Simulations for Xray Binaries with e XTP Xiangdong

Simulations for X-ray Binaries with e. XTP Xiangdong Li(NJU), Long Ji(IHEP), and Mingyu Ge(IHEP) 2015 -10 -27

Science Objectives • The magnetic field distribution of neutron stars in X-ray binaries, and their relation with Lx • Mechanisms of the spectral state changes and k. Hz QPOs • The spin frequency distribution of neutron stars in X-ray binaries 2

1. Magnetic field • Detection of assumed cyclotron absorption line in IGR J 16328− 4726 within 10 -100 ke. V • Burst state: peak flux ~10 m. Crab，continnum model: wabs*cutoffpl or wabs*powerlaw*highecut (Romano et al. 2013) 3

Spectral Models Gaussian absorption line and continuum Model 1 Model 2 With s =15，EW=[5, 10, 15, 20]， EC=[10, 20, 30, 40, 50, 60, 70](ke. V) 4

Simulation Results • With 1 ks exposure times, large error bars prevent constraining EW and EC of the Cyclotron absorption line for XTP • If exposure time 10 ks or 100 ks, the Cyclotron absorption line can be measured with high significance, comparing with Swift and Integral 5

Simulation Results with 10 ks exposure for XTP Left: simulated spectral；Right: residuals if the Cyclotron absorption line is not included 6

Simulation Results with 10 ks exposure for e. XTP No significant improvement including LAD 7

Targets Mode Exposur Note e（ks） IGR J 16328− 4726 Pointing 10 SFXT GX 301 -2 Pointing 10 Magnetar (? ) SXP 1062 Pointing 100 Magnetar (? ) （associated with SNR） 4 U 2206+54 Pointing 10 Magnetar (? ) Her X-1 Pointing 10 Long-term decay of Ecyc Cep X-4 Pointing 10 Positive/negative correlation between Ec and Lx 4 U 1822 -37 Pointing 10 High B NS in a LMXB Cir X-1 Pointing 10 Youngest LMXB (associated with SNR) M 82 X-2 Pointing 100 NS ULX 8

2. LMXB timing and spectrum • Evolution of M-dot on the Color-Color diagram (CCD) • Parallel tracks of k. Hz QPO 4 U 1608 -52 9

Sco X-1: spectral components and luminosity • Spectral components ：Compton, reflection and hard power law D: distance，FTT and FPEG : Comptonization , reflection and power law，TDB : temperature at the inner radius of the accretion disk D’Ai et al. 2007 (Ap. J, 667, 411) 10

Simulation for CCD • Simulation processes： （1） Spectra calculation: convolved with ARF and RMF(exposure: 256 s) （2）Light curve simulation: time resolution 1 s （3）CCD calculation • Sco X-1 Data (37 -43) from D’Ai et al. 2007 (Ap. J, 667, 411) http: //astro. unituebingen. de/software/idl/aitlib/timing/timm 11

Left：spectra with LFA for obs. of 37 -43 Right：comparison of spectra with XTP LFA, LAD and RXTE/PCU 2 12

RXTE XTP e. XTP CCD 13

X-ray flux versus CCD RXTE e. XTP 14

Simulations for QPO • Assumption: QPO related with Rin of Diskbb Left：QPO frequency vs. Rin, red points are the simulated results，green line is input；Right：QPO frequency vs. flux 15

RXTE • Results for RXTE PCA with the same parameters 16

QPO frequency versus photon energy QPO RMS=20%，exposure 512 s RXTE e. XTP QPO frequency versus photon energy (Δf=50 Hz) 17

QPO frequency versus Fe line Assumption: QPO frequency and RMS only vary with Fe line and the RMS reaches its maximum at the Fe line energy. RXTE e. XTP 18

4 U 1728 -34: k. Hz QPO RMS and Q factor versus energy with e. XTP and RXTE 19

Summary • The properties of QPO versus energy • The spectra components are determined better than with RXTE PCA because of good energy resolution of e. XTP • Measurements of RMS and Q factor for e. XTP are better than with RXTE/PCA, especially in low energy band (<3 ke. V) and high energy band(>10 ke. V) 20

3. Spin frequency measurements for neutron star with accretion • Sco X-1，the limits for the pulse fraction • Exposure: 10 ks or 100 ks • Simulation: the pulse signal added to the light curve with different pulse fractions 21

Exposure: 10 ks 22

Exposure: 100 ks 23

Results with e. XTP 1. 37 Ms 24

Summary • If exposure 10 ks, pulse fraction limit ~0. 05% • More exposure time needed if pulse fraction <0. 05% • Detection efficiency higher than RXTE 25

Targets Mode Exposure Notes （ks） Sco X-1 Pointing 100 first XRB discovered 4 U 1728 -34 Pointing 100 Cir X-1 Pointing 100 youngest LMXB Aql X-1 Pointing 100 intermittent accreting X-ray pulsar 26

Thank you! 27