Show Notes for April 16, 2013 (UT)
Hosts: Ryan, Jesse, Lianne
Title: Stars Will Find a Way
Paul takes a rare (and much deserved) night off from the York Universe broadcast. Dark matter has been all over the major news outlets; we chat about the recent AMS and SuperCDMS data, and their hints at dark matter. It appears Dr. Ian Malcolm was right (…sort of), ALMA has found stars forming close to Sagittarius A* (our Milky Way’s supermassive black hole), and CFHT has helped discover stars forming in the tidal tail of galaxy being torn apart. Ryan’s ‘What’s the latest?’ podcast debuts tonight! You should check it out. Thanks for listening everyone. Show notes and podcast below.
NOTE: We go live at 8 pm EDT (Tuesday at 12 am UT ) next week! So make sure to tune in!
This week in space/astronomy history:
1. April 11-17 1970: Apollo 13 – USA Lunar Flyby
2. April 15,1867: Wilbur Wright was born
3. April 14, 1629: Happy Birthday Christiaan Huygens
1. A coronal mass ejection (CME) hit Earth’s magnetic field on April 13th
‘The magnetic field of sunspot AR1719 erupted on April 11th at 0716 UT, producing an M6-class solar flare. NASA’s Solar Dynamics Observatory recorded the explosion’s extreme ultraviolet flash’
2. Dark matter SuperCDMS has 3 sigma detection of possible dark matter particle
http://www.science.tamu.edu/articles/1052 – press release
– Old data from an unused detector – researchers decided to look at the data due to increased interest in the low mass WIMP region.
http://cdms.berkeley.edu/CDMSII_Si_DM_Results.pdf – paper
3. WALLOPS ISLAND, Va. — NASA’s commercial partner, Orbital Sciences Corporation of Dulles, Va., is scheduled to launch its first Antares rocket from Mid-Atlantic Regional Spaceport Pad-0A at the agency’s Wallops Flight Facility on Wednesday, April 17.
4. NASA has a new proposed budget
http://www.nasa.gov/news/budget/index.html – NASA
http://www.slate.com/blogs/bad_astronomy/2013/04/11/nasa_budget_increase_for_asteroids_cuts_for_planets_and_education.html – Phil Plait OpEd
TUNE IN NEXT WEEK!
5. Mars comet in 2014 ruled out as ‘non impacting;’ check out the Universe Today article
6. Plug for Ryan – ‘What’s the latest?’ Premiere tonight between YorkUniverse and WW
To request shows – visit Ryanmarciniak.com, or comment on the yorkuniverse.com website.
7. Promo for next week 150th episode – 8pm to 10pm (00:00 to 0200 UTC)
Major Topics Discussed:
1. First Results from the Alpha Magnetic Spectrometer
The AMS is the most powerful and sensitive particle physics spectrometer ever deployed in space. The detector was deployed on the ISS in May 2011, the last shuttle flight, to detect Cosmic Rays (see the show notes for our ‘Exploding stars and Life on Mars?’ episode for more on cosmic rays). The collaboration, of 16 countries and over 600 physicists, released their first set of results since deployment.
The grouped analyzed over 25 billion cosmic rays, of which 6.8 million (or 0.03% of the events) were identified unambiguously as electrons and positrons. The AMS observed over 400 000 positrons, with no significant variation in time or direction. The results are consistent with that flux expected from annihilation of dark matter particles, but also cannot rule out astrophysical sources yet. More time collecting data, specifically at the higher energy end will most likely allow stronger constraints.
The AMS may also be noted as AMS-02. It is the second generation. The first, or the prototype AMS-01, flew aboard the Space Shuttle Discovery on STS-91 in 1998. AMS-02 was tested at CERN before flown to be installed at the ISS. Estimates place cost at $1.5 billion.
The detector has two major goals: to directly look for anti-matter, and to look for evidence of dark matter.
By measuring the amount of anti-matter through cosmic rays, AMS is making an independent and direct measurement of the available anti-matter. Anti-matter is the same as matter, but opposite in charge.
AMS is directly looking for the positrons, antiprotons, or gamma rays. The presence of these may indicate neutralinos (dark matter) are colliding in space. However, there are other sources of these.
2. ALMA detects star formation near Sag A*.
Astronomers have discovered star formation at a very small distance from Saggitarius A*, the super massive black hole that resides in the centre of our Milky Way. ALMA, the Atacama Large Millimeter Array, has observed collimated jets bursting out of what appear to be dusty-gaseous regions. This observation, in any other place, would be taken as an indication of star formation. Perhaps the turbulent region around the SMBH has allowed dense regions to exist long enough to begin star formation.
Specifically, ALMA was used to trace the molecule Silicon Monoxide (SiO), which is an excellent tracer of molecular outflows. When excited, SiO cascades through its orbital energies in a very predictable way. This may help answer the question of why there are stars so near to our SMBH.
Canada is a part of the ALMA collaboration!
3. Blue supergiant found in a tidal stream
Our understanding of how stars form is that a giant molecular cloud, also known as a ‘HII region,’ collapses down to form groups of 100s to 1000s of stars. These are known as Stellar Nurseries; the Orion Nebula (M42) is a good example of this phenomenon. Astronomers Taiwan and India, have found a blue giant star that did not form in a giant molecular cloud, but in the tidal stream of a galaxy in the middle of a galaxy cluster.
The Virgo cluster, located about 55 million light years away, holds approximately ~1500 galaxies; the local group (MW+Andromeda and outliers) is considered part of this cluster. Inside of a galaxy cluster, the region between galaxies, there is large amounts of super heated gas, usually seen in the X-ray. This gas has been stripped off the cluster galaxies as they have orbited the cluster.
Galaxy IC3418 is currently plunging through the Virgo cluster, being pulled apart as it does. A long tidal stream results, tracing the path of IC3418. It is in this tidal stream that the astronomers noticed a blue giant star had formed. There were no tell-tale signs of giant molecular clouds, meaning this star formed in an entirely different way.
Starting 8 pm EDT 12 AM UT
Thanks for listening!
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