The type two civilization is stellar.

little while in a more metal rich stellar population.

So I salute each of you and your stellar achievements.

And, consistent from what we expect from stellar evolution laws.

And, moreover, they merge, so their total stellar mass increases.

Meaning, ellipticals of all different masses have the same stellar populations.

A black hole does not make a kind neighbor to a stellar nursery.

Top left is proportion between black hole mass, and the luminous stellar mass.

Well that's it for now, next time we will actually talk about stellar distance indicators.

Quasars originally meant quasi stellar object, which means things that look a bit like stars.

If you can think of stellar masses for luminosity then that means that mass to

To presence of young stars and so your galaxies were evolving so stellar populations were aging.

Still, keep in mind these are Messy stellar explosions which we can barely model in computers today.

But thus you go to larger radii, stellar density decreases, the relative importance of the dark matter rises.

Compact Halo Objects. If we look at distribution of stellar masses, it is a very steep power load.

Anyway, if you picked such a stellar student, but if that student is lazy, and doesn't work hard!

Recall that for a pure stellar population the mass to light ration would be on the order of few.

Plot of stellar masses and directly from integration of visible light versus the nominal masses, which are now inferred.

I have a grant to study, uh... possible structures in stellar interiors... and the implications regarding their radiation characteristics.

looking at China with its stellar growths of eight, nine, 10 percent and wondering, why can we do the same?

Cyril Hazard was one of the radio astronomers who obtained precise measurements of few quasi stellar sources and their positions.

There is so called Baade Wesselink method that uses pulsating stars. That too makes assumptions about stellar atmospheres and thing, things like that.

Now it turns out that more metal rich stellar populations have more absorption lines in the blue part of the spectrum, removing some blue light.

Only if its been recently secreted, but there is plenty of gas all cold and that gas comes largely as a product of stellar evolution.

The question then is can we minimize the effects of galaxy evolution by going to say mid inferred where stellar populations do not evolve very much.

Chemical compositions is from pure hydrogen and helium which is primordial gas, through all the way to solar composition gas, which is produced by stellar evolution.

But we want to find out how much mass is in those stars, and for that, we need the circled mass to light ratios of stellar populations.

The first one was that the mass of the black hole is proportional to the total stellar mass of the host galaxy, amounting to something like 0.1 .

But interestingly, in a non linear fashion, whereas the masses of black holes were proportional to the luminous stellar mass or at least for the bulge component.

But Pension Fund 1 wants to make sure that they'll definitely get the money, because they can't lend money to people with anything less than stellar credit ratings.

There are many more low mass stars than there are high mass stars and because stellar luminosity scales roughly, as the fourth power of stellar mass, that means that the faint end of the luminosity function would contribute least amount of light, but most of the mass, and the critical issues is where is the cutoff if any, at the low mass end.

Milky Way has on the order of twenty of them orbiting around, they do not contain much in terms of Stellar mass, indeed, millions to 100 millions of solar

This is gas that was partly ejected from galaxies, due to the supernova driven stellar winds, and partly simply leftover gas from the original formation of structure fell into the potential well.

Converting that into grams per cubic centimeter and dividing it by the critical density gives us the omega in visible stellar populations and it's only about half a percent of the total.

So there has to be a dissipative self enrichment component to the formation of ellipticals that then reflects itself through this dependence of stellar population as in the function of red shift.

Lithium is a little more complicated, because it's also generated in stars, and it's subject to uncertainties in stellar structure and evolution. And so this is why it's not really used to constrain, constrain nucleosynthesis.

Stars of different mass and different ages produce energy of different rates, and so, we have to integrate over all production of light for stellar population of certain age or mixture of ages and see.

If you have a largely 2 dimensional stellar components, such as this galaxy, and then you merge it into an elliptical galaxy, the stars will still stay on sort of 2 dimensional surface until sometime

And in principle, if we could somehow estimate the look back time to a family of objects, say, galaxies, through the age of their stellar populations, we could perform direct tests of look back time versus redshift.

And so, here it is for a variety of galaxies of different Hubble types, and by and large, it doesn't change a lot for stellar populations we see in galaxies is of the order four or five.

The first major revision was due to Walter Baddey who recognized that there are really two very different kinds of pulsating stars, one of which is confused for the other, and he came up with the concept of stellar populations.

That is, on average, stellar populations are less efficient in producing light per unit mass, and the reason for that, is that there is a lot of mass in very low mass stars which are not very good light producers.

So here is a set of correlations produced by John Kormendy that shows some properties of elliptical galaxies, dwarf spheroidals, and globular clusters, which really don't belong in this diagram at all, but they're there just for symmetry's sake as all stellar systems.

There is a reasonable physical model how that can happen, that the supernova driven stellar winds can expel a lot of gas from our galaxy, but they do not expel the dark matter, because it does not react to the pressure it's just non gravitational.

If someone can consistently pick winners in both politics and baseball, then we should probably trust him or her to keep on picking winners in both politics or baseball, though maybe not in other things where his or her track record may be less stellar.