Radio Galaxy Zoo: New tools in Talk

For Zooniverse projects, the science teams have always been really impressed by the users who actively participate in Talk and engage in close inspections and discussions. This is especially true for our newest project, Radio Galaxy Zoo, and the number of excellent questions about larger structure for the powerful radio jets has spurred us to add some new tools to the Talk interface.

The new tools we’ve set up (with the invaluable help of Zooniverse developer Ed) show images of the galaxies and their associated radio jets from other surveys. New images include radio observations from the NRAO VLA Sky Survey (NVSS) and optical images from the Sloan Digital Sky Survey (SDSS). We’ve also included direct links to the FIRST (radio) and WISE (infrared) datasets that we use to make the classification images in the first place.

The new tools in RGZ now link to four catalogs (FIRST, NVSS, SDSS, and WISE) for each galaxy along the bottom of each image. FIRST and NVSS are radio surveys, SDSS is optical, and WISE is infrared.

Radio images with wider fields of view, such as NVSS, help to identify structures that may extend beyond the boundaries of the standard RGZ image. These include many of the images being labeled as #overedge in Talk. The NVSS images were taken using the same telescope (the Very Large Array in New Mexico) and at the same wavelength at the FIRST radio images. The main difference is the spacing of the telescopes used to take the observation. NVSS images have a much larger beam size, and are better at resolving large and extended structures. FIRST has a smaller beam size and are more sensitive to compact structures with very accurate positions. FIRST is also about 2.5 times more sensitive than NVSS.

By looking at the NVSS images, both RGZ volunteers and scientists have been able to work together and find potentially new examples of giant radio galaxies in these surveys. Larry Rudnick (@DocR) has started a great discussion on Talk, and we’re still identifying more as the project continues.

RGZ image ARG0002gt4, as seen in three of the surveys accessible in the new tools. The wide-field radio NVSS image of the jets is on the left; in the middle is the radio FIRST image, showing the better-resolved galaxy core, and on the right is the infrared WISE image showing the host galaxy. Image from Larry Rudnick (UMN).

We’ve also added links to the infrared and optical catalogs that show the galaxies themselves. The infrared images that we show in RGZ come from the WISE spacecraft, an orbiting infrared telescope that carried out an all-sky survey. The new link shows you infrared images of the galaxy in four different infrared bands (3.4, 4.6, 12, and 22 microns), as opposed to the single 3.4 micron image we normally show. Detecting the galaxy at longer wavelengths might mean that it contains more dust than expected, or show whether a feature in one band might be an artifact (not showing up in any of the other bands). We’ve also linked to the optical image from the SDSS; these dusty and distant galaxies are often too faint to show up there, but an optical detection there makes it much more likely that we already have a spectrum for the object.

WISE infrared images of the galaxy ARG0002h6v. Note how the central galaxy shows up strongly in the two bands on the left (3.4 and 4.6 microns), but is not detected in either of the bands on the right (12 and 20 microns).

Let us know if you have suggestions or questions about the new tools; we hope that they’ll continue to lead to many future discoveries with Radio Galaxy Zoo!