Abstract
The XMM-Newton Serendipitous Ultraviolet Source Survey (XMM-SUSS) is a catalogue of ultraviolet (UV) sources detected serendipitously by the Optical Monitor (XMM-OM) on board the XMM-Newton ...observatory. The catalogue contains UV-detected sources collected from 2417 XMM-OM observations in one to six broad-band UV and optical filters, made between 2000 February 24 and 2007 March 29. The primary contents of the catalogue are source positions, magnitudes and fluxes in one to six passbands, and these are accompanied by profile diagnostics and variability statistics. XMM-SUSS is populated by 753 578 UV source detections above a 3σ signal-to-noise ratio threshold limit which relate to 624 049 unique objects. Taking account of substantial overlaps between observations, the net sky area covered is 29-54 deg2, depending on UV filter. The magnitude distributions peak at m
AB = 20.2, 20.9 and 21.2 in UVW2 (λeff = 2120 Å), UVM2 (λeff = 2310 Å) and UVW1 (λeff = 2910 Å), respectively. More than 10 per cent of the sources have been visited more than once using the same filter during XMM-Newton operation, and >20 per cent of sources are observed more than once per filter during an individual visit. Consequently, the scope for science based on temporal source variability on time-scales of hours to years is broad. By comparison with other astrophysical catalogues we test the accuracy of the source measurements and define the nature of the serendipitous UV XMM-OM source sample. The distributions of source colours in the UV and optical filters are shown together with the expected loci of stars and galaxies, and indicate that sources which are detected in multiple UV bands are predominantly star-forming galaxies and stars of type G or earlier.
Two UV serendipitous source catalogues are presented which were compiled based on the observations with two similar UV telescopes, one being on-board the ESA’s XMM Newton observatory and ...another—on-board the NASA’s Swift satellite. Both telescopes have similar optical and registration systems providing photometry in three ultraviolet and three visible bands. After processing a 10 years long series of observations from XMM and 5 years from Swift, we have compiled two source catalogues containing more than 4 million sources for XMM and 6 million sources for Swift. We describe the processing algorithms and present catalogue characteristics in comparison with each other.
Abstract
Gravitational-Wave Transient Catalogues (GWTC) from the LIGO-Virgo-KAGRA collaborations (LVC and LVK) contain almost a hundred gravitational wave (GW) detection cases. We explore them from ...the perspective of the two-body problem in curved spacetime, starting with the first case, GW150914, which marks the GW discovery 1. In this paper, the LVC authors estimated the characteristic (chirp) mass of the binary blackhole system emitted this signal. Their calculation was based on Numerical-Relativity (NR) templates and presumably accounted fully for the non-linearity of GR. The same team later presented an alternative analysis of GW150914 2, using the quadrupole post-Newtonian (PN) approximation of GR. Both analyses gave similar results, despite being based on quite different assumptions about the linearity or non-linearity of the coordinate reference frame near the GW source. Here we revisit the PN-analysis of GW150914 for which we use less noisy input GW frequencies, as we have filtered them by reading them from the time-frequency map of GW150914. As in paper 2, our result also agrees with the NR-based chirp mass value published in 1. Additionally, we apply the PN-approximation formalism to the rest of the GWTC cases, finding that practically all of their PN-approximated chirp masses coincide with the published NR-based values from GWTC. In our view, this implies that the NR-based theory, which is currently in use for processing GW signals, does not fully account for the difference between the source and detector reference frames because the PN-approximation, which is used for the comparison, does not account for this difference by design, given the flat-spacetime initial assumptions of this approximation. We find that the basis of this issue lies in the source-to-detector coordinate transformation. For example, when obtaining the equation of motion of a coalescing binary system by integrating its energy-momentum tensor and varying the corresponding reduced action functional, the lapse and shift functions are not involved within the Arnowitt-Deser-Misner (ADM) parametrisation scheme, which is typically used for the NR-based calculation of GW waveforms A similar non-involvement of the lapse and shift functions is known to occur in the description of motion of an orbiter around a Schwarzschild blackhole. Here the GR expression for the orbital angular frequency, as seen by a remote observer, coincides with the Keplerian non-relativistic formula until the very last orbits before the plunge phase (although being fully GR-compliant). This non-involvement of the time lapse function renders the source-to-detector coordinate transformation suitable for building GW waveforms corresponding to the detector frame. However, the inverse (detector-to-source) transformation requires the derivatives of GW frequencies to be known in the source reference frame. The lack of this knowledge leads to a systematic error in the estimated chirp masses of GW sources. The corresponding luminosity distances of these sources also turn out to be overestimated.
ABSTRACT
It is possible to reduce the discrepancy between the local measurement of the cosmological parameter H0 and the value derived from the Planck measurements of the cosmic microwave background ...(CMB) by considering contamination of the CMB by emission from some medium around distant extragalactic sources, such as extremely cold coarse-grain dust. Though being distant, such a medium would still be in the foreground with respect to the CMB, and, as any other foreground, it would alter the CMB power spectrum. This could contribute to the dispersion of CMB temperature fluctuations. By generating a few random samples of CMB with different dispersions, we have checked that the increased dispersion leads to a smaller estimated value of H0, the rest of the cosmological model parameters remaining fixed. This might explain the reduced value of the Planck-derived parameter H0 with respect to the local measurements. The signature of the distant foreground in the CMB traced by supernovae (SNe) was previously reported by the authors of this paper – we found a correlation between the SN redshifts, zSN, and CMB temperature fluctuations at the SNe locations, TSN. Here we have used the slopes of the regression lines $T_{\rm SN}\, /\, z_{\rm SN}$ corresponding to different Planck wavebands in order to estimate the possible temperature of the distant extragalactic medium, which turns out to be very low, about 5 K. The most likely ingredient of this medium is coarse-grain (grey) dust, which is known to be almost undetectable, except for the effect of dimming remote extragalactic sources.
Using the telescopes ZA-320 M and MTM-500 M of Pulkovo Observatory (Russia), we have carried out astrometric and photometric observations of the asteroid (367943) Duende (2012 DA14) immediately after ...its close approach to the Earth occurred on 2013 February 15. We have obtained a series of its astrometric positions, colour indices and two fragments of its light curve. By numerically integrating, we have studied the evolution of the asteroid's orbit. Also, the influence of solar radiation pressure and Yarkovsky effect on the asteroid was estimated. The fitting of the asteroid rotation model to the observed light curve indicates that during its closest approach to the Earth, it had tumbling rotation regime.
By using the Planck map of the cosmic microwave background (CMB) radiation, we have checked and confirmed the existence of a correlation between supernova (SN) redshifts, z
SN, and CMB temperature ...fluctuations at the SNe locations, T
SN, which we previously reported for the Wilkinson Microwave Anisotropy Probe data. The Pearson correlation coefficient for the Planck data is r = +0.38 ± 0.08, which indicates that the correlation is statistically significant (the signal is about 5σ above the noise level). The correlation becomes even stronger for the Type Ia subsample of SNe, r
Ia = +0.45 ± 0.09, whereas for the rest of the SNe it is vanishing. By checking the slopes of the regression lines T
SN/z
SN for Planck's different frequency bands, we have also excluded the possibility of this anomaly being caused by the Sunyaev–Zeldovich effect. The remaining possibility is some, unaccounted for, contribution to the CMB from distant (z > 0.3) foreground through either the integrated Sachs–Wolfe effect or thermal emission from intergalactic matter.
Redshifts of supernova (SN) and gamma-ray burst (GRB) samples are compared with the pixel temperatures of the Wilkinson Microwave Anisotropy Probe (WMAP) seven-year data, the pixel locations ...corresponding to the SN and GRB sky coordinates. We have found a statistically significant correlation of the SN redshifts with the WMAP data, the average temperature deviation being
for redshifts z ranging from 0.5 to 1.0 and
for z∈ (0.0, 0.4). The latter value accords with the theoretical estimates for the distortion of the cosmic microwave background due to the integrated Sachs-Wolfe effect, whereas the larger anomaly for higher redshifts should be studied in more detail in the future.
The identification of the stellar companions to binary pulsars is key to studying the evolution of the binary system and how this is influenced by the interactions between the two stars. For only a ...fraction of the known binary pulsars, the stellar companions have been identified. Here, we used 11 source catalogues available from multiwavelength (ultraviolet, optical, infrared) imaging sky surveys to search for the stellar companions of a sample of 144 field binary pulsars (i.e. not in globular clusters) selected from the Australia Telescope National Facility data base (version 1.48) and from the public list of γ-ray pulsars detected by Fermi. We found positional associations in at least one source catalogue for 22 pulsars, of which 10 are detected in γ-rays by Fermi, including 15 millisecond pulsars. For six pulsars in our compilation, we confirm their identifications. For another seven pulsars that had yet not been identified, we examine potential identifications. In particular, we identified a likely companion star candidate to PSR J2317+1439, whereas for both PSR B1953+29 and PSR J1935+1726 the companion star identification is more uncertain. Follow-up observations of these three pulsars are needed to settle the proposed identifications. For the remaining nine pulsars that had been already identified, we provide additional spectral information in at least one of the surveys’ spectral bands, which we will use to better constrain the stars’ spectral energy distributions.
The aim of the study was to analyze the results of the electrical muscle stimulation (EMS) usage in patients with venous ulcers developed on top of a post-thrombotic syndrome (PTS).
Sixty patients ...(60 legs) with active venous ulcer (C6EsAsdpPr according to CEAP classification) were divided into two groups. In addition to the background therapy consisting of a standardized compression with ULCER X and intake of micronized purified flavonoid fraction (MPFF 1000 mg daily), all the patients in the main group underwent EMS with Veinoplus® V.I. for at least 3 times a day. Follow-up examinations were performed on days 30, 60 and 90. These included pain severity assessment with 100-mm Visual Analogue Scale (VAS), disease severity measurement with VCSS (Venous Clinical Severity Score) and ankle circumference above malleolus, as well as recording number of healed venous ulcers.
At day 90 pain severity was reduced in both main and control groups. However, according to VAS pain reduction rates were significantly higher in patients of the main group (from 8.7 ± 0.6 to 1.9 ± 0.3 in the main group and 8.4 ± 0.6 to 3.9 ± 0.5 in the control group). At the end of the study, ankle circumference decreased from 270.9 ± 4.6 mm to 257.1 ± 4.2 mm in the main and from 269.7 ± 5.3 mm to 263.4 ± 5.2 in the control group. VCSS before treatment was 7.3 ± 0.6 in the main group and 6.8 ± 0.5 in the control group. By day 90 VCSS significantly decreased to 2.3 ± 0.4 and 4.6 ± 0.5 in the main and control groups respectively. Healing rates were significantly higher in the main group. On day 90, the number of open venous ulcers in the main group was 3 times lower than in the control group (4 vs. 12).
EMS demonstrated high efficacy and good tolerability and provided significant reduction in pain severity, VCSS score and ankle edema, as well as a 3-fold increase in the number of healed venous ulcers.
A system of isophotes of the cosmic microwave background (CMB) is constructed for several regions on the celestial sphere using data from the Planck spacecraft. The fractal dimensionality of the ...isotherms is estimated to be D
c
≈ 1.78 ± 0.03. Our results agree with earlier work based on the ILC charts with WMAP data. Our simulations confirm the previous conclusion that a similar dimensionality is obtained for a gaussian spectrum of initial perturbations.
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