A black hole is a fascinating object. In some cases, when paired with a normal star, it starts to vacuum off and eat the atmosphere of the star (like in the picture below). As the gaseous matter from the star falls in, it needs to lose angular momentum. Hence it form a spiral structure which we refer to as an accretion disk. As the matter spirals inwards it gets heated up due to frictional forces, and radiation originating close to the black hole itself. When it is very close to the black hole, it gets so hot that it predominantly emits X-ray radiation.
Here is where I (and a bunch of other scientists) come in. We use satellites in outer space (thankfully X-rays are filtered by the earth’s wonderful atmosphere) to detect these X-rays and try to understand what happens close to a black hole. Using X-ray data, I am trying to address some simple, yet important questions such as: ‘How does the inner radius of the accretion disk behave?’, ‘In what way does the accretion disk interact with the radio jet?’, ‘In what way does the accretion disk interact with the corona?’.
My main interest is a beast of a black hole that is know as GRS 1915+105. I have used a vast collection of data on GRS 1915+105 obtained using the Proportional Counter Array detector on board the Rossi X-ray Timing Explorer (RXTE). My goal is to fit the steady state X-ray observations found within this data set with the simplest possible model and attempt to address the questions I have for this system. Answering these questions (while posing us with more questions!) will help us move closer to understanding the beast that is GRS 1915+105.