This page is for the development of group C participant science case projects.

Participants are encouraged to submit their science cases. These can be in the form of a summary of project goals, or in conceptual steps. For example, 'search for objects of a particular type, or in particuar catalogues or archives, cross match particular catalogues, search for spectroscopy, search for theoretical models...'. We hope to help you identify where VO tools can help with your projects, and to define small projects that may be developed witin the workgroups during the 'Projects' sessions of the school.

A few examples from previous schools are linked at the bottom of this page.

Please use the following template, and feel free to create additional wiki pages if needed.

Project 1.

Participant Name: Ana Lalovic

Project description: Create a catalogue of HI galaxies that have optical counterparts and IR counterparts to obtain full information on their properties. For example, we could cross-correlate HIPASS, SDSS and 2MASS.

  • HI: HI blind survey enables investigation of non-biased sample of galaxies. We could calculate HI mass content and maximum rotational velocity. Only early-type galaxies will be undersampled (but only to some extent since many ellipticals show emission and will be detected).
  • OPTICAL:We need reliable photometry in the optical domain to calculate Petrosian radii, dynamical mass, concentration index, colours etc. (some of these quantities are already present in SDSS database). We would also need spectra to measure velocity dispersions which are the key factor in many scaling relations (this task can be done using for example GANDALF or ULYSS packages).
  • IR: We could measure IR-luminosity to determine SFR (additionally, we can compare it to Hα derived SFR from optical - in the case of SDSS spectra it can be taken from the database). Further, using K-band images we could calculate inclination of galaxies with e.g. GIM2d (IRAF package) or Galfit with input parameters derived using Sextractor plugin available in Aladin.

Final goal: Choosing relevant quantities such as effective radius, luminosity in various bands, colour, Hubble type, mass (HI, dynamical and stellar), SFR etc. in order to find planes such as the fundamental plane for ellipticals and/or to find (and hopefully improve) existing correlations which should provide insight in the general features of nearby galaxies of all Hubble types.

Project 2.

Participant Name: John Swinbank

Over the course of 2010, LOFAR's Transients Key Science Project will start operating its Radio Sky Monitor (RSM). The RSM will provide frequent monitoring of the low-frequency radio sky for transients over a range of timescales. We will provide alerts of new transients to the community, as well as a searchable archive of transient lightcurves, annotated with as much additional information (classification, etc) as possible.

Our interest in the VO is threefold:

  1. When a new transient is detected, we hope to use VO tools to obtain as much additional information about the source as possible, to assist with classification and to determine what response should be taken and alerts sent, if any. This system must be highly automated: we are talking of using VO APIs to enable machines to access the data, not tools for human astronomers.The level of complexity here can vary enormously. In the simplest case, a cone search to establish if our detection corresponds to already known sources is useful; one can also imagine imagine classification algorithms which make use of much more elaborate algorithms. We expect "many" potentially interesting transients: what query rate can we sensibly submit to the VO?
  2. We will use the VOEvent system for distributing alerts of new (or updated) transients to the wider community, and also listen to VOEvent feeds from various brokers in the hope of triggering LOFAR. We would like to investigate the various tools for generating, receiving and processing VOEvents automatically.
  3. The transient lightcurve archive should be easily accessible from and well integrated with the VO. What steps can we take to ensure this process is as painless as possible?

Project 3.

Participant Name: Georgi Petrov

Project description: Comparison of properties between two classes of Seyfert 2 galaxies – with and without broad lines in polarized light

1. Create two samples of Seyfert galaxies (classified as type 1.8 – 2) for the objects with and without detected polarized broad lines.
2. Search for column densities of neutral hydrogen N_H for X–ray radiation.
3. Search for observed hard X-ray (2-10 keV) fluxes.
4. Search for available fluxes of [OIII] λ5007 emission.
5. Search [OIII] FWHM.
6. Check for differences in N_H between the two samples.
7. Calculate the Eddington ratios using the masses of the central massive black holes (calculated from [OIII] FWHM) and X-ray (2-10 keV) fluxes, and calculate the same ratios using [OIII] λ5007 fluxes.

Project 4.

Participant Name: Frédéric Meynadier

Project description: Search for multiple stellar systems in existing catalogues - obtaining test data for the Gaia data processing.

  1. Identify catalogues with RV data for stars (whole sky, 6<Vmag<17).
  2. Cross-match catalogues if they have only 1 epoch of RV data
  3. Look for RV variability and/or hints of multiplicity.
  4. Retrieve spectra information for those objects (range : 8470-8740 Angstrom, resolution >= 10000)
  5. Additionaly, cross-match with an existing list of stars, identified by their Hipparcos ID.

Project 5.

Participant Name: Florent Rostagni

Project description: We perform statistical and detailed analysis of galaxy clusters selected
from large optical multiwavelength imaging surveys.

We think VO could be an efficient way to complete our analysis along 4 axis:

1/ Automatic search and cross match of complementary data in the cluster
fields ("cone search"?)
-spectroscopic information
-extended and point X-ray sources
-radio information
-Near-IR and IR fluxes of galaxies
-all optical information

2/ Perform automaticly some "standard" analysis through WEB services if
they exist for example :
-analysis of X-ray extended sources
-analysis of radio source
-estimating photometric redshifts by combining the optical fluxes we
have at hand with any additional information we would have found in 1/
-various statistical analysis

3/ Visualize all data gathered in a cluster field:
-superimposition of images, contours and catalogues
-produce good quality jpegs of these

4/ Compare results of our analysis with results of simulations

These various points would, ideally, be addressed in interactive and/or
batch modes.

This description may be approximative because we do not know all the VO
capacities and so we can not imagine all the science we are able to do
through it, this school is the best way to learn usefull tools to do
better science.

Help on editing and creating wiki pages is available here , and with more than you want to know here . Usually the best advice is to just keep it simple!

Example Projects

-- MarkAllen - 18 Dec 2009

Edit | Attach | Watch | Print version | History: r9 < r8 < r7 < r6 < r5 | Backlinks | Raw View | Raw edit | More topic actions
Topic revision: r9 - 20 Jan 2010 - FlorentRostagni
This site is powered by the TWiki collaboration platform Powered by Perl This site is powered by the TWiki collaboration platformCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback