Research Blogging - Astronomy - English

Once upon a time there was a star

2012-05-25T15:14:59Z

Why do we think that Population III stars exist? The term “Population III” could be assigned to two types of stars: “1) the ones which form out of the pristine gas left over after cosmological nucleosynthesis and generated the first metals; and 2) the ones which have been hypothesized to provide the dark matter in galactic halos” – Carr. The first type definitely exists, since we have metals in our disposal, and we know that elements heavier than H and He could only be generated through stellar nucleosynthesis. The second type, however, not necessarily exist, because first galactic halos could also be made of some ancient pre-atomic particles. I am going to discuss the first type of Population III stars. Note that both types of Population III stars might have formed during the first phase of galaxy formation or even before first galaxies were formed....

ResearchBlogging.org, & Bromm V. and Larson R. (2009) The First Stars in the Universe . Scientific American. info:/

Bromm, V. (2010) The Very First Stars: Formation and Reionization of the Universe. Proceedings of the International Astronomical Union, 5(S265), 27. DOI: 10.1017/S1743921310000116

Stacy, A., Greif, T., & Bromm, V. (2010) The first stars: formation of binaries and small multiple systems. Monthly Notices of the Royal Astronomical Society, 403(1), 45-60. DOI: 10.1111/j.1365-2966.2009.16113.x

Looking for Earths by Looking for Jupiters

2012-05-08T13:03:49Z

In the search for Earth-like planets, it is helpful to look for clues and patterns that can help scientist narrow down the types of systems where potentially habitable planets are likely to be discovered. New research from a team including Carnegie’s Alan Boss narrows down the search for Earth-like planets near Jupiter-like planets. Their work [...]...

Steffen, J., Ragozzine, D., Fabrycky, D., Carter, J., Ford, E., Holman, M., Rowe, J., Welsh, W., Borucki, W., Boss, A.... (2012) Kepler constraints on planets near hot Jupiters. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1120970109

What PhD's Want To Be When They Grow Up

2012-05-07T12:23:03Z

Almost everyone who goes to grad school in physics does so thinking that they will one become a tenured professor at a large university. And anyone who has been around a physics graduate program for a while knows that for most of us that is simply not going to happen. A recent book by Paula Stephan entitled "How Economics Shapes Science" shows that 23% of physics PhD's hold tenure-track appointments 6 years after their PhD, which means that less than one-quarter of those that survive grad school will get to be a professor in the way they imagined when they started. That's a dismal way to look at grad school, but I've made a strong assumption in the preceding paragraph that some of you probably already noticed. I assumed that every grad student wants to have a tenure-track position at a large research university. It turns out that what grad students want is far more diverse than that, and that it changes over the course of the average student's grad school experience. A recent study by a pair of management experts looked at exactly those questions and the results are fascinating. I recommend reading the entire paper as it's very well-written and accessible, but here at the two points that I found most interesting. First, they showed that even when asked to disregard the likelihood of actually getting a job in one of six areas, only 37% of beginning grad students in physics rated a tenure-track faculty position at a research university as "highly desirable" and that the percentage of students with that opinion didn't change over the course of grad school. Note that the percentages can add up to more than 100% because respondents could indicate multiple areas as "highly desirable". This indicates that new physics PhD's are not facing 1-in-4 odds of getting a tenure-track position, but rather that the odds are more like 1-in-2, assuming that there was little overlap between those that liked the "faculty-research" and "faculty-teaching" options. The second highlight is the way that students' opinions of the six career paths change over the course of grad school. They tracked what percentage of students rated each career path at the end of their graduate careers versus their ratings when they entered grad school. This shows that the faculty options were the two that took the biggest hits, meaning that a significant fraction of grad students realized that they didn't really want to be professors after getting effectively apprenticed to one for 5-7 years. Presumably replacing that career goal are fields like R&D at start-up firms and government labs, which saw the biggest increases in attractiveness. I find it very encouraging that most grad students realize that there are good things to do with a PhD in physics other than become your adviser, and that grad school actually does help open minds to other options. Sauermann, H., & Roach, M. (2012). Science PhD Career Preferences: Levels, Changes, and Advisor Encouragement PLoS ONE, 7 (5) DOI: 10.1371/journal.pone.0036307...

Sauermann, H., & Roach, M. (2012) Science PhD Career Preferences: Levels, Changes, and Advisor Encouragement. PLoS ONE, 7(5). DOI: 10.1371/journal.pone.0036307

Robotic Telesurgery in Space

2012-04-23T07:27:00Z

Telemedicine is a field that uses telecommunications technology to provide healthcare at a distance. Certain computer systems can be linked to a physician’s office for diagnostic purposes. Different clinics and hospitals can be linked together. In the future, telemedicine could be used to perform robotic surgeries in space. Some forms of telemedicine have been in [...]...

Himpens J. (2012) Surgery in space: the future of robotic telesurgery (Haidegger T, Szandor J, Benyo Z. Surg Endosc 2011; 25(3):681-690). Surgical Endoscopy, 26(1), 286. PMID: 21858579

"Fireballs" Snuffed

2012-04-20T13:41:00Z

So the story begins thusly: somewhere out there in the universe, something is producing really high energy cosmic rays. I mean, really high energy. Energies above 10^18 electronvolts (that's a one followed by eighteen zeros). That's nearly a million times more energetic than the LHC upgrade. Boggles-the-mind high energy....

Abbasi, R., Abdou, Y., Abu-Zayyad, T., Ackermann, M., Adams, J., Aguilar, J., Ahlers, M., Altmann, D., Andeen, K., Auffenberg, J.... (2012) An absence of neutrinos associated with cosmic-ray acceleration in γ-ray bursts. Nature, 484(7394), 351-354. DOI: 10.1038/nature11068

The Merging of Biology and Electronics [Research]

2012-04-19T12:10:32Z

The boundary between electronics and biology is blurring with the first detection by researchers at Department of Energy’s Oak Ridge National Laboratory of ferroelectric properties in an amino acid called glycine. A multi-institutional research team led by Andrei Kholkin of the University of Aveiro, Portugal, used a combination of experiments and modeling to identify and [...]...

Heredia, A., Meunier, V., Bdikin, I., Gracio, J., Balke, N., Jesse, S., Tselev, A., Agarwal, P., Sumpter, B., Kalinin, S.... (2012) Nanoscale Ferroelectricity in Crystalline γ-Glycine. Advanced Functional Materials. DOI: 10.1002/adfm.201103011

Explosions in the dark...?

2012-04-18T21:25:36Z

Picture the scene. You're drifting in intergalactic space. There are no stars punctuating the darkness, like there are here on Earth. Instead of stars, the points of light you can see are fuzzier looking. Far fewer points of light than you'd see from home here in the Milky Way, those lights you're seeing are whole galaxies. Indescribably distant. You're all alone, lost in the inky blackness of intergalactic space. There's nothing out here but silent drifting clouds of hydrogen gas, and ultraviolet photons. Or is there? Suddenly, a bright light illuminates the void. A supernova. But where did it come from?(Read more ...)...

P. -C. Zinn, M. Stritzinger, J. Braithwaite, A. Gallazzi, P. Grunden, D. J. Bomans, N. I. Morrell, & U. Bach. (2011) Supernovae without host galaxies? The low surface brightness host of SN 2009Z. Astronomy . arXiv: 1111.1833v1

Magnetic Fields Can Send Particles to Infinity

2012-04-17T09:59:48Z

I’ve always thought that if we’re ever to achieve long-range intersteller space travel, magnetics will play a fairly large role in the process. This is especially true if we’re going to get away from the dependence of currently used rocket fuel in the process. I’m not quite certain of the physics/mechanics involved (yet) but surely [...]...

Díaz-Cano, A., & González-Gascón, F. (2012) Escape to infinity in the presence of magnetic fields. Quarterly of Applied Mathematics, 70(1), 45-51. DOI: 10.1090/S0033-569X-2011-01248-4

A New First – Uranus Auroras Glimpsed from Earth

2012-04-13T12:39:10Z

For the first time, scientists have captured images of auroras above the giant ice planet Uranus, finding further evidence of just how peculiar a world that distant planet is. Detected by means of carefully scheduled observations from the Hubble Space Telescope, the newly witnessed Uranian light show consisted of short-lived, faint, glowing dots – a [...]...

Lamy, L., Gladstone, G., Barthelemy, M., Achilleos, N., Guio, P., Dougherty, M., Melin, H., Cowley, S., Stallard, T., Nichols, J.... (2012) Earth-based detection of Uranus' aurorae. Geophysical Research Letters. DOI: 10.1029/2012GL051312

The Universe at the Speed of Light [Infographic]

2012-04-13T02:46:10Z

I try to stay active on Twitter so that I can keep up with what’s happening in the world of #astronomy and #science. I actually learn a great deal from many of those that I follow (one of the reasons I love Twitter). One astronomer that I learn from regularly is Dr. Michael Brown (@plutokiller). [...]...

Richard Davies, Hauke Engel, Erin Hicks, Natascha Foerster Schreiber, Reinhard Genzel, Linda Tacconi, Frank Eisenhauer, & Sebastian Rabien. (2010) Dissecting Galaxies with Adaptive Optics. Conference Proceedings. arXiv: 1005.5010v1