Submillimetre Wavelengths on Google Sky

February 21, 2008 — Leave a comment

Over the summer I created a Google Sky layer that enabled anyone to access the entire SCUBA submm catalogue of maps and objects in a dynamic fashion. Google Sky was released in August and the open file format means anyone can create data for display. This layer is now publicly available thanks to help from the Canadian Astronomy Data Centre (CADC), the Joint Astronomy Centre (JAC) and my colleagues at Cardiff University.

All you have to do is install the latest version of Google Earth and then download this KML file.

Once initialized for the first time, the file will make a download of a 9MB catalogue. This takes a minute or two and once complete you can roam the sky, viewing any regions of it covered by SCUBA in submillimetre wavelengths.

As well as the data points (which appear in green) you can also view images taken by the SCUBA camera. These will only load when you are close enough on the sky to see them, to save on time and disk space.

The best thing about this Google Sky layer is that it will enable you to place side-by-side things which you can’t see with things that you can. The image below of the Horsehead Nebula is a perfect example.

horsehead.png

In the top, in purple you can see the optical light. This is the outline of the classic Horsehead, which is located in Orion. In orange below it, you can see the dusty, SCUBA-mapped material. It slots almost perfectly into the dark region of the Horse’s head. That’s because the reason the Horse’s head exists is that the dust obscures he light and creates the shape.

If you look carefully you’ll see the ‘lozenge’ of dust in the horse’s throat. This is a clump of cold material, with a submillimetre source at the centre (the green hexagon). This is thought to be a pre-stellar core – an object which may go on to form a star.

This ‘dust’, as it is called by astronomers has the consistency of smoke and accounts for huge amount of the material in our galaxy. Many of the shapes of the nebula you will have seen arise from dark, dusty material in between the light and your point of view.

You will possibly be familiar with dust from images such as he Pillars of Creation from the Eagle Nebula. This shown below with the SCUBA map layered on top, semi-transparently.

scubage_eagle.png

Included with the SCUBA Google Sky layer is a set of interesting features, which will take you to certain objects or regions of the sky, to get you started. All the green hexagons come with a popup of scientific data from the CADC catalogue.

For more screenshots, see my Flickr photo set about this project.

SCUBA was a camera on the James Clark Maxwell Telescope (JCMT) in Hawaii. It was a submillimetre continuum array receiver, with a field of view 2.3 arcmin in diameter. It had two hexagonal arrays of detectors, which mapped a fair chunk of the sky in 850 microns and 450 microns.

The device was made to study regions of the universe normally dark in optical frequencies. The things you’ll see in the SCUBA data are dusty areas of our galaxy and of more distant galaxies. These are the areas where stars are born and they are being studied all the time by researchers like myself and my colleagues.

This layer adds to a growing collection of ways to look at Google Sky. there are already layers for

Download the SCUBA Google Sky KML file here (approx 1.0kB) This will officially launch later in the week, so if you have trouble try forcing Google Earth to refresh the KML file by right-clicking and selecting ‘Revert’ or ‘Refresh’.

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