1. Tycho’s SNR – Obs ID 115 ds9 analysis by Matt P. & Leah S. PURPOSE: To use ds9 software to analyze the X-ray spectrum of the Tycho Supernova Remnant, determine the elements present, and investigate the distribution of these elements in the remnant.

2. HYPOTHESIS: What elements do you expect to find? Where will the heavier elements be found in the remnant? Where will the light elements be? Explain your reasoning. I think the lighter elements will be around the middle and edge of the remnant and the heavier ones will be in the center mostly, and also distributed throughout the rest of the remnant because the heavy elements will blow out farther than the lighter ones and the lighter ones won’t be ejected as much, they’ll only move a little. (Leah s.) My hypothesis is based upon evidence that white dwarfs which eventually become supernovae are primarily comprised of carbon oxygen and helium. I expect that these elements will be present, but that other, heavier elements will also be formed by fusion in the supernova explosion. I should find relatively large amounts of Si, S, Ar, Ca, and Fe, and smaller amounts of O, Ne, and Mg. I also expect that these heavy elements which are fused when the core collapsed will be found in the center and the outer edge of the supernova remnant. (Matt P.)

3. X-ray spectrum of Tycho’s SNR

4. 0.80 keV 1.29 keV 1.81 keV 2.14 keV Zooming in on emission peaks to get energy

5. 2.38 keV3.06 keV 3.83 keV6.37 keV Zooming in on emission peaks to get energy

6. 0.80 1.29 1.81 2.14 2.38 3.06 3.83 6.37 Identified elements in Tycho’s SNR Fe Si Mg Si S Ar Ca Fe

7. 0.1-10 keV0.7-0.9 keV (Fe)1.2-1.4 keV (Mg) 2.3-2.5 keV (S)1.7-1.9 keV (Si) 3.0-3.2 keV (Ar) 3.8-4.0 keV (Ca)6.3-6.5 keV (Fe) 4-6 keV continuum

8. Fe Spectrum of a knot high in Fe

9. Spectrum around shockwave

10. Spectrum of a high intensity region

11. CONCLUSIONS: 1. What elements did you identify and how were they distributed within the remnant? Do the results of your ds9 analysis support your hypothesis? Why or why not? The findings did not support my hypothesis, because I expected there to be a pattern in the way that the elements were distributed, and there was no obvious pattern, they appear to be very randomly placed. The elements we found were sulfur, silica, iron, argon, magnesium and calcium. These are the elements expected to be found in a type 1a supernova, with very little magnesium, oxygen and neon. I did not identify any oxygen and neon, and the magnesium that I did identify was such a small amount that it was barely noticeable. (Leah S) After conducting some preliminary research about supernova remnants, I hypothesized that Iron (Fe), Silicon (Si), Sulfur (S), Argon (Ar) and Calcium (Ca) would be the most abundant elements, with trace amounts of Magnesium (Mg) and Oxygen (O). I was excited to find that my original intuitions were indeed correct. All of these elements were present, and they were distributed mostly near the outer edge of the remnant. The absence of material in the center of the remnant leads me to believe that Tycho’s supernova remnant is the aftermath of a type 1A supernova. (Matt P)

12. 2. How do the spectra of different regions you investigated within the Tycho SNR compare to each other? What are their similarities and differences? The regions all had the same elements, except for the shockwave, which had no iron. However, different regions were more concentrated in certain elements, such as iron and silica. (Leah S) All of the elements were fairly well dispersed in the outer regions of the remnant. Apart from a few clusters of concentrated Iron and Silicon, each element was present in all of the outer regions. (Matt P) 3.Describe the shape of the region for the energy cut of the continuum that contained no spectral lines. What could this represent? Why doesn’t it contain spectral lines? This region is from 4 to 6 KeV, this is in the interstellar medium, the dust between the stars. It is where the supernova shockwave hit the ISM. (Leah S) The region with no spectral lines, measured to be approximately 4 – 6 keV can best be described as the supernova shockwave. There are no elements present, but rather a powerful shockwave plowing into the interstellar medium. (Matt P)

13. 4. Describe the features and shape of the Tycho SNR. Tycho is relatively circular, there is no central source that I can see, so that shows that this is a type 1a supernova. The elements are randomly placed, there seems to be no pattern to the explosion, and there are a few knots of elements, the highest concentration of elements is silica. (Leah S) My analysis shows the Tycho supernova remnant to be very spherical in shape with few protrusions and few element clusters. The elements seem to be dispersed fairly evenly throughout the remnant. There is no evidence of material in the center which indicates that this is a type 1A supernova remnant. (Matt P)