
- Try 'with no filter' for a simple listsing of the IDs
- Try with 'Simbad filter' (colorized) to see how the same info can be presented in detail
(optional - open the 'properties' window for the Simbad plane to see or edit the filter)
- Filtering of sources can also be done interactively with Topcat. Start Topcat, and send the SIMBAD plane to Topcat (right-click on the plane in the stack, and 'Broadcast selected tables to..'
- View the table values in Topcat. Make a plot of the positions and try the area selection tools to select a number of points in the plot. Note how the selected subset may be transmitted back to Aladin to highlight sources from the original Simbad plane.
- Make a subset of the brightest HII regions, and send the table back to Aladin using the Topcat 'Interop' menu
- Search for spectra available in the VO with the 'all VO' button in the server selector window.
- Find spectra available from the Hubble Space Telescope, and view the positions of the spectra (and sometimes thespectral slit aperture) on the image. Make a plane containing all the spectra positions, and cross match these with the positions of the HII regions.
- Start VOSpec ( Web Start: http://esavo.esac.esa.int/webstart/VOSpec.jnlp
) and display some of the spectra, by clicking on the spectra in the server selector window, and 'Load in -> VOSpec'.
- Check VizieR for more detailed catalogues of HII emitting regions in M51. This can be done via Aladinor via the more detailed VizieR interface.
- (Advanced - compile a list of bright HII regions in M51 and query VizieR with this list
Use Case4
Elisabet Leitet
Download IUE and FUSE catalouges (Aladin)
Extract specific object type (TOPCAT)
Cross-correlate the catalogues (TOPCAT)
Measure the EWs of emission lines (VOSpec)
Name LastName
Problems encountered
Please list here any problems, big or small that you found with the VO tools used.
- Aladin: querying for images with the All-VO capability of aladin, the DSS images selected from the aladin image server entries in the returned list do not load, and report an error about RA and DEC rows.
- aladin filters - it is not obvious that one needs to 'apply' a filter before exporting the results to a plane
- topcat - how can one give a table a name so that it shows up with that name in the aladin stack when broadcast there?
- The Aladin (and also the
VizieR ) produced fewer targets than downloading directly from the MAST
- Aladin display of row numbers in catalouges (as shown in the layers) not correct
- It would be useful to be able to fit line profiles when measuring EWs in the VO spec (deblending lines). Also, it would be useful to be able to mask regions (or interpolate between chosen points), for example we had a narrow absorption line inside an emission line. Also, it would be nice to control the continuum fit interactively.
- ExtraGal2.1.pdf: Presentation of project done by participants Ranieri Baldi, Letizia Cassarà, François Finet, Hugo Messias, Benedetta Vulcani