CephC-LABS Question log
(Questions for march 15)
(the next week should always be on top)
Questions for March 8
LMR example question: Where did you guys find the graphic that shows the entire Ceph OB3 region? LMR example answer: In the Sargeant 1977 article. That's the discovery paper that named Ceph C, Ceph C. It's in the Box drive, in the papers directory, in the "maybe less relevant" subdirectory.
From Sam: Here are my questions...sort of a flurry all related to what the data we're going to be analyzing means...
So if a picture is just an array or grid of numbers that get assigned colors...What do those numbers represent or mean? Number of photons collected? The total energy of the photons collected during the collection window? Can multiple sources in the field of view send photons to a single pixel? How do we know which source sent the photons to each pixel?
I can learn more about HOW each pixel turns the collected photons into a number later, but I am just curious about WHAT the pixel does with the collected photons and what it outputs. In other words, what does the raw data we will be working with represent? What do the FITS file numbers mean? I imagine that a pixel collecting 5 high energy photons could feasibly give the same 'output value' as a pixel that collects 10 lower energy photons...assuming it is able to collect and count photons of different energies and filters weren't involved (even though they usually are). The material in the CCD probably only responds in certain ways to certain photon energies...hmm.
Response from Tom: The photons that are being collected have passed through a filter so they are of approximately the same energy-- the ones with too little or too much energy (they are the wrong "color") don't make it through the filter and so aren't detected. This filter may be a physical filter in front of the detector or it could be a limit of the detector itself.
From Olivia: I would like Tom to share with us the logistics of bringing students into the project. What kind of information did you initially share with them? Was it all done during your Research class?
Related to Sam's train of thought: energy per photon of IR is going to have less energy than photons of visible light, UV or X-rays - does this matter?
Response from Luisa (stuck on iPhone): energy of photon given by h*nu where h is Planck's constant and nu is frequency of light. So yes, bluer=more energy. If you want to make an X-ray detector you have to think (design, etc) differently than for FIR detector. This is why light detected very differently across EM spectrum.
