Okay, so welcome to the lecture, Galaxies and Cosmology by Jeroen Worms.

I'm today replacing Jeroen Worms.

My name is Ingo Kraigenboom.

I'm a scientist at the observatory in the working group of Jeroen Worms.

My main job is either looking at neutron stars from a scientific point of view or mostly

in these days writing software for future x-ray missions.

The lecture will always be on Mondays or on Tuesdays, Mondays from 12 to 2 and Tuesdays

from 4 to 6.

But please note that since this is a 3 plus 1 lecture, so three semester hours per lecture

and one for exercises, there will be times when there is no lecture on a Tuesday or on

a Monday.

So please always check the plan that I will show on the next slide, whether there is a

lecture or not.

In terms of content, as the name implies after an introduction where I will just recap some

basic stuff from the introduction lecture, we will look at all the things that we need

to know about galaxies.

So starting from observing galaxies over nearby galaxies to various types of galaxies, active

galaxies, finally going to get the clusters which then already lays the way for cosmological,

cosmology so we can then go into the world model so to, we will talk about the theory

what cosmology actually is about, the big bang, inflation, parameters of cosmology,

then how the whole thing really started, structure formation and how we can observe all these

things nowadays.

Okay, so this is the detailed plan.

As I said, it's a plan, it might be updated depending on travels or as I already said

before if somebody has to be away.

So this week we will only have a lecture today, the same in the next two weeks so there will

only be a lecture on Mondays and only starting from November on there will be something also

on Tuesday.

Okay, so in terms of the exercises, so there will be exercises, the exercises will be also

graded, but we don't do this conventional thing where you solve some equations, put

some numbers, hand that in and get the grade for your homework.

We do something else, in this lecture you will write an observing proposal.

The point here is that for, when being a scientist one of the most important things that you

need to do several times a year usually, you have to write an observing proposal because

nobody is just pointing a 100 million plus Euro telescope at some object for a couple

of days just because you like it and you think it should be observed, but you have to justify

why you need to observe this object for a few hours, a few days, a few weeks.

So I'll put in other numbers, if you use a satellite observatory typically one second

observing time of a satellite costs about 1000 Euros.

For the cheap ones it might be a factor of 10 or so more if you go for Hubble or so.

So you can imagine if you want to observe something for like a day which is 100,000

seconds about and each second is 1000 Euros, these data then have a worth of hundreds of

thousands of Euros.

So this is nothing that you just make a phone call and hey please point a satellite at that

location I think that's cool, that's not going to work.

So you have to write a detailed proposal explaining why you need that and why so much money in

principle should be spent.

So this is a very important part of being a scientist and of doing astronomy, so that's

why we are also doing that as an exercise.

Of course not on this high level that professional astronomers need to do, but you have to go