NICER observation list: Target ID 358601

Abstract

We propose to use the advanced energy and time resolutions of NICER to search and identify ashes of thermonuclear burning during strong X-ray bursts from the neutron star in the ultra-compact low mass X-ray binary 4U 1820-30. Indeed, the released flux does temporarily drive the photosphere to large radii, ejecting nuclear burning ashes that can imprint the burst spectra. It has been proven that numerous bursts from this source observed with NICER can significantly improve the potential to measure several lines. A positive detection and identification of spectral features from a number of heavy elements will constrain the thermonuclear burning processes as well as the gravitational redshift from the neutron star.
Obsid RA DEC l b Start End Exposure Number of
Modules		 Number of
Processing		 Status of
Processing		 Date of
Processing		 Public
date
3586010101 275.919 -30.361 2.788 -7.914 59163.8076 59163.8375 531.0 46 3 VALIDATED 59167.7 59177
3586010102 275.919 -30.362 2.788 -7.914 59164.3877 59164.9956 650.0 46 4 VALIDATED 59169.6 59178
3586010103 275.919 -30.362 2.788 -7.914 59165.4212 59165.5120 301.0 46 3 VALIDATED 59169.7 59179
3586010104 275.919 -30.361 2.789 -7.913 59166.8039 59166.9361 518.0 51 3 VALIDATED 59170.7 59180
3586010105 275.919 -30.360 2.789 -7.913 59166.9980 59167.2588 474.0 51 3 VALIDATED 59171.6 59181