Typography: general typing rules

The following should be used to improve the readability of the text:

Their use is best explained in the following example.

Vectors:

\vec{Symbol}, vectors may only appear in math mode.

Input examples:
$\vec{A} \times \vec{B} \cdot \vec{C}$

$\vec{A\/}^{\rm T} \otimes \vec{B} \otimes \vec{\hat D}$

Tensors:

\tens{Symbol}], tensors may only appear in math mode.

Input example:
\tens{ABC}

Ions:

\ion{<element symbol>}{<degree of ionization>}, the degree of ionization in the \ion command has to be given as lower case roman numerals (e.g. \ion{H}{ii} which yields H II).

Input examples:
\ion{H}{II}

\element[ ][13]{C}

Elements:

\element[<electrical charge>][<number of nucleons>] [<number of protons>]
[<number of neutrons>]{<element symbol>}
Note, that if you want to have for example ¹³C, the last two optional arguments may be omitted: \element[ ][13]{C}.

 

Signs and characters

You may need to use special signs. The available ones are listed in different books (LaTeX User's Guide & Reference Manual, The LaTeX Companion, etc.). We have created further common astronomy symbols:

In	Explanation	Out	In	Explanation	Out
\sun	sun symbol		\fs	fraction of second
\degr	degree		\fdg	fraction of degree
\diameter	diameter	Ø	\fp	fraction of period
\farcs	fraction of arcsecond
\fd	fraction of day		\farcm	fraction of arcmin
\arcsec	arcsecond		\fh	fraction of hour
\arcmin	arcminute		\fm	fraction of minute

 

In	Out	In	Out
\la		\ga
\cor		\sol
\sog		\lse
\gse		\grole
\leogr		\loa
\goa		\getsto
\lid		\gid

 

Mathematical formulae

All equations that you are referring to with \ref must have the corresponding \label - please use this mechanism only. Punctuate a displayed equation in the same way as ordinary text.

\left(     \left[

\right)     \right]

 

 

Note that the sizes of the parentheses or other delimiter symbols used in equations should ideally match the height of the formulas being enclosed. This is automatically taken care of by these LaTeX commands.

Italic and roman type in the math mode

In math mode LaTeX treats all letters as though they were mathematical or physical variables; hence they are typeset in italics. However, any textual elements within formulas should be set in roman. Roman should also be used for subscripts and superscripts in formulas where these are merely labels and not in themselves variables, e.g.

$T_\mathrm{eff} =
5\times 10^{9}\ \mathrm{K}$	produces
$T_\mathrm{K}$	produces	TK (K = Kelvin)
$m_\mathrm{e}$	produces	me (e = electron)

However, do not use roman if the subscripts or superscripts represent variables, e.g. . Please ensure that physical units (e.g. pc, erg s^-1 K, cm^-3, W m^-2 Hz^-1, m kg s^-2 A^-2) and abbreviations such as Ord, Var, GL, SL, sgn, const. are always set in roman type with an appropriate inter-word spacing. To ensure this, use the \mbox command: \mbox{Hz}.

On p. 44 of the LaTeX User's Guide & Reference Manual (2nd ed.) by Leslie Lamport, you will find the names of common mathematical functions, such as log, sin, exp, max, and sup. These should be coded as \log, \sin, \exp, \max, \sup and will then automatically appear in roman.

In order to distinguish "d" used as the "differential sign" and "e" used as the "exponential function" from normal variables, set these letters in roman. Chemical symbols and formulas should be set in roman, e.g. Fe not Fe, H₂O not H₂O, H not H.