Grad School Lesson #1

Well, I feel like a jerk. I wrote a post about how much schoolwork we grad students get, but then we get a week off of homework. Dang.

So, now I've decided to keep a running, improvised set of lessons from grad school. Perhaps these tidbits will be useful to you. Or... perhaps not. But, for the sake of knowledge, my first lesson is:

Lunchables are made for children, and do not make a good meal substitute.

I was hungry the entire day, and the sugar from the dang thing put me in a very silly mood. Case in point: this picture made me laugh for way longer than it should have....

Hmmm... I really should have wolfed down some caffeine, just to see the awesomeness that would have ensued. But, alas, I didn't, and I spent the rest of the day giggling in my office. I wonder what my office mates thought about that...

Also, do not touch other people's erasers.

Don't even do this by accident. Some grad students are very territorial about this.  Even if it's not their erasers.

Until next time, happy computing. I'll be kicking my computer in anticipation of the next post. :)

Advisor Meeting Analog

I'm pretty sure this is how most advisor meetings go.Thanks to Ryan Shea for finding this. Hopefully he won't find out that I shamelessly stole this from him on facebook.

The World Is Beautiful

This past week was a bit stressful. I felt like I was running around doing things, but not really accomplishing anything. Things happened that were out of my control. 

Sometimes it's hard to let these things go.

Sometimes it's hard to keep going through grad school, because I realize how little I know. Sometimes I get caught up with trying to be the best, when the "best" is some ficticious concept we all made up.

I remember when, as an adolescent, I picked up a telescope and stared at the wonders of the sky. I felt pretty good about myself. Then I went through high school and college and got into a great grad school. University of Arizona is the $#&%. Everybody is intelligent. Everybody is passionate. Compared to these people, I felt at best average. Suddenly, being good wasn't... well... good enough. I wanted to be best. It wasn't enough to pick up a telescope anymore and have fun.

Ah...  the shackles I imprison myself in!

So, this morning (while procrastinating on starting on some homework), I was surfing through some youtube videos. I stumbled on one made by the amazing photographer Terje Sorgjerd. I don't know if everyone has already seen this video, but I think it's breathtakingly beautiful. It reminds me that the world is beautiful and that it's more than made-up definitions of success. But enough of me, I'll let you decide for yourself (only, I highly recommend you go full screen on this one).

AGN Activity Increased by Galaxy Mergers?

Sometimes I forget the amazing things we take as given. Some months ago, a friend of mine asked if scientists had ever figured out if black holes exist. I replied by saying:

"Well, DUH! Of course they exist! They exist at the centers of every known galaxy. That's something everybody knows, right?".

If you really think about it, though, black holes, and their existence, are astounding. They are so astounding, in fact, that the man who predicted their existence was convinced they were too weird to exist in nature. That man was Albert Einstein.

Today, it's pretty conclusive that black holes are ubiquitous throughout the universe. They range in size from about the mass of our sun to gargantuan masses of billions of times as large (although there seems to be a curious deficiency in intermediate mass black holes - which would connect the smaller, stellar mass ones with the supermassive ones at galactic centers).

Establishing that black holes do exist, and are quite common, I'm going to go further and say that astronomers have seen two main types - those that are actively accreting gas, and those that lie dormant. Our Milky Way's black hole is a dormant type, and the ones currently feeding are called AGNs (Active Galactic Nuclei).The pretty picture below (stolen shamelessly from somewhere on the internet), shows a representation of an AGN.

Though there are different types of AGNs, they all are thought to stem from one physical model (more or less, there are still fights about specifics). In short, the rotating supermassive black hole is surrounded by a heated accretion disk. The continuum radiation from the infall of gas into the black hole photoionizes the surrounding gas, which creates emission lines we can see on Earth. In addition, a large disk of clumpy, optically thick clouds (or, clouds too thick to see through in some wavelengths, mainly optical in this case) surround the accretion disk, which can obscure some AGNs if the AGN is oriented in such a way that the clouds are between us and the black hole. Some AGNs also host twin collimated jets. These outflows emerge in opposite directions from the central black hole, and travel at velocities close to the speed of light. Heated bubbles from these jets can reach massive sizes, and how these jets impact galactic evolution (for it seems very likely they must have some effect), is not well known.

This all brings me to a paper I presented at Science Coffee last Thursday: The Impact of Galaxy Interactions on AGN Activity in zCOSMOS by Silverman et al. This study looked at pairs of interacting galaxies using Chandra X-ray data and the spectroscopic redshifts from zCOSMOS. The main point of this study was to see if galaxy mergers could increase the chances of AGN activity. The main thought is that if a gas-rich galaxy began the process of merging, the gas transferred from that galaxy could provide the fuel to feed the supermassive black hole.

Previous studies have been inconclusive about the effect of galaxy mergers on the probability of AGN activity. These studies (well, the ones mentioned) used Hubble Space Telescope (HST) observations to detect AGN activity, and they tended to conclude that they saw no significant increase in AGNs with merging galaxies. However, Hubble observes in optical wavelengths. Because of this, the thick clouds around the accretion disk could hide AGN activity, depending on the orientation of the galaxy. In an effort to get a more complete sample of AGNs, this new study uses X-rays from Chandra to detect AGNs, which are able to pass through the clouds.

To determine if galaxies in their survey sample were interacting, the authors looked at interacting pairs of galaxies between 0.25<z<1.05, distances of less than 75 kpc apart, and velocity differences of less than 500 km/s. This, of course, does not include galaxies that have already merged. The figure below shows some of their interacting pairs. The left panels show Chandra X-ray data (AGN detections), and the right panels show HST images. The red crosses denote AGNs, and the yellow crosses denote centers of normal galaxies. (Sorry this is so small. This is the largest size I can get on the blog).

They found that AGN activity was more common for interacting systems by about a factor of 2 over AGN activity in galaxies not interacting. In addition, for just the interacting pairs, they found a higher fraction of AGNs for lower physical separations and lower velocity differences. This seems to support the idea that more closely interacting galaxies were more likely to host an AGN. They even found a slight increase in AGN probability for interacting galaxies that were more comparable in size (though their sample was not statistically large enough to make that a very strong conclusion).

I think this study does make a point that galaxy mergers may have an effect on the probability of a galaxy hosting an AGN. How big is that effect? I don't know. Like the authors, I do agree that galaxy mergers can't be a dominant factor in deciding if a galaxy is active or not (about 80% of the AGN sample were in galaxies not interacting). However, they do seem more likely to spur AGN activity, and because of that, shouldn't be discounted entirely. 

Montage!

Hello all! I realize that I've been on a doom and gloom mood as far as blog posts go. My life could be much worse right now - I could, in fact, have been forced to TA. For those of you who do, I give you full permission to slap me across the face whenever I complain about anything.

I'm not kidding about this. 

I am actually in quite a good mood right now, despite the fact that SExtractor doesn't work consistently for all my survey images. Overall, I'd say this semester is going much better than last year. I've only cried a couple of times so far (just kidding... mostly) :) .

In celebration of this, and because I'm a pro at procrastinating, I give you two montages. Montages are always fun. These particular ones are stellar-centric, because I'm supposed to be doing work for my Stars and Accretion class right now. My homework guilt has convinced me that if these videos are related, I'm doing something productive... Anyway, less words, more show!

Life of a Star: 12 Billion Years in 6 Minutes
Sorry, this video won't embed. Just click on the title. It'll link you to the youtube video.

Sol Invictus
This video has some annoying text over some of the images, but I still enjoy it. If you know me on facebook, you'll have seen this before. So deal with it!

The Future of Astronomy?

Let me start off by saying that I had a really, really bad day.

I started off by making a major mistake. After I made sure my program was still chugging along, I surfed the web for current outlooks on the astronomy job market. Yes, I'm an f-ing genius. It was, as so many post docs say, positively depressing. Too many PhDs, too little money, too little opportunities... etc.

Post docs spend the majority of their time stressing about the number of papers they publish. It's considered that any less than 1-2 papers a year is a death sentence for getting a faculty job, no matter how good their papers may be. Despite what most people say, in astronomy, quantity trumps quality.

Then, in a quirky twist of fate, I went to Science Coffee, where we briefly discussed a paper on applying economic principles to astronomy. The gist of the paper was about how the scientific community could gauge the "value" of a theory (though I assume this applies to most research projects in general). The value of a theory could be determined by such factors as growth rate in the field, number of faculty jobs, number of cited papers, etc. With this in mind, appropriate projects could be pursued, and grant money would be allocated to the projects deemed most valuable. Now, this paper in and of itself may not have much lasting impact. Most people in the room kind of snickered at it or dismissed it entirely, but it made me angry.

No. It made me really, really angry.

My idealized, rose-colored vision of how astronomy functions is quickly diminishing, and this paper is a symptom of it. With all this focus on publication rates, it's no wonder arXiv papers have become so boring. Nobody can tell me why their research is important, because nobody wants to do a risky project. Nobody wants to do a project that will take longer than 1-2 years to complete. That could impact publication rates! No, it's much better to choose a safe, non-threatening project that can be done will minimal effort. Plus, if it's safe, it's much easier to get that research grant approved.

This, in my opinion, has only one effect. It breeds conservatism and stagnation within the field.

Once upon a time, I thought scientists were the heroic people who did science for the love of science. In reality, scientists are forced to do science for the publications. I understand that research will always be impacted by what money-granting institution thinks is in vogue, but that's no reason to buy into it entirely. Yes, some major discoveries were intentional, but the vast majority of major discoveries came by accident. If we all knew where to look, don't you think we would have done it already?

Discoveries are built upon surprises and the unexplained. They are built upon innovation, creativity, and a healthy heap of luck. How can you put a number of publications on that? How do you define if this risk is good or bad?

I was once told that the hard work science demanded was rewarded when you got to be the first person in the world to understand something. Think about that feeling for a second. I wonder how much it happens anymore.

A part of me understands that astronomy is a field in contraction. The competition is so fierce for so few academic job openings, that nobody will dare go against the status quo. That would be career suicide. But some part of me wistfully thinks back to Agent Fox Mulder of the X-Files, who always pushed his wild theories because he knew he was onto something. It didn't matter what the people around him said, or how much he jeopardized his career. He was going to try and collect the proof he needed.

Corny, I know, but I think the spirit of it is beautiful.

Why Intrinsic Ability Does Not Matter

I'll let you in on a secret.

I am not naturally good at math. I am not naturally intelligent. If you were to put me on a distribution of general "smartness", I would be smack dab in the middle.

This is not easy for me to say.

In third grade, I remember being tested for the Gifted Program, which was just a group dedicated to teaching the best and brightest kids at an accelerated rate. Though I scored extremely high on the reading portion, I tested two grades below on mathematics. Needless to say, I did not get in.

I remember when I was told of my deficiency in math. At that time, I didn't want to be a scientist. I didn't want to be anything. To tell you the truth, I would have been perfectly happy to spend all my days reading. But, for some reason, my lack of mathematical ability bothered me. It truly, truly made me upset - not at the teachers, but at myself. So I went home and told my mother that I had to learn the subject, and that I would be willing to devote my entire summer to it if I had to.

I kept true to my word.

In high school, I consistently scored perfectly on anything written or literature based. I always scored consistently lower on math. It was a great source of shame for me, because by that time, I knew I wanted to go into science. What scientist isn't good at math? I knew that if I didn't understand math, the framework for how the universe works fundamentally, then my understanding of how the world works would be severely impaired. So I kept trying, and enrolled in the highest level math classes I could. By the time I graduated high school, I had taken two years of Calculus. Not shabby for someone who used to be two grades behind.

My friends at the time told me they admired my natural math ability. They said they couldn't ever do math because they weren't wired for it. They claimed people had to be born with the ability, because it couldn't be taught. I tried to tell them how wrong they were.

I now have a minor in Mathematics. I have more training in math than most people in the world. The thing is, I'm not naturally "wired" to do it. I just did it.

Now, I don't want to claim that intrinsic ability doesn't matter at all. It does. I will always have to work twice as hard to learn concepts or complete research. I positively suck at programming. I probably won't ever stand a chance getting a job in academia, because truly talented people work just as hard as I do. But you know what? I've made my peace with that. I went into a hard field because I like it and because I needed to at least try.

There comes a time in most people's lives when they realize that life isn't fair. Some people are born with it all - whether it be beauty, intelligence, charisma, or all these things. I don't know what separated me from my old friends, the ones who were content to throw their hands up in the air. I don't know why I was spurred into action, when so many people around me passively accepted their "inabilities". I don't know why knowledge, for it's own sake, was so important to me, but not necessarily to others. I usually give up pretty easily, to tell you the truth. Today, I could learn a lot from my younger self.

I don't know if there's a point to this, other than nothing should hamper your ability to learn. Don't believe for a second that anything is above your understanding - not math, not physics, not anything. Don't let other people make up your mind for you. It all comes down to what skills you actively pursue.

And though it may be above my level to be the best scientist, I can certainly become a good one. That counts for something.