Chris Lintott’s Universe

I wrote, just before my laptop left my life (incidentally, if you happen to be in Shepherd’s Bush with a newly acquired MacBookPro which, shall we say, fell into your hands, then I’m desperate enough to pay to have it back. Drop me an email?) a long piece about a fantastic paper released last week by some of my UCL colleagues.

They’ve produced what is being billed as the largest three-dimensional survey of galaxies across the entire sky ever to be produced. I’m a sucker for these kinds of things; there’s something special about being able to map our place in the Universe, and being able to identify exactly where in the many millions and billions of galaxies we are. The deepest survey to date - the Sloan digital sky survey - looks in detail at only a small fraction of the sky, whereas this more recent work uses galaxy positions from the 2MASS survey which covers the entire celestial sphere.

So what does our cosmic neighbourhood look like? The maps reach out 600 million light-years, and in all that space the largest supercluster is the Shapley supercluster, some 400 million light-years away. This structure is enormous, at least 20 million light-years across. Our local movements, though, are detemined primarily by the presence of the Great Attractor, around three times closer but pulling the Local Group, including our own Milky Way, toward it at the media-friendly velocity of a million miles an hour.

The maps are based on a technique which allows astronomers to infer the position of the dominant but invisible dark matter from the observed positions of the galaxies, and the next step will be to test this model by measuring the galaxies’ velocities directly. In the meantime, you can enjoy a spin around our local Universe here (large file).

Update : In response to a comment, stills are available via the RAS press release - scroll down for captions.

I’m sorry for the lack of posts over the weekend; I did have a few posts ready to go, but someone in Shepherd’s Bush decided to steal my laptop instead.

Some sort of service will resume shortly, normal service will resume when I can work out how to afford a replacement.

Sometimes, all too rarely, there is a news story which needs no further explanation. How wonderful is this image? The rovers have been doing incredible things (and I’m looking forward to interviewing their creator, Steve Squyers, again next month) but to see one of them from orbit just illustrates how rapidly Mars exploration is advancing.

More Mars over the weekend…

UPDATE : I forgot to add these pictures and reconstructions which were sent in by Stuart Atkinson.

The fourth of the entries in the Sky at Night magazine’s ‘Hotshots’ competition is our second photo of the Great Orion nebula, M42, which couldn’t look much different from the last one. This one was taken through narrowband filters in order to avoid the worst of the light pollution, which seems to have brought out the extended emission nicely.

You’re going to be sick of hearing about Bang! (the book I’ve written with Patrick and Brian May) before too long, but I’m still extremely excited about it; partly because I really can’t believe that a book came out of the chaotic mess of meetings and emails that spanned the last three years. If you haven’t seen the animation over at the site yet, you should. It’s worth it just for the (Brian May produced) soundtrack. Anyway, if you’re even a tenth as excited as I am about its imminent publication (and who wouldn’t be?), you’ll want one of the wallpapers Brian’s put together. They’re over here.

This month’s Sky at Night, as those of you who have seen it might have noticed, was a little different than normal in that we essentially had three seperate topics (on the extended, BBC4, version). I would be very interest to receive ANY feedback - positive or negative, in the comments or via email - about any of the three items.

I’ll try and remember to ask this again once the program goes up on the web…

More content to follow with any luck later today, but for now here’s the third of the hotshots; the Moon over St Paul’s cathedral. I really can’t make up my mind over this shot. The cross in front of the full Moon is fantastic, but the plane (amusing though it is) seems to detract from the sight. I end up looking at the cross, and then the plane, and then back to the cross again, and never really looking at the Moon. Still, make your own minds up.

The second entry for the competition is this shot of the great Orion nebula. This happens to be my favourite object in the sky (and if it isn’t yours, why on Earth not?); I saw it first through my own six inch reflector, on a very dark and clear night and I can still remember the feeling as the sheer three-dimensional nature of it struck me. I also remember the colour; a green that you just don’t seen anywhere else, so I’m always slightly biased against pictures that show it as pink. Don’t let that put you off, though.

One of the most enjoyable tasks I’ve had in the last few weeks (along with moving office to a different city, and finding a flat, and submitting my thesis…) was judging the Sky at Night magazine’s photo competition. Now, they’re not having any sort of public vote, relying on a panel of judges to select ‘Hotshots image of the year’, but the images are so good I thought I’d post them here over the next two weeks or so.

I’ll reveal who took what once all eleven are up. The first is below.