Grace Stephens
Earth Science
10/24/14
Big Black Holes Can Block New Stars
This article is about how some of the black holes that have formed are preventing gas to heat up and cool, to form into baby stars. Researchers from Johns Hopkins University are wondering why they stop forming stars at some point and the question is: Why? Basically, these active black holes give a reason for why stars stop forming in the universe. The gas that is forming the black holes is not cooling. It is remaining hot, or becoming even hotter which is only making the black hopes become more massive. Therefore, no new stars can be formed. Scientists are using the “SZ effect” to see why this is happening. The Sunyaev-Zeldovich Effect describes the scattering of cold cosmic microwave background photons off hot gas in the atmospheres of galaxy clusters. The SZ signal changes brightness with the mass of the cluster, but does not change as a function of redshift. This makes it an excellent tracer of large structures in the Universe, since it can be used to characterize the properties of a cluster at any distance. These scientists hope to find more answers beyond the temperatures of the black holes and so on.
I decided to write about this current event article because it has a lot to do with what we are studying in class. We just learned about the redshift effect and how stars die and form again. I also found this article really interesting because it is amazing to think about how we can find information about objects millions of miles away. Stars start off as stellar nebulas, become an average or massive star, then will become a red giant or red supergiant. The small stars turn into planetary nebulas, and the massive stars explode into supernovas. Lastly, after planetary nebulas those stars will become white dwarfs, and the supernovas will become black holes. We just discussed this in class, and its interesting to see it actually taking place in real life.
I thought that this article was pretty well written. Although, at times it was pretty confusing because they jumped around a lot. I enjoyed learning about this topic because it gave me a broader idea of the universe and space. In the article they included a lot of quotes and names of scientists which helped explain to me more about this topic. In conclusion I recommend this article to anyone who is interesting in studying stars and astronomy.
Great current event grace!
ReplyDeleteYou did a really nice job explaining the summary and the heating and expansion of black holes is stopping new stars from being born. You also explained the SZ affect very clearly and i could understand it without knowing what it was before reading your current event. Your connection to class is very accurate and well connected.
It interested me that black holes are taking up that much space and aren't letting stars be born. It also interested me that scientist are using the SZ effect as a tracer of large structures in the universe. This current event was awesome but maybe to make it clearer as a suggestion you could have added more background on what a black hole is!
Nice job!!!!
This comment has been removed by the author.
ReplyDelete3 things I was impressed by/learned:
ReplyDeleteI had no idea that the lack of the cooling process can cause black holes to expand. It's interesting that black holes can affect the growth of stars, even though they are two completely different space matters. Also, it's surprising that the SZ effect can track down large structures in the universe.
2 aspects of the review that were well presented:
You described the SZ effect very well. Someone who was unfamiliar with the effect would easily grasp the subject matter. Also, you did a great job with the summary of what steps stars go through in their lifetime.
1 suggestion for how the review could have been even better:
The first paragraph is a little repetitive. For example in the statement about why black holes prevent the formation of stars, you repeat yourself.
Overall, it was an excellent current event!