[Tex/LaTex] cases-like without brace

Question

I want to know if there is a cases-like environment which has no braces?
I want to do the following without a curly brace:

\documentclass[12pt]{scrartcl}

\usepackage{amsmath}
\usepackage{mathtools}    
\begin{document}
\begin{equation*}
        \begin{cases}
            I^{(r)} = I_0 - \frac{\int_{A_{1,i}} \langle \vec{S} \rangle_t d\vec{A}}{\int_{A_1}d\vec{A}} \\
            I^{(t)} = \frac{\int_{A_{2,i}} \langle \vec{S} \rangle_t d\vec{A}}{\int_{A_2}d\vec{A}} \\
        \end{cases}
        \text{mit $i$ beliebig, fest}
    \end{equation*}
\end{document}

which produces:

But this is not what I want. I want this, without the brace.
Many thanks in advance.

Answer 1

You can use aligned environment:

\documentclass[12pt]{scrartcl}

\usepackage{amsmath}
\usepackage{mathtools}    
\begin{document}
\begin{equation*}
        \begin{aligned}
            &I^{(r)} = I_0 - \frac{\int_{A_{1,i}} \langle \vec{S} \rangle_t d\vec{A}}{\int_{A_1}d\vec{A}} \\
            &I^{(t)} = \frac{\int_{A_{2,i}} \langle \vec{S} \rangle_t d\vec{A}}{\int_{A_2}d\vec{A}} \\
        \end{aligned}
        \qquad\text{mit $i$ beliebig, fest}
    \end{equation*}
\end{document}