scholarly journals The CHANDRA data of the Classical Nova RR Pic (1925): A possible Magnetic Cataclysmic Variable Candidate

2004 ◽  
Vol 190 ◽  
pp. 172-173
Author(s):  
Şölen Balman ◽  
Aybuke Küpcü-Yoldaş

AbstractDuring 25ksec of CHANDRA ACIS-S3 observations of the old nova RR Pic 1925 a count rate of 0.067±0.0017 c/s was detected. The results show evidence (spatial and spectral) for X-ray emission from the region around the prominent SW blob in the Hα images. Shell emission is detected with count rate ≥ (1.95±1.33)×10−3 c/s. The spectral analysis shows that the source spectrum can not be explained by a single or two temperature bremsstrahlung or VMEKAL models including photoelectric absorption, only models using powerlaw distribution of temperature fit the data well and indicate excess O, Al, Mg, S, and Si in the source spectrum. A soft excess in the CHANDRA data could be explained by a partial covering absorber model with covering fraction in a range 14-86 % consistent with characteristics of the Magnetic Cataclysmic Variable systems. The light curve shows significant orbital and other modulations.

2013 ◽  
Vol 9 (S304) ◽  
pp. 153-154
Author(s):  
Murray Brightman ◽  
Kirpal Nandra

AbstractWe present the results from the X-ray spectral analysis of active galactic nuclei (AGN) in the Chandra Deep Field-South, AEGIS-XD and Chandra-COSMOS surveys, focussing on the identification and characterisation of the most heavily obscured, Compton thick (CT, NH > 104 cm−2) sources. Our sample is comprised of 3088 X-ray selected sources, which has a high rate of redshift completeness (97%). The aim is to produce the largest and cleanest uniform sample of these sources from the data as possible. We identify these sources through X-ray spectral fitting, utilising torus spectral models designed for heavily obscured AGN which self consistently include the spectral signatures of heavy absorption, being Compton scattering, photoelectric absorption and iron Kα fluorescence. We identify a total of 163 CT AGN covering an intrinsic 2-10 keV X-ray luminosity range of 102 −3 × 105 erg s−1 and from z = 0.1-7.


2006 ◽  
Vol 2 (S238) ◽  
pp. 373-374
Author(s):  
O. González-Martín ◽  
J. Masegosa ◽  
I. Márquez ◽  
E. Jiménez-Bailón

AbstractWe report the analysis of the X-ray data for a sample of 48 LINER nuclei with available X-ray Chandra imaging. In González-Martín et al. 2006 21 objects had enough count rate to make the spectral analysis. Here we enlarge the sample performing the spectral analysis of the XMM-Newton observations of 7 additional galaxies. Our aim is to investigate the physical mechanisms which power the nuclear activity of LINERs. The use of multiwavelength information at radio, UV, optical HST and X-ray lead us to conclude that at least 60% of the LINERs are hosting a low luminosity AGN in their nuclei.


2007 ◽  
Vol 3 (S246) ◽  
pp. 373-374
Author(s):  
M. Servillat ◽  
N. A. Webb ◽  
D. Barret ◽  
R. Cornelisse ◽  
A. Dieball ◽  
...  

AbstractWe report on XMM-Newton and Chandra observations of the globular cluster NGC 2808. We detect one quiescent low mass X-ray binary of the 3±1 expected, if these systems are formed through encounters, and we show evidence for the presence of 20±10 bright cataclysmic variables in the core with a luminosity above 4×1031 erg s−1. We also review the specific nature of cataclysmic variables in globular clusters with reference to recent VLT/FORS1 observations of a cataclysmic variable in M 22.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1153
Author(s):  
Ivan Pavlenko ◽  
Jozef Zajac ◽  
Nadiia Kharchenko ◽  
Ján Duplák ◽  
Vitalii Ivanov ◽  
...  

This article deals with improving the wear resistance of multilayer coatings as a fundamental problem in metal surface treatment, strengthening elements of cutting tools, and ensuring the reliability of machine parts. It aims to evaluate the wear depth for multilayer coatings by the mass loss distribution in layers. The article’s primary purpose is to develop a mathematical method for assessing the value of wear for multilayer steel-based coatings. The study material is a multilayer coating applied to steel DIN C80W1. The research was performed using up-to-date laboratory equipment. Nitrogenchroming has been realized under overpressure in two successive stages: nitriding for 36 h at temperature 540 °C and chromizing during 4 h at temperature 1050 °C. The complex analysis included several options: X-ray phase analysis, local micro-X-ray spectral analysis, durometric analysis, and determination of wear resistance. These analyses showed that after nitrogenchroming, the three-layer protective coating from Cr23C6, Cr7C3, and Cr2N was formed on the steel surface. Spectral analysis indicated that the maximum amount of chromium 92.2% is in the first layer from Cr23C6. The maximum amount of carbon 8.9% characterizes the layer from Cr7C3. Nitrogen is concentrated mainly in the Cr2N layer, and its maximum amount is 9.4%. Additionally, it was determined that the minimum wear is typical for steel DIN C80W1 after nitrogenchroming. The weight loss of steel samples by 25 mg was obtained. This value differs by 3.6% from the results evaluated analytically using the developed mathematical model of wear of multilayer coatings after complex metallization of steel DIN C80W1. As a result, the impact of the loading mode on the wear intensity of steel was established. As the loading time increases, the friction coefficient of the coated samples decreases. Among the studied samples, plates from steel DIN C80W1 have the lowest friction coefficient after nitrogenchroming. Additionally, a linear dependence of the mass losses on the wearing time was obtained for carbide and nitride coatings. Finally, an increase in loading time leads to an increase in the wear intensity of steels after nitrogenchroming. The achieved scientific results are applicable in developing methods of chemical-thermal treatment, improving the wear resistance of multilayer coatings, and strengthening highly loaded machine parts and cutting tools.


2001 ◽  
Vol 7 (S2) ◽  
pp. 1050-1051 ◽  
Author(s):  
S.W. Nam ◽  
D.A. Wollman ◽  
Dale E. Newbury ◽  
G.C. Hilton ◽  
K.D. Irwin ◽  
...  

The high performance of single-pixel microcalorimeter EDS (μ,cal EDS) has been shown to be very useful for a variety of microanalysis cases. The primary advantage of jxcal EDS over conventional EDS is the factor of 25 improvement in energy resolution (∽3 eV in real-time). This level of energy resolution is particularly important for applications such as nanoscale contaminant analysis where it is necessary to resolve peak overlaps at low x-ray energies. Because μcal EDS offers practical solutions to many microanalysis problems, several companies are proceeding with commercialization of single-pixel μal EDS technology. Two drawbacks limiting the application of uxal EDS are its low count rate (∽500 s−1) and small area (∽0.04 mm for a bare single pixel, ∽5 mm2 with a polycapillary optic). We are developing a 32x32 pixel array with a total area of 40 mm2 and with a total count rate between 105 s−1 and 106 s−1.


2014 ◽  
Vol 176 (3-4) ◽  
pp. 597-603 ◽  
Author(s):  
S. J. Lee ◽  
S. R. Bandler ◽  
S. E. Busch ◽  
J. S. Adams ◽  
J. A. Chervenak ◽  
...  

2017 ◽  
Vol 30 (10) ◽  
pp. 104005
Author(s):  
Sang-Jun Lee ◽  
Joseph S Adams ◽  
Simon R Bandler ◽  
Gabriele L Betancourt-Martinez ◽  
James A Chervenak ◽  
...  

2012 ◽  
Vol 83 (10) ◽  
pp. 10E114 ◽  
Author(s):  
C. M. Huntington ◽  
C. C. Kuranz ◽  
G. Malamud ◽  
R. P. Drake ◽  
H.-S. Park ◽  
...  

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