NICER observation list: Target ID 668902
- Proposal Number = 6689
- Target ID = 668902
- Target Name = 4U_1820-303
- Proposal Title = CONSTRAINING THE GEOMETRY IN ACCRETING WEAKLY MAGNETIZED NEUTRON STARS IN LOW MASS X-RAY BINARIES
- PI = ALESSANDRO DI MARCO
- Proposal Category = X-RAY BINARIES
- Cycle number = 6
- Observation Type = NOR
Abstract
Accreting weakly magnetized Neutron Stars in X-ray Binaries are amongst the brightest X-ray sources. Thanks to IXPE, there is now the possibility to have X-ray polarimetric data allowing to disentangle parameters/scenarios which at present can equally describe spectral/temporal properties of these sources. IXPE, during its 2nd observing period, will observe Sco X-1, for which there are hints for a polarization above 4keV, 4U 1820-303 and Cir X-1, whose polarization has never been studied before. However, these sources are highly variable: therefore, we propose a simultaneous 100ks NICER and IXPE observation to monitor their energy spectra. NICER s better energy resolution allows obtaining a better spectral model reducing the free parameters in the joint IXPE spectro-polarimetric analysis.
| Obsid |
RA |
DEC |
l |
b |
Start |
End |
Exposure |
Number of
Modules |
Number of
Processing |
Status of
Processing |
Date of
Processing |
Public
date |
| 6689020101 |
275.918 |
-30.360 |
2.789 |
-7.912 |
60049.0508 |
60049.9671 |
10270.0 |
51 |
7 |
VALIDATED |
60069.8 |
60063 |
| 6689020102 |
275.919 |
-30.360 |
2.789 |
-7.913 |
60050.0209 |
60050.9521 |
13698.0 |
51 |
4 |
VALIDATED |
60062.1 |
60064 |