Data Discovery Portal: Pan-Archive Search and Retrieval

Contents

• Data Discovery Portal: Pan-Archive Search and Retrieval
  • Science Story
  • Tools and Files
  • Finding High Resolution Images of T Tau
  • Finding Infrared Catalogs about T Tau
  • Independent Exercise

Science Story

The two science stories for the Discovery Portal tutorial are Discovering new data on the Enigmatic T Tau YSO and Evidence for Galaxy Mergers. In both cases we are trying to discover images about these objects; in the first case to study the protostellar binary and in the latter to look for tidal tails indicative of a merger event.

Questions

• What HST ACS images of T Tau are available?
• Are tidal tails optically visible in NGC 3393?
• What mid-IR catalogs are available to use for T Tau?

Tools and Files

This tutorial uses the

• Discovery Portal web application
• ds9 desktop imaging and data visualization application
• TOPCAT Java based desktop application

Finding High Resolution Images of T Tau

1. Load the Discovery Portal website.
2. Enter “T Tau” as the object.
3. Given the small size of the object enter 10 and “arcsec” into the search radius boxes.

Note

The Discovery Portal is an asynchronous search. New results stream in as remote services respond unless the query has been cached. T Tau r=10s will be cached!

1. Filter on “Images” in the Category facet.
2. Enter “ACS” into the free text search to narrow the results list.
3. Select HLA.ACS. A popup window will tell you about that resource.
4. From the popup window, hit Load to render the results into a new table.
5. Scan the results different columns reflecting passband, duration, etc.
6. Use the Format facet to find a JPG version. For each row a popup window describes the individual image. At this point you can spawn a JPG version into a new tab.

Finding Infrared Catalogs about T Tau

This example picks up from the previous one, except instead of looking for images one is looking for catalogs.

1. Reset the filters for “Catalogs” and “Infrared”
2. Load the 2MASS data into a new table.
3. Export the results to one of CSV or if TOPCAT is open Broadcast the table there.

Independent Exercise

Question

Can we identify tidal tails in NGC 3393 from archival data?

Approach

Find optical HST or radio HI images of NGC 3393 and visually inspect them.

Resources & Outline

Target HST ACS datasets.

Analysis

Download the images and load them into ds9.