Hints and Comments

• You may have to read up more on string manipulation in Fortran. You will find ``Fortran-90 Handbook'' available on-line at

  http://beige.ucs.indiana.edu:8888/
  

  In particular, you may wish to use the following features of Fortran:

  1.

  You can use Fortran write statement to write on a string instead of writing on a logical unit. This is equivalent to sprintf in C.

  2.

  Remember that Fortran strings should be padded with spaces (you may have to pad them yourself on creation), and Fortran function len_trim returns a non-space length of a space padded string. Fortran string concatenation operator, //, is quite useful in manipulating strings too.

• The HDF documentation can be found in

  /afs/ovpit.indiana.edu/common/doc/HDF/Users_Guide
  

  The manual ug41r2.pdf can be read on-line with acroread. In particular you will probably want to know that HDF flag for a 32-bit floating point number is DFNT_FLOAT32. This and other HDF flags are defined on module hdf, which lives in

  /afs/ovpit.indiana.edu/@sys/HDF/modules
  

  See also ``HDF User's Guide, version 4.1r2, June 1998'', page 2-14 (page 34 in acroread).
• Beware: Fortran HDF examples from the ``User's Guide'' are F77 examples, not F90. An F90 compiler may have problem with them. F77 compiler on the Ships cluster may have problems too. Use g77 instead. g77 can be found in

  /afs/ovpit.indiana.edu/@sys/gnu/bin
  

• Remember that your Fortran programs prepared for this assignment should use F90 features discussed in the lecture. They should not be F77 programs.
• GNU make documentation lives in

  /afs/ovpit.indiana.edu/common/doc/gnu/make-3.76.1
  

  You can read this document using Emacs info too.
• GNU RCS documentation is available as man pages. Try man rcsintro for the beginning.
• FWEB documentation can be found in

  /afs/ovpit.indiana.edu/common/doc/teTeX/fweb-1.62
  

  FWEB documentation is also available via Emacs info.
• Tamman and Sandage paper can be read on-line by connecting to

  http://adsabs.harvard.edu/
  

  Select ADS Article Service, and then go to Online Journals. Click on Astrophysical Journal, and fill volume and page boxes at the top of the page. The volume you want is 452, the page is 16. The article is

  ``The Hubble Diagram for Supernovae of Type Ia. II. The Effect on the Hubble Constant of a Correlation Between Absolute Magnitude and Light Decay Rate.'', G. A. Tammann and Allan Sandage, The Astrophysical Journal, 452, pp. 16-24, 1995, October 10.

• The supernovae of type Ia are considered ideal candles for cosmological measurements, because with very few exceptions they are characterised by nearly identical light curves. In other words a Ia supernova explosion looks always the same and has always the same brightness. The reason for that is that Ia occurs when a white dwarf has accreted so much mass from its companion that it detonates on reaching the Chandrasekhar limit. Because the initial condition is nearly the same for all such events, they unfold in much the same way too.
• In case of any problems or difficulties contact me electronically, by phone, or in person. My CU-SeeMe address is 129.79.207.179.