ASTR 5460, Fall 2017, Brotherton Instructor

Introduction to Cosmology

This is a graduate level class designed to provide the fundamentals of cosmology aimed at observational extragalactic astronomers. Other courses in our program will provide galaxy topics in detail.

Here is the syllabus.

Here is an old midterm (2011) for you to help prepare for the upcoming midterm.

Here is an old final (2011) for you to help prepare for the upcoming final exam.

Figures of Interest (will add to this during the semester):

Chapter 6 Figures.

Chapter 7 Figures.

Chapter 10 Figures.

Papers/Websites of Interest (will add to this during the semester):

Hubble (1929).

Freedman et al. (2001). (A modern update of the Hubble law.)

Zwicky 1937. (Analysis of the Coma cluster leads to the dark matter hypothesis.)

Clowe et al. (2006). (The bullet cluster is the smoking gun for dark matter.)

Penzias and Wilson 1965 -- the Nobel prize paper, and the Princeton group's explanation: Dicke et al. 1965.

Smoot et al. 1992 (First CMBR fluctuations).

Goldhaber et al. 2001 on time dilation in supernova light curves.

Loeb (1998) on a direct mesaurement of the cosmological expansion.

Hogg (1999) on distance measures and cosmological calculations.

Riess et al. (1998) on supernovas and acceleration.

Wayne Hu Cosmology Tutorials

Ned Wright Cosmology Calculator and FAQs

Hogg et al. (2002) on the K-correction.

Pretty good, current, and accessible article about dark matter. (H/t to Brad Lyke)

Artificial Intelligence finding gravitational lenses.

Bennet et al. (2012) Summary of WMAP Results.

Planck 2013: Overview of Products and Scientific Results and the Planck team page of papers.

Max's Cosmic Cinema

Ata et al. (2017) on BAO measurements. Of particular interest should be figures 14 and 15.

Interesting criticism of inflation theory.

Two-part video series suggested by Mohamed about ``How far back can we go?" Here is Part 1 and Part 2.

Line Fitting Papers:

Hogg et al. (2010). Akritas and Bershady (1996). Isobe et al. (1990). Regression Lines: More Than Meets the Eye.

Research-Related Papers

Pennell, Runnoe, and Brotherton (2017). Xu et al. (2012) Shen et al. (2011) Also of interest, quasars as standard candles: Risaliti and Lusso (2015)


Project 1: The Modern Hubble Constant. Please read the website courtesy of John Huchra giving some history regarding the Hubble Constant: Your assignment, in addition to this reading, is to plot your own Hubble diagram using modern and measure a Hubble constant. I don't care how you do this as long as you make a good effort and your write-up to accompany your plot explains what you did, how, and why. The goal is not to get the right answer, but to develop some independent research skills looking up astronomical values and exercising your own judgment. I'm also evaluating the technical skills of the class looking toward doing a real research paper later in the semester. Put a reasonable effort into this, but don't shoot for perfection. Please read a couple of the papers linked below, namely Hubble (1929) and Freedman et al. (2001) (feel free to skim the technical details of galaxy distances in Freedman et al.). I'll provide suggestions, but won't explicitly tell you how to do this -- research is a creative endeavor, for better or worse. Let me remind you of a few things and a few resources. Real data have uncertainties, which can be both formal and systematic. You can write your report like a real paper and use LaTeX template from the astronomy journal of your choice. Papers can be found using NASA's Astrophysics Data Service (ADS), while information on individual objects can be found using NASA's Extragalactic Database (NED) (including redshift-independent distances!), and both are essential resources to learn to use. You also need to have tools to make publication-quality plots and do statistics. Use citations. Good luck! Due in class Wednesday September 20, 2017.

Problem Set 1 due ine class Wednesday September 14. Problems 2.1, 2.2, 2.3, 2.4, 2.5, and 2.6 from Ryden (second edition).

Problem Set 2 due in class Wednesday October 11. Problems 4.1, 4.2, 4.3, 5.1, 5.2, 5.5, and 5.9 from Ryden (second edition). Additional problem: Read Loeb (1998) that is linked to from the course webpage. Write a short (1 paragraph) summary of the paper. Derive equation 2 for yourself. Comment on the observational proposal -- is the argument pessimistic or optimistic?

Problem Set 3 due in class Wednesday November 15. Problems 6.1, 6.2, 6.3, 6.6, 7.1, 7.2, 7.5 from Ryden (second edition).

Problem Set 4 due by Monday December 11. Problems 8.2, 8.4, 9.1, 9.2 from Ryden (second edition). Additionally, do the introductory and intermediate tutorials to the CMB on Wayne Hu's webpage linked above. Please write a brief essay explaining the relationship between the CMB fluctuation power spectrum and the relevant cosmological parameters (e.g., curvature, matter density, baryon density, etc.), as well as summarizing the related physics. Additional research problem: Using VIZIER, cross the Lusso et al. (2016) sample with that of Shen et al. 2013 and the WISE catalog from Cutri et al. (2013) (as linked in the email). Determine the 4.6 micron rest-frame flux density (in mJy) and determine the ratio f_2500 (from S11) to f_4.6. Note that you will need to make what we call a "k-correction." See the Hogg link above. Make a plot of this vs. Lbol (from S11). Email me your data table. OK to work in group of 2-3. We will go from there. REVISION: Given my own results I shared in class, please focus just on the Lusso et al. (2016) table 1 (the detections) and the benefits of including Gamma_x in the prediction of the UV luminosity. Think about what single figure would show this best. I suggest looking at the correlation of Gamma_x with the residuals of an alpha_ox based prediction of L_UV, and perhaps the residuals before/after a prediction that also includes Gamma_x. We'll want numbers describing the correlations and the standard deviations of the residual distributions.

Links/items you might find of use (will be regularly updated):

Also helpful for the homework, and life/research in general, are a number of statistics packages. Freely available code from the Penn State Astrostatics group is available from their webpage.. Gaussfit, from the Texas astronomy statistics people, is available from their webpage.. Also, here at UW on the campus PCs you can use minitab. If you're interested writing your own codes, the Penn State papers/webpage is probably the place to get the equations with derivations, and is the best source for analyzing censored data. Gaussfit is a powerful, general fitting program. Minitab is probably the simplest for quick look analysis. Many people in the department swear by IDL, which Chip Kobulnicky will use in his grad class. Python is the new big thing.

Ned Wright's webpage which includes tutorials at a range of levels as well as his very useful javascript cosmology calculator.

Wayne Hu's webpage which includes great tutorials at a range of levels, and many of them!

An on-line source about LaTeX.

AASTeX website is your one-stop shopping for LaTeX templates (samples and downloads) and additional documentation.

A plotting package I particularly like is called Super Mongo. It is called from linux with "sm". The linked page has sm manuals, examples, and more.

An on-line resource you'll find useful is NED, which stands for NASA Extragalactic Database. It's good for finding out about individual objects as well as a source of review papers.

I use IRAF to do my data reduction and analysis. IRAF is documented in a number of places (as it different parts are written in a number of places). The usually most useful site, is from NOAO, and it has tutorials for basic CCD image/spectroscopy reductions.

NASA's Astrophysical Data System, or ADS, is very useful, primarily as a way to look up papers online. Suggested exercise: look up the papers by the astronomers in the department.

Astronomy Picture of the Day is a great webpage to visit every day.

So is the astro-ph preprint server.