Additional sections introduced when compiling with Optimizations

I'm currently working on a Windows application, developed in C++ using Visual Studio and the Intel C++ 15.1 compiler.

It would appear that when I compile with any kind of optimizations, a few additional sections appear in the output executable, increasing the size of it by a significant margin, and possibly introducing information that I would otherwise not rather have in a release build.

Here's an outline of the different optimization options and the section they generate from an empty test application I made which simply prints to the console:

Optimization: Disabled (/Od)

        2000 .data
        3000 .data1
        2000 .rdata
        1000 .reloc
       12000 .text

Optimization: Minimize Size (/O1)

        3000 .data
        2000 .data1
        3000 .rdata
        1000 .reloc
        A000 .text
        1000 .text1
        1000 _RDATA

Optimization: Maximize Speed (/O2) or Full Optimization (/Ox) or Highest Optimizations (/O3)

        3000 .data
        3000 .data1
        1000 .debug_o
        3000 .rdata
        2000 .reloc
        E000 .text
        1000 .text1
        1000 _RDATA

I was unable to find any information in regards to those sections in the documentation, so any information as to what their purpose is and whether they can be removed would be greatly appreciated.

Thanks in advance.