NICER observation list: Target ID 261601

Abstract

The unique ultracompact X-ray binary (UCXB) 4U 1626-67 is the only known UCXB hosting a strongly-magnetized, slowly-rotating accreting neutron star. This system has a plethora of interesting properties, with a short (~42 min) orbital period, strong and disk-broadened emission lines of neon and oxygen, an unusually weak and possibly variable iron fluorescence line, a cyclotron resonance scattering feature (CRSF), and variability on short and long timescales. The X-ray variability in particular is essential both for proper interpretation of the spectral lines and for constraining the binary orbit. We are requesting a 40 ks NICER observation, which will give us the opportunity to carry out the most detailed study of variability to date in this source.
Obsid RA DEC l b Start End Exposure Number of
Modules
Number of
Processing
Status of
Processing
Date of
Processing
Public
date
2616010101 248.061 -67.459 321.787 -13.088 58740.6618 58740.9914 2063.0 52 3 VALIDATED 58745.7 58754
2616010102 248.063 -67.460 321.788 -13.089 58741.1106 58741.9604 4705.0 52 3 VALIDATED 58746.7 58755
2616010103 248.065 -67.460 321.788 -13.089 58742.0171 58742.9947 3186.0 52 3 VALIDATED 58746.8 58756
2616010104 248.064 -67.459 321.788 -13.089 58743.0521 58743.1238 1402.0 52 2 VALIDATED 58748.2 58757
2616010105 248.062 -67.460 321.787 -13.089 58746.6445 58746.9308 7503.0 52 2 VALIDATED 58750.7 58760
2616010106 248.069 -67.461 321.788 -13.091 58755.8715 58755.9442 496.0 52 4 VALIDATED 58763.8 58769
2616010107 248.068 -67.460 321.788 -13.091 58755.9982 58756.9778 4264.0 52 3 VALIDATED 58763.8 58770
2616010108 248.069 -67.461 321.788 -13.092 58757.1032 58757.8826 3901.7 52 2 VALIDATED 58764.0 58771
2616010109 248.069 -67.461 321.788 -13.092 58758.0039 58758.0766 819.0 52 4 VALIDATED 58767.6 58772