Hey Space Placers!
Here's Part 2 to yesterday's blog on AAS highlights.
Supermassive Black Holes in Dwarf Galaxies
It was a bit of a surprise to learn that dwarf galaxies - galaxies that are much smaller than galaxies like our own Milky Way - harbor supermassive black holes. What was even more of a surprise is that no one had ever looked before to see if this was the case. The prevailing belief was that only big galaxies could have massive black holes at their center. A large sample review of dwarf galaxies found over 100 of them had black holes at their center. This definitely changes the landscape on black holes and galaxies. I look forward to more research findings.
Speaking of Dwarf Galaxies, Hubble Space Telescope (HST) Finds Ancient Dwarfs
HST has found the "Holy Grail" of ancient dwarf galaxies suspected to exist but never imaged, until now. In a deep (i.e. long exposure) photograph taken by HST in ultraviolet light 58 dwarf galaxies at a distance of over 10 billion light years were found thanks to a cosmic magnifying lens. Using a massive cluster of galaxies to act as a gravitational lens - a byproduct of general relativity wherein objects behind the gravitational lens can be seen due to the bending of background light by gravity caused by the mass of the cluster - these dwarfs were found. Long suspected as being 100 times more numerous than galaxies like our Milky Way Galaxy, but 100 times dimmer, they have been elusive to detection until now. These dwarf galaxies were imagined as they looked when the Universe was only 3.4 billion years old and undergoing an intense period of star formation. In addition, astronomers believe that these dwarf galaxies are only the tip of the cosmic iceberg because they are the bright ones and many more existed that were too dim to be seen. The most amazing finding to me is that these dwarf galaxies are thought to be responsible for the majority of stars born at that time in the Universe.
Exoplanets and Brown Dwarfs
There were many poster papers, presentations and press releases devoted to exoplanets - planets beyond our solar system - and brown dwarfs - failed stars that were too small to initiate nuclear fusion to become stars. I have followed both topics closely and covered a brown dwarf observing run in 2003 at the 200-inch Hale Telescope. My, how far we have come. The hope in 2003 was to directly image a brown dwarf, which has been done. Now, astronomers are detecting clouds in the atmosphere of brown dwarfs and getting an idea as to atmospheric conditions on these fascinating objects.
A really exciting development was the unveiling of a new and powerful camera designed to directly image exoplanets - the Gemini Planet Imager. The latest from NASA's planet hunting spacecraft, Kepler, was fascinating as well.
Weather on Other Worlds (WOW)
This was a fascinating subject at AAS as astronomers can now detect clouds and weather on brown dwarfs and some exoplanets. My good friend of many years, Dr. Stanimir Metchev, a principal investigator for WOW using the space-based NASA Spitzer Telescope, headed up an international team to study brown dwarfs. Their conclusion based on observations with Spitzer is that most, if not all brown dwarfs have clouds and storms. The research capability will only grow as larger telescopes and better imagers and techniques come on line which will mean even better data. A lot of people are working in this area and I expect we will see some amazing results in the coming years.
American astronomy is dealing with funding issues as is everybody else. But there are a number of large telescopes coming online in the future and international collaboration is the name of the game as evidenced in the authors of many of the papers and posters. There are over 7,000 professional members of AAS and about 50% of them are women which is a wonderful change from years gone by. Youth is also prevalent in the AAS, or at least for those who attended this AAS meeting - about 3,000 people. Many of them are social media connected and enthralled with what they are doing. I just hope the pipeline continues to be replenished by up and coming astronomy students.
Sky Guy in VA