Molecules in space Flashcards
Preservation of bacteria in bees in amber
-Bacteria turned into spores to protect themsevles
- When placed in culture they cam back to life
- 40 Million yrs ago
Density of H atom in ISM
One atom per cubic-metre
What happens to H atoms in ISM?
Heated by UV radiation and move fast so bonding is hard.
UV disrupts bonding
Where is creating molecules easy?
Giant Molecular Clouds
How big are GMCs
150 light years across
How long do GMCs last?
10 to 100 million years
How do GMCs help molecule forming?
Grahphite dust shields from UV light and acts as catalyst by providing a surface for atoms to meet.
How close do atoms need to be to react?
1 nanometre
What are most of the molecules in GMCs?
Molecular hydrogen and Carbon monoxide
How to infer level of Hydrogen?
Detect CO radio emissions
Why can CO emissions be used to detect H2?
CO emissions caused by colliding H2 molecules.
Increasing density of H2 gas causes more collisions with CO and increase in emissions
What makes it possible to detect molecules?
Molecules emit and absorb radiation at specific frequencies so look at radio observations
What tool to use to detect molecules?
Masers - microwaves amplification by stimulated emission of radiation
Detect OH molecule first
Why do masers detect OH first?
OH needs very little energy to form compared to H2 and O2
What is telescope is used to detect molecules?
ALMA in northern Chile
66 radio telescopes at 5km
Observes in mm and sub-mm wavelengths
