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R. Krivonos A. Tkachenko R. Burenin E. Filippova I. Lapshov I. Mereminskiy S. Molkov M. Pavlinsky S. Sazonov M. Gubarev J. Kolodziejczak S. L. O’Dell D. Swartz Vyacheslav E. Zavlin B. D. Ramsey 《Experimental Astronomy》2017,44(1):147-164
The Astronomical Röntgen Telescope X-ray Concentrator (ART-XC) is a hard X-ray telescope with energy response up to 30 keV, to be launched on board the Spectrum Röntgen Gamma (SRG) spacecraft in 2018. ART-XC consists of seven identical co-aligned mirror modules. Each mirror assembly is coupled with a CdTe double-sided strip (DSS) focal-plane detector. Eight X-ray mirror modules (seven flight and one spare units) for ART-XC were developed and fabricated at the Marshall Space Flight Center (MSFC), NASA, USA. We present results of testing procedures performed with an X-ray beam facility at MSFC to calibrate the point spread function (PSF) of the mirror modules. The shape of the PSF was measured with a high-resolution CCD camera installed in the focal plane with defocusing of 7 mm, as required by the ART-XC design. For each module, we performed a parametrization of the PSF at various angular distances Θ. We used a King function to approximate the radial profile of the near on-axis PSF (Θ < 9 arcmin) and an ellipse fitting procedure to describe the morphology of the far off-axis angular response (9 < Θ < 24 arcmin). We found a good agreement between the seven ART-XC flight mirror modules at the level of 10%. The on-axis angular resolution of the ART-XC optics varies between 27 and 33 arcsec (half-power diameter), except for the spare module. 相似文献
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Karasev D. I. Sazonov S. Yu. Tkachenko A. Yu. Khorunzhev G. A. Krivonos R. A. Medvedev P. S. Zaznobin I. A. Mereminskiy I. A. Burenin R. A. Pavlinsky M. N. Eselevich M. V. 《Astronomy Letters》2019,45(12):836-846
Astronomy Letters - We continue the study begun in Karasev et al. (2018) and present the results of our optical identifications of four hard X-ray sources from the INTEGRAL sky surveys. Having... 相似文献
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E.?V.?FilippovaEmail author I.?A.?Mereminskiy A.?A.?Lutovinov S.?V.?Molkov S.?S.?Tsygankov 《Astronomy Letters》2017,43(11):706-729
The dependence of the spin frequency derivative \(\dot \nu \) of accreting neutron stars with a strongmagnetic field (X-ray pulsars) on the mass accretion rate (bolometric luminosity, Lbol) has been investigated for eight transient pulsars in binary systems with Be stars. Using data from the Fermi/GBM and Swift/BAT telescopes, we have shown that for seven of the eight systems the dependence \(\dot \nu \) (Lbol) can be fitted by the model of angular momentum transfer through an accretion disk, which predicts the relation \(\dot \nu \) ～ L6/7bol. Hysteresis in the dependence \(\dot \nu \) (Lbol) has been confirmed in the system V 0332+53 and has been detected for the first time in the systems KS 1947+300, GRO J1008-57, and 1A 0535+26. Estimates for the radius of the neutron star magnetosphere in all of the investigated systems have been obtained. We show that this quantity varies from pulsar to pulsar and depends strongly on the analytical model and the estimates for the neutron star and binary system parameters. 相似文献
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We report the discovery of low-frequency quasi-periodic oscillations (QPOs) in the power spectrum of the X-ray nova MAXI J1535-571 at the initial stage of its outburst in September 2017. Based on data from the SWIFT and INTEGRAL instruments, we have traced the evolution of the QPO parameters (primarily their frequency) with time and their correlation with changes in the X-ray spectrum of the source (changes in the emission flux and hardness). We place constraints on the theoretical QPO generation models. 相似文献
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I. A. Mereminskiy E. V. Filippova R. A. Krivonos S. A. Grebenev R. A. Burenin R. A. Sunyaev 《Astronomy Letters》2017,43(3):167-174
During the scanning observations of the Galactic center region in late August–September 2016 we detected a new (third) outburst of the historical X-ray nova GRS 1739-278, a presumed black hole in a low-mass X-ray binary. This was reported in the Astronomer’s Telegrams (Mereminskiy et al. 2016). In this paper we present the results of INTEGRAL and Swift observations of the outburst development. According to these observations, the flux from the source in the hard X-ray band (20–60 keV) rose from ~11 (September 3) to ~30 mCrab (September 14), was at the attained level for ~8 days, and then returned to ~15 mCrab. The spectrum of the source taken at its peak brightness in the energy range 0.5–150 keV could be fitted by a single power law with a photon index of 1.86 ± 0.07 distorted only by photoabsorption corresponding to the hydrogen column density log10 (N H) = 22.37 under the assumption of a solar abundance. This means that the source at this time was in the low/hard state. Infrared observations with the RTT-150 telescope near the X-ray brightness peak of the source revealed no emission down to \(22_ \cdot ^m 0\) (in the r’ band) and \(20_ \cdot ^m 9\) (in the i’ band). At the time of writing the paper we do not yet know whether this outburst ended or only its initial stage was observed. If it ended, then based on the light curve and spectra, we can state that it was a “failed” outburst, i.e., the amount of accreted matter in this episode was insufficient to reach the high or very high state with a soft blackbody component in the spectrum characteristic of developed outbursts. 相似文献
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I. V. Chelovekov S. A. Grebenev I. A. Mereminskiy A. V. Prosvetov 《Astronomy Letters》2017,43(12):781-795
We present the results of our analysis of the JEM-X/INTEGRAL data obtained from January 2003 to January 2015 aimed at searching for type I X-ray bursts from known and new bursters. Such bursts are caused by thermonuclear explosions on the surface of a neutron star. We have searched for bursts in the records of the count rate of the JEM-X detectors in the 3–20 keV energy band. We have separately reconstructed and analyzed the light curves of 104 X-ray bursters known to date based on the JEM-X data. A similar search for bursts was previously carried out in the 15–25 keV data from the IBIS/ISGRI telescope onboard the INTEGRAL observatory obtained in 2003–2009. We have continued to analyze the data from this telescope up until the observations in January 2015. The joint catalog of bursts detected by the two instruments includes 2201 events; their basic parameters are given. The large size of the sample of bursts makes it one of the most representative of the existing one and allows various statistical studies of bursts to be performed. In particular, we have constructed the dependence of the mean rate of type I bursts from bursters on the luminosity (accretion rate), revealed an appreciable burst rate from sources with a near-Eddington luminosity, and investigated the population of multiple bursts with a recurrence time much shorter than the time it takes for a critical mass of matter required for the initiation of an explosion to be accumulated on the neutron star surface. Almost all of the detected bursts are associated with already known bursters,we have found only one previously unknown burster, IGRJ17380-3749, in the archival data, and one more known, but poorly studied source, AX J1754.2-2754, has been identified as a burster. Several similar sources have previously been identified as bursters directly during the INTEGRAL observations. 相似文献
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Grebenev A. S. Dvorkovich Yu. A. Knyazeva V. S. Ostashenko K. D. Grebenev S. A. Mereminskiy I. A. Prosvetov A. V. 《Astronomy Letters》2020,46(4):205-223
Astronomy Letters - Based on long-term SWIFT, RXTE, and MAXI observations of the X-ray novae H 1743-322 (IGR J17464-3213) and GX 339-4, we have investigated the morphology and classified the light... 相似文献
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