scholarly journals Dips and eclipses in the X-ray binary Swift J1858.6–0814 observed with NICER

2021 ◽  
Author(s):  
D J K Buisson ◽  
D Altamirano ◽  
M Armas Padilla ◽  
Z Arzoumanian ◽  
P Bult ◽  
...  
Keyword(s):  
Orbital Period ◽  
Light Curves ◽  
Period Ratio ◽  
X Ray ◽  
Eclipse Phase ◽  
Binary Orbit ◽  
Stream Interface

Abstract We present the discovery of eclipses in the X-ray light curves of the X-ray binary Swift J1858.6–0814. From these, we find an orbital period of $P=76841.3_{-1.4}^{+1.3}$ s (≈21.3 hours) and an eclipse duration of $t_{\rm ec}=4098_{-18}^{+17}$ s (≈1.14 hours). We also find several absorption dips during the pre-eclipse phase. From the eclipse duration to orbital period ratio, the inclination of the binary orbit is constrained to i > 70○. The most likely range for the companion mass suggests that the inclination is likely to be closer to this value than 90○. The eclipses are also consistent with earlier data, in which strong variability (‘flares’) and the long orbital period prevent clear detection of the period or eclipses. We also find that the bright flares occurred preferentially in the post-eclipse phase of the orbit, likely due to increased thickness at the disc-accretion stream interface preventing flares being visible during the pre-eclipse phase. This supports the notion that variable obscuration is responsible for the unusually strong variability in Swift J1858.6–0814.

scholarly journals Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115)

2015 ◽  
Vol 2 (1) ◽  
pp. 50-54
Author(s):  
P. A. Mason ◽  
E. L. Robinson ◽  
S. Gomez ◽  
J. V. Segura
Keyword(s):  
Black Hole ◽  
Orbital Period ◽  
Light Curves ◽  
Optical Data ◽  
Published Data ◽  
Type I ◽  
Optical Photometry ◽  
Mean Intensity ◽  
X Ray ◽  
Low Mass

We present new optical observations of V1408 Aql (= 4U 1957+115), the only low mass X-ray binary, black hole candidate known to be in a persistently soft state. We combine new broadband optical photometry with previously published data and derive a precise orbital ephemeris. The optical light curves display sinusoidal variations modulated on the orbital period as well as large night to night changes in mean intensity. The amplitude of the variations increases with mean intensity while maintaining sinusoidal shape. Considering the set of constraints placed by the X-ray and optical data we argue that V1408 Aql may harbor a very low mass black hole. Optical light curves of UW CrB display partial eclipses of the accretion disk by the donor star that vary both in depth and orbital phase. The new eclipses of UW CrB in conjunction with published eclipse timings are well fitted with a linear ephemeris. We derive an upper limit to the rate of change of the orbital period. By including the newly observed type I bursts with published bursts in our analysis, we find that optical bursts are not observed between orbital phases 0.93 and 0.07, i.e. they are not observable during partial eclipses of the disk.

scholarly journals Unveiling the nature of the 321s Orbital Period X-ray source RX J0806.3+1527

2004 ◽  
Vol 190 ◽  
pp. 338-344
Author(s):  
GianLuca Israel ◽  
Luigi Stella ◽  
Stefano Covino ◽  
Sergio Campana ◽  
Gianni Marconi ◽  
...  
Keyword(s):  
Phase Shift ◽  
Orbital Period ◽  
Black Body ◽  
Light Curves ◽  
X Ray ◽  
Body Component ◽  
First Time ◽  
Irradiation Process ◽  
Good Agreement

AbstractA nearly simultaneous X-ray/optical (Chandra and VLT) observational campaign of RX J0806.3+1527 has been carried out during 2001. These observations allowed us to phase the X-ray and optical light curves for the first time. We measured a phase–shift of ~0.5, in good agreement with the presence of two distinct emission regions and with the X-ray irradiation process predictions. The Chandra data allowed us also to study in details the X-ray spectrum of RX J0806.3+1527, which is consistent with a soft (kT<70eV) and small (RBB <20km) black-body component. We discuss the present findings in the light of the models proposed so far to account for the X-ray emission detected from RX J0806.3+1527, and its twin source RX J1914.4+2456.

scholarly journals Observations of Low Mass X-Ray Binaries

1996 ◽  
Vol 158 ◽  
pp. 349-358
Author(s):  
Alan P. Smale
Keyword(s):  
Neutron Stars ◽  
Orbital Period ◽  
Binary Systems ◽  
Light Curves ◽  
X Ray ◽  
Fast Timing ◽  
Low Mass ◽  
And Behavior ◽  
X Ray Binaries

AbstractIn this paper I review the properties and behavior of low-mass X-ray binary systems (LMXBs) that contain neutron stars (NS), concentrating on the Galactic bulge sources and bursters. I describe the observed characteristics of LMXBs including their light curves, spectra, eclipses, dips, bursts, flares, pulsations, QPO, long-term periodicities and orbital period changes, and explain how fast timing results and the distinction between ‘Z’ and ‘atoll’-type sources provide the key to a unified model of LMXB behavior.

scholarly journals Face changing companion of the redback millisecond pulsar PSR J1048+2339

2019 ◽  
Vol 621 ◽  
pp. L9 ◽  
Author(s):  
Y. X. Yap ◽  
K. L. Li ◽  
A. K. H. Kong ◽  
J. Takata ◽  
J. Lee ◽  
...  
Keyword(s):  
Orbital Period ◽  
Light Curves ◽  
Optical Observations ◽  
Millisecond Pulsar ◽  
High Quality ◽  
X Ray ◽  
Compact Binary ◽  
Modeling Analysis ◽  
Irradiation Power ◽  
Pulsar Wind

We present optical observations of the redback millisecond pulsar PSR J1048+2339, which is a 4.66 ms radio pulsar in a compact binary with an orbital period of six hours. We obtained high-quality light curves of PSR J1048+2339 with the Lulin 1 m Telescope. The system shows two distinct six-hour orbital modulations, in which an ellipsoidal modulation changes into a sinusoidal-like profile in less than 14 days. In addition to the change, the brightness of the companion increased by one magnitude, suggesting that the latter type of modulation is caused by the pulsar wind heating of the companion and that the heating became dominant in the system. While the changes are not unexpected, such a timescale is the shortest among similar systems. We performed modeling analysis to extract the properties of the system. We obtained a derived pulsar mass of 2.1 M⊙ and a companion star mass of 0.4 M⊙ for the system. The irradiation power increased by a factor of 6 during which the pulsar wind heating dominates. We also report on the two archival Chandra X-ray observations and discuss several possibilities that might cause the varying heating on the companion.

scholarly journals New JHK Photometry of LS I +61 303

2000 ◽  
Vol 175 ◽  
pp. 727-730
Author(s):  
S. Martínez-Núñez ◽  
J. Fabregat
Keyword(s):  
Orbital Period ◽  
Compact Object ◽  
Light Curves ◽  
Circumstellar Envelope ◽  
Be Stars ◽  
X Ray ◽  
Close Orbit ◽  
Infrared Wavelengths ◽  
Ir Light

AbstractWe present new JHK photometry of the Be/X-ray binary L SI +61 303, obtained during the period 1994-1998. The IR light curves do not show the modulation with the orbital period apparently present in the smaller photometry set analyzed by Paredes et al. (1994).The reddening-corrected standard photometric values indicate that the circumstellar envelope is optically thick at infrared wavelengths, and much denser than those of isolated Be stars. It is argued that this higher density is produced by disk truncation due to the presence of the compact object in a close orbit.

scholarly journals Identification of 3XMM J000511.8+634018 as a new polar at Porb = 133.5 min – is it inside or outside the period gap?

2020 ◽  
Vol 637 ◽  
pp. A35
Author(s):  
A. D. Schwope ◽  
H. Worpel ◽  
N. A. Webb ◽  
F. Koliopanos ◽  
S. Guillot
Keyword(s):  
Optical Spectroscopy ◽  
Orbital Period ◽  
Thermal Plasma ◽  
White Dwarf ◽  
Cataclysmic Variables ◽  
Light Curves ◽  
Cataclysmic Variable ◽  
Minimum Period ◽  
X Ray ◽  
Bright Phase

Aims. We aimed to identify the variable X-ray source 3XMM J000511.8+634018, which was serendipitously discovered through routine inspections while the 3XMM catalogue was compiled. Methods. We analysed the archival XMM-Newton observation of the source, obtained BUSCA photometry in three colours, and performed optical spectroscopy with the LBT. These data were supplemented by archival observations from the Zwicky Transient Facility. Results. Based on its optical and X-ray properties, 3XMM J000511.8+634018 is classified as a magnetic cataclysmic variable, or polar. The flux is modulated with a period of 2.22 h (8009.1 ± 0.2 s), which we identify with the orbital period. The bright phases are highly variable in X-ray luminosity from one cycle to the next. The source shows a thermal plasma spectrum typical of polars without evidence of a luminous soft blackbody-like component. It is non-eclipsing and displays one-pole accretion. The X-ray and BUSCA light curves show a stream absorption dip, which suggests an inclination 50° < i <  75°. The phasing of this feature, which occurs at the end of the bright phase, requires a somewhat special accretion geometry with a stream running far around the white dwarf before it is magnetically channelled. The period of this polar falls within the period gap of the cataclysmic variables (2.15−3.18 h), but appears to fall just below the minimum period when only polars are considered.

scholarly journals On V603 Aql and Magnetic Novae

1990 ◽  
Vol 122 ◽  
pp. 73-75
Author(s):  
A. Schwarzenberg-Czerny ◽  
A. Udalski
Keyword(s):  
Orbital Period ◽  
Small Amplitude ◽  
Light Curves ◽  
X Rays ◽  
X Ray ◽  
Beat Period

Our photometry revealed that the old nova V603 Aql has four different coherent periods, including a period present in X-rays and so it is quite unique among all novae. Thus we classify V603 Aql as an intermediate polar (IP) system. Some time ago Hefner and Metz (1985) found that the period of the sinusoidal light variations of V603 Aql is 3.5 hour and thus it is longer by about 5 percent than the spectroscopic orbital period of 3.3 hour. Our observations covering over 30 hours and spanning 30 days confirm their result. However, we discovered also another coherent oscilation with a small amplitude of 0.02 mag and period of 61 min (Udalski and Schwarzenberg-Czerny, 1989). Our analysis of the X-ray observations by Drechsel et al. (1983) revealed 25 percent modulation with the same period and thus confirmed our discovery (Fig. 1). Additionaly we found in our light curves evidence of the 2.5 day beat period of the 3.3 and 3.5 hour periods.

scholarly journals Unveiling the super-orbital modulation of LS I + 61°303 in X-rays

2012 ◽  
Vol 8 (S290) ◽  
pp. 255-256
Author(s):  
Jian Li ◽  
Diego F. Torres ◽  
Shu Zhang ◽  
Daniela Hadasch ◽  
Nanda Rea ◽  
...  
Keyword(s):  
Time Evolution ◽  
Orbital Period ◽  
Count Rate ◽  
Light Curves ◽  
X Rays ◽  
X Ray ◽  
Orbital Modulation ◽  
Radio Frequencies ◽  
Sinusoidal Function

AbstractWe found evidence for the super–orbital modulation in the X-ray emission of LS I + 61°303 from the longest monitoring date by the RXTE. The time evolution of the modulated fraction in the orbital light curves can be well fitted with a sinusoidal function having a super-orbital period of 1667 days. However, we have found a 281.8±44.6 day shift between the super-orbital variability found at radio frequencies and our X-ray data. We also find a super-orbital modulation in the maximum count rate of the orbital light curves, compatible with the former results, including the shift.

The Eclipsing Binary WX Eridani

1979 ◽  
Vol 46 ◽  
pp. 385
Author(s):  
M.B.K. Sarma ◽  
K.D. Abhankar
Keyword(s):  
Light Curve ◽  
Spectral Type ◽  
Orbital Period ◽  
Primary Component ◽  
Light Curves ◽  
Absorption Feature ◽  
Primary Star ◽  
Eclipsing Binary ◽  
The Times ◽  
Phase Angles

AbstractThe Algol-type eclipsing binary WX Eridani was observed on 21 nights on the 48-inch telescope of the Japal-Rangapur Observatory during 1973-75 in B and V colours. An improved period of P = 0.82327038 days was obtained from the analysis of the times of five primary minima. An absorption feature between phase angles 50-80, 100-130, 230-260 and 280-310 was present in the light curves. The analysis of the light curves indicated the eclipses to be grazing with primary to be transit and secondary, an occultation. Elements derived from the solution of the light curve using Russel-Merrill method are given. From comparison of the fractional radii with Roche lobes, it is concluded that none of the components have filled their respective lobes but the primary star seems to be evolving. The spectral type of the primary component was estimated to be F3 and is found to be pulsating with two periods equal to one-fifth and one-sixth of the orbital period.

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

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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