Knowledgebase: Catalog Search

Catalog Search Documentation

Quick Guide


Program Interface Guide

How do I display all the column names (instead of an abbreviated default) when loading a catalog?

In the "Search Catalog" pane, click on the "Set Column Restrictions" link in the lower left. At the top of the dialog box that pops up, select the "Long Form" menu item. Then click "OK" and "Search".

How can I make my very large catalog query run faster?

Here are some tips for making your large catalog search return faster:

1. If you suspect that your query might return results larger than 2 GB, you will need to break it up into smaller queries. It can be difficult to predict the size of the returned results. It depends on the constraints you are interested in, the number of columns you want, and the density of objects on the sky. You can do a test on a 1 sq deg patch of the sky, for instance, and scale up until the result is just under 2 GB.

2. Query on indexed columns as much as possible. If you are using the web interface, you can see which columns are indexed in the table that allows you to select which columns to download. The indexed columns are marked with an X. For the AllWISE catalog, the indexed columns are dec and glat.

3. Polygon searches do take advantage of the spatial indexing. If users have spatial constraints, they can be entered as polygon limits or entered into the column constraint table.

How do I select the most robust sources in the Spitzer Source List?

To retain only the most robust flux densities, apply the following cuts:

1. Make a SNR cut. Each source has 5 columns ending in “FluxType”, four for each of the IRAC channels and one for MIPS-24. Flux densities directly detected in an image with SNR>=3 have *FluxType=1.

2. Eliminate IRAC flux densities that may be affected by a nearby saturated source or a nearby extended source. There are four *FluxFlag columns, one for each IRAC channel. Choose *FluxFlag=0.

3. Eliminate MIPS flux densities that may be affected by a nearby saturated source or a nearby  extended source by choosing M1_BrtFrac<0.5 and M1_ExtFrac<0.5.

4. Remove IRAC flux densities affected by soft saturation. There are four *SoftSatFlag columns,  one for each IRAC channel. Choose *SoftSatFlag=0.