Radio whispers from our neighbouring galaxy

Extended Radio sources in the direction of the Small Magellanic Cloud (SMC)

The Small Magellanic Cloud (SMC) is our nearest neighbouring galaxy and a satellite of our own Milky Way galaxy. Volunteers will be asked to identify sources that look like bubbles, clouds or galaxies while being shown optical images from the superCOSMOS Sky Surveys with visual aid elements shown on these images. Figuring out what these radio sources are, and whether they are part of the SMC galaxy itself is important for our understanding of how galaxies evolve and how the stars in them form.

Among the sources shown to volunteers, there will be sources which are already catalogued and studied. These sources will be seen as "rediscoveries" as was done in the famous Galaxy Zoo project on Zooniverse. The uncatalogued and not yet studied sources will be the proverbial gold at the end of the rainbow for this research.

What are extended Radio Sources?

Most of the radio sources detected in these MeerKAT images are single, identifiable sources with sizes consistent with the radio “beam” used to observe them. These are "radio point sources" and not radio extended sources:

In some cases, however, we see radio emission from an extended area in the sky. This could be the case for a supernova remnant, often displaying a bubble shape:

Or the double lobes of the radio jets formed by an active galactic nucleus:

Why we need you

Our automated source-finding algorithms are good at finding radio point sources, and some categories of extended sources, but they lack the nuance to understand when extended radio sources may be part of the same “source complex”, or be related in some way. For example, a source like the one below has 2 bright spots linked to some extended emission, however, the source-finding algorithms would not indicate that these sources and emissions could possibly be associated with each other:

Another example would be this source which has a bright point-like radio source linked to an optical source that looks like a galaxy. It might be a bright radio core of a galaxy that does not have jets detectable in this MeerKAT image:

Artificial intelligence-driven programs are still being developed to help astronomers identify & classify sources found in the images taken by various telescopes. They require tens of thousands of identified sources to train the algorithms. These have to already be labelled and classified with confidence, and we just do not have large enough datasets that meet the requirement for effective training for AI models yet. This is why we need volunteers like you to help us look through all the data contained inside these images.

What we'd like to learn from this project

We want to build a catalogue of the extended sources detected in 2 observations taken by the MeerKAT telescope. The MeerKAT telescope array is a precursor to the Square Kilometer Array project. It is capable of creating very deep field images in radio wavelengths because all 64 dishes are linked together to observe together -- a technique known as radio interferometry. 'Rediscoveries' are useful for the researchers since it allows them to ‘calibrate’ the efforts of volunteers against previously known objects. The uncatalogued and not yet studied sources will be the main targets in this research.

In this Zooniverse project, we cut out optical composite images from the Super Cosmos All Sky Survey (SSS). These images are overlaid with contour lines showing the brightness of corresponding radio sources. We hope you can help us figure out whether the radio sources are point-like or show extended radio emission, and whether they match any object in the optical images.

The MeerKAT Telescope

The MeerKAT radio telescope is a 64-dish radio telescope located in the Karoo in South Africa. It hass been collecting radio data from the universe since 2018. In due course, these dishes will form part of the Square Kilometre Array, an ambitious telescope that requires contributions from scientists and industry across the world. Many are excited to see what science can be produced with MeerKAT and the future SKA project.

[credit: https://www.sarao.ac.za/wp-content/uploads/2019/01/2018-MeerKAT-1-1030x557.jpg]