Astronomy problems Technology Coursework Research Paper

(3 pts: qualitative)
Briefly discuss what each of these features tell us about an individual circumstellar disk/young star in which they are seen:
- Black body spectrum with UV excess
- Black body spectrum with infrared excess
- Black body spectrum with infrared excess but with a drop in the SED at near-lR wavelengths.
(3 pts: quantitative and qualitative)
Draw an example SED for a star of one solar mass with temperature T = 5800K with a young (i.e., not yet photo-evaporating) gaseous protoplanetary disk surrounding it. Label both axes clearly. The values on the y-axis do not concern us here - focus on the shape of the SED and values on the x-axis! Mark the peak wavelength (or frequency) of radiation that you, as a human, are emitting. (Hint: what does Wien’s Law tell us?).
(4 pts: qualitative)
The vertical distribution of gas in a PPD is determined by hydrostatic equilibrium.
(a) This is an equilibrium between which two main forces? In which way do these forces point? Arc there any other forces you can think of that could contribute to this equilibrium and possibly change the PPD vertical structure?
(b) Starting with the equation of hydrostatic equilibrium and knowing that the vertical component of gravity felt by a gas particle is gz = fi2z, derive the vertical density profile of a PPD. You may assume that the disk is vertically isothermal and that the pressure within is related to density through the sound speed: P = pcf.