Magnetic tape cartridge and magnetic recording and reproducing device

A magnetic tape cartridge comprising:

• a magnetic tape which is wound around a cartridge reel and accommodated in the magnetic tape cartridge,
• wherein the magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder,
• the magnetic layer includes a plurality of servo bands,
• a magnetic tape deformation amount after storage in an environment of a temperature of 16° C. and relative humidity of 20% for 3 months, storage in an environment of a temperature of 16° C. and relative humidity of 80% for 3 months, storage in an environment of a temperature of 26° C. and relative humidity of 80% for 3 months, storage in an environment of a temperature of 32° C. and relative humidity of 20% for 3 months, and storage in an environment of a temperature of 32° C. and relative humidity of 55% for 3 months is 0.50 um or less,
• a rate of a change in magnetic tape deformation amount with respect to a change in relative humidity, which is obtained from five magnetic tape deformation amounts each measured after the storage in five environments described above, is 0.0001 μm/% to 0.0500 μm/%,
• a rate of a change in magnetic tape deformation amount with respect to a change in temperature, which is obtained from the five magnetic tape deformation amounts, is 0.0010 μm/° C. to 0.1000 μm/° C., and
• a standard deviation of a position error signal denoted as σPES is 45 nm to 70 nm.