Deep Space Imaging: Invisible Light and Gaseous Composition
This will be another blog post about a project from school. This one goes way back, to chemistry class in high school. In all honesty, I don’t quite remember what the assignment was for this project. I know our professor was going to be away at a conference, and I believe we were told to just pick anything related to the course material, create a presentation (and maybe a short paper?), and present to the rest of the class.
For this project, I wanted to learn a bit more about how visual astronomy gathers information from celestial objects. In the class, we had just finished discussing atomic energy levels, which I knew connected back to emission lines and spectral analysis.
Here’s a question, to which you’ll see a more in-depth answer when you read the slideshow. What do the following three images have in common?
The answer is that they all take advantage of human’s trichromatic vision to show new information. Image one, the bow, is the first color photograph ever produced, overlaying red-, green-, and blue-channel images to so we can perceive all of the colors present. The second and third images follow the same principal, although by giving different “data” for the colored channels to represent. In the image of the Horse Head Nebula, the channel displayed as red actually represents Hydrogen Alpha’s emission band. The final image, of the black hole in M87, uses these channels to make radio-wave data perceptible in an image for humans.
While the ability to isolate wavelengths and image outside of the visible spectrum is impactful for visual astronomy, and production of images, it is incredibly beneficial for practical analysis of celestial objects. The ability produce images like these is a result of the development of spectroscopic analysis; wherein emitted light can be used to understand the composition of stars.
While the presentation was kept to a lot of simpler information pertaining to image creation, in doing the research for it, I got to read more about some of the specifics of how spectroscopy is used in astronomy, and the complications that arise. The curiosity and questions that arose from this are finally things that I have been able to begin exploring again in courses like PHYS 0202: Intro to Quantum, and PHYS 0255: Intro to Astrophysics.