Show Notes: March 26th, 2013 UTC
Hosts: Paul, Jesse, Lianne
Title: The Sequester Walks The Planck
A little extra time on the show tonight allowed us to pontificate on the political strife in the United States. The sequestration has caused a massive amount of public funding cuts, including NASA public outreach and education. Of course the Planck Telescope delivers its news that Universe is slightly older than we once thought. Paul, ‘the dean,’ gripes over his failing Aussie cricket team (but mostly off-air). Astronomy Night in Canada starts with York Universe, thanks for listening! See our show notes and podcast below.
Tonight’s hosts are Jesse, Lianne and Ryan! We’ll be chatting about Planck’s new data release, Europa’s salty ocean, water detected on an Exoplanet, and much more! Tune in at 9pm EDT (1am UT) using the link on the home page, or as always at Astronomy.FM!
Okay so 100 million years seems like a big mistake on the part of Astronomers, but in the astronomical community its a small adjustment.
Today the most detailed map of the CMBR ever captured was released by the Planck telescope group at the ESA. Based on 15.5 months of data, it shows the tiny temperature variations that were present when the universe had a temperature of 2700 degrees Celsius and an age of just 380,000 years (trust me that’s small on astronomical scales). This is the point when the dense soup of protons and electrons formed hydrogen atoms, and the universe became transparent.
As the universe has expanded the light has stretched out to microwave wavelengths and now has a temperature of 2.7 degrees above absolute zero, -270 Celsius The tiny temperature fluctuations on the order of millionths of degrees visibly correspond to the structure that would eventually map out the structure of galaxies and galaxy clusters throughout the universe.
The estimate of the age of the universe is now more precise as well, since the CMBR measurements give precise constraints to the Hubble constant, used in the Lambda-CDM model of the universe to generate the time passed since the big bang. The adjustment brings the universe’s age to 13.82 billion years, 100 million years older than previously thought. This seems like a large difference, but as I said before, on astronomical scales we were in the right zone so its not too surprising.
However, some surprise did arise from the new map, pointing to the (known) conclusion that we do not understand the universe on larger scales. On small scales the standard model is correct, which says that CMBR temperature differences are caused by random quantum fluctuations, but on large scales this model falls short, suggesting that there is more to the big picture of understanding the universe. One such shortcoming is that a cold spot in the CMBR is much larger than expected from the standard model.
This is not a big surprise however, as physicists are aware that more theory is needed to explain the universe, since the standard model can’t explain either dark matter or dark energy, the two largest sources of’stuff’ in the universe.
Let’s think about that for a second. We have no clue what most of the universe is made of. And we don’t even have a really complete picture of the stuff we do know. Astronomy and Cosmology are still wide open fields.
Show Notes: March 19th, 2013 UTC
Title: Exploding Stars and Life on Mars?
Hosts: Jesse, Ryan, Lianne
Tonight’s episode was the 145th episode of YorkUniverse! good job team! This week in history was the anniversary of the first ever human space walk by Alexei Leonov back in 1965. Cmdr Chris Hadfield has officially taken over as the commander of the ISS. We also chatter about the origins of Cosmic Rays and a very unique supernova. Make sure you check out the Lunar Orbiter Recovery Project (links below). Thanks for listening Everyone.
…but that’s not the really cool news. The cool news resides in ALMA itself!
The past week this headline (or variations of it) has been floating around the twitter-verse. And, while this headline is cool, I don’t think it addresses the awesome-ness of the topic.
To stat, the Atacama Large Millimeter/Submillimeter Array (or ALMA) is an array of radio telescopes in the Atacama desert of northern Chile. This array consists of 66 12-meter and 7-meter diameter telescopes observing at the millimeter and sub-millimeter wavelengths. Due to the large number of telescopes this array contains, it has a much higher sensitivity and resolution that the existing telescopes of it’s kind (James Clerk Maxwell Telescope, Submillimeter Array, etc.).
The main science goals of ALMA as as follows (from their website):
- The ability to detect spectral line emission from CO or [CII] in a normal galaxy like the Milky Way at a redshift of z=3, in less than 24 hours,
- The ability to image the gas kinematics in protostars and in protoplanetary disks around young Sun-like stars in the nearest molecular clouds (150 pc),
- The ability to provide precise high dynamic range images at an angular resolution of 0.1 arcsec.
To summarize the first of the science goals above, ALMA will be used as a tool for studying star-formation in galaxies billions of years in the past. So, due to their distance away, most of the light from a wide range redshifted objects are observed in the millimeter and submillimeter wavelengths. Due to the unprecedented sensitivity and resolution of this telescope, it’s projected to offer a fantastic look into the distant universe to reveal loads about star-formation in the distance universe.
And, following this, ALMA became operational this month (March 2013) and though it is not fully operational has already released some very interesting results!
The new survey announced the observation of the most distance star-forming galaxy at 12.65 billion light-years (z = 5.7) as well as additional observations of a large number of other star-forming galaxies at high redshifts. These discovers are not out of the blue. An international team of researchers first discovered these distant star-forming galaxies with the National Science Foundations 10-meter South Pole Telescope (SPT; observes in microwave, millimeter-wave, and submillimeter-wave wavelengths), though an independent observation of redshifts was needed. ALMA provided a followup observation of these galaxies in order to preform an accurate redshift calculation of these sources.
The observation of these galaxies was made using gravitational lensing where the light from a distance galaxy is able to be observed due to the presence of a foreground gravitational source (such as a galaxy). Below shows a schematic for such an event.
The light from the distant object is both distorted and magnified due to the gravitational force of the foreground object. The background object forms an Einstein ring around the foreground object. Astronomers are able to correct for the magnification and distortion to calculate various properties of the galaxies.
Of the galaxies found by the SPT, ALMA imaged 47 galaxies and collected spectra on 26. Due to the sensitivity of ALMA, astronomers were able to calculate the redshift of these 26 galaxies straight from the spectra rather than relying on independent visual or IR observations from other telescopes (which is not always possible due to the due to the dust obscuring the galaxy). Because of it’s precision it’s able to detect much more faint spectral lines and be able to determine the redshift out to these galaxies without requiring any multi-wavelength identifications!
From the spectra, ALMA was able to detect strong carbon monoxide lines (CO) in the spectra of these galaxies indicating intense star formation in the galaxy. These results were surprising as only a few starburst (intently star-forming) galaxies had been detected at these distances. It is still not clear how these galaxies could produce stars at such a furious rate so early in the Universe as these galaxies are forming 1,000 stars per year (for comparison the Milky Way galaxy has a star-forming rate of about 1 star per year). Overall, these discovered galaxies may be what today’s massive galaxies looked like in the past. These galaxies create stars many thousands of times faster than galaxies like our own!
Also, many of these galaxies have shown emission form water molecules, which is the most distance detection of water in the universe to date! How neat is that?!
They also found a higher sample mean redshift for these sources. Previously this value was found to be at z = 2.3 (10.76 Gyr), but new study has found the redshift mean to be at z = 3.5 (11.83 Gyr). This indicates that previous samples were biased towards lower redshift galaxies and may have missed a large fraction (≥ 50%) of these galaxies at redshift z>3.
This data is one of the first (if not the first?) data being released from an operational ALMA. And though it is only using 16 of its 66 planned telescopes and is only focusing on brighter galaxies, this study has almost doubled the number of star-forming galaxies seen at high redshifts (within the first 1.5 billion years of the universe). In addition, these observations only took 2 minutes to take, about one hundred times faster than before! Previously, a measurement of redshift for these sources would have to combine data from both visible-light and radio telescopes.
So more than the result, this study shows the capabilities of ALMA and the potential for exciting results to be found in the future. Due to its unprecedented resolution and sensitivity, this telescope should lead astronomers to understand much more about the formation of the early universe.
Well, after much scrounging around I managed to locate comet PAN STARRS in the photos from the plane back from Vancouver.
I really wouldn’t be surprised if you don’t believe me. It took a good hour to confirm what I was looking at, and really this just looks like background noise from my camera…BUT, I checked several images as well as the comets position using various astronomy programs. So this indeed is the correct position of Comet PAN STARRS on March 12, 2013. If you look carefully you can just make out the faint tail from the comet. But, that could just be my eyes playing tricks.
Also, sorry for the blur! Apparently, it’s hard to take clear photos from a large moving object.
Tonight co-hosts Ryan, Jesse, Pat (and maybe Lianne) will be discussing new data from the Curiosity Rover about the possibility of conditions for life in the past, Astronomers find unique supernova, Overwhelming proof that Cosmic Rays are indeed created by Supernovae and much much more!
But, if you miss our live broadcast you can still tune into our re-runs on Astronomy.FM every 4 hours on Astronomy.FM or listen to our podcast published here after the show!
Just a quick post about the comet that’s travelling through out skies right now. While I was on the plane from Vancouver on Tuesday I was fortunate enough to have a fabulous view of the setting crescent moon. As the moon was only about 1% illuminated, the effect was stunning. And, as we talked about on York Universe on Monday night, the comet Pan-STARRS was supposed to be very close to the moon. Unfortunately, I couldn’t see it naked eye (though I spent about 1/4 of the trip craning my head backwards towards the moon). I did manged to take a horribly noisy photo of it with my camera. I’ll post this photo up when I get home tonight, though really it’s even hard to make out in this.
Tonight is supposed to be clear so I’ll take my nice 10″ scope out and hopefully get a much cleaner view of the comet!
Clear skies all!