ObservationalCosmology

Y4 Assessment

The use of "high" redshift supernovae (SN) as standard candles is one of the prime tools to measure the cosmological parameters. In fact, Perlmutter, Schmidt and Reiss were awarded the 2011 Nobel Prize in Physics for "the discovery of the accelerating expansion of the Universe through observations of distant supernovae".

Here you can find the data set that was used in 1999 to produce one of the first results. The file contains the data reported in Tables 1 and 2 of Perlmutter et al. (1999) - see also Perlmutter et al. (1997) and Perlmutter et al (1998) and Riess et al (1998) - in a format that is hopefully useful for numerical manipulations (I have removed the SN id - first column on the Tables in the paper - and the entry in the last column; the rest of the columns are organised exactly as Table 1 and 2, whose data have been merged in this single file.)

The goal of this assignment is to use the data set that I have provided you with, to produce your estimate of the (relevant) cosmological parameters. You should report you results by writing a short (a few pages) report detailing:

1. How high-z SN can be used to measure the cosmological parameters; [3]
2. The method that you've used in your analysis with the necessary details; [8]
3. The estimates of the cosmological parameters coming out of your analysis; [7]
4. The possible limitations/challenges of using high-z SN for determining the cosmological parameters; [4]
5. Other methods that can be/are used to complement high-z SN for precise measurements of the cosmological parameters. [3]

In working on your assignment you may find useful:

• The pedagogical paper by D. Hogg, "Distance measures in cosmology" (1999) which contains many ready-to-use formulae;
• The report of the dark energy task force.

This work counts for 25% of the total score. The split of the marks for the different parts of the assignment is shown above in brackets.

The deadline for submission of the report is Friday 13 December, 2019 at 3:30pm. The report should be uploaded to the canvas page, where it will also undergo plagiarism checks. Also email me a copy of any code (ideally as a tarball) you have in making the results in your report.