如何刪除圖形和子圖中標題的居中？

Question

我在刪除圖中標題的居中時遇到麻煩，我justification==justified也嘗試過，但它不起作用。另外，我\raggedright在標題中嘗試過，它將標題移動到左邊距，但這是不合理的（連字符不會出現）。我也嘗試過\usepackage{ragged2e}，\RaggedRight但沒有任何效果。我preprint在文檔類中使用。

\documentclass[preprint,pre,amsmath]{revtex4-2}
\usepackage[pdftex]{graphicx} 
\usepackage{color}
\usepackage{bm}
\usepackage{epsfig}
\usepackage{latexsym}
\usepackage{subcaption}
\usepackage{caption}
\usepackage[font=small,labelfont=bf,justification=justified]{caption}
\begin{document}
\begin{figure}[t]
 \centering
\begin{subfigure}{0.49\textwidth}
     \centering
     \includegraphics[width=1.0\textwidth]{plot1.png}
     %\caption{}
     \label{figa}
 \end{subfigure}
 %\hfill
 \begin{subfigure}{0.49\textwidth}
     \centering
     \includegraphics[width=1.0\textwidth]{plot2.png}
    %\caption{}
    \label{figb}
 \end{subfigure}
% \hfill
 \caption{\raggedright Solar atmosphere temperature-height distribution.Solar atmosphere temperature-height distribution as determined by \cite{15}. Height is given in kilometers measured above zero point where $\tau=1$. Regions of line formation are also indicated. From right to left: photosphere, temperature minimum (4,000K), chromosphere, transition region (8,500K) and Lyman valley (20,000K).}
\label{fig}
\end{figure}
\end{document}