Need help with Part 2 and Part 3
aw Lab: PHYS 1 X Inbox x Q Edit . PHYS UNIT 4 | Quizle x O X V Sec X + X unt.instructure.com/courses/82672/pages/hubbles-law-lab?module_item_i... * *IA : structure.com/courses/82672/pages/hubbles-law-lab? module_item_id=... [ Q 2 x # IA : Dashboard M gmail mail O quizlet youtube Citrix Cengage hboard M gmail mail Q quizlet youtube Citrix Cengage ends DaJIPg . D. Irregular Part 3: Plotting rents Part 2: Stellarium To graph the data you recorded in Table 2 on the graph provided at the end of this page, you will use the distance (in Mpc) as your x-coordinate and the redshift (a ratio with respect tothe speed of light) as your y-coordinate. Figure 4 shows that your data should follow a linear approximation. Instructions for Setup To get that line of best fit, and thus the slope of the line of best fit (which we call the Hubble constant), we must follow good plotting practice. Use You will notice icons on the menus that we will reference. If you click on each one of them you can see what they do. If you click on something Figure 6 below as an example of fitting a line to a scattered dataset. that you can't undo turn the program off and on again to reset. Here are a few guidelines: A. Open Stellarium - Do not just pick the two data points farthest from each other and draw a straight line between them B. In the lower left-hand corner, click the two small arrows and lock the toolbars in place. Do not "connect the dots" on your graph Do not force the line of best fit to start at the origin C. Click on wrench icon on the left-hand menu (or strike F2). Try to have an even number of points above and below the line of best fit at roughly equal distances from the line a. Click on the 'Information' tab and select the 'Customized' option under 'Selected Object Information. . However, this isn't always possible, i.e., the dataset one has is the dataset one must work with and extreme outliers may skew a best-fit line b. Uncheck all the 'Displayed Fields' except the 'Name', 'Catalog Number', 'distance', and 'Additional Information. c. Close this window. D. Press the 's' key. The ground should disappear in your view so that there's only a sky in every direction. Line of Best Fit Example E. Press the 'a' key and the sky (clouds, etc.) should disappear. Now you should only see a night-time view of space. F. Open up the search window by selecting the spyglass icon on the left-hand menu (or press F3) a. Once here, type the name or catalog number of the first listed galaxy from Table 1 below into the search field and click enter. b. Record the distance and redshift values listed in the top left-hand corner into Table 1 given at the end of the lab. Do no record the error in the value (the number after +). Figure 6: Example of a line of best fit plotted through a scattered set of data points. To find the slope of this line, let the red circles on the left and right be G. Use the 'Page Up' button on your keyboard to zoom-in on the galaxies until you can easily see them. P1 and P2, respectively: a. Using the galactic classification table above (Figure 5), classify each of the galaxies and record the classification in Table 1. P1: (4.4, 7); P2: (24.8, 43) and, therefore, Slope = 24.8 4.4 = 1.76. b. If the galaxy has a common name, note it as well in Table 1. See below for more detail on finding the slope. 8 10 12 14 16 18 20 22 24 26 H. Repeat steps F and G for the rest of Table 2. -Linear (Good Line) Part 3: Plotting To graph the data you recorded in Table 2 on the graph provided at the end of this page, you will use the distance (in Mpc) as your x-coordinate Once you have a good line of best fit, extend the line across the whole graph. You will now find two vertices (a place where two or more lines and the redshift (a ratio with respect tothe speed of light) as your y-coordinate. Figure 4 shows that your data should follow a linear intersect) on your graph that you choose on the simple condition that the line of best fit is very near to (if not directly on top of) the vertices formed by the graph's gridlines. We want thes approximation. ause we know the values of the gridlines very well. To get that line of best fit, and thus the slope of the line of best fit (which we call the Hubble constant), we must follow good plotting practice. If we know the values of the points very well, we can accurately describe the slope of the best fit line (which is the point of this exercise). We want Use Figure 6 below as an example of fitting a line to a scattered dataset. to also pick points that are far from each other, one near the origin and one far from the origin on the line of best fit. This ensures that any ill effect from the inaccuracy of the measuring of the points is greatly reduced. Here are a few guidelines: Picking two points close together would create much more wild swings in the slope value for any error in those points, which we don't want. Fill . Do not just pick the two data points farthest from each other and draw a straight line between them out Table 2 below for the two points where point 1 is the point closest to the origin and point 2 is farthest from the origin. . Do not "connect the dots" on your graph Part 4: Calculations 68. F 4:57 PM Mostly cloudy Q Search D L D O B Z E - N Leg 4/18/2023Data Table 2: Best-fit Slope and Hubble Constant X(Mpc) y1 X2(Mpc) y2 X2 - X1(Mpc) y2 - y1 Slope Ho (km/s/Mpc) I\f11 + B IUAD 2 1 3 4 6 Data Table 1: Distance, Redshift, Galaxy Classification, and Common Name Galaxy Name Distance (Mpc) Redshift Classification Common Name NGC 253 3 0.000864 Spiral Sculptor Galaxy NGC 1068 14 0.003810 Spiral N/A NGC 1097 20 0.004218 Barred Spiral N/A NGC 1316 16 0.005911 Elliptical N/A NGC 1365 18 0.005476 Barred Spiral Great Barred Spiral Galaxy NGC 1532 20 0.03908 Elliptical Haley's Coronet NGC 1566 16 0.005036 Spiral Doradus Cluster NGC 2207 36 0.009292 Interacting Spiral N/A NGC 3034 3.7 0.000730 Irregular Cigar Galaxy NGC 3314 48 0.009323 Interacting N/A NGC 4038 27 0.05593 Interacting Antennae NGC 4486 18 0.004233 Elliptical Virgo Galaxy NGC 4535 27 0.006606 Spiral The Lost Galaxy of Copeland NGC 4472 17 0.003339 Elliptical N/A NGC 5055 11 0.001678 Spiral Sunflower Galaxy NGC 5128 4 0.001826 Elliptical The Hamburger Galaxy NGC 5194 0.001550 Spiral Whirlpool Galaxy NGC 7320 71 0.019470 Irregular Stephan's Quintlet11 + B 1 3 4 Data Table 1: Distance, Redshift, Galaxy Classification, and Common Name Galaxy Name Distance (Mpc) Redshift Classification Common Name NGC 253 3 0.000864 Spiral Sculptor Galaxy NGC 1068 14 0.003810 Spiral N/A NGC 1097 20 0.004218 Barred Spiral N/A NGC 1316 16 0.005911 Elliptical N/A NGC 1365 18 0.005476 Barred Spiral Great Barred Spiral Galaxy NGC 1532 20 0.03908 Elliptical Haley's Coronet NGC 1566 16 0.005036 Spiral Doradus Cluster NGC 2207 36 0.009292 Interacting Spiral N/A NGC 3034 3.7 0.000730 Irregular Cigar Galaxy NGC 3314 48 0.009323 Interacting N/A NGC 4038 27 0.05593 Interacting Antennae NGC 4486 18 0.004233 Elliptical Virgo Galaxy NGC 4535 27 0.006606 Spiral The Lost Galaxy of Copeland NGC 4472 17 0.003339 Elliptical N/A NGC 5055 11 0.001678 Spiral Sunflower Galaxy NGC 5128 4 0.001826 Elliptical The Hamburger Galaxy NGC 5194 7 0.001550 Spiral Whirlpool Galaxy NGC 7320 71 0.019470 Irregular Stephan's Quintlet
