Chenoa Tremblay
Atoms have existed in our Universe from shortly after the Big Bang, 13.7 billion years ago. The observation and study of atoms and molecules plays a critical role in understanding many physical processes within our Universe. By observing signals from atoms and molecules we can study the dynamics and existence of dust, ice, and gas throughout the history of the Universe, in environments unachievable in the laboratory. My work focusses on using a new generation of radio telescopes designed to observe frequencies from half that of your microwave (~1GHz) to below the frequency of your car radio (~70MHz).
Since the first interstellar molecules were discovered with radio telescopes in the 1960s, the technology within our telescopes has greatly improved. By utilising innovative technology built into CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP), the Parkes 64m telescope, and the Murchison Widefield Array (MWA) we can start studying the dynamical processes within our Galaxy in unprecedented detail in a frequency range that has rarely been explored. This poster explains some of the motivation of this work.
Dr. Chenoa Tremblay
CSIRO Postdoctoral Fellow
Follow on Twitter @Chenoachem
One of the challenges astronomers face is we don’t know how stars and galaxies form. However, through the use of molecules we can start to study their live cycle, motions, age, size, and activity. In my work I am using a group of Australian telescopes to look for new molecules and study them in new ways.
The three telescopes in particular I use are the Murchison Widefield Array (MWA), the Australian Square Kilometre Array Pathfinder (ASKAP), and the Parkes 64m Telescope. The Parkes telescope is a single, large, concave radio dish that studies a wide range of astronomical objects. Similar in shape, but smaller in size are the thirty six concave radio dishes that make up ASKAP. The MWA looks completely different. The MWA is made up of a 4096 four-legged spider-shaped dipoles antennas, each that are 50cm tall. These dipole antennas are arranged in a 4 by 4 grid, called a tile, and there are 256 tiles spread out over 5.5km in Western Australia.
Each one of these telescopes have different strengths and weaknesses. By combining these three to study molecules in space we can:
1. Study star formation; stars >8 times the size our sun are the main source of chemical elements in our Galaxy.
2. Look for indication of life:
• Search for complex or bio-molecules.
• Study why we see more organic than inorganic molecules.
3. Ask “are magnetic fields important for stars to form”?
Our view of the sky changes depending on the telescope we use.
The MWA give us large panoramic views with a single pointing of the telescope to observe many objects at once. The trade-off is that we don’t see each object in a lot of detail. The Parkes telescopes gives us amazing sensitivity to the diffuse radiation in our Galaxy. ASKAP has a unique design feature that allows us to look at objects in great detail but also covers a larger field-of-view than most traditional radio telescopes. Not only are they all unique in how they view the sky, they are sensitive to different molecular activity as well. So by using them together we can get a better understanding of our Universe.
Radio signals are important as they are not blocked by the Earth’s atmosphere, they allow us to peer through the dust layers in our Galaxy, and we are looking at molecules that are sitting within the gas layers around astronomical objects like stars. When molecules are spinning in space they are bombarded with energy from nearby stars. Each time the molecule is hit with the energy it changes its speed and produces a signal that can travel to our telescopes. Each molecule gives off energy that it unique to itself, like a fingerprint, so we can identify what it is and study the profile of that fingerprint to tell how fast that gas is moving.