Science Lab – $20

Due August 3, 2013 by 11:30pm central time. Please see attached documents and instructions below:

 Five documents:  * “Appleby Galaxy Zoo Lab Project ” packet (informational with questions)  * “Galaxy Zoo report ” (to turn-in)  * “Galaxy Zoo Parts II & III objects Data Sheet.xls” (to turn-in)  * “The NED website entry page ” (informational)  * “NGC 3310 Example spectra ” (informational)  In this lab, you will use the Galaxy Zoo web site and help real research astronomers analyze real data. Definitely do your best to classify each object,  but remember that it is OK to make a mistake as you will not be the only person looking at and categorizing each object. 

The NED website entry page:

http://nedwww.ipac.caltech.edu/

Choose “By Name” under “Objects” and this screen pulls-up:

Type in the object name, as listed in the date sheet (e.g. NGC 33

1

0), and click “Submit query.” As an example, I have typed in LMC (Large Magellanic Cloud). The screen will look like:

Notice the blue box along the bottom of the above screen shot. To the left of it is a small image with the “Images” link underneath. Click on the link; this will open-up a new window/tab that will look something like this:

Scroll down and look at the thumbnail images along the left. Find one that is in color. If you find one, check the 5th column (Band, Wavelength) to see if the color on the image corresponds to visible light or if it is representative.

For example, sometimes an image is in color, but the color corresponds to the intensity of the light, or to different wavelengths outside of the visible light spectrum. Some color images are from the 2MASS, which stands for the 2 micron all-sky survey. The visible light we see has a wavelength of roughly 400 to 700 nanometers, or billionths of a meter. A micron is a millionth of a meter, or a thousand times larger in wavelength than visible light. This puts it in the infrared part of the spectrum. So the color in the 2MASS images are referring to differing infrared wavelengths.

Thus, when you find an image that appears to be in color, look in the 5th column, labeled “Band, Wavelength.” If there is a V with a number either between roughly 400 nm to 700 nm, OR 4000 Å to 7000 Å (Å = angstroms, or 1/10 nm), then it is within the visible part of the spectrum and can be used.

If there is a color image for the object, describe in the data sheet what colors you see in the column labeled “Your observed color”. If there is no image available, write “NA” on your data sheet.

Even if there is no color image, do look at the images of the galaxy. By looking at it, determine what type of galaxy you think it is: elliptical or spiral. Write that answer in the “Galaxy Type” column of your data sheet.

You are now done with this screen/page/tab/window and may navigate away from it by either closing it or just switching back to the previous screen shown on page 3.

Referring to the screen on page 3, notice the blue box along the bottom towards center. Click on that blue box. This will either open a new window/tab (if you closed the previous one) or change the “images” screen (if you only navigated away from it without closing it) found on page 4.

This tab/window will look something like the one below:

Scroll down and you will see something like this:

In the 2nd column (Observed Passband), look for the BT and VT magnitudes (labeled as B (B_T) and V (V_T), respectively). Record these in the data sheet. (As an example, B (B_T) is in the 5th row.) Switch back to the first tab/window (on pg. 3) and click on “spectra (to the right of the blue box).

VERY strange that the LMC has no spectra!! Some of the objects on the data sheet may not, either. But those that do, record the number of emission lines you see and a short description of it. You may want to include the wavelength range (listed along the x-axis). Also, under the “Spectra?” column on the data sheet, type “yes” if it does have a spectra and “no” if it does not.

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1

NGC 3310 – spiral galaxy

Emission lines (3)

Absorption lines (5)

Directions:

Right-click on the circle below, choose ‘copy’, and paste it on your spectra as many times as needed. To move it, place your arrow/curser over it until a four-way arrow appears. Left-click and hold while the four-way arrow is visible and drag it to where you want it.

Copy (

Or, you may print out the spectra, draw circles by hand, and send a scanned copy.

v. 15Jan2011

Observing Project Lab: GalaxyZoo.org Project

YOU MUST COMPLETE THIS OBSERVING PROJECT BY THE START

OF CLASS ON: __________________________.

This project consists of three parts:

1.) Classify at least 250 galaxies as either spiral or elliptical.

2.) Pick 30 galaxies (15 elliptical, 15 spiral) and for each:

a.) Find its color

b.) Examine its spectrum.

Please read
all of the instructions
below before you start. It really will make your job

easier. Note: due to ongoing website changes, some instructions may not be exact

Overview

Part I: Galaxy Classification

In this part of the activity you will do useful science for research astronomers while also learning about galaxies. Your task is to examine 250 galaxies and classify each as either spiral or elliptical. To do this part:

1.) Go to

http://www.zooniverse.org/

and register (the register button is in the upper

right corner of the screen titled “My Account” or “Log In”).

2.) After you register, click on Galaxy Zoo Hubble on the right and do the tutorial “How to Take Part”. (Tutorial is found under “Quick Links” at the bottom.)

3.) After you are done with the tutorial start classifying galaxies!

4.) If you log out and then back in to the site, you get back to the galaxy

classification screen from the link “Classify Galaxies” on the right.

5.) You must classify at least
400 galaxies
for full credit (400 = A, 250 = D) on

this part. (This is really not so bad. Once you get started it won’t take much

more than 1.5 hours. DO NOT spend more than ~15 seconds per object.)

Part II: Galaxy Properties (found on “Galaxy Zoo Parts II & III objects Data Sheet.xls”)

In this part you will look for differences between galaxies other than shape.

1.) Choose 30 of the galaxies from the “Galaxy Zoo Parts II & III objects Data Sheet.xls”, 15 spiral and 15 elliptical, many of which have spectral information. Record the galaxy type in the data table for this project; more detailed instructions are found

under “For more detailed instructions.”

2.) For each galaxy:

a.) Record its BT and VT magnitudes, and calculate the color, B-V. This is pretty

easy to do if you have made a spreadsheet (See “For more detailed instructions.”)

b.) Count the number of emission lines in the spectrum.

Part III: Answer questions (found on “Galaxy Zoo Parts II & III objects Data Sheet.xls”)

1.) What is the average color of the spiral galaxies in your sample?

What about the ellipticals?

2.) Which are redder, the ellipticals or spirals?

3.) For one of your galaxies, print out its spectrum and indicate on the graph at

least 5 absorption lines (“dips”) and at least one emission line (peak).

4.) What differences do you see in the spectra of the ellipticals and spirals?

5.) What differences do you notice in the number of emission lines in the spectra

of ellipticals and spirals?

6.) Explore object ID 587731520668631247. Classify this object as either

elliptical or spiral and give a short explanation (a couple sentences long)

describing why you made the choice you did. Your choice should address

shape, color, and spectrum.

The easy way to see the data on this galaxy is to follow this link:

http://cas.sdss.org/astro/en/tools/explore/obj.asp?id=587731520668631247

What to turn in:

o Copy-Paste of your “My Galaxies” page (link on right) into word document.

o Data sheet (your spreadsheet)

o Typed answers to the questions in Part III above found on Data Sheet

Basic GalaxyZoo Navigation:

For more detailed instructions:

* Go to NED at:

http://nedwww.ipac.caltech.edu/forms/byname.html

* Type in the object name, either an NGC (New General Catalog) number or a UGC (Uppsala General Catalog) number, and push the “Enter” key on your keyboard or click “Submit query.”
* Click on the Images link and look for a color image taken in an optical band or one in the range of 4000 Å to 7000 Å (400 nm – 700 nm). (If a color image does not exist, write NA on your data sheet.)

* Go back to the previous page/tab and click on the blue image next to the Images link.

* Scroll down and look for the BT and VT magnitudes (labeled as B (B_T) and V (V_T), respectively). Record these in the data sheet.

* Go back to the previous page/tab and click on the Spectra link next to the blue image.

* Analyze spectra and record data in data sheet.

* For question 3 Part III: Right-click on a spectra and choose “copy.” Paste it to a word document. Place circles (100% transparent, no fill) around emission and absorption lines.

Images link “blue image”
Spectra link

Page 3 of 3

SuII 10
Name: ________________________________

The Galaxy Zoo

Description:

Astronomy has not yet revealed much about the nature of galaxies. For the most part, astronomers know that they are composed of stars, gas and dust. They appear to have different star formation histories, and differing amounts of the aforementioned constituents, but little is known about how galaxies get to be the way they are.

In order to better understand galaxies, however, astronomers have attempted to divide them into groups by their appearances. It is possible that the appearances of galaxies may be related to their history or evolutionary track. Although, as yet, there is not enough evidence to support this hypothesis, the first step in any endeavor to understand something scientifically, is to classify and compare.

In this exercise, students will look at a number of galaxies and divide them into categories that they determine. Following this, students will compare how their classification scheme compares with the astronomy one.

Introduction:

Galaxies are large groups of gravitationally bound stars, with gas and dust clouds intermingled. In this exercise, you will use the World Wide Telescope to observe several galaxies. You will then divide these galaxies into at least two groups based on their shape and appearance. You will determine the nature of the categories that you develop. At the end of the exercise, you will compare the groupings that you made to those of astronomers and discuss whether grouping galaxies in either way is helpful to understanding the nature of galaxies.

1. Use the World Wide Telescope to observe the galaxies listed in the table at the end of this exercise. Make sure that you look at each galaxy carefully. You can decide how to categorize the galaxies at any point during these observations, but you must designate a category for every galaxy in the table. Your categories can be broad or narrow. You must have at least 2, you should not have more than 10.

[Type answer here – list categories and their abbreviations if any, along with a brief description of each.]

2. Write a description of how you classified the galaxies you observed.
What features did you consider in classifying these galaxies?
What features did you ignore?
Did you develop a symbol or designation for your classifications?
What do your symbols or designations mean?

[Type answers here]

3. Now go back and use the Research button for each galaxy to determine the astronomical classification of each galaxy. The designations should be S for spiral, SB for barred spiral, E for elliptical, I for irregular and pec for peculiar. If you are unsure how to interpret the classification for each galaxy, ask for help from your instructor.

[Type answer here]

4. Now compare your classification scheme with the astronomical one.
(a) Does either lend any insight into the nature of a galaxy?
(b) Is one better than the other?

[Type answers here]

OPTIONAL STEP 5: Read a textbook or other reliable information source to learn more about the morphological classification of galaxies. Write a paper about the insight that has been gained from these designations, if any.

List of Galaxies

NGC 628

NGC 4486

NGC 1300

IC 1623B

NGC 5194

NGC 300

NGC 393

NGC 7331

NGC 3031

NGC 205

NGC 523

NGC 5457

NGC 4472

NGC 1566

NGC 1316

NGC 4594

NGC 221

NGC 536

NGC 620

ESO 286-19

Instructor’s Notes:

It would be best to do this exercise, before discussing galaxy morphology. This will give the students the freedom to choose designations that represent their own way of classifying.

The galaxy morphological classifications of these galaxies can be found using NED and looking for “Basic Data”. In this section, galaxy classification is listed, but classifications will be in designation form, so this will need to be explained to students. The initial information is included in the exercise, but some students will wonder about the numbers following the letter designations. For students who are really getting in to this exercise, there are other, interesting areas to “play” with. Students could be challenged to find an irregular galaxy or a peculiar galaxy that is not interacting, for example.

Sheet1

:

Your

Galaxy

Name

Color

3

NGC 4261

NGC 430

Your

Name

Section #:

Part II

Color

# of

Galaxy

Observed

Index

emission

Type

B (B_T)

V (V_T)

(B – V)

Spectra?

lines

Description of spectra

Example:

NGC 3310

spiral

blue & orange

11.15

10.8

0.35

Yes

4

4241.6 to 5103.6 A, 4 -5 emission lines and 2 absorption lines

NGC 224

NGC 598

NGC 5194

NGC 4579

NGC 430

NGC 5055

NGC 4826

NGC 3623

NGC 3627

NGC 628

NGC 1068

NGC 3031

NGC 5236

NGC 4501

NGC 4569

NGC 4548

NGC 4736

NGC 3351

NGC 3368

NGC 4192

NGC 4254

NGC 4321

NGC 5457

NGC 4594

NGC 4258

NGC 3556

NGC 3992

NGC 3034

NGC 4027

NGC 4314

NGC 955

NGC 221

NGC 4472

NGC 4621

NGC 4649

NGC 4486

NGC 4552

NGC 3379

NGC 205

NGC 2300

NGC 4261

NGC 4881

NGC 3377

UGC 145

UGC 206

NGC 147

UGC 387

NGC 185

NGC 227

UGC 579

NGC 315

UGC 610

NGC 380

NGC 385

NGC 393

NGC 392

NGC 410

NGC 507

UGC 973

NGC 533

Part III

Questions from “Appleby Galaxy Zoo Lab Project v.July 2010 “

#1.

Average color index of spirals:

Average color index of ellipticals:

#2.

A color index of less than 0.45 is considered red.

A color index greater than 0.45 is considered blue.

Which are redder: spirals or ellipticals?:

(#3.)

Choose one of your galaxies above and copy-paste its spectrum to a word document.

Use circles to identify at least 5 absorption lines (“dips”).

Use circles to identify at least 1 emission line (“peak”).

Hint: See “NGC 3310 Example spectra “

#4.

How do elliptical and spiral spectra differ?:

#5.

How do the quantity of emission lines differ between galaxy types?:

#6.

Object ID 587731520668631247

Galaxy type:

Reason for classification type:

http://cas.sdss.org/astro/en/tools/explore/obj.asp?id=587731520668631247

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