R markdown: how to insert space between images

I want to add two images side by side in R markdown, but with some space between them.
How can I adjust the space between the images? Thank you!

![](/Users/filename/black.png){width=50%} 
![](/Users/filename/gray.png){width=50%}

>Solution :

One option could be using ggdraw() + draw_image from {cowplot}

---
title: "Untitled"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```


```{r side_by_side, fig.align='center'}

library(cowplot)

ggdraw() + 
  draw_image("test_logo.png", width = 0.4) + 
  draw_image("test_animal.jpg", width = 0.4, x = 0.5)

```

Which looks like