Dark Matter Possibilities

1. HOT DARK MATTER - Neutrinos (3 types- electron-, muon-, and tau-neutrinos).

2. Characteristics: 1) found everywhere 2) 100,000 times less mass than an electron- incredibly tiny. 3) They are just there... they exist with other ones, usually around places that would have hot dark matter, but are not bound to certain places. They are made through nuclear fusion and can be very common in supernovas and emission from stars. 4) They move too quickly to be pulled into an individual galaxy, but heavy neutrinos might be able to affect larger structures like galaxy superclusters. 5) They contribute to dark matter because they are incredibly difficult to detect, but we know that they are produced through nuclear fusion, which occurs in pretty much every star out there, which means there are literally millions and millions of neutrinos out there, explaining some of the mysterious mass we call dark matter. 6) Instruments with vacuums deep within the ground are built to detect the teeny-tiny particles, but even then, very few neutrinos are detected. An example of such an instrument: the DRIFT-I detector. They're virtually indetectable otherwise.

BASICS OF NEUTRINOS:

Neutrinos are classified as WILPs (weakly-interacting, light particles), and are a type of HOT dark matter. They travel at ultra-relativistic velocities, meaning they travel incredibly close to the speed of light. They have a mass of 100,000 times less than an electron, and they only interact with regular matter through the "weak nuclear force", a force that requires no contact and is incredibly weak, involving radioactivity and the emission of particles by neutrons/protons in an atomic nucleus.

REFLECTION: Wow! Just knowing how tiny these particles are can open up millions of possibilities. Space probably isn't as empty as we thought if there are particles THAT hard to detect... oh gosh, I wish I could live until I choose to die so I could see what people discover. Maybe I'd even get to go to space. Or to another planet. Or even another galaxy (I wish).

Research Article on WIMPS and other Dark Matter

Research Article

Questions:

1) It is set up as any other scientific experiment data would be: an abstract, an introduction, then the method, then the data/results, then any conclusions that were drawn.

2) The abstract is sort of a preview of what the experiment covers, providing background information of the subject and a very general overview.

3) Data collected included amounts of WIMPS detected in the underground contraption that detects them, the DRIFT-I detector. The DRIFT-I is a vacuum that is specifically designed to detect neutrinos and other WIMPS, with customized settings for different particles, even detecting the direction from which the neutrinos are coming using electron avalanches to amplify the movement of them.

4) These amounts of "events" (times neutrinos were detected) averaged out to a very scattered "less than one event per kg of target" per day. The conclusion? The DRIFT-I detector was a success at directional sensitivity, their original goal.

5) At first, the scientists thought that it would be possible to construct such a machine to detect even the direction of a neutrino, so they calculated various factors such as the earth/sun rotation and their relation to neutrino motion, and then discovered a method to amplify that movement. This led to a hypothesis- then the implementation of the ideas into the machine. Tests were made, data was collected, and the experiment was proven a success.

REFLECTION: This pertains to the class because it's talking about dark matter and the sensitivity of some devices meant to detect what is thought to be dark matter, like neutrinos. The article was kind of hard to understand because of all the lingo, but looking some stuff up and trying to extrapolate helped a little. XD

Galaxy Sort/Weighing a Galaxy

GALAXY SORT:

By Appearance:

Group 1: Leo 1, Large Megellanic Cloud

Group 2: M51, NGC 6946, M101

Group 3: Arp 252, NGC 1365

Group 4: M65, M81, M109

Group 5: NGC 4650a, NGC 253, M104, NGC 4565

Group 6: M32, M87, M59

Group 7: NGC 1073, M82, NGC 2146

By Actual Category:

Elliptical Galaxies: M59, M32, M87,

Starburst Galaxies: M82, NGC 253

Dwarf Galaxy: Leo 1

Spiral Galaxies: M51, NGC 6946, M101, M65, M81, M104, NGC 4565

Barred Spiral Galaxies: M109, NGC 1365, NGC 1073, NGC 2146

Irregular Galaxy: LMC (Large Megellanic Cloud)

Interacting Galaxy Pair: Arp 252

Ring Galaxy: NGC4650a

Reflection: Sorting galaxies can be tough... if you go by color, size, shape, makeup, other characteristics.. it just depends on what you arbitrarily choose. We went through them and divided them based on appearance, then later went back and actually looked up what each of the galaxy types were, coming up with the second list. Classification is a good tool in science, and this is no different. Knowing what a type of galaxy is can give us clues as to how it's going to react/chance/evolve (etc).

WEIGHING A GALAXY:

1. Apply this equation to three of the planets in our solar system, given in the table below.

Mass of Earth: 200kg

Mass of Jupiter: 200kg

Mass of Neptune: 196 kg

The masses are all relatively the same.

The mass of the sun would be about 200kg too?

2. DISTANCE: 5.0 - 1.55 x 10^17 km VELOCITY: 95.0 km/s MASS: 2,097,263,869 kg mass.

DISTANCE: 10.0 - 3.1 x 10^17 km VELOCITY: 110.0 km/s MASS: 5,623,688,156 kg mass.

DISTANCE: 15.0 - 4.65 x 10^17 km VELOCITY: 110.0 km/s MASS: 8,435,531,134 kg mass.

What do you notice about the values of the mass as the distance increases?

They get considerably larger.

Can you explain this?

Distance is directly related to mass.

What would you conclude the mass of the galaxy to be?

More than 1,000 solar units.

How much more massive is this galaxy than our sun?

A lot more - not even comparable. See above answer.

Reflection: I wouldn't call this one of the most useful labs, but it does help in clarifying how scientists go about their estimates of distance/mass/etc. I'd say math is neccessary for the survival of science. xD I appreciate math. A lot more.

M100 - Messier Object Research

http://seds.org/messier/m/m100.html

http://www.noao.edu/outreach/aop/observers/m100.html

http://en.wikipedia.org/wiki/Messier_100

M100 is a spiral galaxy about 60,000 klys away from earth, located at 12 hours and +15 degrees in the celestial sphere, right in the Virgo cluster. It is in the southern part of Coma Berenices and is most visible in May, around 9pm. This galaxy, also referred to as NCG 4321 (but does not have a common name), is a galaxy that faces us head-on, showing a spiral of bluish arms, indicating that the galaxy is pretty young. The shape of the galaxy is slightly unbalanced, indicating that there could be interactions with nearby galaxies. The galaxy is about 160,000 light years across and was discovered by Pierre Mechain in 1781. It has one satellite galaxy, NGC 4323, within it. The apparent magnitude of M100 is 9.3. The Hubble Space Telescope has imaged this galaxy a lot, which led to the discovery of cepheids about 56 million light years away, which helped to determine how far away M100 is. A standard telescope or some good astronomic binoculars are required to see it. It has five discovered supernovas, one discovered as early as 1901, and the most recent in 2006.

Week 8 Reflection

Whoo! A test already... I'm not too solid on the math, but I will do my best to suffer through it. The rest of it, though, isn't too bad... mostly just vocabulary and linking ideas together. Three more weeks of school then finals...

Homework Ch 10-13

1. 76.92 parsecs

3. a) 3.35 x 10^28

4. Star A: 4 x 10^12, Star B: 3.8 x 10^13

8. 316 parsecs

10. The greater the mass, the greater the lifespan.. brighter the star, the shorter it will be.

MAGNITUDE PROBLEMS:

1. How many times brighter is: a 5th magnitude than a 10th magnitude: 100 times.

2. 7th than 17th: 10,000 (10... so 100 x 100)

3. 3rd than 5th: 2.5 x 2.5 = 6.25 times

4. 3rd than 6.5th: 19.5 apprx

5. 12th than 22.5: 125 times

6. What is the magnitude of the star if it is 100 times dimmer than a 12th? 22nd magnitude star

7. 10,000 times brighter than 12th mag: -8 magnitude (-20)

Week 8 Sky Journal

Wednesday night I drove to my sisters at about 7:30. The moon was pretty high already, about 35 or 40 degrees altitude and 200 degrees azimuth. It was about an 1/8 of the way full, a lovely little crescent. I could see some stars too, but since I was driving I couldn't really check them out that well. I think I'll do this entry in two parts and come back tonight and add some stars I've seen, if the night sky is clear enough. : )