Which type of electromagnetic radiation do astronomers use to look at neutron stars?

Which type of electromagnetic radiation do astronomers use to look at neutron stars?

Explanation:

We can hunt for hot neutron stars by looking for X-ray sources. Although most of the light from neutron stars is emitted at X-ray wavelengths, the nearest neutron star can also be glimpsed at visible wavelengths.

Gamma radiation

Explanation:

Gamma radiation is used to generate electricity using RTG (radioisotope Thermoelectric Generator). But they must produce it using nuclear reaction because gamma radiation from space is insufficient for that purpose.