Presented by: Jamie Todd ƒ What is a maser? ƒ Optical Amplifier ƒ Astrophysical Masers ƒ Star Formation ƒ Megamasers ƒ Dasars ƒ Summary ƒ Gas is heated causing particle excitation

ƒ Excited molecules are funneled into a resonant cavity

ƒ The spontaneously emitted photons cause stimulated emission from excited molecules

ƒ Excited photons reflected inside a chamber

ƒ Gain exponentially related to resonant cavity length

ƒ There is no resonance cavity

ƒ The radiation enters from a source (star, black hole, etc.) and travels through the gain medium in one pass

ƒ The particles in the lower energy levels are excited though quickly drop to the lower energy level, emitting radiation at the same frequency

ƒ Masers mark the formation of young stars

ƒ As the star begins to spin bipolar outflow occurs

ƒ Circumstellar Disk ƒ H2O and OH

ƒ Shock Front ƒ Can put out as much or greater energy as the Sun –all at single spectral line! ƒ Most powerful are water masers

ƒ Size of or greater than Solar System

ƒ Accretion disk around black hole

ƒ Masers from center and edges ƒ Allow size and rotation to be measured

ƒ Dates existence of water to much earlier than predicted ƒ Formaldehyde de‐excited by collisions

ƒ Absorbs background radiation

ƒ Darkness Amplification by Stimulated Absorption of Radiation ƒ Masers reveal the composition of certain ƒ OH regions of space ƒ CH

ƒ H2CO ƒ They can be used to date the existence of certain molecules ƒ H2O

ƒ NH3 ƒ Masers exist in specific environments, many of ƒ CH3OH which were theorized not to exist naturally ƒ SiS

ƒ Reveal certain areas invisible to regular ƒ HC3N telescopes such as galactic centers ƒ SiO

ƒ HCN

ƒ H ƒ Masers were created over 50 years ago and were thought not to be a natural occurrence

ƒ Astrophysical masers discovered two years after first artificial

ƒ Astrophysical maser is a region of gas which amplifies microwave radiation through stimulated emission

ƒ Tell us of the environments in different areas of space, from young stars, to comets, to super‐massive black holes

ƒ Allow us to date the existence of certain molecules

ƒ Allow the measurement of distances to other galaxies as well as their speed and acceleration ƒ Fundamentals of Photonics,

ƒ How the Laser Happened: Adventures of a Scientist, Charles H. Townes. Oxford University Press. 1999

ƒ Masers, Jerome R. Singer, 1959

ƒ Interstellar hydroxyl and water masers and formaldehyde masers and dasars, D ter Haar and Margaret A. Pelling

ƒ Wikipedia, The Free Encyclopedia, www.wikipedia.org