We observed the isolated neutron star RX J0720.4-3125 with Chandra's Low Energy Transmission Grating Spectrometer, following the XMM-Newton discovery of the long-term spectral evolution of this source. The new observation shows that the spectrum of RX J0720.4-3125 has continued to change in the course of 5 months. It has remained hard, similar to the last XMM-Newton observation, but the strong depression observed with XMM-Newton at long wavelengths has disappeared. Contrary to the XMM-Newton observations, the new Chandra observation shows that the flux increase at short wavelength and the decrease at long wavelength do not necessarily occur simultaneously.
The Astrophysical Journal
- Pub Date:
- July 2004
- Stars: Individual: Alphanumeric: RX J0720.4-3125;
- Stars: Neutron;
- X-Rays: Stars;
- To be published in the Astrophysical Journal Letters. Contains 4 pages with 3 figures, including 1 color figure