X‐Ray Emission from Central Binary Systems of Planetary Nebulae

A variety of linear chain materials exist as polydisperse systems which are difficultly purified. The stability of continuous binary solid solutions assume that the Gibbs free energy of the solution is lower than that of either crystal component, a condition which includes such factors as relative molecular sizes and shapes and perhaps the symmetry of the pure component crystal structures.Although extensive studies of n-alkane miscibility have been carried out via powder X-ray diffraction of bulk samples we have begun to examine binary systems as single crystals, taking advantage of the well-known enhanced scattering cross section of matter for electrons and also the favorable projection of a paraffin crystal structure posited by epitaxial crystallization of such samples on organic substrates such as benzoic acid.

Power Density Spectral analysis as a Method of Compact Object Determination in X-ray Binary Systems

10.2172/800021 ◽

2002 ◽

Author(s):

John R Lee

Keyword(s):

Spectral Analysis ◽

Power Density ◽

Binary Systems ◽

Compact Object ◽

X Ray

X-ray and UV emission of the ultrashort-period, low-mass eclipsing binary system BX Trianguli

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834116 ◽

2018 ◽

Vol 619 ◽

pp. A138

Author(s):

V. Perdelwitz ◽

S. Czesla ◽

J. Robrade ◽

T. Pribulla ◽

J. H. M. M. Schmitt

Keyword(s):

Binary System ◽

Light Curve ◽

Binary Systems ◽

Uv Light ◽

Close Binary ◽

Eclipsing Binary ◽

X Ray ◽

Uv Emission ◽

Low Mass ◽

Orbital Modulation

Context.Close binary systems provide an excellent tool for determining stellar parameters such as radii and masses with a high degree of precision. Due to the high rotational velocities, most of these systems exhibit strong signs of magnetic activity, postulated to be the underlying reason for radius inflation in many of the components. Aims.We extend the sample of low-mass binary systems with well-known X-ray properties. Methods.We analyze data from a singular XMM-Newton pointing of the close, low-mass eclipsing binary system BX Tri. The UV light curve was modeled with the eclipsing binary modeling tool PHOEBE and data acquired with the EPIC cameras was analyzed to search for hints of orbital modulation. Results.We find clear evidence of orbital modulation in the UV light curve and show that PHOEBE is fully capable of modeling data within this wavelength range. Comparison to a theoretical flux prediction based on PHOENIX models shows that the majority of UV emission is of photospheric origin. While the X-ray light curve does exhibit strong variations, the signal-to-noise ratio of the observation is insufficient for a clear detection of signs of orbital modulation. There is evidence of a Neupert-like correlation between UV and X-ray data.

A Machine Learning Approach For Classifying Low-mass X-ray Binaries Based On Their Compact Object Nature

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3899 ◽

2020 ◽

Author(s):

R Pattnaik ◽

K Sharma ◽

K Alabarta ◽

D Altamirano ◽

M Chakraborty ◽

...

Keyword(s):

Machine Learning ◽

Black Hole ◽

Neutron Star ◽

Binary Systems ◽

Compact Object ◽

X Ray ◽

Average Accuracy ◽

Machine Learning Approach ◽

Low Mass ◽

X Ray Binaries

Abstract Low Mass X-ray binaries (LMXBs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. It is challenging to unambiguously determine whether a LMXB hosts a black hole or a neutron star. In the last few decades, multiple observational works have tried, with different levels of success, to address this problem. In this paper, we explore the use of machine learning to tackle this observational challenge. We train a random forest classifier to identify the type of compact object using the energy spectrum in the energy range 5-25 keV obtained from the Rossi X-ray Timing Explorer archive. We report an average accuracy of 87±13% in classifying the spectra of LMXB sources. We further use the trained model for predicting the classes for LMXB systems with unknown or ambiguous classification. With the ever-increasing volume of astronomical data in the X-ray domain from present and upcoming missions (e.g., SWIFT, XMM-Newton, XARM, ATHENA, NICER), such methods can be extremely useful for faster and robust classification of X-ray sources and can also be deployed as part of the data reduction pipeline.

X-Ray Sources in Close Binary Systems

Highlights of Astronomy ◽

10.1017/s1539299600001842 ◽

1974 ◽

Vol 3 ◽

pp. 89-107

Author(s):

M. J. Rees

Keyword(s):

Binary Systems ◽

Close Binary ◽

Rapid Variability ◽

X Ray ◽

Close Binary Systems ◽

General Order ◽

Typical Distances ◽

Astronomical Research ◽

Orbital Periods ◽

Galactic Sources

The discovery by Giacconi and his colleagues of variable X-ray sources in close binary systems certainly ranks as one of the highlights of astronomical research during the last 3 years. These remarkable objects have already been extensively studied, by optical and radio observations as well as in the X-ray band; and they seem likely to prove as significant and far-reaching in their implications as pulsars.The ‘Third Uhuru Catalogue’ (Giacconi et al., 1973a) contains about 160 sources, of which about 100 lie in our Galaxy. Their distribution over the sky (together with other arguments) suggests that these sources have luminosities of the general order 1036–1038 erg s−1, and that their typical distances are ˜ 10kpc. These galactic sources generally display rapid variability. Little else is known about most of them, but they are probably of the same general class as systems such as Her X1, Cen X3, Cyg X1 and Cyg X3. These sources have been investigated in detail, and in all cases one infers a system where the X-ray source is orbiting around a relatively ordinary star. Six sources have been optically identified, and there are some others whose binary nature is established by the occurrence of an X-ray eclipse. Orbital periods range from 4.8 h (Cyg X3) up to ˜ 10 days.

Abundance Anomalies in the X‐Ray Spectra of Planetary Nebulae NGC 7027 and BD +30o3639

The Astrophysical Journal ◽

10.1086/374414 ◽

2003 ◽

Vol 589 (1) ◽

pp. 439-443 ◽

Cited By ~ 18

Author(s):

Holly L. Maness ◽

Saeqa D. Vrtilek ◽

Joel H. Kastner ◽

Noam Soker

Keyword(s):

Planetary Nebulae ◽

X Ray ◽

Ngc 7027 ◽

Abundance Anomalies

X-ray emission from colliding winds in pre-main binary systems

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/271.3.667 ◽

1994 ◽

Vol 271 (3) ◽

pp. 667-675 ◽

Cited By ~ 5

Author(s):

S. A. Zhekov ◽

Francesco Palla ◽

A. V. Myasnikov

Keyword(s):

Binary Systems ◽

X Ray ◽

Colliding Winds

Planetary nebulae in planetary and binary systems

Astrophysics and Space Science ◽

10.1007/bf00649462 ◽

1981 ◽

Vol 77 (2) ◽

pp. 319-324 ◽

Cited By ~ 4

Author(s):

Kyu H. Choi ◽

Samuel C. Vila

Keyword(s):

Binary Systems ◽

Planetary Nebulae

High-energy X-ray diffuse scattering

Journal of Applied Crystallography ◽

10.1107/s0021889809011492 ◽

2009 ◽

Vol 42 (3) ◽

pp. 392-400 ◽

Cited By ~ 5

Author(s):

I. B. Ramsteiner ◽

A. Schöps ◽

H. Reichert ◽

H. Dosch ◽

V. Honkimäki ◽

...

Keyword(s):

Multiple Scattering ◽

Diffuse Scattering ◽

Binary Systems ◽

High Energy ◽

Absorption Length ◽

Time Resolved ◽

X Ray ◽

Order Of Magnitude ◽

Extinction Length ◽

Scattering Volume

Diffuse X-ray scattering has been an important tool for understanding the atomic structure of binary systems for more than 50 years. The majority of studies have used laboratory-based sources providing 8 keV photons or synchrotron radiation with similar energies. Diffuse scattering is weak, with the scattering volume determined by the X-ray absorption length. In the case of 8 keV photons, this is not significantly different from the typical extinction length for Bragg scattering. If, however, one goes to energies of the order of 100 keV the scattering volume for the diffuse scattering increases up to three orders of magnitude while the extinction length increases by only one order of magnitude. This leads to a gain of two orders of magnitude in the relative intensity of the diffuse scattering compared with the Bragg peaks. This gain, combined with the possibility of recording the intensity from an entire plane in reciprocal space using a two-dimensional X-ray detector, permits time-resolved diffuse scattering studies in many systems. On the other hand, diffraction features that are usually neglected, such as multiple scattering, come into play. Four types of multiple scattering phenomena are discussed, and the manner in which they appear in high-energy diffraction experiments is considered.

A Multi-Wavelength View of the XMM-Newton Galactic Plane

Acta Polytechnica CTU Proceedings ◽

10.14311/app.2014.01.0123 ◽

2014 ◽

Vol 1 (1) ◽

pp. 123-126

Author(s):

Ada Nebot Gómez-Morán ◽

Christian Motch

Keyword(s):

Surface Density ◽

Binary Systems ◽

Galactic Plane ◽

Galactic Centre ◽

Galactic Latitude ◽

X Ray ◽

Model Predictions ◽

Science Centre ◽

Multi Wavelength ◽

Galactic Longitude

We present an X-ray survey of the Galactic Plane conducted by the Survey Science Centre of the XMM-Newton satellite. The survey contains more than 1300 X-ray detections at low and intermediate Galactic latitudes and covering 4 deg<sup>2</sup> well spread in Galactic longitude. From a multi-wavelength analysis, using optical spectra and helped by optical and infrared photometry we identify and classify about a fourth of the sources. The observed surface density of soft X-ray (<2 keV) sources decreases with Galactic latitude and although compatible with model predictions at first glance, presents an excess of stars, likely due to giants in binary systems. In the hard band (>2 keV) the surface density of sources presents an excess with respect to the expected extragalactic contribution. This excess highly concentrates towards the direction of the Galactic Centre and is compatible with previous results from Chandra observations around the Galactic Centre. The nature of these sources is still unknown.