reminders due by the end of the day: – analysis of 10 datasets – questions from section 2 of...
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Reminders
Due by the end of the day:– Analysis of 10 datasets– Questions from Section 2 of Searching for and
Analyzing Pulsars
Tonight: I will (along with Mrs. Hedrick) be grading your responses for Section 1 questions.
Bellwork
Degenerate Matter and PressureA review from yesterday
Why do you think degenerate gas behaves more like a sold than the gas you are familiar with here on Earth?• Discuss your predictions with your group
Q: Why do degenerate gases resist compression?
A:
Q: Describe how the source of pressure in normal matter and degenerate matter differ.A: Normal Matter Degenerate matter
Electromagnetic Repulsion from atoms (in the case of you and me and planet Earth)OrThermal and radiative pressure from thermonuclear fusion (in the case of stars)
Degeneracy Pressure Electron degeneracy pressure (in the case of a white dwarf star)Neutron degeneracy pressure (in the case of a neutron star)
Both examples depend on the temperature of the atoms/particles in the system
The pressure depends only on the degenerate electrons – if heat is added the electron pressure does not increase.
Follows Ideal Gas law
DOES NOTFollow Ideal Gas law
Q: What happens to the volume of a white dwarf or neutron star when mass is added onto its surface? How is this different from normal matter?A: Volume when mass is added
Normal Matter Increases
Degenerate Matter Decreases
Q: What is the name of the mass limit for white dwarf stars? It is the boundary between what two evolutionary endpoints?A: Chandrasekhar Limit ~ 1.44
Size Comparison
• What is the mass limit for neutron stars? What is the name and value for this limit?
A: The Tolman-Oppenheimer-Volkoff Limit ~ 3
Do the pulsar masses fit the
predicted models developed by
Chandrasekhar and the TOV
group?
Size comparison
The Interiors of Neutron Stars
An article review
Whale of a Burst
Artists conception of Magnetar Gamma Ray Burst (SGR 1806-20)
Artists conception of Star Quake
SWIFT Spike in gamma photons
You can get this on a T-shirt
Neutron Star Crust is Stronger than Steel
Gianormous flare caused by Star Quakes!
Solid Crust – Fluid Interior
Possibly small mountains on the surface – really
small!
Journey to the Center of a Neutron StarWatch an animation of a glitch pulse here: http://www.nasa.gov/mpg/108574main_neutron_%20star_animation.mpg
Chemistry of a neutron star modeled for first time
Gamma and X-ray emission during zombie-ismhttp://www.nasa.gov/centers/goddard/mpeg/97911main_Puff.0539.mpeg
Exploded Star Reveals Strange New MatterCas A Supernova Remnant: http://www.youtube.com/watch?v=mJaFHq3OaMg
Cas A is a young pulsar. It has slowed down tremendously over the last 10 years ~ 4%.
This is believed to be due to the rapid cooling of the inside.
Forming superfluid and super conductors (Resistance free material – this allows electrons to flow freely)
Superfluid's on Earth: (small clip)http://www.youtube.com/watch?v=2Z6UJbwxBZISuperfluid’s on Earth (long clip)http://www.youtube.com/watch?v=bmvlIdNXxjM
Now, let’s put all the information about the interior of a neutron star together and create a 2-
D or 3-D model representing what we have learned.
• Groups of 2 or 3• You can create a 2-D model using markers• Or a 3-D model using play doughEither way you must have a way to label and describe each layer