Thursday, December 31, 2009

Fun with digital cameras

Keely and I got a fancy new DSLR Canon camera for Christmas, supposedly to take pictures of our baby (whenever he comes). But, for now, I'm having way more fun taking funny pictures. Here are some of my favorites:

Here is Jasmine using the "monochrome" setting. She's giving me a look like "I'm already only black and white, what are you doing?"

That flash is bright!

I do not know how she didn't run into that wall...

See how high I can jump!

Ghost Steven and Bella!

I call this one: time-averaged tail wag 

Tuesday, December 15, 2009

The Era of Baby Galaxies

Hello loyal reader.  So, I haven't written to this blog in over three months.  I promise - there is a reason.  Right about then, I started working on a really cool research project.  I thought I would finish it quickly, so I told myself when I did, I would write up a blog post about it.  Days turned into weeks and weeks into months, but finally its finished.  If you really want to torture yourself, you can read the paper here:

But, its in scientist-speak, so you can save yourself the trouble, and read my non-scientist friendly summary :)  And, if you want to skip straight to the pretty pictures, go here:

This all started back in May of this year when NASA serviced the Hubble Space Telescope, or HST (the mission was called Servicing Mission 4 - though it was actually the fifth mission to HST).  The shuttle Atlantis performed the mission, and they did a number of tasks, including fixing the main camera (the Advanced Camera for Surveys -- or ACS -- which had broken over a year earlier) and installing the new camera, Wide Field Camera 3 (or WFC3 in astronomer - speak).  Although WFC3 can also take visible-light images, its real power lies in its capability to detect light just bluer than the eye can see -- the near-ultraviolet -- and just redder than the eye can see -- the near-infrared.

One reason why this was so exciting, was that we believed that WFC3 would give us the capability to discover the most distant galaxies.  This is precisely because we know the Universe is expanding.  The further away a galaxy is, the faster it appears to be receding from us. Due to the Doppler effect, this recessional velocity actually stretches out the light we see from these galaxies, such that they appear redder. The further away they are, the faster they're moving and thus the redder they appear.  Us astronomers call this redshift, and we give it a number.  The higher the redshift, the more distant a galaxy is.  Until recently, the most distant galaxies known have redshifts of ~ 6.5 - 7.  We are thus seeing these galaxies as they were about 12.5 billion years ago.  The Universe is 13.6 billion years old, thus we were seeing them as they were only a billion years after the Big Bang.

Just a few months after WFC3 was installed, HST spent 60 orbits (~ 60 hours) staring at one area in the sky known as the Hubble Ultra Deep Field.  These observations were proposed by Dr. Garth Illingworth, a professor at UC Santa Cruz, but the data became publicly available immediately.  The area in this deep field is tiny, only 3% the angular extent of a full moon, but the image can see objects one billion times fainter than the human eye!  A number of papers came out within week, publishing the first discovery of large numbers of galaxies at redshifts > 7.  This was not previously possible, because we did not have the necessary instruments.  These galaxies are so distant that their visible light has been shifted completely to the infrared.  It is difficult to observe in the infrared from the ground since the sky actually glows at those wavelengths.  So, we need to go to space, and thats what WFC3 has given us.

We examined these data, and searched for galaxies which are moving so fast, that their light has been shifted nearly out of the optical and in the infrared.  To do this, we used the new WFC3 data in conjunction with existing ACS optical data, and looked for objects which were apparent in the WFC3 infrared image, but either very red or nonexistent in the ACS optical image.  We found 35 such objects, and from their colors they appear to be at redshifts from 7 - 8.  The light we see left these objects 13 billion years ago, which corresponds to a time when the Universe was only 700 million years old!!

Our goal was to do a detailed analysis to understand the physical make-up of these galaxies.  We have been studying in detail over the last few decades or so what galaxies at lower redshifts look like.  By comparing to higher redshift, we can really gain a sense of how galaxies are evolving, which we can turn around and use to probe the conditions at the beginning of the Universe.

The first interesting thing we wanted to look at was the dust and metal content of these galaxies.  In the Big Bang, only hydrogen and helium were formed.  Any elements heavier than that we astronomers call "metals", and when we talk about metallicity, we mean how many atoms of metal elements exist when compared to the number of hydrogen atoms.  Although we haven't seen them yet, the first stars by definition should have had no metals in them.  These stars should be blazing hot, and galaxies composed of these stars will appear extremely blue.  Similarly, dust, which is material between stars in galaxies composed of silicon and other metals, is also interesting to study, as it typically forms in the supernovae (the deaths of massive stars) as well as in the atmospheres of very old stars.  Thus, if you see dust or non-zero metallicity in a galaxy, it is a good indicator that a previous generation of stars has existed, and thus you're not quite seeing the first galaxies.

To assess the properties of the galaxies in our sample, we compared them to typical local star-forming galaxies.  What we found was that our galaxies at redshifts of 7-8 are significantly bluer than typical local galaxies.  This implies that they are some combination of younger, dustier and lower metallicity.  This is very interesting, as in Dr. Casey Papovich's thesis work (along with a number of other studies) we learned that galaxies at a redshift of 3 are very similar to local star-forming galaxies.  The time elapsed from now until redshift of 3 is ~ 12 billion years, and only another billion years goes by from redshift 3 to redshift 7, thus it is very striking that galaxies have evolved significantly in such a short period of time!!!

Since our galaxies are bluer, could it mean that we've finally found the first galaxies in the universe?  Well, I said above that we compared them to "typical" local galaxies.  What we did next was to compare them to some of the bluest galaxies we see nearby.  And, we found that our high redshift galaxies appear very similar in color to locally very blue galaxies!  What does this mean?  Well, these galaxies have almost no dust, and very low metallicities.  But, they do not have zero metallicities, so we conclude that these distant galaxies, while fairly primitive in their composition, are not the first-ever galaxies in the universe.

From their brightness, we are also able to measure the amount of stellar mass they contain.  We find that they are from 1 - 10% as massive as the Milky Way.  To put this into context, galaxies at a redshift of 3 are about as massive as the Milky Way (maybe a tiny bit less), so again we have discovered strong evolution in typical galaxies over only one billion years in cosmic time.  Putting all of the pieces above together, it really does look like at redshifts of 7-8, we are really probing the era of baby galaxies.  The larger, Milky Way size galaxies that are common at lower redshifts are nowhere to be seen, and everything we see appears to be fairly young and primitive.  But, we have not yet found the infant galaxies, containing the metal-free stars, but with the launch of the James Webb Space Telescope in 2014/2015 we should come awfully close.

One other interesting thing we investigated was the effect these galaxies would have on their environment.  We know that soon after the Big Bang (a few hundred thousand years), the Universe was filled with neutral hydrogen.  When we look between galaxies today, there is still hydrogen, but it is ionized, meaning that its electron has been stripped away, so the space between galaxies is filled with a proton and electron soup (what we would call a plasma).   One of the burning questions in astronomy is, what caused the reionization of the intergalactic gas?  One theory is that young galaxies in the early universe did it, but that was far from determine.  In order for this to happen, very energetic ultraviolet light has to be able to "escape" from a galaxy in order to ionize the intergalactic hydrogen.  When we look at the Milky Way, only a few percent of this light can escape.  So, if we look at our galaxies, if only a few percent of the energetic light escapes, they are not close to being able to reionize the intergalactic gas.  But, as we learned in our study, our galaxies are NOT like the Milky Way.  The most important difference is that they have little-to-no dust.  Dust can block this energetic light from escaping, so if you take it away, then the light can escape, and these galaxies can explain reionization!  When we actually look at how bright our galaxies are, we find that if on average 50% of the energetic light escapes, typical galaxies are the dominant source behind reionization.  We do not (yet) have a way to directly measure this escape fraction, but the fact that these galaxies appear fairly primitive in their physical make-up implies that they likely have large escape fractions.

Saturday, September 12, 2009

So far from home

To show our support for the impending end of the Huskies losing streak, Keely and I wore our husky jerseys to the HEB grocery store to go buy some snacks for the game.*. We're checking out, and the checker looks at us, and asks if they're is a high school game going on today. I said no, and that these were college jerseys. She looked confused, so I said they were for the university of Washington, as I swiped my UW debit card. She thought a second, and then said "what are you wearing those for?". The aggie aren't even playing today, and I even wore my aggie hat to calm people down. She was at least nice enough to ask who we were playing, but she didn't look impressed when I said Idaho, but she might not even know where Idaho is..

*Keely has a new Jake locker jersey, but I still have a rich Alexis one. I think maybe I'll get a Nick Montana one in a few years.

-- Posted from my iPhone

Monday, September 7, 2009

Our Aggie gameday experience

Howdy y'all!  Keely and I enjoyed our first Aggie game together this weekend, an emphatic, although predictable, 41-6 victory over the New Mexico Lobos (which I learned means Wolf in Spanish).  We started the weekend by going to the Midnight Yell Practice on Friday night, which is a Texas A&M tradition before every home game (and I think they might do it before away games too)*.  As you can see in this picture, a ton of people show up, I'd guess at least 20,000.  It started off with a speech from the head coach, Mike Sherman, saying something like "we'll kick the crap outta the Lobos, y'all" or something.  Then the Yell leaders take over.  A&M is pretty unique, in that we don't have female cheerleaders, but five male yell leaders - three seniors and two juniors - which are elected by a campus wide vote in the spring (you see campaign signs all over town then).

* My favorite thing I overhead while walking in was one girl saying to another "my date is hotter than y'alls".  I know that y'all isn't really a word, so how do they get y'alls?  And should it have two apostrophes, like y'all's?  These are the things I need to know!

They lead everyone in a number of cheers, which everyone seems to know, thanks to the weeklong "fish" camp all freshman go to (I get the sense that > 90% of the people there were freshman at A&M at one time or another).  My favorite song is the "Aggie War Hymn", which is the A&M fight song.  Its basically a big f@#k you to UT Austin, with lines like "goodbye to texas university" and "so long to the orange and white."*  The coolest part is when they sing "saw varsity's horns off," everyone puts their arms around the people to either side, and all the rows sway back and forth, like a saw blade.  This lasted for about a half an hour, then all the college students went on their way to go back to drinking.

*They also refer to A&M as TAMC, which I assume meant that some time in the past it was called Texas A&M College.  This is funny, because while at UW we used to call WSU Washington State College, implying that college was worse than university.  But I suppose that they don't want to change all the yells, and plus TAMC rhymes with Aggie, sort of...

On game days, one of the coolest* things you see here is that all over the place, people have TAMU flags on their houses, in their yards, on their cars, and even all over the grocery store parking lot.  We haven't bought ours yet, but this flag was in our neighbors yard a few doors down.

*Much cooler than the WSU thing where they always have a Coug flag on ESPN Gameday

The game wasn't till 6pm, so we met a few of our friends to tailgate around 3pm.  We met at a grassy area next to our building, which is about a 10 min walk from the stadium, and was surprisingly empty of people.  We hung out, grilled some burgers, and had a few (or five) beers.  We planned to get to the stadium an hour early, so we could check out what all was going on outside, but we ran a little late, so we got inside just as things were getting started.  Right when we got to our seats, they sang the Alma Mater, and the whole football team stopped their practice and lined up to sing it, which was pretty cool.  This was followed by the national anthem, played by the band from their seats (I guess they don't do a pregame marching show)*.  This was followed by the State of Texas Anthem, though I didn't realize what was going on, but I was wondering why most people didn't put their hats back on after the national anthem.  The picture to the right shows the view from our seats - not too bad!

*Probably my favorite thing about Husky Band was the making of the flagpole and unfurling of the flag we did on the field before everygame, and how during America the Beautiful, the whole stadium would stand up.  I actually left my Physics GRE exam early so that I wouldn't miss this for the last home game my Senior year.

After the game started, we settled down to kick some Lobo butt.  We scored right away, though our offense struggled a bit after that, though at halftime we had a 21-3 lead.  Here's a few pics of the halftime show, including a big block "T" that they do every game.  They are a military style band, so they only played military songs, and did only corps-style movements.  They were very good at it, but I like to Husky Band's style better (of course).

The rest of the game was pretty boring, but I guess thats what you get when you play a crappy team and its 85 and humid out.  But overall I think we both had a great time, and we're looking forward to our next game in two weeks.  Gig 'em!

Thursday, September 3, 2009

The wait is over

Football begins tonight, starting with a great top-25 matchup between Oregon and Boise State on the smurf turf over in Idaho.  I think its pretty crucial for Oregon to leave with a win if they really feel like they can be a top 10-15 team this year.  So even though I hate the Ducks down to my very soul, I'll put on my Pac 10 hat tonight, and root for a Duck victory (I think I just threw up in my mouth a little bit).

Stay tuned for a post about this weekend as Keely and I have our first Aggie Football experience.  We're pretty pumped!

Oh yeah, look out for which uniform Oregon is wearing, they have like 37089346290 options.

Thursday, August 27, 2009

Big Friday

We're having our first ever astronomy internal symposium tomorrow, which I (stupidly?) volunteered to run. Here's hoping all goes well, especially the BBQ lunch!

Remember Detlef Scrempf? He was cool, I wonder if this is worth any money?

-- Post From My iPhone

Tuesday, August 25, 2009


Two-run walk-off homerun in the 10th to win it for the M's.  Even though his picture kind of makes him look like a douche-y frat-guy, you gotta love his name, and his game winning power.

Okay, so my top five players on the M's this year are:

1) Franklin Gutierrez - No, I don't say it all spanish-like like Dave Sims, but he still kicks serious butt.
2) Felix Hernandez - He's been slacking a bit lately, but I hope the M's are willing to pay up to $100M to keep him (though not more)
3) David Aardsma - Where'd this guy come from?  I guess his season really makes the Met's look like tools for paying ~ $10M to K-rod.  But no sense kicking them while they're down.
4) Russell the Muscle - Would have been higher, but he's been striking out more times daily than I check my email.
5) Adrian "not so balls-of-steel" Beltre - Probably the hardest working guy on the team.

Honorable Mention - Ken Griffey Jr. - Even though he sucks most of the time, its amazing how any time he comes up in a crucial situation, I nearly stop breathing.
Best "Hans" - Hannahan and Langerhans!

Back to blogspot! + XM radio renovation

I've decided to take my blog back to blogspot. I was writing it and uploading it myself using iWeb, but then I could only write when I was around my laptop, and you couldn't leave comments! So for my loyal fan (singular, you know who I'm talking to), I've switched it over to here. I still plan to advertise on facebook anytime I post, and I'll point my old blog here.

So, to kick things off, I drove down to the Apple Store* in Houston today after work to pick up my laptop. I took it there yesterday morning on the way back from the airport (after a weekend in BoMo, congrats B & B) because it would click anytime the sudden motion sensor engaged. This might not seem serious, but it is hyper-sensitive, so that anytime it even shifts on my lap (like when I typed this last sentence), I hear "click." Anyways, according to Apple, this is "normal", which I guess means I get to look forward to hearing this clicking sound for the next three years.

*Among the bad things about College Station is its lack of an Apple Store. They may tell you Mac Resource will fix your stuff, but they would be lying, and then you'd be out $75.**
** Yes, I stole this asterisk/footnote thingy from the infamous Joe Posnanski (see Joe's Blog, especially the Yuni posts).***
*** Don't you just love footnotes? They say "I want to say something, but I'm too lazy to reconfigure this sentence around it. "

So I'm driving back, wondering why Jasmine is trying to sleep sitting up in the passenger seat (she really doesn't like driving in my CRV, but for some reason she was too afraid to move to the back seat), and I'm flipping through my XM stations, and I come across channel 25, which is called "The Blend", but might as well be called "Rod Stewart and Phil Collins lull you to sleep" because I swear they are always on. So instead of flipping past it, I decide its high time to redo my XM presets (who needs to watch the road anyways). After flipping through all 247647563 channels, here are my top 10 which I've saved:

Channel 9: "The 90's" - because I need me some MC hammer every now and then. Plus, its only one click from channel 8, "The 80's" (nice numbering scheme XM!).

Channel 20: "20 on 20" -

Channel 21: "Kiss" - Nope, not the band, but the national station. I think their motto is "why wait through 19 songs to hear your favorite song when we'll play it every 19 minutes?"

Channel 22: "The Mix" - I don't really know what it is, but I think Pink plays them to always be playing one of here songs whenever I visit it (yes, I'm that important).

Channel 24: "The Pink Channel" - Believe it or not, this is different to the previous channel, as the pink actually denotes it supports breast cancer research. This is the station that replaced "Rod Stewart 24/7", and I don't even remember what it was playing. I think I kept it since I didn't have to go far to find it.

Channel 26: "The Pulse" - I guess its guaranteed to keep me alive.

Channel 44: "1st Wave" - I don't know what that means, but its probably my favorite of the rock stations.

Channel 47: "Alt Nation" - Rivaling Colbert nation

Channel 49: "Classic Rewind" - Who doesn't love classic rock.

Channel 53: "Boneyard" - Jay Buhner!

Channel 54: "Lithium" - A trace amount of this was created in the Big Bang.

Channel 58: "E Street Radio" - Because I love hearing Max Weinberg in the car.

Stations that got the ax:
Channel 25: "The Blend" - for aforementioned reasons.
Channel 176: "MLB Play-by-play" - I know where it is when I need it, same for:
Channel 193: "Pac 10"

So, if you're bored enough you've read all the way to here, what are your favorite XM stations? Is there anything I'm missing? Let me know.