Hello everyone and welcome back to my blog! I am happy to announce that I am finally starting work on my model galaxy! In this post, I’ll be going over many of the starting parameters of the model and some of the more general parts of the model.

Structure

The model will be split into at least 3 parts. There will be the central quasistar, the outer halo (think of it like a spherical shell of gas and stars), and the middle region between the two. Depending on what I find out later, I may have multiple sections in the middle region and I might also split the quasistar into its central black hole and its outer shell.

Requirements

Before getting into what I did, I will do a quick summary of the requirements for a quasistar’s existence that I touched on in some of my other blog posts. First of all, it needs to be in a galaxy greater than 10^11 times the mass of the sun. Second of all, the gas (at least in the middle region) needs to maintain a temperature of at least 10,000 Kelvin. Third of all, There has to be at least 0.14 solar masses of gas falling into the center per year for the whole time that the quasistar is forming.  Fourth of all, the quasistar needs to exist between redshifts z = 10 – 15 (300 – 600 million years after the big bang). And finally, the quasistar itself needs to have a density of at least 10^17 atoms per cm^3.

Approach

With all that in mind, here are some of the ways that I’ll approach the model. First, I need to have stars forming and going supernova in order to generate enough energy to keep the gas hot. This isn’t exactly the easiest task, because part of the reason the gas needs to be hot is to prevent it from “clumping”, but even though large clumps shouldn’t form, it will still be possible for smaller ones to create stars. I did some math and figured out that if a star begins made completely of hydrogen and fuses it all into iron, it will produce a total of 3.22 * 10^15 Joules of energy per kilogram of hydrogen, mostly in the form of heat. That does assume the most efficient scenario, but it also ignores the energy produced by the star shrinking as well as by the supernova, so it could be more than that. As a reference, if something the mass of our sun were to do that, it would produce 6.4 * 10^45 Joules over its lifetime, making it have a power of 20 billion billion gigawatts for its entire life (yes, that is 2 billions). In terms of the other requirements, the galaxy will need to have a relatively slow rotation to make matter fall in easier, and I’ll have to consider how the matter falls in before the quasistar begins to form.

All that being said, it’s nice to finally be able to start working on the model, and I hope you come back to see my next post!