Intimate photos of two of Mexico’s most famous artists are headed to auction at Sotheby’s tomorrow in New York.

One shows Frida Kahlo with her head wrapped in bandages.

Another shows Diego Rivera posing with a gas mask.

The images date from 1925 to 1946 and are among 78 portraits by the renowned Hungarian-born American photographer Nickolas Muray, who had a decade-long affair with Kahlo after meeting her in 1931.

Each will be auctioned as part of Sotheby’s “Photographs” sale; each with a starting price of $15,000.

There are at least 20 photographs of Kahlo, Rivera or both of them together.

The collection can be seen at the auction house in New York or online on Sotheby’s web site.