**ASTRONOMY 5500. GALACTIC
ASTRONOMY**

**Instructor: David G. Turner
Office: AT319B
Telephone: (902) 420-5635
Email: turner@ap.smu.ca
Lecture Times: Monday, Wednesday, 13:00-14:15 am, AT323
**

**1. Historical Landmarks**: early efforts by Galileo, Halley, Mayer,
Herschel, Argelander, Struve, Kapteyn, van Rhijn, Shapley, Hubble, Lindblad, Oort,
Trumpler, Baade, Reber.

**2. Current View of the Galaxy**: disk, bulge & halo constituents
and dimensions, distance to the Galactic centre, metallicity gradient, population
types, evidence for origin.

**3. Stellar Reference Frames**: precession, meridian telescopes and position
measures, proper motions from fundamental catalogues (FK3, FK4, FK5, *Hipparcos*),
proper motions with respect to galaxies, relative proper motions for open clusters
and membership probabilities.

**4. Stellar Parallaxes**: relative and absolute parallax, refractors versus
astrometric reflectors, luminosity calibrations based on parallax data, statistical
corrections for parallax bias, errors in parallax, *Hipparcos* and HST measures,
remaining uncertainties.

**5. Stellar Radial Velocities**: spectrograph systems for radial velocities,
heliocentric corrections, measuring errors as functions of spectral type and dispersion,
problems caused by telescope flexure, lines used, rotation, emission, line
asymmetries, etc., radial velocity scanners, Griffin-type, CORAVEL, atmospheric
calibrations, limitations.

**6. Spectral Classification**: review of astrophysical basis for tying visible
spectral features to stellar parameters, MK system, roles of temperature, gravity,
chemical composition, rotation, companions, etc., designations for the various
different types of stars encountered in astronomical studies, peculiar stars.

**7. Photometric Systems**: photometry as a substitute for spectroscopy, broad-band
systems (*UBV*), intermediate-band systems (*uvby*), narrow-band systems
(*H*-line), Balmer jump sensitivity, the role of extinction corrections and
interstellar reddening, temperature and abundance influences, favourites: Walraven system,
Strömgren system, DDO system, *H*-beta photometry, *K*-line photometry,
*khg* photometry, etc.

**8. Interstellar Reddening**: intrinsic colours for stars and the reddening
curve, reddening slope variations in the galactic plane, techniques for determining
R = AV/EB-V, anomalies.

**9. Absolute Magnitude Calibrations**: statistical and secular parallaxes,
trigonometric parallaxes, moving cluster parallax and ZAMS fitting, Upton's
modification for cluster shrinkage or expansion, ZAMS construction, *H*-line
equivalent width calibrations, Ca II *K*-line reversal.

**10. Basics of Stellar Evolution**: nuclear processes, convective and
radiative energy transport, high mass stars and low mass stars, pre-main-sequence
and post-main-sequence stages, core sizes, Schönberg-Chandrasekhar limit,
isothermal cores, changing from static, spherically-symmetric models to realist
models, rotation, overshooting, mixing.

**11. Open Clusters, Globular Clusters & Associations**: cluster CMDs,
metallicity, open cluster designations, globular clusters and their characteristics,
OB associations, R & T associations, nomenclature, catalogues, Elmegreen &
Lada mechanism for progressive star formation.

**12. Star Count Analysis**: star counts as functions of magnitude, cumulative
star counts, treatment of interstellar absorption, Olber's paradox, observed
characteristics of star counts in the Galaxy, Gould's Belt, fundamental
equation of star count analysis, general solutions and restricted solutions.

**13. Stellar Density Functions**: *m*-log π tables, numerical
solutions, the Local System, Wolf diagrams and dark cloud distances, Herbst-Sawyer
technique, star density variations perpendicular to the Galactic plane, *Z*
scale heights for different stellar types.

**14. Luminosity Function**: Kapteyn's studies, general techniques of
deriving the luminosity function, mean parallaxes, trigonometric parallaxes,
spectroscopic parallaxes, mean absolute magnitudes from proper motions (Luyten's
technique), variations in the general luminosity function for different populations, initial
luminosity (Saltpeter) function, initial mass function and star clusters.

**15. Chemical Composition of the Galaxy**: halo, bulge & disk metallicities.

**16. Solar Motion**: fundamental standard of rest, local standard of rest,
solar motion from proper motions and radial velocities, dynamical versus kinematical
solutions, the drift term, observational effects, standard solar motion, basic
solar motion, solar motion relative to the dynamical LSR, correction for drift,
methods of calculating the local circular velocity.

**17. Statistical Parallaxes and Secular Parallaxes**: upsilon and tau
components of proper motions, method of secular parallax (upsilon components),
method of statistical parallax (tau components and radial velocities), applications,
restrictions, recent results for RR Lyrae stars.

**18. Kinematic Groups**: velocity ellipsoid, vertex deviations for different
stellar types, moving groups, high velocity stars and their percentages among common stellar
types.

**19. Galactic Rotation**: general formula for galactic rotation, Oort's formulae
and the *A* & *B* constants, the *AR*_{0}
relation, recent determinations of the local rotation constants, *A*, *B*,
*R*_{0}, *θ*_{0}.

**20. Galactic Structure Studies**: 21-cm line data and analysis, rotational
velocity curves for the Galaxy and other galaxies, flat rotation curves, the Galactic
warp and the Magellanic Stream, locations of spiral arm edges, use of molecular line
and radio continuum studies, optical tracers and local spiral arm structure,
nomenclature for local spiral arm features.

**21. Propagation of Spiral Arm Patterns**: spiral density-wave theory, resonances,
preference for two-armed spirals, evidence in the vertex deviation of the velocity
ellipsoid and streaming motions along spiral arms, stochastic self-propagating star
formation, "feathery" features in spiral galaxies, importance of DW versus
SSPSF modes.

**22. Galactic Dynamics**: force law perpendicular to the Galactic plane,
simplifications and method of determination, local space density and the missing mass
problem, runaway stars inside and outside the Galactic plane, formation from supernovae
and star cluster evolution, presence near OB associations, initial *Z* velocities,
WR and OB runaways, recent studies.

REFERENCE MATERIAL:

GRADING SYSTEM:

COMPONENT | PERCENTAGE OF GRADE |

Homework Assignments (Exercises) | 35% |

Take Home Midterm Test (November) | 15% |

Take Home Final Examination (December) | 50% |

Total | 100% |

**UNDERGRADUATE CELESTIAL CO-ORDINATES:**

**ELEMENTARY LEVEL MEASURING STARS:**

**ELEMENTARY LEVEL STELLAR EVOLUTION:**

**EXAMPLE OF STATISTICAL PARALLAX:**

**MILKY WAY FUNDAMENTAL PARAMETERS:**

**INTERSTELLAR REDDENING PARAMETERS:**

**SECTIONS 1-3 INSTRUCTOR NOTES:**

**SECTIONS 4-6 INSTRUCTOR NOTES:**

**SECTIONS 7-8 INSTRUCTOR NOTES:**

**SECTIONS 9-11 INSTRUCTOR NOTES:**

**SECTIONS 12-15 INSTRUCTOR NOTES:**

**SECTIONS 16-18 INSTRUCTOR NOTES:**

**SECTIONS 19-22 INSTRUCTOR NOTES:**

**INSTRUCTOR SOLUTIONS, ASSIGNMENT 1:**

**INSTRUCTOR SOLUTIONS, ASSIGNMENT 2:**

**INSTRUCTOR SOLUTIONS, ASSIGNMENT 3:**

**INSTRUCTOR SOLUTIONS, ASSIGNMENT 4:**

NON-PARAMETRIC REGRESSION FORTRAN PROGRAM

CARTESIAN TRANSFORMATION FORTRAN PROGRAM

STATISTICAL PARALLAX FORTRAN PROGRAM