Xtend NXB Spectral Model

Xtend NXB spectral model version 1

NXB model: xtend_nxb_average.mo

Corresponding RMF: xtend_nxb.rmf

When fitting data and model, don't apply the source RMF and ARF to the background model, but use only the RMF above instead and without ARF. The model will be entered as model 2.

data 1:1 <data>

resp 1:1 <rmf>

arf 1:1 <arf>

resp 2:1 xtend_nxb.rmf

• Time-averaged spectral model for FoV but 360 < DETY < 1440 (to avoid Fe-55 out-of-time events)
• Phenomelogical model, consists of continuum (PL) and several gaussians
• Event selection criteria:
• (abs(rawy-0)>3 && abs(rawy-80)>3 && abs(rawy-160)>3 && abs(rawy-240)>3 && abs(rawy-320)>3 && abs(rawy-400)>3 && abs(rawy-480)>3 && abs(rawy-560)>3) && (grade==0 || grade==2 || grade==3 || grade==4 || grade==6) && status[1]==b0 && status[2]==b0 && DETY>360 && DETY<1440 && SAA==0 && ELV<-5 && DYE_ELV>100 && T_SAA_SXI>300
• Changing normalization without changing shape will be sufficient for most cases.
• Notes
• Normalization depends on detector coordinates, COR, and time.
• There might be detector coordinate dependence of spectral shape.
• Check energy scale as it changes with time.
• Some faint detector lines such as Al-K are not included.
• High solar activity may enhance the NXB and modify the spectral shape.
• Average NXB spectrum vs. model
• 
• Example of a simultaneous fit for source & NXB spectra (spectral model used: n132d_xtend_test.mo). In this example, the N132D spectrum '000126000_xtend_circle.pi' is fit with both a source model (model 1) and the NXB model (model 2); and the NXB spectrum is fit with just the NXB model (model 2). The model 2 parameters are tied between N132D and the NXB spectrum. Replace the source data, RMF, and ARF here with the versions for your own observation.
#N132D spectrum
data 1:1 000126000_xtend_circle.pi
resp 1:1 xtend_source.rmf
arf 1:1 xtend_source.arf
resp 2:1 xtend_nxb.rmf
#NXB spectrum
data 2:2 xtend_nte_scaled.pi
resp 2:2 xtend_nxb.rmf
@n132d_xtend_test.mo
setp com r x 1.0 13.
ig *:*
no *:1.0-13.
pl ld


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