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

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

1998 ◽  
Vol 188 ◽  
pp. 354-355 ◽  
Author(s):  
K. Asai ◽  
T. Dotani ◽  
K. Mitsuda ◽  
H. Inoue ◽  
Y. Tanaka ◽  
...  

Absorption line features were detected at 4.1 keV from X 1636-536 with the Tenma satellite in the spectra of X-ray bursts (Waki et al., 1984). Similar features were also detected from X 1608-52 and EXO 1747-214 during bursts (Nakamura et al., 1988; Magnier et al., 1989). These features at 4.1 keV may be interpreted as the redshifted Kα absorption line of helium-like iron atoms. However, such interpretation requires extremely soft equation of state for the nuclear matter, and confirmation with high resolution detectors is urged (Lewin et al., 1993). To investigate the line features, we observed X 1636-536 with ASCA for ~ 240 ksec.


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

1998 ◽  
Vol 492 (2) ◽  
pp. 782-787 ◽  
Author(s):  
Y. Ueda ◽  
H. Inoue ◽  
Y. Tanaka ◽  
K. Ebisawa ◽  
F. Nagase ◽  
...  
Keyword(s):  
X Ray ◽  

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase

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.


2016 ◽  
Vol 461 (1) ◽  
pp. 79-92 ◽  
Author(s):  
Marcio G. B. de Avellar ◽  
Mariano Méndez ◽  
Diego Altamirano ◽  
Andrea Sanna ◽  
Guobao Zhang

2018 ◽  
Vol 619 ◽  
pp. A138
Author(s):  
V. Perdelwitz ◽  
S. Czesla ◽  
J. Robrade ◽  
T. Pribulla ◽  
J. H. M. M. Schmitt

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.


Author(s):  
C. S. Anderson ◽  
G. H. Heald ◽  
J. A. Eilek ◽  
E. Lenc ◽  
B. M. Gaensler ◽  
...  

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.


Author(s):  
Nicolas Scepi ◽  
Mitchell C Begelman ◽  
Jason Dexter

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.


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