Detailed Information on Publication Record

@article{28250,
   author = {Stuchlík, Zdeněk and Schee, Jan and Toshmatov, Bobir and Hladík, Jan and Novotný, Jan},
   article_number = {6},
   doi = {http://dx.doi.org/10.1088/1475-7516/2017/06/056},
   keywords = {gravitational waves / theory; star formation; stars},
   language = {eng},
   issn = {1475-7516},
   journal = {Journal of Cosmology and Astroparticle Physics},
   title = {Gravitational instability of polytropic spheres containing region of trapped null geodesics: a possible explanation of central supermassive black holes in galactic halos},
   url = {http://iopscience.iop.org/article/10.1088/1475-7516/2017/06/056/meta},
   volume = {neuveden},
   year = {2017}
}

TY  - JOUR
ID  - 28250
AU  - Stuchlík, Zdeněk - Schee, Jan - Toshmatov, Bobir - Hladík, Jan - Novotný, Jan
PY  - 2017
TI  - Gravitational instability of polytropic spheres containing region of trapped null geodesics: a possible explanation of central supermassive black holes in galactic halos
JF  - Journal of Cosmology and Astroparticle Physics
VL  - neuveden
IS  - 6
SP  - „056- i, ii, 1“-„056-25“
EP  - „056- i, ii, 1“-„056-25“
SN  - 1475-7516
KW  - gravitational waves / theory
KW  - star formation
KW  - stars
UR  - http://iopscience.iop.org/article/10.1088/1475-7516/2017/06/056/meta
L2  - http://iopscience.iop.org/article/10.1088/1475-7516/2017/06/056/meta
N2  - We study behaviour of gravitational waves in the recently introduced general relativistic polytropic spheres containing a region of trapped null geodesics extended around radius of the stable null circular geodesic that can exist for the polytropic index N > 2.138 and the relativistic parameter, giving ratio of the central pressure p_c to the central energy density rho_c, higher than sigma = 0.677. In the trapping zones of such polytropes, the effective potential of the axial gravitational wave perturbations resembles those related to the ultracompact uniform density objects, giving thus similar long-lived axial gravitational modes. These long-lived linear perturbations are related to the stable circular null geodesic and due to additional non-linear phenomena could lead to conversion of the trapping zone to a black hole. We give in the eikonal limit examples of the long-lived gravitational modes, their oscillatory frequencies and slow damping rates, for the trapping zones of the polytropes with N is an element of (2.138, 4). However, in the trapping polytropes the long-lived damped modes exist only for very large values of the multipole number l > 50, while for smaller values of l the numerical calculations indicate existence of fast growing unstable axial gravitational modes. We demonstrate that for polytropes with N >= 3.78, the trapping region is by many orders smaller than extension of the polytrope, and the mass contained in the trapping zone is about 10^(-3) of the total mass of the polytrope. Therefore, the gravitational instability of such trapping zones could serve as a model explaining creation of central supermassive black holes in galactic halos or galaxy clusters.
ER  - 

STUCHLÍK, Zdeněk, Jan SCHEE, Bobir TOSHMATOV, Jan HLADÍK and Jan NOVOTNÝ. Gravitational instability of polytropic spheres containing region of trapped null geodesics: a possible explanation of central supermassive black holes in galactic halos. \textit{Journal of Cosmology and Astroparticle Physics}. 2017, neuveden, No~6, p.~„056- i, ii, 1“-„056-25“, 27 pp. ISSN~1475-7516. Available from: https://dx.doi.org/10.1088/1475-7516/2017/06/056.