PHYS-333-13s: Problem set #2
Solutions
Version of February 23, 2013.
1. Visual binary (15 points):
Over a period of 10 years, two stars separated by an angle of 1 arcsec are observed to
move through a full circle about a point midway between them on the s
Phys333-13s HW7 Solutions
#1 Application of Tully-Fisher relation
z = 0.23;
Dl = 0.0013;
mI = + 17.6;
c = 3 10 ^ 5 km s ;
a. Orbital velocity Vrot
Vrot = c * Dl 2; H* Doppler width is from 2*Vrot,
so need to divide by factor 2 to get Vrot*L
NumberForm@Vro
PHYS-333: Fundamentals of Astrophysics
Stan Owocki
Department of Physics & Astronomy, University of Delaware, Newark, DE 19716
Version of October 26, 2013
I. STELLAR PROPERTIES
Contents
1 Observational vs. Physical Properties of Stars
1.1
2 Inferring Astr
Phys333-13s HW6 Solutions
#1 Stellar Collisions
2
hw6-solns.nb
#2 Galactic Orbital Periods
hw6-solns.nb
#3 Virial Mass of Cluster
3
4
hw6-solns.nb
#4 Galactic Rotation from 21 cm Radio observations
hw6-solns.nb
#5 Quasar properties from redshift
5
6
hw6-s
Welcome to Phys333-13S
Fundamentals of Astrophysics
Course Instructor:
Prof. Stan Owocki
205 Sharp Lab
(302)831-8357
astroprof@bartol.udel.edu
Course Theme
The physical laws and forces that govern our lives.
e.g. gravity, ele
!
!Homework Reading Quiz!
!
What is orbital speed of earth around sun, in km/s?!
!
2 au/yr = 30 km/s = 10-4 c!
!
!
How many powers of ten between size scale of people
(1m) and that of the observable universe?!
!
Log[10 Gly/m] ~ 26!
!
!
What are 3 observab
1
2
3
4
7
9
Hydrogen energy levels
11
Light as Information Bearer
We can separate light into its different wavelengths (spectrum).
By studying the spectrum of an object, we can learn its:
1Composition
2Temperature
3Velocity
PHYS-333: Problem set #1
Solutions
VERSION of February 12, 2013 .
1. Energy ux and magnitude:
a. Suppose two objects have energy uxes of f and f + f , where f
f . Derive
an approximate expression for the magnitude dierence m between these two objects.
(Hi
PHYS-333: Problem set #3
Due Classtime Mar. 7
Please write neatly and show your work. Answers correct to two decimal places
will receive full credit, so try to compute by hand without a calculator. Big magnitude
answers should be given in scientic notatio
Phys333-13s HW4 Solutions
#1 Opacity of people vs. electrons
a. Cross section of standing person
cm =.; h = 1.8 m; w = 0.5 m; m = 100 cm; s = h * w; NumberForm@s, 2D
9000. cm2
b. Opacity for m=60 kg
m = 60 kg;
kg = 1000 g;
k = s m;
NumberForm@k, 2D
0.15 c
PHYS-333: Problem set #7
Due classtime Tuesday May 10
Please write neatly and show your work. Please put a box around all your final
answers. Answers without a box may not receive credit. Big magnitude answers
should be given in scientific notation. Answe