Astronomers believe that black holes that are as large as a billion solar masses can be found at the centre of most galaxies. Here the fundamental questions to be answered are: If the galactic central black hole mass is 10 billion solar masses and density is less than 1 kg/m 3 - with such a small density and large mass, without collapsing - how it is able to hold a gigantic galaxy? What force makes the black hole stable? Recent observations indicate that, instead of collapsing, galactic central black holes are growing faster and spinning faster than they expected. From this it can be suggested that, in the universe – ‘black hole geometry’ is most important than its mass and density. In this regard, considering the classical force and power limits an attempt is made to understand the black hole geometry, radius, angular velocity and temperature. If one is willing to consider the ‘black hole geometry’ as primordial, if universe constitutes so many galaxies, if each galaxy constitutes a central fast growing and fast spinning black hole and if black hole’s growth accelerates with its increasing mass, then considering universe as a ‘growing and light speed rotating primordial black hole’ may not be far away from reality. May be the vastness of the universe making our observations limited and forcing us to believe that – universe is flat. Thinking in this way and with reference to the Planck scale an attempt is made to fit the present Hubble’s constant and its obtained value is 66.895 (km/sec)/Mpc. It can be compared with the recently recommended value (67.80 ± 0.77) (km/sec)/Mpc

/pdf/light-speed-rotating-black-holes-the-special-holes-7gy4ge0xfn.pdf

Light speed rotating black holes: The special holes

During the final moments of a binary black hole (BH) merger, the gravitational wave (GW) luminosity of the system is greater than the combined electromagnetic output of the entire observable universe. However, the extremely weak coupling between GWs and ordinary matter makes these waves very difficult to detect directly. Fortunately, the inspiraling BH system will interact strongly--on a purely Newtonian level--with any surrounding material in the host galaxy, and this matter can in turn produce unique electromagnetic (EM) signals detectable at Earth. By identifying EM counterparts to GW sources, we will be able to study the host environments of the merging BHs, in turn greatly expanding the scientific yield of a mission like LISA.

Electromagnetic Counterparts to Black Hole Mergers

The Hard X-ray Imager (HXI) is one of the instruments onboard International X-ray Observatory (IXO), to belaunched into orbit in 2020s. It covers the energy band of 10 40 keV, providing imaging-spectroscopy with aeld of view of 8 × 8arcmin 2 . The HXI is attached beneath the Wide Field Imager (WFI) covering 0.1 15 keV.Combined with the super-mirror coating on the mirror assembly, this conguration provides observation of X-raysource in wide energy band (0.1 40.0 keV) simultaneously, which is especially important for varying sources. TheHXI sensor part consists of the semiconductor imaging spectrometer, using Si in the medium energy detector andCdTe in the high energy detector as its material, and an active shield covering its back to reduce background inorbit. The HXI technology is based on those of the Japanese-lead new generation X-ray observatory ASTRO-H,and partly from those developed for Simbol-X. Therefore, the technological development is in good progress. Inthe IXO mission, HXI will provide a major assets to identify the nature of the object by penetrating into thickabsorbing materials and determined the inherent spectral shape in the energy band well above the structurearound Fe-K lines and edges.Keywords: International X-ray Observatory, Hard X-ray Imager, X-ray Astronomy

The hard x-ray imager onboard IXO

This thesis is conceptually divided into two parts. The first and main part concerns
the generation of gravitational radiation that is emitted from merging black-hole
binary systems using Numerical Relativity methods. The second part presents
the methodology of the search for gravitational-wave bursts that are emitted in
core-collapse Supernovae.
My approach to Numerical Relativity is to utilise the late-time gravitational
radiation of merging binary black holes to extract key astrophysical parameters
from such systems via standard parameter estimation techniques. I begin with
an introductory chapter that outlines the standard theories of stationary and
perturbed black holes. In addition, up-to-date techniques in performing binary
black hole simulations, the current and near-future status of the global network
of gravitational-wave detectors, as well as the most promising gravitational-wave
sources. I conclude the chapter with elements on parameter estimation techniques,
such as Bayesian analysis and the Fisher information matrix. In Chapter 2, I discuss
detection issues and parameter estimation results from the late-time radiation
of colliding non-spinning black holes in quasi-circular orbits, and propose a practical
test of General Relativity, as well as of the nature of the merged compact
object. Chapter 3 involves similar parameter extraction calculations, but involves
a more realistic approach, whereby the effect of the various angular parameters
on parameter estimation is considered, placing an emphasis on the actual science
benefit from measuring the gravitational radiation from perturbed intermediate
and supermassive black holes. In Chapter 4 we present the results of an extensive
Numerical Relativity study of merging spinning black hole binaries and argue that
the mass ratio and individual spins of a non-precessing progenitor binary can be
measured solely by observing the late-time radiation.
Chapter 5 presents the methodology in carrying out searches for gravitationalwave
bursts (GWB) from core-collapse Supernovae with a dedicated for GWB
searches pipeline (X-Pipeline) and presents the sensitivity performance of XPipeline
in detecting GWBs associated with certain Supernova candidates during
the two most recent LIGO-Virgo-GEO Science Runs.

Gravitational-wave radiation from merging binary black holes and Supernovae

The concept of `dark energy' is still facing and raising a number of fundamental unresolved problems. `Cosmic acceleration',`dark energy' and `inflation', are the results of Edwin Hubble's incomplete conclusions. If there is a misinterpretation in Hubble's law - flat model of cosmology can not be considered as a correct model of cosmology. \textbf{If the \textit{primordial universe} is a natural setting for the creation of black holes and other nonperturbative gravitational entities, it is also possible to assume that throughout its journey, the whole universe is a \textit{primordial cosmic black hole.}} Planck particle can be considered as the baby universe. Key assumption is that, ``at any time, cosmic black hole rotates with light speed''. Cosmic temperature is inversely proportional to the geometric mean of cosmic mass and planck mass. For this growing cosmic sphere as a whole, while in light speed rotation, `rate of decrease' in temperature is a ``primary'' measure of cosmic `rate of expansion'. It can be suggested that, `rate of increase in galaxy red shift' from and about the cosmic center is a ``secondary'' measure of cosmic `rate of expansion'. Present `cosmic mass density' and `cosmic time' are fitted with the natural logarithm of ratio of cosmic volume and planck particle's volume. If present CMBR temperature is isotropic at 2.725 ${}^{0}$Kelvin, present angular velocity is 2.17 x 10${}^{-18}$ rad/sec = 67 Km/sec/Mpc.

/pdf/modified-hubble-s-law-and-the-primordial-cosmic-black-hole-1qffe4nk8o.pdf

Modified Hubble's Law and the Primordial Cosmic Black Hole

One of the main themes in extragalactic astronomy for the next decade will be the evolution of galaxies over cosmic time. Many future observatories, including JWST, ALMA, GMT, TMT and E-ELT will intensively observe starlight over a broad redshift range, out to the dawn of the modern Universe when the first galaxies formed. It has, however, become clear that the properties and evolution of galaxies are intimately linked to the growth of their central black holes. Understanding the formation of galaxies, and their subsequent evolution, will therefore be incomplete without similarly intensive observations of the accretion light from supermassive black holes (SMBH) in galactic nuclei. To make further progress, we need to chart the formation of typical SMBH at z>6, and their subsequent growth over cosmic time, which is most effectively achieved with X-ray observations. Recent technological developments in X-ray optics and instrumentation now bring this within our grasp, enabling capabilities fully matched to those expected from flagship observatories at longer wavelengths.

The Growth of Supermassive Black Holes Across Cosmic Time

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The Growth of Supermassive Black Holes Across Cosmic Time

The Growth of Supermassive Black Holes Across Cosmic Time