Development of an xspec-based spectral analysis system for the coded-aperture hard X-ray balloon payload EXITE2

Bloser, Peter F.; Chou, Yi; Grindlay, Jonathan E.; Narita, T.; Monnelly, G.

doi:10.1016/s0927-6505(01)00165-7

Cited by 4 publications

(11 citation statements)

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“…The EXITE2 flux, however, seems rather more in keeping with that expected for the dimmer 1 state: 5:2 ; 10 À4 and 3:5 ; 10 À4 photons cm À2 s À1 keV À1 at 100 keV for the first and the second data sets, respectively (compare to Ling et al 1997). The cause of this discrepancy is unknown; during the same flight, spectral fits to the Crab yielded the correct normalization at 100 keV (Bloser et al 2002). Figure 4 indicates that the hard X-ray flux of Cyg X-1 is variable by $30% on timescales on the order of 10 minutes.…”

Section: Observation Resultsmentioning

confidence: 75%

“…10.0) implementation for coded aperture imaging given by Bloser et al (2002). Inputs to the software included the following files: (1) the Pulse Height Analyzer (PHA) data file containing the count spectrum and detector live time, (2) the redistribution matrix file (RMF) describing the instrument response, and (3) the ancillary response file (ARF) containing additional factors for the response as a function of energy such as the collimator response and the atmospheric attenuation.…”

Section: Spectramentioning

confidence: 99%

“…The response matrix (RMF file) is constructed by modeling the EXITE2 detector, its surrounding materials, its PSD efficiencies, and its image functions with a Monte Carlo simulation using the MGEANT package (Seifert et al 1997). The procedural details for generating the EXITE2 spectra are discussed in further detail in Bloser et al (2002).…”

Section: Spectramentioning

confidence: 99%

“…In recent years, we have designed and developed a hard X-ray imaging coded aperture telescope with the secondgeneration Energetic X-ray Imaging Telescope Experiment (EXITE2, Lum et al 1994;Manandhar 1995;Chou et al 1998;Bloser et al 2002;Chou 2001). The telescope detects and images cosmic X-ray sources in the hard X-ray band from a high-altitude balloon.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, we present the results for the EXITE2 hard X-ray observations of Cyg X-1. Results for the Crab Nebula and 3C 273/GRS 1227+025 are given by Bloser et al (2002) and Grindlay et al (2005), respectively.…”

Section: Introductionmentioning

confidence: 99%

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Observations of Cygnus X‐1 with the EXITE2 Hard X‐Ray Balloon Payload

Chou

Bloser

Grindlay

et al. 2005

ApJ

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We present results from the second-generation Energetic X-ray Imaging Telescope (EXITE2) observations of the black hole X-ray binary Cyg X-1 during the experiment's 1997 and 2001 flights. The EXITE2 phoswich [NaI(Tl)/CsI(Na)] detector is designed to image cosmic X-ray sources in the hard X-ray band by using the codedaperture imaging technique from a high-altitude scientific balloon. The sky image reconstruction methodology used for EXITE2 is also discussed in detail. Background reduction (PSD rejection), subtractive flat-fielding, pixel shuffling, and image functions are introduced. During the observations from the EXITE2 1997 and 2001 flights, Cyg X-1 is easily detected in the 37-237 keV energy range. During the 1997 observations, the spectrum is well fitted by a Comptonization model. The spectral signatures and the observed 100 keV flux, together with the RXTE ASM light curve, indicate that the source was in the typical low state during this observation. Evidence is seen for hard X-ray variability on timescales on the order of 10 minutes. During the 2001 flight the spectrum is best fit by an extended power law with no observable cutoff. This is possible evidence of a transition to the high state, which is indeed seen in the RXTE ASM light curve shortly after our observation.

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Section: Observation Resultsmentioning

confidence: 75%

Section: Spectramentioning

confidence: 99%

Section: Spectramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Observations of Cygnus X‐1 with the EXITE2 Hard X‐Ray Balloon Payload

Chou

Bloser

Grindlay

et al. 2005

ApJ

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MARGIE — minute of arc resolution hard X-ray/gamma ray imaging telescope for an ultra long duration balloon mission

Altice

Cherry

Band

et al. 2002

Advances in Space Research

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EXITE2 Observation of the SIGMA Source GRS 1227+025

Grindlay

Chou

Bloser

et al. 2005

ApJ

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We report the EXITE2 hard X-ray imaging of the sky around 3C273. A 2h observation on May 8, 1997, shows a $\sim$260 mCrab source detected at $\sim4\sigma$ in each of two bands (50-70 and 70-93 keV) and located $\sim$30' from 3C273 and consistent in position with the SIGMA source GRS1227+025. The EXITE2 spectrum is consistent with a power law with photon index 3 and large low energy absorption, as indicated by the GRANAT/SIGMA results. No source was detected in more sensitive followup EXITE2 observations in 2000 and 2001 with 3$\sigma$ upper limits of 190 and 65 mCrab, respectively. Comparison with the flux detected by SIGMA shows the source to be highly variable, suggesting it may be non-thermal and beamed and thus the first example of a ``type 2'' (absorbed) Blazar. Alternatively it might be (an unprecedented) very highly absorbed binary system undergoing accretion disk instability outbursts, possibly either a magnetic CV, or a black hole X-ray nova.Comment: 12 pages, 4 figures, accepted for publication in Ap

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Development of an xspec-based spectral analysis system for the coded-aperture hard X-ray balloon payload EXITE2

Cited by 4 publications

References 11 publications

Observations of Cygnus X‐1 with the EXITE2 Hard X‐Ray Balloon Payload

Observations of Cygnus X‐1 with the EXITE2 Hard X‐Ray Balloon Payload

MARGIE — minute of arc resolution hard X-ray/gamma ray imaging telescope for an ultra long duration balloon mission

EXITE2 Observation of the SIGMA Source GRS 1227+025

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