The Assignment

This is our first assingment, and you should treat it like a half-semester take home exam, which is very much what it is, because it goes towards your assessment. The assignment has been handed out to you on the $20^{\textrm{\scriptsize th}}$ of October and you have a fortnight to complete it, i.e., it is due on the $3^{\textrm{\scriptsize rd}}$ of November.

• Table 2.5 shows some selected data from a paper by G. A. Tammann and Allan Sandage.
• The data corresponds to the maximum observed B-band and V-band magnitudes ( $m_V(\hbox{max})$ and $m_B(\hbox{max})$) of Supernovae of type Ia, observed over many years in various galaxies of the Virgo cluster, versus their redshift velocities.
• Only galaxies whose redshift velocities are greater than $1179\,\textrm{km}\,\textrm{s}^{-1}$ are taken into account. The velocities are corrected for the effect of the Virgo Cluster deceleration on the local expansion field using an infall velocity of $220\,\textrm{km}\,\textrm{s}^{-1}$.
• Columns 5 and 7 contain uncertainties in $m_V(\hbox{max})$ and $m_B(\hbox{max})$ respectively. The redshift velocity is measured with such accuracy that for the purpose of this calculation it can be assumed exact.

 

Table 2.5: Data from Tammann and Sandage

SN	Galaxy	$\log{v_{220}}$	$m_B(\hbox{max})$	$\pm$	$m_V(\hbox{max})$	$\pm$
1956A	NGC3992	3.161	12.7	0.1	12.5	0.1
1959C	UGC8263	3.512	13.7	0.1	13.8	0.1
1961D	M05/30/101	3.894	16.5	0.1	16.7	0.1
1962A	M05/31/132	3.804	15.6	0.1	15.7	0.1
1962E	M04/27/10	4.154	17.4	0.1	17.5	0.1
1964E	NGC6983	3.178	12.6	0.1	12.1	0.1
1965I	NGC4753	3.211	12.5	0.1	12.7	0.1
1966K	NGC3074	3.992	17.0	0.1	17.0	0.1
1967C	NGC3389	3.185	13.3	0.1	13.3	0.1
1969C	NGC3811	3.538	14.15	0.1	14.1	0.1
1970J	NGC7619	3.589	14.35	0.1	14.6	0.1
1971G	NGC4165	3.337	14.2	0.1	14.2	0.1
1971L	NGC6384	3.284	13.1	0.1	12.6	0.1
1972J	NGC7634	3.512	14.35	0.1	14.6	0.1
1973N	NGC7495	3.698	15.4	0.1	15.1	0.1
1974J	NGC7343	3.882	15.65	0.1	15.9	0.1
1975N	NGC7723	3.270	13.65	0.1	13.45	0.1
1976J	NGC977	3.650	15.05	0.1	15.15	0.1
1979B	NGC3913	3.127	12.7	0.1	12.4	0.1
1980N	NGC1316	3.158	12.49	0.01	12.44	0.01
1981B	NGC4536	3.072	12.00	0.01	11.96	0.01
1981D	NGC1316	3.158	12.59	0.01	12.40	0.01
1983G	NGC4753	3.211	13.1	0.1	12.8	0.1
1984A	NGC4419	3.072	12.3	0.1	12.2	0.1
1990N	NGC4639	3.072	12.70	0.01	12.61	0.01
1990af	Anon	4.176	17.86	0.01	17.81	0.01
1991T	NGC4527	3.072	11.64	0.01	11.48	0.01
1991ag	IC4919	3.621	14.72	0.01	14.62	0.01
1992A	NGC1380	3.158	12.60	0.01	12.55	0.01
1992P	IC3690	3.879	16.11	0.01	16.13	0.01
1992ae	Anon	4.351	18.50	0.01	18.42	0.01
1992aq	Anon	4.485	19.34	0.01	19.25	0.01
1992bc	ESO300/G9	3.781	15.17	0.01	15.24	0.01
1992bo	ESO352/G97	3.753	15.86	0.01	15.85	0.01

 

• Develop a Fortran (F90!) program to

  1.

  Read the data from a file virgo.dat, which you will find in

  /afs/ovpit.indiana.edu/common/www/htdocs/gustav
  

  You can copy that file to your working directory. The program should be constructed so that it can read any reasonable (in this context) amount of data without having to predefine arrays of fixed length.

  2.

  The data should then be transferred onto an HDF file as scientific data sets, and annotated by attaching attributes to the data sets and to the file itself. Use separate data sets for $\log{v_{220}}$, $m_B(\hbox{max})$, $\sigma_B$, $m_V(\hbox{max})$, and $\sigma_V$.

  3.

  The same, or another program, should then perform $\chi ^2$ fitting in order to model $m_B\left(\log{v_{220}}\right)$ and $m_V\left(\log{v_{220}}\right)$ as linear relationships of the form
  

  $$m_{[B,V]} = a_{[B,V]} + b_{[B,V]} \log{v_{220}}$$

  
  

  4.

  Evaluate uncertainties in a_B, a_V, b_B and b_V, as well as the goodness of fit, Q_B and Q_V.

  5.

  Write the results back onto the HDF file as a file attribute.

  6.

  Write a Fortran (F90!) program to read the HDF file, extract all file and data set attributes, and print them on standard output.

  7.

  Remember that you must disconnect from every attached scientific data set and from the file itself, at the end, before quitting the program.

  8.

  All programs should be managed by RCS and should have Makefiles provided for them. Assume GNU make.

  9.

  Optionally you may wish to annotate the programs using FWEB.

  10.

  Programs developed within this assignment should be placed in your AFS directory, subdirectory assignment_1. Provide a Readme file describing compilation and use.