Monday, 15 August 2011

Galactic Punctuation and Collisions

VV340 (also known as Arp 340 or UGC 9618) is a pair of interacting gas rich spiral galaxies in the Bootes constellation. Located ~450 million light years from Earth.

It is classified as Luminous Infrared Galaxy (LIRG). LIRGs produce high amounts of IR radiation and can emit from tens to hundreds times more energy than typical galaxies. Actively growing supermassive black holes (AGN) or an intense period of star formation are normally attributed to be the cause of this energy production.

Spitzer data shows that the majority of the IR emissions is coming from the edge on galaxy (VV340 North), and coupled with data from Chandra there is strong evidence for a growing supermassive black hole (SMBH) at its centre obscured by the rest of the galaxy - however only a small proportion of the IR radiation is emitted from SMBH region. However in the UV and short wavelength optical emissions from GALEX and Hubble observations, show that VV340 South to be the brighter suggesting that it has a much higher level of star formation.

Colliding galaxies like this are a premonition of our own Milkyway's future. As we are predicted to be on a collision course with Andromeda. But before anyone starts preaching the apocalypse it's not going to happen for another 3 to 5 billion years. So where safe! Galactic cannibalism is not rare! In fact there are 2 BHs in Andromeda's nucleus. The second BH may well be from a galactic collision.

Thursday, 11 August 2011


The Space mission not the film about the pregnant girl with Michael Cera playing his usual role. Set sail last friday as part of NASA's new frontiers program, it will take about five years to get to Jupiter where it will then spend a year orbiting the gas giant.

The main objectives of Juno are to peer into Jupiter's interior to determine how it formed and to map its atmosphere below the clouds to determine its global structure and motion. Also to be probed is Jupiter's magnetosphere by directly sampling charged particles and measuring the magnetic field while observing the auroras in the UV-region. It is suspected that in the inner atmosphere the hydrogen it contains is under such high pressure it becomes a fluid known as metallic hydrogen which is thought to be the source of Jupiter's magnetic field hopefully Juno will shed some light on this.

The name for Juno is very apt as in Greek-Roman mythology Jupiter drew a vail of clouds around him self to hide his mischief and it was Jupiter's wife Juno who peered though the clouds and exposed Jupiter. Hopefully the spacecraft will live up to it's name.

Lego figures of (From left to right) the gods Jupiter and Juno as well as astronomer Galileo Galilei made of aluminium have been sent along for the ride.