Where do galaxies form? how big can they be? Do galaxies 'prefer' to lie closer to one another or further apart? And how does all of this change across Cosmic Time? These are just some of the questions Jaehong Park asked within the DRAGONS team in this paper. To explore how galaxies grow near one another, known as clustering, and how they grow within the larger dark matter halos, aka bias, Jaehong analysed countless thousands of simulated galaxies. Compared against one another, at different outputs from the simulated universe of DRAGONS, the overall distributions were robustly analysed with statistical tools that then permitted comparison with images from Hubble. The work is a staggering scale and one I'm sure Jaehong will be proud of for many years to come.
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This is a great honour (and also a fun award title!) to be one of Victoria's 2017 Tall Poppies, an award recognising up and coming scientists for their research and efforts to translate this into the public domain. I have to say I felt humbled to be alongside colleagues investigating new solar technologies, cancer treatments and more!
That I got to celebrate it with the two Sarah's in my life (my boss and my wife!) was a real thrill for me.
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It was a very special evening spent celebrating the 21st Birthday of Lateral Events, they of the L'Etape Australia / Brian Cox / Sir David Attenborough speaking tour fame. If you can judge a person by the company they keep then you can certainly judge this company by the people they invite! I was able to bore everyone from ABC's MD Michelle Guthrie, Ray Martin, Adam Spencer, Lateral CEO Simon Baggs too the host Prof Brian Cox himself. A wonderful evening that I am incredibly happy to boast of, especially as the wines were selected by none other than the Queen's wine advisor herself Jancis Robinson!
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A lovely piece of work by my student Yuxiang Qin, and amazingly rapid turn around of a paper using the DRAGONS series of supercomputer models. The newly discovered galaxy ZF-Cosmos-20115 had some remarkably strange properties that at first glance seemed to bend the laws of galaxy formation to be so large so soon after the Big Bang. This work instead revealed that the rapid stellar mass gain, and the resulting quiescence thereafter, can be naturally explained by significant mergers of smaller objects that created the large stellar nucleus - but this large central bulge itself then inhibited future star formation. This was then tracked back in time in the DRAGONS universe to reveal that the rapidly growing black holes of the earlier universe could indeed by housed in what then becomes these strange quiescent galaxies at later times.
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As radio telescopes become ever larger, and evermore capable, they can see ever further into the Universe. Together with my coauthors, quite literally some of the greatest radio astronomers in the world, we realised that several equations used in radio observations were just too inaccurate (if not wrong!) for the distant universe. This paper is our attempt to give a guidebook and rigorously derived, and checked, equations for this future era of radio observation with the Square Kilometre Array. You can also have fun with the online observation calculator to see what we mean. Fun story I first started doing these calculations with Martin and rest about 6 years ago. Happy to finally see this published!
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This is an incredible honour and something I'm delighted to finally announce but after a national application process I've been chosen as the new Lead Scientist of the Royal Institution of Australia, home of Australia's Science Channel.
Australia, and the world, faces significant challenges ahead but it will be more science and technology not less that will see us through. That’s why it’s so critical we continue to explain and share the latest breakthroughs by Australia’s researchers and inspire the next generation into STEM. At Australia’s Science Channel we can ensure the best and most inspiring science stories are fed directly into classrooms around the nation, and further shared around the world.
I hope I live up to the great legacy of the Royal Institution and am able to play a positive role in raising science's profile, and science literacy more generally, in Australia!
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This is one of the most fun papers I have ever written (and not just because of the title). The picture astronomers have of the early universe is one of galaxies growing rapidly, turning vast quantities of gas rich clouds into stars in a boom-time of star formation. By using the Smaug simulations of this period I and my DRAGONS colleagues were able to explore this picture. We found that cold gas is indeed consumed rapidly, in just 300 million years irrespective of how stars explode or that gas can cool. However, theres so much material pouring into the galaxies at this time that they simply can't consume it all! A system where demand (gas turing into stars) can't raise to meet supply (of new primary material flowing in) is a recession.
Far from a booming bull-market, the early Universe was a recessionary bear-market and that's why I love this paper...
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This is a spectacular study by my Yuxiang Qin, one of my PhD students I am fortunate to co-supervise with Dr Simon Mutch and Prof Stuart Wyithe as part of DRAGONS. In this work Yuxiang compares the growth of dark matter structures in the early universe both with and without the impact of gas physics (in particular the fact that giant clouds of atoms have a pressure that prevents them collapsing unlike dark matter). Most simulations ignore that effect to save computational time. Yuxiang showed that's potentially a disastrous step for first structures where the gas prevents the halo from collapsing and through its gravitational pull can also slow the collapse of dark matter itself meaning simulations that take a computational shortcut can produce early haloes that are far larger than they should otherwise be.
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I loved making this short ABC ME series with the wonderfully talented and ever enthusiastic Grace Koh trying to explain the answers to questions that we all think of, while restricting ourselves to a green screen and about 3 minutes in total. You can watch all 5 episodes on iView or catch them as interstitials between your favourite shows on ABC ME. Also who doesn't love a big red button?!
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Todd Sampson is insane. There. I said it. I understand physics, I trust 100% in the universality of the laws we explore in Life on the Line, but I certainly don't have 100% trust in the engineering. In episode 3 we discuss Friction by throwing Todd off a bungee jump without it being secured (simply interleaved pages of a phonebook). The principle of geometric amplification of the friction means that these phonebooks won't slip by. Everything else however could go wrong. In episode 4 we discuss Conversation of Energy by using a one tonne wrecking ball. This actually DOES go wrong. Yet still he risks his life. I love Todd's trust in my calculations, I just wish he wouldn't actually put his Life on the Line with them.
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Awesome. In the truest sense of the word. How else to describe Stargazing Live? A national science extravaganza that involved the great on screen scientists of our age (Prof Brian Cox, Prof Chris Lintott, A/Prof Lisa Harvey-Smith) explaining the latest science from the gorgeous Siding Spring Observatory. I was a permanent panel member trying to answer the public's questions on the Back to Earth show that followed Stargazing each night. The public were asked to help us find alien worlds using Exoplanet Explorer, by the of the three nights Brian was able to announce a world with four super-Earths all closer in than Mercury... Insane. I still can't understand how it formed. Truly one of the most incredible experiences I've ever been part of, thanks Stargazing!
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I've been involved in some mammoth science communication events, and I firmly believe to ensure the role of STEM in our society we need these huge shows to make science cool again. I shared my thoughts on this and alarming decline in STEM enrolment rates on theconversation.
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A stunningly beautiful project to explain the night sky to a younger audience on ABC ME by Camilla Hannan. If you don't feel captivated by the visuals, and awed by the wonderful dialogue (my bits aside) then you have no soul. Seriously though, have a watch on iView, I'm so proud to have been involved in this.
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The new ABC Radio National science podcast hit the airwaves and I cannot be prouder of this show. Alongside my rantings is the insightful, measured yet ever enthusiastic explanations of my friend and co-star Dr Amanda Bauer. The entire series is run by the ABC's astoundingly talented producer Joel Werner. Subscribe and have a listen wherever you get your podcasts (iTunes).
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A lovely prediction paper from Chuanwu Liu of the DRAGONS collaboration showing the expected sizes for the most distant galaxies that current (and future) telescopes are trying to observe. The tentative existing detections appear to be well explained by our model of galaxy formation with the effective radius (i.e. the size of the disk of the galaxy) being larger for brighter objects but only with a power law scaling of 0.25! In other words a galaxy ten thousand times more luminous will be a disk galaxy only ten times wider. Finally, we make clear that the successor to the Hubble Space Telescope (the James Webb Space Telescope) will be unlikely to see these tiny disks and instead we will have to wait for ground based extremely large telescopes like the Giant Magellan Telescope (and critically one in which Australia is heavily invested).
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The alignment of the setting Sun with Melbourne's Hoddle Grid only occurs twice a year, causing a beautiful sight of the Sun framed by a mile-long corridor of skyscrapers. The astronomy is easy, but where is the best location to view this? Which of the East-West streets (Collins, Bourke, Lonsdale or LaTrobe?) and what intersection as the trams and trees can get in the way... I asked the City of Melbourne to get out and snap photos and post online with their location using the hashag #Melbhenge to crowd-source the answer. Incredibly the request was shared on ABC Melbourne radio, The Age, Broadsheet and finally to a world-wide audience on the BBC. Amazing. Stay tuned for the best location for November 3rd's event as I go through all the incredible photos (like the image I've grabbed from Rachel Dexter on Collins St) from this event.
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Super bizarre but cool honour to find myself featured in Qantas Magazine! I travel ridiculous amounts for work and find myself flicking through this mag on take off and landing, never thought I'd be reading about myself! Thanks iQ for uncovering my secret shame that I am rubbish with DVD players.
As you can tell I was a little excited about seeing myself at the end of an international flight in the Spirit of Australia inflight magazine..!
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So this is absurdly cool, the Chief Scientist has named me as one of Australia's Science Superheroes... I honestly can't claim this (and especially not when you see the other superheroes) but it gave me a chance to answer some fun questions about what my 'superpower' in science actually is.
How do you become a superhero scientist? Well firstly you don't need to get bitten by a radioactive (and very smart) spider instead during National Science Week in August 2016, Australia’s Chief Scientist launched the #5ScientistPledge to recognise Australian Scientists. Those scientists are now getting recognised with a new tag – #AusScienceHeroes
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The recent discovery by Oesch et al. (2016) of a far-off galaxy seen just 400 million years after the Big Bang but already having accumulated a billion Sun's worth of stars was considered a bizarre object. Yet the simulated DRAGONS universe apparently contains several analogues as shown in this beautiful work by my colleague Dr Simon Mutch. We show that such a monstrously oversized baby galaxy is possible if it grows rapidly but consistently throughout time and not as a result of cannibalising neighbouring objects through galaxy mergers as is oft suspected.
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My regular column in theconversation (as well as appearance on ABC Breakfast News) explored a Thanksgiving meal that was out of this world, as well as the beginning of the end for the Cassini mission (but not without a spectacular final view) and a new fuel-less rocket that set the internet alight might be a misfire after all.
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