We investigated the time-averaged high-energy spectral characteristics of the persistent anomalous X-ray pulsars (AXPs) 1RXS J1708-4009, 4U 0142+61, 1E 2259+586, and 1E 1048.1-5937, using RXTE PCA ...(2-60 keV), RXTE HEXTE (15-250 keV), and INTEGRAL IBIS ISGRI (20-300 keV) data. We discovered hard spectral tails for energies above 10 keV in the total and pulsed spectra of AXPs 1RXS J1708-4009, 4U 0142+4009, and 1E 2259+586, but 1E 1048.1-5937 appeared to be too weak to be detected. Improved hard X-ray spectral information for AXP 1E 1841-045 is also presented. The pulsed and total spectra above 10 keV have power-law shapes, and there is so far no significant evidence for spectral breaks or bends up to 6150 keV. The pulsed spectra above 10 keV are exceptionally hard with indices for four AXPs in the range -1.0 to 1.0. Below 10 keV these indices were in the range 2.0-4.3, indicating the very drastic spectral changes in a narrow energy interval around 10 keV. The best-fit power-law models to the total spectra between 610 and 150 keV are significantly softer, with indices measured for 1E 1841-045, 1RXS J1708-4009, and 4U 0142+61 in the range 1.0-1.4. For the latter AXPs the pulsed fractions are consistent with 100% around 100 keV but are different at 10 keV: 610% for 4U 0142+61, 625% for 1E 1841-045, and consistent with 100% for 1RXS J1708-4009. The luminosities of these total and pulsed spectral tails (10-150 keV) largely exceed the total available spin-down powers by factors ranging from 6100 to 6600. We also reanalyzed archival CGRO COMPTEL (0.75-30 MeV) data: no AXP detections can be claimed, and the obtained upper limits indicate for 1RXS J1708-4009,4U 0142+61, and 1E 1841-045 that strong breaks or bends must occur somewhere between 6150 and 750 keV. We discuss predictions from first attempts to model our hard X-ray and soft gamma-ray spectra in the context of the magnetar model.
ABSTRACT We present new Chandra and XMM-Newton observations of a sample of eight radio-quiet (RQ) γ-ray pulsars detected by the Fermi Large Area Telescope. For all eight pulsars we identify the X-ray ...counterpart, based on the X-ray source localization and the best position obtained from γ-ray pulsar timing. For PSR J2030+4415 we found evidence for a ∼10″-long pulsar wind nebula. Our new results consolidate the work from Marelli et al. and confirm that, on average, the γ-ray-to-X-ray flux ratios (Fγ/FX) of RQ pulsars are higher than for the radio-loud (RL) ones. Furthermore, while the Fγ/FX distribution features a single peak for the RQ pulsars, the distribution is more dispersed for the RL ones, possibly showing two peaks. We discuss possible implications of these different distributions based on current models for pulsar X-ray emission.
Millisecond pulsars (MSPs) are a growing class of gamma-ray emitters. Pulsed gamma-ray signals have been detected from more than 40 MSPs with the Fermi Large Area Telescope (LAT). The wider radio ...beams and more compact magnetospheres of MSPs enable studies of emission geometries over a broader range of phase space than non-recycled radio-loud gamma-ray pulsars. We have modeled the gamma-ray light curves of 40 LAT-detected MSPs using geometric emission models assuming a vacuum retarded-dipole magnetic field. We modeled the radio profiles using a single-altitude hollow-cone beam, with a core component when indicated by polarimetry; however, for MSPs with gamma-ray and radio light curve peaks occurring at nearly the same rotational phase, we assume that the radio emission is co-located with the gamma rays and caustic in nature. The best-fit parameters and confidence intervals are determined using a maximum likelihood technique. We divide the light curves into three model classes, with gamma-ray peaks trailing (Class I), aligned (Class II), or leading (Class III) the radio peaks. Outer gap and slot gap (two-pole caustic) models best fit roughly equal numbers of Class I and II, while Class III are exclusively fit with pair-starved polar cap models. Distinguishing between the model classes based on typical derived parameters is difficult. We explore the evolution of the magnetic inclination angle with period and spin-down power, finding possible correlations. While the presence of significant off-peak emission can often be used as a discriminator between outer gap and slot gap models, a hybrid model may be needed.
Purpose
Inguinal-related groin pain (IRGP) in athletes is a multifactorial condition, posing a therapeutic challenge. If conservative treatment fails, totally extraperitoneal (TEP) repair is ...effective in pain relief. Because there are only few long-term follow-up results available, this study was designed to evaluate effectiveness of TEP repair in IRGP-patients years after the initial procedure.
Methods
Patients enrolled in the original, prospective cohort study (TEP-ID-study) were subjected to two telephone questionnaires. The TEP-ID-study demonstrated favorable outcomes after TEP repair for IRGP-patients after a median follow-up of 19 months. The questionnaires in the current study assessed different aspects, including, but not limited to pain, recurrence, new groin-related symptoms and physical functioning measured by the Copenhagen Hip and Groin Outcome Score (HAGOS). The primary outcome was pain during exercise on the numeric rating scale (NRS) at very long-term follow-up.
Results
Out of 32 male participants in the TEP-ID-study, 28 patients (88%) were available with a median follow-up of 83 months (range: 69–95). Seventy-five percent of athletes were pain free during exercise (
p
< 0.001). At 83 months follow-up, a median NRS of 0 was observed during exercise (IQR 0–2), which was significantly lower compared to earlier scores (
p
<0.01). Ten patients (36%) mentioned subjective recurrence of complaints, however, physical functioning improved on all HAGOS subscales (
p
<0.05).
Conclusion
This study demonstrates the safety and effectivity of TEP repair in a prospective cohort of IRGP-athletes, for whom conservative treatment had failed, with a follow-up period of over 80 months.
1RXS J170849-400910 is one of four anomalous X-ray pulsars which emit persistent luminous radiation in soft X-rays (<10 keV) as well as in hard X- rays (>10 keV). In this paper we present detailed ...spectral and temporal characteristics over the whole X-ray band. For this purpose data have been used from INTEGRAL, RXTE and XMM-Newton. The hard X-ray (>10 keV) time- averaged total spectrum, accumulated over four years with the imager IBIS- ISGRI onboard INTEGRAL adding up to 5.2 Ms net exposure, can be described by a power law with a photon index Gamma = 1.13 pm 0.06 and extends to similar to 175 keV. The 20-175 keV flux is (7.76 pm 0.34) times 10 super(-11) erg cm super(-2) s super(-1) which exceeds the 2-10 keV (unabsorbed) flux by a factor of similar to 2.3. No evidence for a spectral break is found below 300 keV. Also, no significant long-term time variability has been detected above 20 keV on time scales of 1 and 0.5 year. Pulsed emission is measured with INTEGRAL up to 270 keV, i.e. to much higher energies than the total emission, with a detection significance of 12.3\sigma (20-270 keV). The pulse profiles from 0.5 keV up to 270 keV show drastic morphology changes below similar to 20 keV. Three different pulse components can be recognized in these pulse profiles: 1) a hard pulse peaking around phase 0.8 which contributes to the pulse profiles above similar to 4 keV; 2) a softer pulse which peaks around phase 0.4 not contributing in the hard X-ray domain and 3) a very soft pulse component below 2 keV. A combined time-averaged pulsed spectrum (2.8-270 keV) from INTEGRAL, RXTE-PCA and HEXTE (collected over nine years) can be described with a soft and a hard power-law component: Gamma_{{s}} = 2.79 pm 0.07 and Gamma_{{h}} = 0.86 pm 0.16. In the pulsed spectrum extracted from a 25.5 ks net exposure XMM-Newton observation we find a discontinuity between 2 keV and 3 keV. Above these energies the spectrum is consistent with the spectrum taken with RXTE-PCA. The pulse profiles and the total-pulsed spectrum prove to be stable over the whole nine-years time span over which the data have been taken. Also detailed phase-resolved spectroscopy of the pulsed emission confirms the long-term stability as the spectra taken at different epochs connect smoothly. The phase-resolved spectra reveal complex spectral shapes which do not follow the shape of the total-pulsed spectrum. The spectral shape gradually changes with phase from a soft single power law to a complex multi-component shape and then to a hard single power law. The spectrum switches from a very hard (\Gamma = 0.99 pm0.05) to a very soft (\Gamma = 3.58 pm 0.34) single power- law shape within a 0.1-wide phase interval. The discontinuity measured between 2 keV and 3 keV with XMM-Newton is a result of a curved component. This component which is most apparent within phase interval 0.7- 0.9 significantly contributes in the energy range between 4 keV and 20 keV. It has a very steep spectrum below 5 keV with a photon index Gamma similar to -1.5. From the phase-resolved spectra we identify three independent components with different spectral shapes which together can accurately describe all phase- resolved spectra (2.8-270 keV). The three shapes are a soft power law (\Gamma = 3.54), a hard power law (\Gamma = 0.99) and a curved shape (described with two logparabolic functions). The phase distributions of the normalizations of these spectral components form three decoupled pulse profiles. The soft component peaks around phase 0.4 while the other two components peak around phase 0.8. The width of the curved component ( similar to 0.25 in phase) is about half the width of the hard component. After 4U 0142+61, RXS J1708-40 is the second anomalous X-ray pulsar for which such detailed phase-resolved spectroscopy has been performed. These results give important constraints showing that three dimensional modeling covering both the geometry and different production processes is required to explain our findings.
We report on the results of a deep 1.6 Ms INTEGRAL observation of the Cassiopeia region performed from December 2003 to February 2004. Eleven sources were detected with the imager IBIS-ISGRI at ...energies above 20 keV, including three new hard X-ray sources. Most remarkable is the discovery of hard X-ray emission from the anomalous X-ray pulsar 4U 0142+61, which shows emission up to ~150 keV with a very hard power-law spectrum with photon index $\Gamma = 0.73$ ± 0.17. We derived flux upper limits for energies between 0.75 MeV and 30 MeV using archival data from the Compton telescope COMPTEL. In order to reconcile the very hard spectrum of 4U 0142+61 measured by INTEGRAL with the COMPTEL upper limits, the spectrum has to bend or break between ~75 keV and ~750 keV. 1E 2259+586, another anomalous X-ray pulsar in this region, was not detected. INTEGRAL and COMPTEL upper limits are provided. The new INTEGRAL sources are IGR J00370+6122 and IGR J00234+6144. IGR J00370+6122 is a new supergiant X-ray binary with an orbital period of 15.665 ± 0.006 days, derived from RXTE All-Sky Monitor data. Archival BeppoSAX Wide-Field Camera data yielded four more detections. IGR J00234+6144 still requires a proper identification. Other sources for which INTEGRAL results are presented are high-mass X-ray binaries 2S 0114+650, γ Cas, RX J0146.9+6121 and 4U 2206+54, intermediate polar V709 Cas and 1ES 0033+595, an AGN of the BL-Lac type. For each of these sources the hard X-ray spectra are fitted with different models and compared with earlier published results.
Millisecond pulsars, old neutron stars spun up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" ...rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2.5-millisecond pulsar, PSR J1311—3430. This unambiguously explains a formerly unidentified gamma-ray source that had been a decade-long enigma, confirming previous conjectures. The pulsar is in a circular orbit with an orbital period of only 93 minutes, the shortest of any spin-powered pulsar binary ever found.
The Inguinal Hernia Application (IHAPP) is designed to overcome current limitations of regular follow-up after inguinal hernia surgery. It has two goals: Minimizing unnecessary healthcare consumption ...by supplying patient information and facilitating registration of patient-reported outcome measures (PROMs) by offering simple questionnaires. In this study we evaluated the usability and validity of the app. Patients (≥18 years) scheduled for elective hernia repair were assessed for eligibility. Feasibility of the app was evaluated by measuring patient satisfaction about utilization. Validity (internal consistency and convergent validity) was tested by comparing answers in the app to the scores of the standardized EuraHS-Quality of Life instrument. Furthermore, test-retest reliability was analyzed correlating scores obtained at 6 weeks to outcomes after 44 days (6 weeks and 2 days). During a 3-month period, a total of 100 patients were included. Median age was 56 years and 98% were male. Most respondents (68%) valued the application as a supplementary tool to their treatment. The pre-operative information was reported as useful by 77% and the app was regarded user-friendly by 71%. Patient adherence was mediocre, 47% completed all questionnaires during follow-up. Reliability of the app was considered excellent (
α
> 0.90) and convergent validity was significant (
p
= 0.01). The same applies to test-retest reliability (
p
= 0.01). Our results demonstrate the IHAPP is a useful tool for reliable data registration and serves as patient information platform. However, further improvements are necessary to increase patient compliance in recording PROMs.
The magnetar 1E 1547.0-5408 exhibited outbursts in 2008 October and 2009 January. In this paper, we present in great detail the evolution of the temporal and spectral characteristics of the ...persistent total and pulsed emission of 1E 1547.0-5408 between ~1 and 300 keV starting on 2008 October 3 and ending in 2011 January. We analyzed data collected with the Rossi X-ray Timing Explorer (RXTE) the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), and the Swift satellite. We report the evolution of the pulse frequency, and the measurement at the time of the onset of the 2009 January outburst of an insignificant jump in frequency, but a major frequency derivative jump delta nuof +(1.30 + or - 0.14) x 10 super(-11) Hz s super(-1) ( delta nu/nu of -0.69 + or - 0.07). Before this nu glitch, a single broad pulse is detected, mainly for energies below ~10 keV. Surprisingly, ~11 days after the glitch a new transient high-energy (up to ~150 keV) pulse appears with a Gaussian shape and width 0.23, shifted in phase by ~0.31 compared to the low-energy pulse, which smoothly fades to undetectable levels in ~350 days. We report the evolution of the pulsed-emission spectra. For energies 2.5-10 keV all pulsed spectra are very soft with photon indices gamma between -4.6 and -3.9. For ~10-150 keV, after the nu glitch, we report hard non-thermal pulsed spectra, similar to what has been reported for the persistent pulsed emission of some anomalous X-ray pulsars. This pulsed hard X-ray emission reached maximal luminosity 70 + or - 30 days after the glitch epoch, followed by a gradual decrease by more than a factor of 10 over ~300 days. These characteristics differ from those of the total emission. Both, the total soft X-ray (1-10 keV) and hard X-ray (10-150 keV) fluxes, were maximal already 2 days after the 2009 January outburst, and decayed by a factor of > ~3 over ~400 days. The total spectra can be described with a blackbody (kT values varying in the range 0.57-0.74 keV) plus a single power-law model. The photon index exhibited a hardening (~ - 1.4 to ~ - 0.9) with time, correlated with a decrease in flux in the 20-300 keV band. We discuss these findings in the framework of the magnetar model.
We examined the maximum bolometric peak luminosities during type I X-ray bursts from the persistent or transient luminous X-ray sources in globular clusters. We show that for about two thirds of the ...sources the maximum peak luminosities during photospheric radius expansion X-ray bursts extend to a critical value of $3.79 \pm 0.15 \times 10 ^{38}$ erg s-1, assuming the total X-ray burst emission is entirely due to black-body radiation and the recorded maximum luminosity is the actual peak luminosity. This empirical critical luminosity is consistent with the Eddington luminosity limit for hydrogen poor material. Since the critical luminosity is more or less always reached during photospheric radius expansion X-ray bursts (except for one source), such bursts may be regarded as empirical standard candles. However, because significant deviations do occur, our standard candle is only accurate to within 15%. We re-evaluated the distances to the twelve globular clusters in which the X-ray bursters reside.
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