Making Research

Making Research

One of the joys, frustrations, most loved, and most hated parts of being a professor is attempting to do research. I say attempting because sometimes the data just doesn’t want to produce anything useful. There are good times. For instance, in about three months this summer and fall Fraser Cain and I, with the help of undergraduate Rebecca Bemrose-Fetter and graduate student Georgia Bracey, managed to do a quick a solid study on who listens to Astronomy Cast and responds to surveys. The paper is already published and you can find it here. That was fun, challenging to analyze in a “I need a brain but not a Nobel prize” kind of way. That’s the type of low-hanging-fruit every researcher likes to pick and munch every now and again. The...

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Seyfert’s Sextet, Stephan’s Quintet, and Compact Groups

Seyfert’s Sextet, Stephan’s Quintet, and Compact Groups

This morning I was flipping digitally through the preprints on arXiv, and I stumbled on a rich paper on the evolution of Seyfert’s Sextet. In the paper, they discuss Seyfert’s Sextet as a more evolved version of Stephan’s Quintet. Now, these two compact galaxy groups (CGG) are two of my favorite objects to image, so I couldn’t resist pausing to read the article. But I have to admit that I had to do a bit of googling first. This is because Seyfert’s Sextet doesn’t have 6 member galaxies, and Stephan’s Quintet doesn’t have 5 member galaxies. And while I didn’t remember just how many the two of them had, I knew the answer was attached to the captions of the two pretty pictures above. So, here’s the...

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Lensing Lenses & Einstein’s Cross

Lensing Lenses & Einstein’s Cross

While going through journal articles today, I came across a really neat paper on teh apparent variability of the different images of the famous lensed quasar, Einstein’s Cross (Q2237+0305, in science speak). The light from this distant quasar is blocked from reaching us directly, and is instead bent toward us along 4 different paths by the nucleus of an intervening spiral galaxy (image left, credit:  J. Rhoads (STScI) et al., WIYN, AURA, NOAO, NSF). Each different image provides us a snap shot of the quasar from slightly different angles. While many quasars with split up images have significant time delays between one image and another, the images in this situation have negligible time delay. Astronomers in Switzerland and Washington, lead by A....

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Building Galaxies

Building Galaxies

I just finished watching the Universe series episode on “Alien Galaxies.” I have to admit that their constant use of the word “Alien” forced me to look up the word alien in the dictionary (or at least on dictionary.com). I have to admit that while it is legitimate to call galaxies alien, it’s probably a bit of a stretch of the definition. That aside, this episode did a good job high lighting all the different types of galaxies that are our there. What it didn’t discuss (let’s face it, you can only do so much in 50 minutes), is how this zoo of galaxies represents a continuum of evolution. A paper published by Searle and Zinn in 1978 and substantiated by countless papers since then, states one of the possible explanations...

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Finding Dark Galaxies

Finding Dark Galaxies

One of the great mysteries of our universe is whether there are dark matter galaxies, devoid of stars, haunting the universe. From the COSMOS survey, we know that dark matter and visible matter are not always located in the same place. This implies that there may be galaxies out there made entirely out of dark matter. The question is: how can we prove they do or don’t exist? Proving they completely don’t, never ever, no where in the visible universe exist is actually impossible. No matter how hard we look, it will always be possible for one dark galaxy to be hiding. On the other hand, proving the do exist, is tedious but possible. This is because even dark galaxies exert a gravitational pull on the stuff around them. In a recent survey, lead by Igor...

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It’s raining stars!

It’s raining stars!

It has long been known that there are stellar interlopers in the solar neighborhood. These stars just passing through as they orbit the galaxy on a path that originates in galactic halo. Unlike the stars like the sun that normally live in the galactic disk, these stars are poor in metals (have low amounts of atoms like iron), and extremely old. Recent work by a team lead by Amanda Kepley (Case Western Reserve University / University of Wisconsin), seeks to untangled the history and structure of immigrants from the halo. Kepley’s team looked at 231 stars within 25,000 2,500 parsecs of the Sun that are less than 1/10th the metal content of the Sun. This sample includes stars with accurate distances, velocities, and metallicities. They find 5% of these stars...

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