Hyperinflation and Stabilisation: Cagan Revisited

Miller, Marcus; Zhang, Lei

doi:10.1111/1468-0297.00169

Cited by 209 publications

(306 citation statements)

References 0 publications

Supporting

Mentioning

297

Contrasting

Order By: Relevance

“…Broad iron line profiles have been seen in these accreting systems that harbor a black hole (e.g., Fabian et al 1989;Miller 2007;Reis et al 2008Reis et al , 2009a or a neutron star (NS; e.g., Bhattacharyya & Strohmayer 2007;Cackett et al 2008Cackett et al , 2009Cackett et al , 2010Papitto et al 2008;di Salvo et al 2009;Egron et al 2013;Miller et al 2013) as the primary accreting compact object. The asymmetrically, broadened profile of the Fe a K line gives a direct measure of the position of the inner disk since the effects of gravitational redshift and Doppler redshift/boosting on the emission line become stronger closer to the compact object (Fabian et al 1989).…”

Section: Introductionmentioning

confidence: 99%

Nustar and XMM-Newton Observations of the Neutron Star X-Ray Binary 1rxs J180408.9-34205

Ludlam

Miller

Cackett

et al. 2016

ApJ

View full text Add to dashboard Cite

We report on observations of the neutron star (NS) residing in the low-mass X-ray binary 1RXS J180408.9-34205 taken 2015 March by NuSTAR and XMM-Newton while the source was in the hard spectral state. We find multiple reflection features (Fe a K detected with NuSTAR; N VII, O VII, and O VIII detected in the RGS) from different ionization zones. Through joint fits using the self-consistent relativistic reflection model RELXILL, we determine the inner radius to be 11.1 R g . For a 1.4  M NS with a spin of * = a 0, this is an inner disk radius of 22.2 km. We find the inclination of the system to be between 18°and 29°. If the disk is truncated at a radius greater than the NS radius, it could be truncated by a boundary layer on the NS surface. It is also possible that the disk is truncated at the magnetospheric radius; conservative estimates would then imply ( -) B 0.3 1.0 10 9 G at the magnetic poles, though coherent pulsations have not been detected and the source is not identified as a pulsar.

show abstract

Section: Introductionmentioning

confidence: 99%

Nustar and XMM-Newton Observations of the Neutron Star X-Ray Binary 1rxs J180408.9-34205

Ludlam

Miller

Cackett

et al. 2016

ApJ

View full text Add to dashboard Cite

show abstract

“…If the compact object is a black hole (BH), modelling of the Fe line profile in the discdominated spectral state provides an estimate of the BH spin (see e.g. Miller 2007;Reynolds & Fabian 2008), assuming that the disc is truncated at the innermost stable circular orbit (ISCO). In case of a neutron star (NS), a measurement of the inner edge of the disc sets directly an upper limit on the NS radius, as the inner disc radius has to be larger than, or equal to, the equatorial radius of the star (see e.g.…”

Section: Introductionmentioning

confidence: 99%

Broad iron line in the fast spinning neutron-star system 4U 1636−53

Sanna

Hiemstra

Méndez

et al. 2013

Monthly Notices of the Royal Astronomical Society

111

View full text Add to dashboard Cite

We analysed the X-ray spectra of six observations, simultaneously taken with XMMNewton and Rossi X-ray Timing Explorer (RXTE), of the neutron star low-mass X-ray binary 4U 1636-53. The observations cover several states of the source, and therefore a large range of inferred mass accretion rate. These six observations show a broad emission line in the spectrum at around 6.5 keV, likely due to iron. We fitted this line with a set of phenomenological models of a relativistically broadened line, plus a model that accounts for relativistically smeared and ionised reflection from the accretion disc. The latter model includes the incident emission from both the neutronstar surface or boundary layer and the corona that is responsible for the high-energy emission in these systems. From the fits with the reflection model we found that in four out of the six observations the main contribution to the reflected spectrum comes from the neutron-star surface or boundary layer, whereas in the other two observations the main contribution to the reflected spectrum comes from the corona. We found that the relative contribution of these two components is not correlated to the state of the source. From the phenomenological models we found that the iron line profile is better described by a symmetric, albeit broad, profile. The width of the line cannot be explained only by Compton broadening, and we therefore explored the case of relativistic broadening. We further found that the direct emission from the disc, boundary layer, and corona generally evolved in a manner consistent with the standard accretion disc model, with the disc and boundary layer becoming hotter and the disc moving inwards as the source changed from the hard in to the soft state. The iron line, however, did not appear to follow the same trend.

show abstract

“…A prominent spectral feature, which is believed to originate when hard Xray photons are reflected from the inner part of the geometrically thin accretion disc around a black hole, is an Fe Kα broad emission line near 6.4 keV. Such a line is broadened and skewed by the Doppler and relativistic effects, and hence is a useful tool to measure the black hole spin (Miller (2007) and references therein). The quasi-periodic oscillations (QPOs) of the X-ray intensity in a frequency range spanning several orders of magnitude are also observed from accreting black holes.…”

Section: Introductionmentioning

confidence: 99%

A tilted and warped inner accretion disc around a spinning black hole: an analytical solution

Chakraborty

Bhattacharyya

2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Inner accretion disc around a black hole provides a rare, natural probe to understand the fundamental physics of the strong gravity regime. A possible tilt of such a disc, with respect to the black hole spin equator, is important. This is because such a tilt affects the observed spectral and timing properties of the disc X-ray emission via Lense-Thirring precession, which could be used to test the theoretical predictions regarding the strong gravity. Here, we analytically solve the steady, warped accretion disc equation of Scheurer and Feiler (1996), and find an expression of the radial profile of the disc tilt angle. In our exact solution, considering a prograde disc around a slowly spinning black hole, we include the inner part of the disc, which was not done earlier in this formalism. Such a solution is timely, as a tilted inner disc has recently been inferred from X-ray spectral and timing features of the accreting black hole H1743-322. Our tilt angle radial profile expression includes observationally measurable parameters, such as black hole mass and Kerr parameter, and the disc inner edge tilt angle W in , and hence can be ideal to confront observations. Our solution shows that the disc tilt angle in 10 − 100 gravitational radii is a significant fraction of the disc outer edge tilt angle, even for W in = 0. Moreover, tilt angle radial profiles have humps in ∼ 10 − 1000 gravitational radii for some sets of parameter values, which should have implications for observed X-ray features.

show abstract

Hyperinflation and Stabilisation: Cagan Revisited

Cited by 209 publications

References 0 publications

Nustar and XMM-Newton Observations of the Neutron Star X-Ray Binary 1rxs J180408.9-34205

Nustar and XMM-Newton Observations of the Neutron Star X-Ray Binary 1rxs J180408.9-34205

Broad iron line in the fast spinning neutron-star system 4U 1636−53

A tilted and warped inner accretion disc around a spinning black hole: an analytical solution

Contact Info

Product

Resources

About