Tidal disruptions by supermassive black holes - Hydrodynamic evolution of stars on a Schwarzschild background

Laguna, Pablo; Miller, Warner A.; Zurek, Wojciech H.; Davies, Melvyn B.

doi:10.1086/186885

Cited by 116 publications

(154 citation statements)

References 0 publications

Supporting

Mentioning

146

Contrasting

Order By: Relevance

“…For concreteness, we have assumed that the limiting radius is intermediate between the two extreme cases mentioned above; we have used the limit r T > 2r g . Yet another source of uncertainty derives from the fact that we have used Newtonian dynamics in our analysis, whereas it is clear that relativistic effects should be important (Luminet & Marck 1985;Laguna et al 1993;Frolov et al 1994;Diener et al 1997).…”

Section: Summary and Discussionmentioning

confidence: 99%

The Giant X‐Ray Flare of NGC 5905: Tidal Disruption of a Star, a Brown Dwarf, or a Planet?

Li¹,

Narayan²,

Menou³

2002

ApJ

124

View full text Add to dashboard Cite

We model the 1990 giant X-ray flare of the quiescent galaxy NGC 5905 as the tidal disruption of a star by a supermassive black hole. From the observed rapid decline of the luminosity, over a timescale of a few years, we argue that the flare was powered by the fallback of debris rather than subsequent accretion via a thin disk. The fallback model allows constraints to be set on the black hole mass and the mass of debris. The latter must be very much less than a solar mass to explain the very low luminosity of the flare. The observations can be explained either as the partial stripping of the outer layers of a low-mass main-sequence star or as the disruption of a brown dwarf or a giant planet. We find that the X-ray emission in the flare must have originated within a small patch rather than over the entire torus of circularized material surrounding the black hole. We suggest that the patch corresponds to the '' bright spot '' where the stream of returning debris impacts the torus. Interestingly, although the peak luminosity of the flare was highly sub-Eddington, the peak flux from the bright spot was close to the Eddington limit. We speculate on the implications of this result for observations of other flare events.

show abstract

Section: Summary and Discussionmentioning

confidence: 99%

The Giant X‐Ray Flare of NGC 5905: Tidal Disruption of a Star, a Brown Dwarf, or a Planet?

Li¹,

Narayan²,

Menou³

2002

ApJ

124

View full text Add to dashboard Cite

show abstract

“…In the case of timelike geodesics it can be used for studying the behavior of extended objects moving in the Kerr and more general geometries. In particular, it facilitated the study of tidal forces acting on a mov-ing body, for example a star, in the background of a massive black hole (see, e.g., [171], [162], [87], [64], [213], [113]). Even more useful is to solve the parallel transport along null geodesics.…”

Section: Introductionmentioning

confidence: 99%

Hidden Symmetries of Higher-Dimensional Rotating Black Holes

2007

View full text Add to dashboard Cite

In this thesis we study higher-dimensional rotating black holes. Such black holes are widely discussed in string theory and brane-world models at present.We demonstrate that even the most general known Kerr-NUT-(A)dS spacetime, describing the general rotating higher-dimensional asymptotically (anti) de Sitter black hole with NUT parameters, is in many aspects similar to its fourdimensional counterpart. Namely, we show that it admits a fundamental hidden symmetry associated with the principal conformal Killing-Yano tensor. Such a tensor generates towers of hidden and explicit symmetries. The tower of Killing tensors is responsible for the existence of irreducible, quadratic in momenta, conserved integrals of geodesic motion. These integrals, together with the integrals corresponding to the tower of explicit symmetries, make geodesic equations in the Kerr-NUT-(A)dS spacetime completely integrable. We further demonstrate that in this spacetime the Hamilton-Jacobi, Klein-Gordon, and stationary string equations allow complete separation of variables and the problem of finding parallel-propagated frames reduces to the set of the first order ordinary differential equations. Moreover, we show that the Kerr-NUT-(A)dS spacetime is the most general Einstein space which possesses all these properties. We also explicitly derive the most general (off-shell) canonical metric admitting the principal conformal Killing-Yano tensor and demonstrate that such a metric is necessarily of the special algebraic type D of the higher-dimensional algebraic classification. The results presented in this thesis describe the new and complete picture of the relationship of hidden symmetries and rotating black holes in higher dimensions. PrefaceWhen in 1963 Kerr discovered an astrophysically relevant but relatively complicated metric describing the gravitational field of a rotating black hole, it seemed that no analytical predictions were possible even for the simplest particle geodesic motion. However, a 'miracle' happened, and it turned out that not only the geodesic motion can be analytically solved, but also the equations describing various perturbations of this background can be 'drastically' simplified. This opened a way for studying astrophysical processes, such as the plasma accretion around black holes, the radiation produced by infalling matter, the origin of jets, the production and propagation of waves produced in the vicinity of black holes, and it even led to estimates of the gravitational wave production in star collisions and galaxy merges. It also facilitated the study of more theoretical problems, such as the problem of stability of the Kerr solution, the calculation of the quasinormal modes, or the study of the Hawking radiation. A hidden symmetry responsible for this miracle can be mathematically described by a simple antisymmetric object, called the Killing-Yano tensor.Recently, higher-dimensional rotating black hole spacetimes have become of high interest due to various developments in gravity and high energy physic...

show abstract

“…Relativistic modifications on the stellar orbit and on the tidal field significantly appear when the star approaches the black hole's gravitational radius. Due to relativistic precession, the parabolic-type orbit must eventually intersect once in the Schwarzschild space-time, and depending on the position of the crossing point, the star can be subjected to several successive compressions during its motion within the tidal radius (Luminet & Marck 1985;Laguna et al 1993).…”

Section: Resultsmentioning

confidence: 99%

Relativistic tidal compressions of a star by a massive black hole

Brassart

Luminet

2010

A&A

View full text Add to dashboard Cite

Aims. We investigate the stellar pancake mechanism during which a solar-type star is tidally flattened within its orbital plane as it passes close to a 10 6 M black hole. Methods. We simulated the relativistic orthogonal compression process and follow the associated shock waves formation. We considered a one-dimensional hydrodynamical stellar model moving in the relativistic gravitational field of a non-rotating black hole. The model is numerically solved using a Godunov-type shock-capturing source-splitting method to correctly reproduce the shock wave profiles. Results. Simulations confirm that the space-time curvature can induce several successive orthogonal compressions of the star, which give rise to several strong shock waves. The shock waves finally escape from the star and repeatedly heat up the stellar surface to high-energy values. Such a shock-heating could interestingly provide a direct observational signature of strongly disruptive starblack hole encounters through the emission of hard X or soft γ-ray bursts. Timescales and energies of such a process are consistent with some observed events such as GRB 970815.

show abstract

Tidal disruptions by supermassive black holes - Hydrodynamic evolution of stars on a Schwarzschild background

Cited by 116 publications

References 0 publications

The Giant X‐Ray Flare of NGC 5905: Tidal Disruption of a Star, a Brown Dwarf, or a Planet?

The Giant X‐Ray Flare of NGC 5905: Tidal Disruption of a Star, a Brown Dwarf, or a Planet?

Hidden Symmetries of Higher-Dimensional Rotating Black Holes

Relativistic tidal compressions of a star by a massive black hole

Contact Info

Product

Resources

About