An Extreme Ultrviolet imager telescope is used to observe the sun and corona.it has four filters which are sensitive to different wavelenghts of UV radiation.These are:
filter:
17.1nm
19.5nm
28.4nm
30.4nm
Question:
which filters are most likely to be of most use in mapping coronal holes and why?
which filter is most likely to be of most use in mapping the solar transition region?
explain why the sequence of filters 17.1, 19.5 and 28.4 nm represent a sequence of incresing temperture of emitting regions
thank you very much
To determine which filters are most likely to be of most use in mapping coronal holes, we need to understand the nature of coronal holes and the specific wavelengths of UV radiation they emit.
Coronal holes are regions in the Sun's corona where the magnetic field lines extend out into space, allowing high-speed solar wind to flow out. They appear as dark areas in ultraviolet and X-ray images since they emit less radiation compared to the surrounding regions. Coronal holes are also known to have lower temperatures compared to the surrounding plasma.
Based on this information, the filters that are most likely to be of most use in mapping coronal holes are the ones that are sensitive to lower temperature UV radiation. In this case, the 17.1nm and 19.5nm filters are the most appropriate choices. These filters are designed to specifically detect UV radiation emitted from relatively cooler regions of the corona, which is where coronal holes are likely to be observed.
Moving on to the filter most likely to be of most use in mapping the solar transition region, we need to understand what the solar transition region is. The solar transition region is a region in the Sun's atmosphere where the temperature rapidly increases from about 10,000 Kelvin in the photosphere to over 1 million Kelvin in the corona.
To map the solar transition region, we need a filter that is sensitive to the specific wavelength of UV radiation emitted in this temperature range. Among the filters mentioned, the 30.4nm filter is most likely to be of most use for mapping the solar transition region. This filter is designed to detect UV radiation emitted from plasma with temperatures in the range of the transition region.
Lastly, to understand why the sequence of filters 17.1nm, 19.5nm, and 28.4nm represent a sequence of increasing temperature of emitting regions, we need to know the temperature dependence of UV radiation emitted by different plasma regions in the Sun's corona.
Generally, higher temperature regions emit higher energy UV radiation, which corresponds to shorter wavelengths. So, as we move from the 17.1nm filter to the 19.5nm filter, we are shifting to slightly higher temperature plasma regions. Similarly, when we move further to the 28.4nm filter, we are detecting UV radiation emitted from even higher temperature regions.
Therefore, the sequence of filters 17.1nm, 19.5nm, and 28.4nm represents a sequence of increasing temperature of emitting regions because they are designed to detect UV radiation emitted from plasma regions with progressively higher temperatures.
I hope this explanation helps! Let me know if you have any further questions.