Physics Team Drs. James & Sarah Higdon Study Star Formation in Galaxies
HST color images of ring galaxies AM 0644-741 and Arp 147 currently being observed with ALMA. The blue rings indicate high rates of star formation, triggered by the collision with a companion galaxy. They are, respectively, 300 and 430-million light years distant.
A study by James & Sarah Higdon investigating the peculiar star formation law of the Cartwheel ring galaxy was accepted for publication by the Astrophysics Journal Letters. Data obtained with the Atacama Large Millimeter Array (ALMA) telescope, located high in the Chilean Andes, played a crucial role in this research. They have been invited to present these (and other) results at a special ALMA workshop organized by the National Radio Astronomy Observatory (NRAO) in Charlottesville, Va. in April.
The Ataama Large Millimeter Array (ALMA) is an interferometer array operating at millimeter and sub-millimeter wavelengths. Signals from the (currently) 45-telescopes in the array are combined to provide detailed images and spectra of forming solar systems, dusty star forming regions, colliding galaxies, and young galaxies in the early Universe. Since light at these wavelengths are attenuated in passing through the Earth’s atmosphere (mainly water vapor) ALMA was built at an elevation of 5,000 km (16,400 ft) above sea level.
They were also recently awarded additional observing time with the ALMA telescope to study cold molecular gas in two additional ring galaxies (AM0644-741 and Arp 147) to gain further insight into star formation in extreme environments.
The Higdon’s and their collaborators at Cornell University were awarded time with the Karl Jansky Very Large Array (JVLA), the premiere radio telescope in the world, to probe star formation in galaxies in the very distant universe, corresponding to an epoch only 3.6-billion years after the Big Bang.
In addition, they were also successful in being awarded observing time with NASA’s SOFIA (Stratospheric Observatory For Infrared Astronomy), an infrared telescope mounted in a converted Boeing 747. Our group will be studying star formation in the core of the “nearby” (35.5-million light years) spiral galaxy M 83. Both the JVLA & SOFIA observing proposals were written while visiting Cornell University over the Summer 2015.
The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a modified Boeing 747 outfitted with a 2.5 meter diameter reflecting telescope plus cameras and spectrographs that operate at infrared wavelengths. SOFIA observes faint emission from planets, star forming regions, and distant galaxies from an altitude (42,000 ft) above most of the absorbing layers of the Earth’s atmosphere.
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