![]() ![]() The FLTT distortions are expected to have an impact on matched filter bubble detection where it is most convenient to use a spherical template for the filter. This is reversed in the later stages of growth where the bubble appears compressed. The bubble initially appears elongated along the LOS. There are two distinct FLTT distortions in the bubble's image: (i) its apparent center is shifted along the line of sight (LOS) towards the observer from the quasar (ii) it's shape is anisotropic along the LOS. We find that the FLTT, whose effect is particularly pronounced for large bubbles, causes the bubble's image to continue to grow well after it's actual growth is over. ![]() We consider two models for the growth of spherical ionized bubbles to study the apparent shapes of the bubbles in redshifted 21-cm maps, taking into account the finite light travel time (FLTT) across the bubble. The detection of ionized bubbles around quasars in redshifted 21-cm maps is possibly one of the most direct future probes of reionization. For k=0.15 and 0.41Mpc−1 the optimum bandwidth is ∼11 and ∼16 MHz respectively. We find that if one is willing to accept a 10% error due to the light cone effect, the optimum frequency bandwidth for k=0.056Mpc−1 is ∼7.5 MHz. Finally, we calculate an optimum frequency bandwidth below which the light cone effect can be neglected when extracting power spectra from observations. We also calculate the two-point correlation functions parallel and perpendicular to the line-of-sight and find them to differ. We argue that for the power spectrum to become anisotropic, the light cone effect would have to make the ionized bubbles significantly elongated or compressed along the line-of-sight, which would require extreme reionization scenarios. We do not find any significant anisotropy in the 21-cm power spectrum due to the light cone effect. We find a factor of ∼4 amplification of the power spectrum at the largest scale available in our simulations. We find that the light cone effect has the largest impact at two different stages of reionization: one when reionization is ∼20% and other when it is ∼80% completed. We use numerical as well as semi-numerical simulations of reionization in a cubic volume of 607 Mpc across to study this so-called light cone effect on the HI 21-cm power spectrum. Quartz is one of nature’s hardest minerals and Caesarstone contains approximately 93 per cent natural quartz for surfaces that combine practicality with stunning design.Measurements of the HI 21-cm power spectra from the reionization epoch will be influenced by the evolution of the signal along the line-of-sight direction of any observed volume. 'It plays in the boundaries between natural and industrial materials: when the natural starts to look industrial and when an industrial object ages and starts to look more organic.'Ĭaesarstone manufactures premium quartz surfaces that are used in residential and commercial projects as countertops, vanities, wall cladding, floors and other interior surfaces. ![]() 'Its imperfections, delicate patinas and rough texture give Primordia its unique beauty,' says Mor Krisher, head of design at Caesarstone. The effect is completed by subtle traces of yellow and washed green, which give the design depth and body. Against its light grey base, soft mineral marks in off-whites and greys combine with darker veils of grey and brown to reflect the oxidised rusts found in nature. Primordia’s cool grey complexion echoes the character of concrete, evoking a contemporary feel. The versatile surface design has an industrial look accentuated by its unique imperfections, a theme common to the rest of the collection. Caesarstone has added a new design called 4043 Primordia to its Metropolitan engineered quartz collection.
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