Monthly Archives: July 2015

The Very Hungry Supermassive Black Hole

We all get the munchies, but when you’re a supermassive black hole (SMBH) your hunger might have dire consequences. And just like that an SMBH has outgrown its galaxy and jumped to the top of the heavyweight objects in the universe.

About 12 billion light years from us, there is a galaxy called CID-947. It has a mass similar to our own Milky Way (about 1000 billion times the mass of the Sun) and it was only remarkable because it had an active galactic nucleus (AGN, i.e. an accreting SMBH).

Lord of the Rings distance pinpointed

As I mentioned in a previous post, there are a few ways to measure the distance of a star in our galaxy. Unfortunately when the Luminosity is unknown and it is too far away to use parallaxes method, we are stumped for ways to estimate the distance.

Once in a while though we get lucky and we have events that allow us to calculate distance in other ways. Circinus X-1 is one of these events. Circinus X-1 is an x-ray binary; an x-ray binary is a system of two stars where material from one companion is accreting on the neutron star, which in turns emits x-rays.

How do we know how massive stars are?

As we discussed in the previous vlog our understanding of stars is still incomplete, but there are areas which we are very confident on what we know.

In general we tend to know three things about stars: their brightness, their spectrum, and if they are close enough or of known luminosity, we can also know their distance.

I’m the Universe, hear me roar.

The cosmos has plenty of terrifying Lovecraftian features, but one of my favourites is the Space Roar.

There is a loud radio signal, described as a constant hiss, that seems to pervade the cosmos. It is louder than the radio signature of radio galaxies, and it is without explanation.