THE GOAL AS OUTLINED IN THE PROPOSAL IS TO OBTAIN A PHASE CONNECTED TIMING SOLUTION FOR LE 1207.4-5209 FOLLOWING AN APPARENT GLITCH. WE WILL PIECE TOGETHER A NEW TIMING SOLUTION USING ALL THE AVAILABLE MULTI-MISSION OBSERVATIONS FOR THIS PULSAR. WE WILL EXTRACT TOA MEASUREMENTS FROM EACH OBSERVATIONS AND FIT THEM COLLECTIVELY USING THE TEMPO SOFTWARE PACKAGE. WE WILL REDUCE AND ANALYZE DATA FROM THE 5 PROPOSED XMM-NEWTON OBSERVATIONS ALONG WITH 4 CHANDRA OBSERVATIONS OBTAINED AS PART OF A ON-GOING MULTI-YEAR PROPOSAL. OUR HOPE IS TO OBTAIN A NEW TIMING EPHEMERIS FOR LE 1207.4-5209 THAT TAKES INTO ACCOUNT EVERY TURN OF THE PULSAR. WE WILL COMPARE THIS NEW EPHEMERIS WITH THE PREVIOUS ONE TO ASSESS THE MAGNITUDE OF THE CHANGE IN SPIN FREQUENCY AND/ OR ITS FREQUENCY DERIVATIVE IN ORDER TO BETTER PROBE THE PHYSICS OF THE NEUTRON STAR. AN IMPORTANT COMPONENT TO THIS ENDEAVOR IS A SIMULTANEOUS SPECTRAL STUDY. WE WILL UNDERTAKE A COMPREHENSIVE PHASE-RESOLVED SPECTRAL ANALYSIS OF THE PULSAR TO LOOK FOR CHANGES BEFORE DURING AND AFTER THE GLITCH.

The Trustees Of Columbia University In The City Of New York

Investigators