We use Enzo, a hybrid Eulerian AMR/N-body code including nongravitational heating and cooling, to explore the morphology of the X-ray gas in clusters of galaxies and its evolution in current generation cosmological simulations. We employ and compare two observationally motivated structure measures: power ratios and centroid shift. Overall, the structure of our simulated clusters compares remark...

Time-domain astronomy has come of age with astronomers now able to monitor the sky at high cadence, both across the electromagnetic spectrum and using neutrinos and gravitational waves. The advent of new observing facilities permits new science, but the ever-increasing throughput of facilities demands efficient communication of coincident detections and better subsequent coordination among the ...

We study a viable connection between the circular-equatorial orbits and reflection symmetry across equatorial plane of vacuum stationary axis-symmetric spacetime in general relativity. The behavior circular direction perpendicular to is studied, different outcomes presence absence are discussed. conclude that neither stable nor unstable orbit can exist on plane. Moreover, address observational ...

Abstract We study the appearance of sexaquark (uuddss) as a candidate dark matter in core neutron stars while there has been no experimental evidence this particle laboratories so far. Regarding observational constraints supermassive pulsars well gravitational waves, we encounter dilemma for which introduce solution by quark deconfinement fulfilling all present from multi-messenger astronomy, i...

Black holes play a pivotal role in the foundations of physics, but there is an alarming discrepancy between what considered to be black hole observational astronomy and theoretical studies. Despite claims contrary, we argue that identifying observed astrophysical candidates as genuine not justified based on currently available data, elaborate necessary evidence required support such remarkable ...

Direct detection of gravitational waves was for a long time the holy grail observational astronomy. The situation changed in 2015 with first registration wave signal (GW150914) by laboratory interferometers on Earth. Now, successful operating runs LIGO/Virgo detectors, resulting numerous observations signals from coalescing double compact objects (mainly binary black hole mergers) evidence neut...

X-ray emission from stars in the cool half of the Hertzsprung-Russell diagram is generally attributed to the presence of a magnetic corona that contains plasma at temperatures exceeding 1 million K. Coronae are ubiquitous among these stars, yet many fundamental mechanisms operating in their magnetic fields still elude an interpretation through a detailed physical description. Stellar X-ray astr...

Under the assumption that the Milky Way’s dark halo consists of primordial black hole MACHOs (PBHMACHOs), the mass density of the halo can be measured by the low frequency gravitational waves (10 Hz ∼< νgw ∼< 10 Hz) from PBHMACHO binaries whose fraction is ∼ 10. We find that ten years observation by LISA will detect ∼ 700 PBHMACHO binaries and enable us to determine the power index of the densi...

Under the assumption that the Milky Way’s dark halo consists of primordial black hole MACHOs (PBHMACHOs), the mass density of the halo can be measured by the low frequency gravitational waves (10 Hz ∼< νgw ∼< 10 −1 Hz) from PBHMACHO binaries whose fraction is ∼ 10. We find that ten years observation by LISA will detect ∼ 700 PBHMACHO binaries and enable us to determine the power index of the de...