Main Spectral Components Research Articles

Discovery of a strong rotation of the X-ray polarization angle in the galactic burster GX 13+1

Weakly magnetized neutron stars in X-ray binaries show a complex phenomenology with several spectral components that can be associated with the accretion disk, the boundary, and/or a spreading layer, a corona, and a wind. Spectroscopic information alone, however, is not enough to distinguish these components. The analysis of the timing data revealed that most of the variability, and in particular, kilohertz quasi-period oscillations, are associated with the high-energy component that corresponds to the boundary and/or spreading layer. Additional information about the nature of the spectral components, and in particular, about the geometry of the emission region, can be provided by X-ray polarimetry. One of the objects of the class, a bright, persistent, and rather peculiar galactic Type I X-ray burster was observed with the Imaging X-ray Polarimetry Explorer (IXPE) and the X-ray Multi-Mirror Mission Newton ( Using the data, we obtained the best-fit values for the continuum spectral parameters and detected strong absorption lines associated with the accretion disk wind. IXPE data showed the source to be significantly polarized in the 2--8 keV energy band, with an overall polarization degree (PD) of $1.4<!PCT!> at a polarization angle (PA) of $-2 (errors at the 68<!PCT!> confidence level). During the two-day long observation, we detected rotation of the PA by about 70 with the corresponding changes in the PD from 2<!PCT!> to nondetectable and then up to 5<!PCT!>. These variations in polarization properties are not accompanied by visible spectral state changes of the source. The energy-resolved polarimetric analysis showed a significant change in polarization, from being strongly dependent on energy at the beginning of the observation to being almost constant with energy in the later parts of the observation. As a possible interpretation, we suggest a constant polarization component, strong wind scattering, or a different polarization of the two main spectral components with an individually peculiar behavior. The rotation of the PA suggests a misalignment of the neutron star spin from the orbital axis.

Controlling the frequency of periodic self-modulation in gyrotrons with external reflections

We develop the theory of electron–wave interaction in gyrotrons with reflections of part of the radiation, focusing on the implementation of self-modulation generation regimes with controlled frequencies. The optimal conditions for the simultaneous excitation of neighboring axial modes of the electrodynamic system of a gyrotron with a reflecting diaphragm in the output waveguide path are found. When the gyrotron is powered by an electron beam under these conditions, periodic self-modulation regimes are realized with the distance between the main spectral components controlled by varying the distance to the reflector. The conclusions of the theory are confirmed by the results of direct particle-in-cells simulation.

Band-stop-filter-based repetitive control of fast tool servos for diamond turning of micro-structured functional surfaces

Fast tool servo (FTS) is a promising technique for the high-speed diamond turning of micro-structured functional surfaces due to its fast response capacity. However, the inherent actuator non-linearity, the lightly damped vibration mode and the external disturbance of the FTS would degrade its tracking performance severely and thus restrict its machining ability. To overcome this limitation, a band-stop-filter-based repetitive control (BSF-RC) scheme is proposed in this article to improve the operating performance of the FTS. Firstly, the spectra of the FTS tool paths (FTS-TPs) for machining typical micro-structured functional surfaces with the cylindrical coordinate machining method are analyzed in detail. The results reveal that the frequency components concentrate on the tiny neighborhoods of the rotational frequency of the spindle and its harmonic frequencies. Afterwards, the comb-like band-stop filter used by the BSF-RC is elaborately designed via the cascade of three comb-like notch filters to generate a comb-like band-stop loop shape for covering main spectral components of the FTS-TPs. The analytical expression of the comb-like band-stop filter amplitude as well as the stability condition of the closed-loop control system are derived to provide effective criteria for the parameter selection of the BSF-RC. The experimental validation of the developed BSF-RC scheme is conducted on a five-axis ultra-precision lathe equipped with a self-developed FTS via the diamond turning of three typical micro-structured functional surfaces. The experimental results show that good surface qualities with the maximal form error of a few hundred nanometers and the surface roughness of a several nanometers are achieved for all the obtained micro-structured surfaces by using the BSF-RC scheme under a high spindle speed.

Diffraction-based dual path multispectral imaging

Abstract Diffraction based multispectral imaging is a method for obtaining snapshot multispectral image information by using a structured diffraction grating or computer-generated hologram in an intermediate image plane of an imaging system. Without the need of complicated filter manufacturing it becomes possible to realize application specific spatio-spectral sampling of an image. The spectral resolution is coupled with the spatial resolution because the central stop of the imaging system serves also as the main spectral filtering component. By using two image sensors and the zeroth order of the computer-generated holograms it becomes possible to obtain high resolution spatial information as well as spectral information on a coarser sampling grid.

Prevalence of Extra Power-Law Spectral Components in Short Gamma-Ray Bursts

Abstract A prompt extra power-law (PL) spectral component that usually dominates the spectral energy distribution below tens of keV or above ∼10 MeV has been discovered in some bright gamma-ray bursts (GRBs). However, its origin is still unclear. In this paper, we present a systematic analysis of 13 Fermi short GRBs, as of 2020 August, with contemporaneous keV–MeV and GeV detections during the prompt emission phase. We find that the extra PL component is a ubiquitous spectral feature for short GRBs, showing up in all 13 analyzed GRBs. The PL indices are mostly harder than −2.0, which may be well reproduced by considering the electromagnetic cascade induced by ultrarelativistic protons or electrons accelerated in the prompt emission phase. The average flux of these extra PL components positively correlates with that of the main spectral components, which implies they may share the same physical origin.

The first simultaneous X-ray broadband view of Mrk 110 with XMM-Newton and NuSTAR

Context. Soft and hard X-ray excesses, compared to the continuum power-law shape between ∼2−10 keV, are common features observed in the spectra of active galactic nuclei (AGN) and are associated with the accretion disc-corona system around the supermassive black hole. However, the dominant process at work is still highly debated and has been proposed to be either relativistic reflection or Comptonisation. Such an investigation can be problematic for AGN that have significant intrinsic absorption, either cold or warm, which can severely distort the observed continuum. Therefore, AGN with no (or very weak) intrinsic absorption along the line-of-sight, called bare AGN, are the best targets for directly probing disc-corona systems. Aims. We aim to characterise the main X-ray spectral physical components from the bright bare broad-line Seyfert 1 AGN Mrk 110, as well as the physical process(es) at work in its disc-corona system viewed almost face-on. Methods. We perform the X-ray broadband spectral analysis thanks to two simultaneous XMM-Newton and NuSTAR observations performed on November 16−17, 2019, and April 5−6, 2020. We also use a deep NuSTAR observation obtained in January 2017 for the spectral analysis above 3 keV. Results. The broadband X-ray spectra of Mrk 110 are characterised by the presence of a prominent and absorption-free smooth soft X-ray excess, moderately broad O VII and Fe Kα emission lines, and a lack of a strong Compton hump. The continuum above ∼3 keV is very similar at both epochs, while some variability (stronger when brighter) is present for the soft X-ray excess. A combination of soft and hard Comptonisation by a warm and hot corona, respectively, plus mildly relativistic disc reflection reproduce the broadband X-ray continuum very well. The inferred warm corona temperature, kTwarm ∼ 0.3 keV, is similar to the values found in other sub-Eddington AGN, whereas the hot corona temperature, kThot ∼ 21−31 keV (depending mainly on the assumed hot corona geometry), is found to be in the lower range of the values measured in AGN.

ХВИЛЬОВА СТРУКТУРА СЕРЦЕВОГО РИТМУ ПРИ ОРТОПРОБІ У ОСІБ З РІЗНИМ РІВНЕМ ВЕГЕТАТИВНОГО ТОНУСУ

Introduction. It is known that there are typological features among healthy young people according to the level of autonomic tone. Accordingly, there are groups of sympatho-, normo- and vagotonics. Work has been carried out to study the influence of the initial level of autonomic tone on thereactions of the cardiovascular system in respiratory hypocapnia, pulsed ophthalmic photostimulation, in different phases of the biological cycle for women. However, there is no work on the analysis of changes in the wave structure of heart rate depending on the initial level of autonomic tone. Purpose. The aim was to determine the features of the wave structure of the heart rhythm during orthoprobe for healthy young men with different levels of tone of the autonomic nervous system at rest. Methods. Measurements were performed in conditions close to the main exchange. 117 healthy young men aged 18-23 years were examined in compliance with the requirements of bioethics. Three main spectral components were analyzed in the tRR spectrum: HF (0.15-0.4 Hz) LF (0.04-0.15Hz); VLF (0-0.04 Hz); TP (0-0.4 Hz). The amplitude of the largest peak of the tRR spectrogram in the frequency range 0.04-0.15 Hz (aLF) and its frequency (tLF) were calculated. Normalized median spectrograms of tRR oscillations were constructed.Results.A significant decrease in HF was observed in individuals of all three groups during orthoprobe. The median reactivity of reactivity was -67.3%, -77.5%, -77.9% for groups I, II and III, respectively. There were no differences between the groups due to the reactivity of this indicator. The reactivity of LF to changes in body position for sympathotonics was significantly different.The frequency of the maximum peak of the spectrogram in the range of low often resting heart rate did not differ between groups. This indicator probably decreased during orthoprobe in groups IIand III. It was found that the wave has two peaks in the vertical position in persons with different baseline levels of autonomic tone for vagotonics and normotonics in the frequency range from 0.04 to0.15 Hz. Originality. Differences in the reactivity of heart rate waves to orthoprobe for healthy young men with different baseline levels of autonomic tone were detected for the first time. Conclusions. The greatest differences in changes in the wave structure of the heart rhythm during orthoprobe for persons with different baseline levels of autonomic tone are manifested in therange of low heart rate. Spectrum reduction reactions in this range were predominant for sympathotonics. The reactions of increasing LF and the amplitude of the maximum peak of the spectrogram were predominant for normo- and parasympathotonics. It was found that the wave has two peaks in the vertical position in persons with different baseline levels of autonomic tone for vagotonics and normotonics in the frequency range from 0.04 to 0.15 Hz. Sympathotonics have one wave of orthopedic reactivity with maxima at 0.09 Hz in the low heart rate range. Normotonics have two waves of reactivity per orthoprobe with frequencies of 0.08Hz and 0.11 Hz. Parasympathotonics also have two waves with frequencies of 0.07 Hz and 0.09Hz. Prospects for further research include elucidation of the mechanisms of tRR wave formation depending on the level of vegetative tone under different conditions. Key words: wave structure of heart rhythm, vegetative tone, sympathotonics, normotonics, vagotonics.

Acoustic Noise in Moscow during the Covid-19 Quarantine Period in 2020

This paper addresses the results of instrumental observation of acoustic oscillations in the atmosphere above the city of Moscow during the COVID-19 quarantine period. Instrumental observations made by the Geophysical Monitoring Center (GMC) at the Institute of Geosphere Dynamics (IGD), Russian Academy of Sciences, show that the quarantine-related decrease in production activity caused significant changes in the amplitude and spectral characteristics of acoustic noise above the city, as compared to the long-term averages. During the quarantine period, the amplitude of the main spectral components and the average amplitude of acoustic noise decreased by more than two times. The diurnal variation of the amplitude of noise caused by production activities in the daytime was much less evident. Our findings can be useful in determining the characteristics of technogenic noise sources and assessing its contribution to the total acoustic noise level of the city.

Partition of Relative Maximum Region Band Based Image Compression

The proposed work presents a novel multispectral image compression method using Partition of Relative Maximum Region Band Algorithm (PRMSB). In the proposed method, 2D multispectral image is decorrelated in the first and second stage of intra and inter band correlation. From this process, the main spectral band component for analysis is selected. These components were given to Partition Band Selection Method, where the sequences of band components are extracted. In this approach, the spectral bands are treated dependently, so there will be 6 sequences as the number of bands. Relative Region Algorithm generate a spectral sub band wavelet transforms, performs better in terms of maximum estimation and compression efficiency. Throughout the experiments, the proposed work shows good performance with the surveyed methods.

Raman mapping coupled to self-modelling MCR-ALS analysis to estimate active cosmetic ingredient penetration profile in skin.

Confocal Raman mapping (CRM) is a powerful, label free, non-destructive tool, enabling molecular characterization of human skin with applications in the dermo-cosmetic field. Coupling CRM to multivariate analysis can be used to monitor the penetration and permeation of active cosmetic ingredients (ACI) after topical application. It is presently illustrated how multivariate curve resolution alternating least squares (MCR-ALS) can be applied to detect and semi-quantitatively describe the diffusion profile of Delipidol, a commercially available slimming ACI, from Raman spectral maps. Although the analysis outcome can be critically dependent on the a priori selection of the number of regression components, it is demonstrated that profiling of the kinetics of diffusion into the skin can be established with or without additionnal spectral equality constraints in the multivariate analysis, with similar results. Ultimately, MCR-ALS, applied without spectral equality contraints, specifically identifies the ACI as one of main spectral components enabling to investigate its distribution and penetration into the stratum corneum and underlying epidermis layers.

Observation of doubly periodic solutions of the nonlinear Schrödinger equation in optical fibers.

We report the first, to the best of our knowledge, experimental observation of doubly periodic first-order solutions of the nonlinear Schrödinger equation in optical fibers. We confirm, experimentally, the existence of A-type and B-type solutions. This is done by using the initial conditions that consist of a strong pump and two weak sidebands. The evolution of power and phase of the main spectral components is recorded using heterodyne time-domain reflectometry. Another important part of our experiment is active loss compensation. We reach a good agreement between theory and experiment.

Using information processing algorithms that factor in the effect of secondary modulation of radar signals

The article provides an assessment of the impact the dynamic structures of power systems of aircraft systems have on the spectrum of the reflected radar signal. In the conditions of autonomous actions of the fighter, the tasks of long-range detection of airborne targets are assigned directly to the onboard radar station. It is necessary to resolve the contradictions associated with increasing the detection range without changing the energy indicators of the onboard radar station. This is possible by optimizing the processing of many spectral components of the signal reflected from the propeller and turboprop engine of airborne targets. The location of propeller reflections in the spectrum of the reflected signal is determined by the technical parameters of the power plant and its mode of operation. The percent of the total energy of the reflected signal spectrum outside the main spectral component is comparable with the energy reflected from the airframe of the aviation complex, most of which is the energy reflected from the rotating elements of power plants. Therefore, the development of an algorithm for detecting a signal with a complex spectral structure that maximizes the probability of detection under time and computational resources restrictions is a very relevant scientific task. The scientific novelty lies in the development of an algorithm for detecting a signal with a complex spectral structure and its detection characteristics taking the effect of secondary modulation into account as well as in the development of practical recommendations for optimizing algorithms for detecting airborne targets. Using the developed algorithm in the fighter’s pulse-Doppler radar station will increase the detection range of an air target against the background of interfering reflections from the water surface.

Filtering motion signals from Microsoft Kinect® in the context of stroke rehabilitation

The Microsoft Kinect® sensor has been employed for developing serious games and for biomechanics analysis. Both applications, when combined in the context of motor rehabilitation, might provide relevant data for therapists. However, the reliability of clinical data obtained with Kinect® is affected by filtering parameters which should be chosen according to spectral characteristics of the signals. In this paper we aim at determining the spectral characteristics of kinematics data collected with Kinect® during a serious game and to suggest adequate filtering. The motor tasks of lateral trunk inclination, trunk rotation, and shoulder abduction performed with heading, ski, and goalkeeper games originated 45 time series derived from 5 healthy people and 87 time series of 4 people with stroke. Time series were analyzed using the Fourier analysis and empirical mode decomposition (EMD). A residual analysis was performed to determine the optimal cutoff frequencies of the fourth-order low-pass Butterworth filters. Fourier and EMD analyses evidenced that the highest spectral power for header and goalkeeper tasks is below 3 Hz and for skiing, it is below 0.8 Hz. The ideal cutoff frequencies were around 3 Hz and 5 Hz and differed between healthy and stroke groups. The range of motion was affected by the cutoff frequencies. The signals captured by Kinect® have the main spectral components at lower frequencies and should be filtered at cutoff frequencies below 6 Hz. We recommend including the determination the impact of signal processing on clinical indicators in the workflow when developing a serious game for rehabilitation.

Experimental Wavelet Analysis of Rotor-Rub Vibration Signal

A common defective phenomenon in rotating machinery is rotor-casing rub that generates impacts when the rotor rubs against the stator. Vibration sensors and data analysis techniques are commonly used for fault signature extraction and mechanical systems diagnosis. In this paper, an experimental characterization of rotor-rub is made by time-frequency analysis by means of the wavelet transform. A rotor kit, equipped with a variable speed DC motor, an accelerometer and a data acquisition system are used to acquire the mechanical vibration data. Vibration signal in frequency and time-frequency domains are shown for no-rubbing, light, and severe rubbing cases. Results show that FFT is unable to report where in time particular components of rubbing appear. However, the time-frequency analysis is able to give location information in time to differentiate light from severe rubbing, and extract the main spectral components showing a spectrum rich in high frequency components, characteristic of this phenomenon.

Pulse shaping by a frequency filtering of a sawtooth phase-modulated cw laser

The spectrum of a CW field whose phase experiences a periodic sawtooth modulation is analyzed. Two types of the sawtooth phase modulation are considered. One is created by combining many harmonics of the fundamental frequency. The second is produced by electro-optic modulator fed by the relaxation oscillator, which generates a voltage slowly rising during charging the energy storage capacitor and dropping fast due to discharge by a short circuit. It is proposed to filter out the main spectral component of the sawtooth phase modulated field. This filtering produces short pulses from CW phase modulated field. Several filters are proposed to remove the selected spectral component. It is shown that such a filtering is capable to produce a train of short pulses. Duty cycle of this train is equal to the modulation period and duration of the pulses can vary from $10^{-1}$ to $10^{-2}$ of the period. Depending on the modulation frequency, the proposed method is capable to produce pulses with duration ranging from nanoseconds to a fraction of picosecond.

Full-field characterization of breather dynamics over the whole length of an optical fiber.

Full-field longitudinal characterization of picosecond pulse train formation in optical fibers is reported. The spatio-temporal evolution is obtained via fast and non-invasive distributed measurements in phase and intensity of the main spectral components of the pulses. To illustrate the performance of the setup, we report, to the best of our knowledge, the first time-domain experimental observation of the symmetry breaking of Fermi-Pasta-Ulam recurrences. The experimental results are in good agreement with numerical simulations.

ХВИЛЬОВА СТРУКТУРА ГЕМОДИНАМІЧНИХ ПОКАЗНИКІВ В ОСІБ ІЗ РІЗНИМ ВИХІДНИМ РІВНЕМ СЕРЦЕВОГО ВИКИДУ ТА КРОВОНАПОВНЕННЯ ОРГАНІВ ГРУДНОЇ КЛІТКИ

Introduction . Wave fe atures of the duration of cardiointervals (t-R-R) and s troke volume of blood are considered as a reflection of the dynamics of regulatory processes in the body. Significant differences in healthy young men in values of cardiac index and blood supply of the thoracic organs condition on the peculiarities of regulation of the cardiovascular system. Purpose . To find out the peculiarities of the wave structure of oscillations (t-R-R) and s troke volume of blood (SV) in individuals with different baseline cardiac output and blood supply. Methods . The resulting time series were analyzed by 5-min implementations of secuential SV and t-R-R in «Caspico» program . For the duration of the cardiointervals, three main spectral components were distinguished: HF (0.15-0.4 Hz), LF (0.04-0.15 Hz), VLF (0-0.04 Hz), and total spectrum power (TP), the power of high-frequency oscillations in normalized units (HFnorm). For SV, such indicators were HF sv , LF sv , VLF sv , TP sv and HF norm SV , respectively. Results . At rest, the highest t- R - R oscillation power in the LF and HF ranges was established in hypokinetics, the SV oscillation power in the 0.04-0.15 Hz frequency band was significantly higher in hyperkinetics compared to eukinetics, in HF norm SV - it was probably higher in hyperkinetics than hypokinetics. When functional tests were performed, the greatest differences between groups of individuals with different typology by cardiac output were observed at dosed physical activity: HFnorm in hypokinetics was authentically smaller than in the representatives of other groups, LF was larger than in eukinetics, and HF was lower than in hyperkinetics. The initial level of blood supply of the thorax also authentically influenced the peculiarities of oscillations of the hemodynamic indicators of healthy young men under different conditions. At rest in the supine position, individuals with low levels of blood supply of thoracic organs had authentically a higher power of high-frequency oscillations t-R-R than men with an average value of this index, and relatively larger intergroup differences were observed in the parameters of SV oscillations. According to the indicators of the wave structure of t-R-R and SV with active orthopedic testing and with mental load, the lowest activation of the sympathetic nervous system was observed in the group of men with low initial level of blood supply of the thoracic organs. . Originality . The peculiarities of the regulatory rhythms of hemodynamics are revealed in persons with different typology by the level of cardiac output and blood supply of the thoracic organs . Significant differences in the power of oscillations of cardio-interval duration and stroke volume are shown in persons of different types of hemodynamics at rest and at the dosed physical activities. Conclusions . At rest and mainly at physical activity , the features of hemodynamics oscillations have been found between persons with different initial levels of cardiac output, which are of compensatory nature for maintaining cardiac output for hypokinetics, and are caused by different levels of blood supply in the thoracic organs. The wave structure of the regulatory rhythms of hemodynamics and its changes at loads significantly depend on the initial level of blood supply of the thorax , which is shown by the relatively less tension of the mechanisms of regulation in persons of the extreme groups. Taking into account individual-typological characteristics of a person can increase the diagnostic value of methods of analysis and evaluation of the wave structure of hemodynamic parameters, as well as identify new directions in preventive medicine and health insurance.

Modulation of the Intensity of the Spectral Components of Polychromatic Light within Certain Regions in Space by Passive Methods by Strategically Using Material Optical Properties and Texture

Recent research indicates that not only blue and green monochromatic light stimulates our circadian system, but polychromatic light as well. Recent work also suggests that the human circadian system also changes its spectral sensitivity with different light levels and spectrum. Usually, indoor architectural spaces are dynamic in light color and quantity, and to a certain extent, the architect is able to modulate these light characteristics to benefit not only of the visual system but the circadian system as well. The purpose of this work was to redirect the three main spectral components (RGB) of indirect light towards different directions and in different quantities as an approach to an understanding of how the spectral composition of an indoor light environment can be modulated by passive methods. In the present work, reflections of blue-enriched polychromatic light off different surface materials with different optical properties and textures were simulated. Spectral radiance values were measured at a specific point in space in order to evaluate how the three main spectral components of the reflected light changed in quantity.

ХВИЛЬОВА СТРУКТУРА ПОКАЗНИКІВ ГЕМОДИНАМІКИ ПРИ РІЗНОМУ ВИХІДНОМУ РІВНІ ЧАСТОТИ ДИХАННЯ У ЧОЛОВІКІВ

Introduction . It is expedient to investigate the features of wave structure of the oscillations of the stroke volume (SV) and duration of R-R interval by the different level of the main vegetative indicators such as respiratory rate and volume of cardiac output which are considered to be constant for each person according to the data of many studies. Purpose . To find out the features of the wave structure of oscillations of SV and duration of R-R interval in healthy young men with a different level of respiratory rate. Methods. The measurements are carried out on 120 healthy young men aged from 17 to 23 years. By the distribution of the initial value of the Mo duration of respiratory cycle men were divided into 3 groups: tachypnea (39 men) – with abnormally rapid breathing, normopnea (62 men) – with normal respiratory rate and bradypnea (19 men) - with abnormally slow breathing. Time series were analyzed with five-minutes implementations of successive stroke volume and R-R duration in the “Caspico” program. For the duration of cardiocycles were distinguished 3 main spectral components: HF (0,15-0,4 Hz), LF (0,04-0,15 Hz), VLF (0-0,04 Hz) and total power of the spectrum (TP), the power of high frequency oscillations in normalized units (HFnorm). These indicators for SV were respectively HF sv , LF sv , VLF sv , ТР sv and HFnorm sv . Results . People with low and high frequency of breathing in a state of rest are characterized by the relatively higher amplitude of oscillations of duration of R-R interval and stroke volume in the range of 0,04-0,15 Hz than normopnea. By bradypnea it is stipulated by a violation of respiratory periodicals in this frequency range and higher level of activation of parasympathetic link of the vegetative nervous system, by tachypnea it is stipulated by a number of factors: relatively higher level of blood-filling of organs in thorax, increase of sympathetic effects on the heart and increase of spontaneous baro-reflex sensitivity. By dosed load it is vice verse – relatively larger sympathetic activation is observed by bradypnea. Conclusion. Taking into account the output frequency of breathing can significantly improve the diagnostic value of the methods for analyzing of the variability of the stroke volume and heart rate.

Spectral analysis of IGR J01572−7259 during its 2016 outburst

We report on the results of the $XMM-Newton$ observation of IGR J01572-7259 during its most recent outburst in 2016 May, the first since 2008. The source reached a flux $f \sim 10^{-10}$ erg cm$^{-2}$ s$^{-1}$, which allowed us to perform a detailed analysis of its timing and spectral properties. We obtained a pulse period $P_{\rm spin}$ = 11.58208(2) s. The pulse profile is double peaked and strongly energy dependent, as the second peak is prominent only at low energies and the pulsed fraction increases with energy. The main spectral component is a power-law model, but at low energies we also detected a soft thermal component, which can be described with either a blackbody or a hot plasma model. Both the EPIC and RGS spectra show several emission lines, which can be identified with the transition lines of ionized N, O, Ne, and Fe and cannot be described with a thermal emission model. The phase-resolved spectral analysis showed that the flux of both the soft excess and the emission lines vary with the pulse phase: the soft excess disappears in the first pulse and becomes significant only in the second, where also the Fe line is stronger. This variability is difficult to explain with emission from a hot plasma, while the reprocessing of the primary X-ray emission at the inner edge of the accretion disk provides a realiable scenario. On the other hand, the narrow emission lines can be due to the presence of photoionized matter around the accreting source.