Engineering topics

Suchy, Slawomir

Publications and source records attributed to Suchy, Slawomir.

5 records

NASA NTRS2012

Broadband Spectroscopy Using Two Suzaku Observations of the HMXB GX 301-2

We present the analysis of two Suzaku observations of GX 301-2 at two orbital phases after the periastron passage. Variations in the column density of the line-of-sight absorber are observed, consistent with accretion from a clumpy wind. In addition to a CRSF, multiple fluorescence emission lines were detected in both observations. The variations in the pulse profiles and the CRSF throughout the pulse phase have a signature of a magnetic dipole field. Using a simple dipole model we calculated the expected magnetic field values for different pulse phases and were able to extract a set of geometrical angles, loosely constraining the dipole geometry in the neutron star. From the variation of the CRSF width and energy, we found a geometrical solution for the dipole, making the inclination consistent with previously published values.

Suchy, Slawomir↗

NASA NTRS2011

Orbital Parameters and Spectroscopy of the Transient X-Ray Pulsar 4U 0115+63

We report on an outburst of the high mass X-ray binary 4U 0115+63 with a pulse period of 3.6s in spring 2008 as observed with INTEGRAL and RXTE. By analyzing the lightcurves we derive an updated orbital- and pulse period ephemeris of the neutron star. We also study the pulse profile variations as a function of time and energy as well as the variability of the spectral parameters. We find clear evidence for at least three cyclotron line features. In agreement with previous observations of 4U 0115+63, we detect an anti-correlation between the luminosity and the fundamental cyclotron line energy.

Mueller, Sebastian↗

NASA NTRS2011

Suzaku Observations of the HMXB 1A 1118-61

We present broad band analysis of the Be/X-ray transient lA 1118-61 by Suzaku at the peak of its 3rd observed outburst in January 2009 and 2 weeks later when the source flux had decayed by an order of magnitude. The continuum was modeled with a cutoffpl model as well as a compTT model, with both cases requiring an additional black body component at lower energies, We confirm the detection of a cyclotron line at approx. 55 keV and discuss the possibility of a first harmonic at approx. 110 keV. Pulse profile comparisons show a change in the profile structure at lower energies, an indication for possible changes in the accretion geometry, Phase resolved spectroscopy in the outburst data show a change in the continuum throughout the pulse period. The decrease in the CRSF centroid energy also indicates that the viewing angle on the accretion column is changing throughout the pulse period. Subject headings: X-rays: stars - X-rays: binaries - stars: pulsars: individual (lA 1118-61) - stars: magnetic fields

Suchy, Slawomir↗

NASA NTRS2010

4U 1909+07: A Hidden Pearl

We present a detailed spectral and timing analysis of the High Mass X-ray Binary (HMXB) 4U 1909+07 with INTEGRAL and RXTE. 4U 1909+07 is a persistent accreting X-ray pulsar with a period of approximately 605 s. The period changes erratically consistent with a random walk expected for a wind accreting system. INTEGRAL detects the source with an average of 2.4 cps (corresponding to 15 mCrab), but sometimes exhibits flaring activity up to 50 cps (i.e. 300 mCrab). The strongly energy dependent pulse profile shows a double peaked structure at low energies and only a single narrow peak at energies above 20 keV. The phase averaged spectrum is well described by a powerlaw modified at higher energies by an exponential cutoff and photoelectric absorption at low energies. In addition at 6.4 keV a strong iron fluorescence line and at lower energies a black body component are present. We performed phase resolved spectroscopy to study the pulse phase dependence of the spectral parameters: while most spectral parameters are constant within uncertainties, the blackbody normalization and the cutoff folding energy vary strongly with phase.

Kreykenbohm, Ingo↗

NASA NTRS2009

A Comprehensive Spectral Analysis of the X-Ray Pulsar 4U 1907+09 from Two Observations with the Suzaku X-Ray Observatory

We present results from two observations of the wind-accreting X-ray pulsar 4U 1907+09 using the Suzaku observatory, The broadband time-averaged spectrum allows us to examine the continuum emission of the source and the cyclotron resonance scattering feature at approx. 19 keV. Additionally, using the narrow CCD response of Suzaku near 6 ke V allows us to study in detail the Fe K bandpass and to quantify the Fe Kp line for this source for the first time. The source is absorbed by fully-covering material along the line of sight with a column density of N(sub H) approx. 2 x 10(exp 22)/sq cm, consistent with a wind accreting geometry, and a high Fe abundance (approx. 3 - 4 x solar). Time and phase-resolved analyses allow us to study variations in the source spectrum. In particular, dips found in the 2006 observation which are consistent with earlier observations occur in the hard X-ray bandpass, implying a variation of the whole continuum rather than occultation by intervening material, while a dip near the end of the 2007 observation occurs mainly in the lower energies implying an increase in NH along the line of sight, perhaps indicating clumpiness in the stellar wind

Rivers, Elizabeth↗