Nichol and Matt go to Chile!

Archive for puc

Clusters, Courses and Everything in Between

As foreshadowed in our most recent post, I thought I’d provide an update on some of my recent astronomy related goings-on. Since March, I’ve been pretty busy with the first few courses of my program as well as trying to fit in some time to work on a bit of data in regard to what will eventually be my thesis. My course work thus far has involved assignments, preparing/giving three 45-minute seminar talks and now the focus is mostly on completing two significant research projects. Two of my talks have been on summarizing recent major review papers. The first was on the idea of a universal stellar initial mass function (don’t ask…you don’t want to know), and the second was a review of what the community knows about the formation of massive young star clusters, the sort that I will be studying in detail for the next few years. The other talk was a lecture to my stellar variability class on various techniques of determining pulsational periods of variable stars…thrilling I know.

As far as the thesis goes, thus far there is exactly zero interesting information to report. Indeed, when time has permitted, I’ve just been trying to reduce some data taken of some large star clusters in the galaxy NGC 5128, or Centaurus A as it’s also called. Unfortunately, the most important task in astronomical observations, transforming what we get from telescopes into clean, usable data, is also one of the hardest, most frustrating and challenging parts. I’m hoping that after the semester is finished at the end of June, that I can work full-time on getting these spectra reduced so that I can move on to the fun part: analysis. In this case, I’ll be trying to measure what kind of chemical abundances are in the clusters, e.g. how much carbon, magnesium, calcium, iron, etc., the systems have. These measurements will tell me what kind of star formation has happened in the past, since all of those elements are created on different timescales by different types of stars. In the long-term, I’ll hopefully be creating some computer models that simulate how such massive groups of stars evolve, and most importantly, form. The observed measurements, combined with those of clusters in other galaxies (and galaxy clusters) will serve as a good test to see if my models may actually be accurate representations of how these structures form.

I’m also working on two other research projects as part of this semester’s courses. For my extra-galactic course, I’m working with two other students on collecting information on a large sample of galaxy clusters in order to compare to work that has previously been done. We’re still quite early in the project though, so I don’t have too much to say about it other than that. This project will be very challenging in that it involves a subject of astronomy that I’m not very familiar with, so it will be interesting to see how it develops.

My other project is being done as part of my stellar variability course. I’m working with another PhD student on this, and so far it is coming along very well! With fingers crossed, we’re hoping to complete a report that might be submitted for publication since the subject matter is quite contemporary. The object we are studying, NGC 6569, is similar to the objects that I’m studying in Centaurus A; it is a collection of a few hundred thousand stars called a globular cluster (GC), in the bulge of the Milky Way. Specifically what we are doing is searching for variable stars, i.e. stars that periodically get brighter and dimmer, and plotting how the stars’ brightnesses change over time. This GC is interesting in that the ‘metallicity’, or how much of the cluster’s stars are made of elements heavier than H or He, is quite high compared to other GCs. Some recent work has suggested that variable stars in other high-metallicity GCs seem to have longer periods, i.e. they take a longer time for their brightnesses to increase and fade, than the same types of variable stars found outside of clusters. It will be interesting to see what kind of results we get. Will they have longer periods, or will they be more in line with what is expected from other GCs? Will the results point toward a fundamentally different sub-class of this type of variable star? One way or another, hopefully we’ll end up with a report that will be interesting to the theorists who incorporate these observational constraints into their models. As well, since these types of variable stars are used as ‘standard candles’, which can be used to estimate distances, this kind of work may effect current distances estimates that have already been done. We’ve still got a lot of work to do, but things are looking promising so far. To bring this update to a close, I’ll just leave this here…

The globular cluster NGC 6569. I wish I could take credit for the gorgeous image, but this was made from our data by my partner. The one I made was nice, but not this nice!


My Star-Called Life

Well, you seem to have accidentally clicked on a link that has brought you to a little page on my geeky astronomy work. Don’t worry, you’ll find that life will be a lot more interesting if you click that little ‘Back’ button in your web browser. What? You clicked on my astronomy link on purpose? Alright then, if you really need to get to sleep that badly then I suppose you can read on about my experiences in the exciting field of astrophysics, but consider this sufficient warning! 😉

My undergraduate research work was a hodge-podge of different astronomy subjects. I tried to spread my research experience between as many different areas as I could, though despite my best efforts some subjects such as star formation and exo-planets have still slipped through my grasp. My main research project was on investigating dynamical and chemical links between the largest star complexes found orbiting our Milky Way galaxy, and relatively newly discovered objects known as ‘ultra-compact dwarf galaxies’. Following this work up, I then assisted in analyzing data from one of the largest surveys of the Kuiper Belt conducted to date known as the Canada France Ecliptic Plane Survey. The Kuiper Belt is a collection of cold, icy debris leftover from the Solar System’s formation, and orbits the Sun beyond the planet Neptune. The main conclusion from my work (only a tiny part of the overall study) was that the ‘hot classical’ and ‘detached disk’ components may in fact be two sides of the same coin! A conclusion only an astronomer could love.

Switching gears a little, I then conducted a small research project involving the geriatric years of a star’s life by employing some really cool numerical simulations. By this, I mean I simulated (through the use of some way-cool code and a way-powerful computer) the life of a star not too unlike our Sun during its final death-throes, but before it casts off its outer layers to live out the rest of eternity as a white-dwarf star. Of course, if said white-dwarf star has a companion, then that’s a whole other story which (for now) I won’t get into. Finally, to pass the time (and to afford the odd food-pellet) during the last eight months before moving to Chile I helped with one last study measuring properties of several million galaxies based on something called ‘broad-band photometry’. The results of this work are still being put together by my last supervisor, but the final measurements will hopefully shed light on what kinds of progenitor stars (the aforementioned white dwarfs with companions) are behind a particular type of supernova known excitingly as ‘Type Ia’.

Now that I’ve started my doctoral work, things have come around full circle so that I may work once again with my first supervisor, Thomas. This means I will continue to study massive star clusters, whether they be the somewhat controversially named ultra-compact dwarf galaxies (controversial because we’re just not sure if they should be called galaxies), hot, bright and blue young clusters that have just recently formed, the tight former cores of dwarf galaxies that have been gravitationally stripped of their outer layers, or the ancient, quiescent globular cluster systems that quietly orbit around the Milky Way and (as far as we can tell) all other galaxies.

I’ll sporadically add to this section as note-worthy developments like data breakthroughs, finished papers, new proposals and such come around but it probably won’t be a daily thing. But if anyone has any questions, or if you find any of this even remotely interesting, please do comment! If there’s one thing astronomers love, it’s people that love astronomy!


Urban nuts & urban mutts.

Feliz cumpleanos Padre!

Today was a pretty big day, and not only because of Matt’s Dad’s birthday. Today we finally visited the San Joaquin campus of Pontificia Universidad Catolica de Chile (PUC), where Matt will be doing his studies. The trip there is quite easy, with one transfer on the metro and a total of about 25 minutes one-way from our apartment in Providencia. We met with Thomas, Matt’s supervisor (who by sheer chance, lives a 30 second walk around the corner from our building) and rode with him to the campus to get our personal tour. The campus itself appears to be slightly smaller than UVic, but PUC as a whole has several campuses spread throughout the city, making it among the largest universities (if not the biggest) in Chile. Thomas took us around the astrophysics building, introducing us to what seemed like the whole department and made sure to acquaint us with the particularly nice espresso machine to which the department is always free to use :D.

It seems that the campus is in a bit of a transitional phase, as new buildings are under construction/renovation everywhere. Three of the places that Thomas tried to take us for lunch were…gone, even though just a month ago he says they were there! We were strangely comfortable with that though, as we instead enjoyed ‘Italianos’ from one of the other eateries. Italianos are probably not what you think. Picture an 8 inch hotdog in a steamed bun, slathered with avocado, fresh salsa and a drizzle of what looked suspiciously like nacho cheese sauce (here’s to your birthday, Dad!). Oddly enough, they were wonderful! More on the university will be said after classes begin, but for now we can’t go without mentioning yesterday’s tour.

Yesterday started with our introduction to the metro. We scanned our Bip! cards in the machine and lunged boldly into the turnstile…that didn’t turn. Another scan: still no turn. It was after the third attempt that a kindly gentlemen indicated that we had to go through the turnstile to the left of the scanner, not the right. We’re not sure if he told us to be friendly or whether he just wanted to catch his damned train, but he was polite about it so we were appreciative. The rest of the metro trip was smooth, and we successfully arrived at la Plaza del Armas. We were not prepared for the throng of humanity that awaited us there! It is truly incredible how many people were milling around, especially since this was mid-afternoon on a weekday. A pedestrian street flows down towards the presidential palace, lined with department stores, cafes, and countless merchant kiosks selling everything from bottled water to tourist trinkets to cell phones to scarfs for your dogs. Speaking of dogs, urban mutts are everywhere here, but they are all amazingly tame. Rather than being the stray dogs that we had them pegged for, it turns out that Chilenos love these lovely perros and have no desire for them to go. The local public, as a city-wide community, feeds them, pays for their vaccinations, and our favourite, even donates the old doggie-clothing retired by their own pooches to the local homeless hounds. It’s nice to know that our local Blacky (black lab cross), Willie (black lab with shorter hair) and Chuck (a brown, uh…dog) are being well taken care of :). We’re still awaiting an opportunity to snap a photo of them, but we promise to post some when we can.

We began our tour in front of the rebuilt Catedral Metropolitano (see the pictures) in a group of about 30-40 people; mostly English speaking, but from all over the world. The tour itself is fourth on the list of Tripadvisors things-to-do in Santiago, and is only funded through tips (about $10 CAD, but worth much more). It is conducted completely on foot and runs about four hours with a short break in the middle. Starting in Plaza del Armas, we got a brief and really fascinating history of Chile, followed by a walk down the aforementioned pedestrian avenue. With the mass of people, it was tricky to keep track of our lone, red-shirt clad tour guide, but it seemed to add to the real hustle-bustle feel of the area. Stopping every so often, we learned of the origins of ‘coffee with legs’, both old (attractive ladies in short skirts serving coffee…no really, just coffee. Seriously!) and new (basically a strip club…serving just coffee). The ‘new coffee with legs’ has blacked out windows and, not surprisingly, both the clients and employees get a little annoyed at tourists taking pictures.

Continuing down a few more side streets, we arrived at the Presidential Palace which was accompanied by a small education of Chile’s more modern history (for which we can’t do justice here, but we highly suggest googling Sept. 11, 1973). On that day, under the command of General Pinochet, two jet planes bombed and destroyed the entire left side of the palace while tanks blocked the exits, allowing the dictator to assume power until 1990. The history is fresh enough that it is still a very sensitive topic to the locals, but the tour guide indicated that the healing process has begun. Indeed, the Museum of Memory and Human Rights (Museo de la Memoria y los Derechos Humanos) was inaugurated in 2010 to commemorate and tell the stories of many of the victims of Pinochet’s regime.

After the Presidential Palace, we were led towards the business district of the city. Here we stopped for roasted peanuts at the ‘Nuts 4 Nuts’ stand kitty-corner to Chile’s version of Wall Street. The history of ‘Nuts 4 Nuts’ is a story in and of itself, but suffice it to say that the down-to-earth millionaire owner is still known to personally man a peanut stand himself on occasion. Of course, this is only when he’s not running the business from New York, where the franchise took off after a failed attempt at selling honey-roasted peanuts in Santiago. Interestingly, a copy-cat business, with suspiciously similar colours, has popped up around the city under the ‘Nuts 5 Nuts’ umbrellas.

We then descended into a much quieter neighborhood, known as Barrio Lastarria, where we walked by a man-made hill named Cerro San Lucia. According to our tour guide, in the 1800s this former rock pile represented the edge of Santiago and was basically the place where the Santaguinos threw their refuse and buried their dead (on separate sides of the hill, of course). At some point, the city officials desired Santiago to become the Paris of South America, and commissioned free labour (in the form of prisoners) to add more rocks to the pile and beautify it to create the park that we see today. Time did not permit us to walk up the hill, but we hope to explore it in the coming weeks. After a brief interlude at a local cafe, off we went for the last part of the tour which, seeing as this post is getting rather long, we will have to describe next time. It may or may not include such ice cream flavours as fish and cheeseburger. Mmmm?