Discovery of an Iron K Absorption Line in the Low-Mass X-Ray Binary GX 13+1

2001 ◽  
Vol 556 (2) ◽  
pp. L87-L90 ◽  
Author(s):  
Y. Ueda ◽  
K. Asai ◽  
K. Yamaoka ◽  
T. Dotani ◽  
H. Inoue
Keyword(s):  
Absorption Line ◽  
X Ray ◽  
Low Mass

scholarly journals AN Fe XXIV ABSORPTION LINE IN THE PERSISTENT SPECTRUM OF THE DIPPING LOW-MASS X-RAY BINARY 1A 1744–361

2012 ◽  
Vol 753 (1) ◽  
pp. 2 ◽  
Author(s):  
Fotis P. Gavriil ◽  
Tod E. Strohmayer ◽  
Sudip Bhattacharyya
Keyword(s):  
Absorption Line ◽  
X Ray ◽  
Low Mass

ChandraHigh‐Resolution Spectroscopy of the Absorption‐Line Features in the Low‐Mass X‐Ray Binary GX 13+1

2004 ◽  
Vol 609 (1) ◽  
pp. 325-334 ◽  
Author(s):  
Y. Ueda ◽  
H. Murakami ◽  
K. Yamaoka ◽  
T. Dotani ◽  
K. Ebisawa
Keyword(s):  
Absorption Line ◽  
X Ray ◽  
Low Mass ◽  
Line Features

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

Detection of Absorption‐Line Features in the X‐Ray Spectra of the Galactic Superluminal Source GRO J1655–40

1998 ◽  
Vol 500 (2) ◽  
pp. 1069-1069 ◽  
Author(s):  
Y. Ueda ◽  
H. Inoue ◽  
Y. Tanaka ◽  
K. Ebisawa ◽  
F. Nagase ◽  
...  
Keyword(s):  
Absorption Line ◽  
X Ray ◽  
Line Features

scholarly journals Phase lags of quasi-periodic oscillations across source states in the low-mass X-ray binary 4U 1636–53

2016 ◽  
Vol 461 (1) ◽  
pp. 79-92 ◽  
Author(s):  
Marcio G. B. de Avellar ◽  
Mariano Méndez ◽  
Diego Altamirano ◽  
Andrea Sanna ◽  
Guobao Zhang
Keyword(s):  
Periodic Oscillations ◽  
X Ray ◽  
Phase Lags ◽  
Low Mass

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

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.

scholarly journals Early Science from POSSUM: Shocks, turbulence, and a massive new reservoir of ionised gas in the Fornax cluster

2021 ◽  
Vol 38 ◽  
Author(s):  
C. S. Anderson ◽  
G. H. Heald ◽  
J. A. Eilek ◽  
E. Lenc ◽  
B. M. Gaensler ◽  
...  
Keyword(s):  
X Ray ◽  
Main Cluster ◽  
Rotation Measure ◽  
Sky Survey ◽  
Low Mass ◽  
Fornax Cluster ◽  
Depth Enhancement ◽  
Projected Distance ◽  
Density Regime ◽  
New Reservoir

Abstract We present the first Faraday rotation measure (RM) grid study of an individual low-mass cluster—the Fornax cluster—which is presently undergoing a series of mergers. Exploiting commissioning data for the POlarisation Sky Survey of the Universe’s Magnetism (POSSUM) covering a ${\sim}34$ square degree sky area using the Australian Square Kilometre Array Pathfinder (ASKAP), we achieve an RM grid density of ${\sim}25$ RMs per square degree from a 280-MHz band centred at 887 MHz, which is similar to expectations for forthcoming GHz-frequency ${\sim}3\pi$ -steradian sky surveys. These data allow us to probe the extended magnetoionic structure of the cluster and its surroundings in unprecedented detail. We find that the scatter in the Faraday RM of confirmed background sources is increased by $16.8\pm2.4$ rad m−2 within 1 $^\circ$ (360 kpc) projected distance to the cluster centre, which is 2–4 times larger than the spatial extent of the presently detectable X-ray-emitting intracluster medium (ICM). The mass of the Faraday-active plasma is larger than that of the X-ray-emitting ICM and exists in a density regime that broadly matches expectations for moderately dense components of the Warm-Hot Intergalactic Medium. We argue that forthcoming RM grids from both targeted and survey observations may be a singular probe of cosmic plasma in this regime. The morphology of the global Faraday depth enhancement is not uniform and isotropic but rather exhibits the classic morphology of an astrophysical bow shock on the southwest side of the main Fornax cluster, and an extended, swept-back wake on the northeastern side. Our favoured explanation for these phenomena is an ongoing merger between the main cluster and a subcluster to the southwest. The shock’s Mach angle and stand-off distance lead to a self-consistent transonic merger speed with Mach 1.06. The region hosting the Faraday depth enhancement also appears to show a decrement in both total and polarised radio emission compared to the broader field. We evaluate cosmic variance and free-free absorption by a pervasive cold dense gas surrounding NGC 1399 as possible causes but find both explanations unsatisfactory, warranting further observations. Generally, our study illustrates the scientific returns that can be expected from all-sky grids of discrete sources generated by forthcoming all-sky radio surveys.

scholarly journals QPOs in compact binaries from small scale eruptions in an inner magnetized disk

2020 ◽  
Author(s):  
Nicolas Scepi ◽  
Mitchell C Begelman ◽  
Jason Dexter
Keyword(s):  
Rapid Heating ◽  
Small Scale ◽  
Type B ◽  
Periodic Oscillations ◽  
X Ray ◽  
Compact Binaries ◽  
Heating And Cooling ◽  
Low Mass ◽  
X Ray Binaries ◽  
Standard Disk

Abstract Dwarf novæ (DNe) and low mass X-ray binaries (LMXBs) are compact binaries showing variability on time scales from years to less than seconds. Here, we focus on explaining part of the rapid fluctuations in DNe, following the framework of recent studies on the monthly eruptions of DNe that use a hybrid disk composed of an outer standard disk and an inner magnetized disk. We show that the ionization instability, that is responsible for the monthly eruptions of DNe, is also able to operate in the inner magnetized disk. Given the low density and the fast accretion time scale of the inner magnetized disk, the ionization instability generates small, rapid heating and cooling fronts propagating back and forth in the inner disk. This leads to quasi-periodic oscillations (QPOs) with a period of the order of 1000 s. A strong prediction of our model is that these QPOs can only develop in quiescence or at the beginning/end of an outburst. We propose that these rapid fluctuations might explain a subclass of already observed QPOs in DNe as well as a, still to observe, subclass of QPOs in LMXBs. We also extrapolate to the possibility that the radiation pressure instability might be related to Type B QPOs in LMXBs.

scholarly journals Drifts of the marginally stable burning frequency in the X-ray binaries 4U 1608–52 and Aql X–1

2021 ◽  
Vol 502 (2) ◽  
pp. 1856-1863
Author(s):  
G C Mancuso ◽  
D Altamirano ◽  
M Méndez ◽  
M Lyu ◽  
J A Combi
Keyword(s):  
Frequency Drift ◽  
Soft Or ◽  
Significance Level ◽  
X Ray ◽  
Intermediate States ◽  
Source State ◽  
Nuclear Burning ◽  
Low Mass ◽  
X Ray Binaries ◽  
Stable Burning

ABSTRACT We detect millihertz quasi-periodic oscillations (mHz QPOs) using the Rossi X-ray Time Explorer (RXTE) from the atoll neutron-star (NS) low-mass X-ray binaries 4U 1608–52 and Aql X–1. From the analysis of all RXTE observations of 4U 1608–52 and Aql X–1, we find mHz QPOs with a significance level >3σ in 49 and 47 observations, respectively. The QPO frequency is constrained between ∼4.2 and 13.4 mHz. These types of mHz QPOs have been interpreted as being the result of marginally stable nuclear burning of He on the NS surface. We also report the discovery of a downward frequency drift in three observations of 4U 1608–52, making it the third source that shows this behaviour. We only find strong evidence of frequency drift in one occasion in Aql X–1, probably because the observations were too short to measure a significant drift. Finally, the mHz QPOs are mainly detected when both sources are in the soft or intermediate states; the cases that show frequency drift only occur when the sources are in intermediate states. Our results are consistent with the phenomenology observed for the NS systems 4U 1636–53 and EXO 0748–676, suggesting that all four sources can reach the conditions for marginally stable burning of He on the NS surface. These conditions depend on the source state in the same manner in all four systems.

scholarly journals Search for intermittent X-ray pulsations from neutron stars in low-mass X-ray binaries

2021 ◽  
Vol 38 ◽  
Author(s):  
Yunus Emre Bahar ◽  
Manoneeta Chakraborty ◽  
Ersin Göğüş
Keyword(s):  
Neutron Stars ◽  
Orbital Period ◽  
Oscillation Frequency ◽  
Orbital Motion ◽  
X Rays ◽  
X Ray ◽  
Second Stage ◽  
Corrected Data ◽  
Low Mass ◽  
X Ray Binaries

Abstract We present the results of our extensive binary orbital motion corrected pulsation search for 13 low-mass X-ray binaries. These selected sources exhibit burst oscillations in X-rays with frequencies ranging from 45 to 1 122 Hz and have a binary orbital period varying from 2.1 to 18.9 h. We first determined episodes that contain weak pulsations around the burst oscillation frequency by searching all archival Rossi X-ray Timing Explorer data of these sources. Then, we applied Doppler corrections to these pulsation episodes to discard the smearing effect of the binary orbital motion and searched for recovered pulsations at the second stage. Here we report 75 pulsation episodes that contain weak but coherent pulsations around the burst oscillation frequency. Furthermore, we report eight new episodes that show relatively strong pulsations in the binary orbital motion corrected data.

Sign in / Sign up

Export Citation Format

Share Document