AN EXTENDED AND MORE SENSITIVE SEARCH FOR PERIODICITIES IN
                    ROSSI X-RAY TIMING EXPLORER
                    /ALL-SKY MONITOR X-RAY LIGHT CURVES

The luminous low mass X-ray binary Cir X-1 has been observed nearly continuously for about 5 years by the X-ray All Sky Monitor on board the RXTE satellite. We carried out a timing analysis on Cir X-1 with the RXTE data. We define the period from the X-ray data, comparing the period change over time with the best current ephemeris. with folded light curves of entire data set, characteristics of the system like long-term lightcurve changes, behavior of flares and dips and super-Eddington accretion were obtained. We also checked and identified the secondary flaring reported in radio band with X-ray data.

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NEWCOMB-BENFORD LAW IN ASTROPHYSICAL SOURCES

International Journal of Modern Physics C ◽

10.1142/s0129183106010054 ◽

2006 ◽

Vol 17 (11) ◽

pp. 1597-1604 ◽

Cited By ~ 10

Author(s):

M. A. MORET ◽

V. de SENNA ◽

M. G. PEREIRA ◽

G. F. ZEBENDE

Keyword(s):

Binary Systems ◽

Cataclysmic Variables ◽

Bimodal Distribution ◽

Light Curves ◽

Nonextensive Statistical Mechanics ◽

X Ray ◽

The Public ◽

Public Data ◽

Sky Monitor ◽

Benford Law

We study the behavior of the numbers in 412 light curves of cataclysmic variables, x-ray binary systems, galaxies, pulsars, supernovae remnants and other x-ray sources present in the public data collected by the instrument All Sky Monitor on board of the satellite Rossi x-ray timing explorer. The temporal light curves were analyzed applying Newcomb-Benford Law. The first digit of the x-ray light curves coming from astrophysical systems obeys the Newcomb-Benford Law as an intrinsic behavior. The nonextensive statistical mechanics behavior of astrophysical sources seem to be the cause for these sources to obey the Newcomb-Benford law. Some x-ray binary systems, however, do not follow this behavior. These systems obey either a gaussian or a bimodal distribution.

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Recurrent ∼24 h Periods in RXTE ASM Data

Publications of the Astronomical Society of Australia ◽

10.1071/as04081 ◽

2005 ◽

Vol 22 (3) ◽

pp. 267-276 ◽

Cited By ~ 9

Author(s):

Sean A. Farrell ◽

Paul M. O'Neill ◽

Ravi K. Sood

Keyword(s):

Low Frequency ◽

Sampling Period ◽

Secular Trends ◽

Light Curves ◽

Spectral Leakage ◽

X Ray ◽

Sky Monitor ◽

Low Frequency Power ◽

Frequency Power

AbstractAnalysis of data from the Rossi X-ray Timing Explorer satellite's All Sky Monitor (ASM) instrument for several X-ray binary sources has identified a recurrent ∼24 h period. This period is sometimes highly significant, giving rise to the possibility of it being identified as an orbital or super-orbital period. Further analysis has revealed the same period in a number of other X-ray sources. As a result this period has been discounted as spurious, described variously as arising from daily variations in background levels, the scheduling of ASM observations and beating between the sampling period and long-term secular trends in the light curves. We present here an analysis of the spurious periods and show that the dominant mechanism is in fact spectral leakage of low-frequency power present in the light curves.

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A minimal timescale for the continuum in 4U 1608-52 and Aql X-1

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slab004 ◽

2021 ◽

Vol 502 (1) ◽

pp. L72-L78

Author(s):

K Mohamed ◽

E Sonbas ◽

K S Dhuga ◽

E Göğüş ◽

A Tuncer ◽

...

Keyword(s):

Black Hole ◽

Neutron Star ◽

Power Spectra ◽

Light Curves ◽

State Transitions ◽

Strong Positive Correlation ◽

Present Evidence ◽

X Ray ◽

X Ray Binaries ◽

The Continuum

ABSTRACT Similar to black hole X-ray binary transients, hysteresis-like state transitions are also seen in some neutron-star X-ray binaries. Using a method based on wavelets and light curves constructed from archival Rossi X-ray Timing Explorer observations, we extract a minimal timescale over the complete range of transitions for 4U 1608-52 during the 2002 and 2007 outbursts and the 1999 and 2000 outbursts for Aql X-1. We present evidence for a strong positive correlation between this minimal timescale and a similar timescale extracted from the corresponding power spectra of these sources.

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The study of multipeaked type-I X-ray bursts in the neutron star low-mass X-ray binary 4U 1636 − 536 with RXTE

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3539 ◽

2020 ◽

Vol 501 (1) ◽

pp. 168-178

Author(s):

Chen Li ◽

Guobao Zhang ◽

Mariano Méndez ◽

Jiancheng Wang ◽

Ming Lyu

Keyword(s):

Neutron Star ◽

Flux Ratio ◽

Light Curves ◽

Type I ◽

X Ray ◽

Soft State ◽

Peak Flux ◽

Low Mass ◽

Two Peaks ◽

Second Peak

ABSTRACT We have found and analysed 16 multipeaked type-I bursts from the neutron-star low-mass X-ray binary 4U 1636 − 53 with the Rossi X-ray Timing Explorer (RXTE). One of the bursts is a rare quadruple-peaked burst that was not previously reported. All 16 bursts show a multipeaked structure not only in the X-ray light curves but also in the bolometric light curves. Most of the multipeaked bursts appear in observations during the transition from the hard to the soft state in the colour–colour diagram. We find an anticorrelation between the second peak flux and the separation time between two peaks. We also find that in the double-peaked bursts the peak-flux ratio and the temperature of the thermal component in the pre-burst spectra are correlated. This indicates that the double-peaked structure in the light curve of the bursts may be affected by enhanced accretion rate in the disc, or increased temperature of the neutron star.

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Breaking the Degeneracy in Magnetic Cataclysmic Variable X-Ray Spectral Modeling Using X-Ray Light Curves

The Astrophysical Journal Supplement Series ◽

10.3847/1538-4365/ac141c ◽

2021 ◽

Vol 256 (2) ◽

pp. 45

Author(s):

Diogo Belloni ◽

Claudia V. Rodrigues ◽

Matthias R. Schreiber ◽

Manuel Castro ◽

Joaquim E. R. Costa ◽

...

Keyword(s):

Light Curves ◽

Cataclysmic Variable ◽

Spectral Modeling ◽

X Ray

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Hydrodynamic Models of Solar and Stellar Flares

International Astronomical Union Colloquium ◽

10.1017/s0252921100031948 ◽

1989 ◽

Vol 104 (1) ◽

pp. 289-298

Author(s):

Giovanni Peres

Keyword(s):

High Resolution ◽

Light Curve ◽

Solar Flares ◽

Impulsive Phase ◽

Light Curves ◽

Physical Parameters ◽

The Sun ◽

Hydrodynamic Models ◽

X Ray ◽

Stellar Flares

AbstractThis paper discusses the hydrodynamic modeling of flaring plasma confined in magnetic loops and its objectives within the broader scope of flare physics. In particular, the Palermo-Harvard model is discussed along with its applications to the detailed fitting of X-ray light curves of solar flares and to the simulation of high-resolution Caxix spectra in the impulsive phase. These two approaches provide complementary constraints on the relevant features of solar flares. The extension to the stellar case, with the fitting of the light curve of an X-ray flare which occurred on Proxima Centauri, demonstrates the feasibility of using this kind of model for stars too. Although the stellar observations do not provide the wealth of details available for the Sun, and, therefore, constrain the model more loosely, there are strong motivations to pursue this line of research: the wider range of physical parameters in stellar flares and the possibility of studying further the solar-stellar connection.

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