8837623
Cluster Mass Reconstruction by a Weak Shear Field
The tidal gravitational field of galaxy clusters causes a coherent distortion of the images of background sources. 
Since the distribution of image distortions, namely the shear field, traces the local gravitational potential of a deflector, it can be used to reconstruct the two-dimensional mass distribution of clusters of galaxies. 
Moreover, the shear field can provide unique information on the redshift distribution of high-redshift galaxies. 
In this review we summarize recently-developed parameter-free methods of cluster-mass reconstruction based on the shear field, and we apply a mass-reconstruction method to the cluster Abell 370 at redshift 0.375.
118710175
AMiBA: SCALING RELATIONS BETWEEN THE INTEGRATED COMPTON-y AND X-RAY-DERIVED TEMPERATURE, MASS, AND LUMINOSITY
We investigate the scaling relations between the X-ray and the thermal Sunyaev-Zel'dovich effect properties of clusters of galaxies, using data taken during 2007 by the Y. T. Lee Array for Microwave Background Anisotropy (AMiBA) at 94 GHz for the six clusters A1689, A1995, A2142, A2163, A2261, and A2390. The scaling relations relate the integrated Compton-y parameter Y 2500 to the X-ray-derived gas temperature T e, total mass M 2500, and bolometric luminosity LX within r 2500. Our results for the power-law index and normalization are both consistent with the self-similar model and other studies in the literature except for the Y 2500-LX relation, for which a physical explanation is given though further investigation may be still needed. Our results not only provide confidence for the AMiBA project but also support our understanding of galaxy clusters.
7201989
The build-up of the colour–magnitude relation as a function of environment
We discuss the environmental dependence of galaxy evolution based on deep panoramic imaging of two distant clusters, RX J0152.7-1357 at z = 0.83 and CL0016+ 1609 at z = 0.55, taken with the Subaru Prime Focus Camera on the Subaru Telescope as part of the Panoramic Imaging and Spectroscopy of Cluster Evolution with Subaru project. By combining with the Sloan Digital Sky Survey data as a local counterpart for comparison, we construct a large sample of galaxies that spans wide ranges in environment, time and stellar mass (or luminosity). This allows us to conduct systematic and statistical analyses of the photometric properties of galaxies based on the colour-density diagrams, colour-magnitude relations, and luminosity functions. We find that colours of galaxies, especially those of faint galaxies (M V > M v * + 1), change from blue to red at a break density as we go to denser regions. This trend is observed at all redshifts in our sample. Based on local and global densities of galaxies, we classify three environments - field, groups and clusters - and look into the environmental dependence of galaxies in detail. In particular, we quantify how the colour-magnitude relation is built up as a function of environment. We show that the bright end of the cluster colour-magnitude relation is already built a z = 0.83, while the faint end is possibly still in the process of build-up. In contrast to this, the bright end of the field colour-magnitude relation has been vigorously built all the way down to the present-day and the build-up at the faint end has not started yet. A possible interpretation of these results is that galaxies evolve in a 'down-sizing' fashion. That is, massive galaxies complete their star formation first and the truncation of star formation is propagated to smaller objects as time progresses. This trend is likely to depend on environment since the build-up of the colour-magnitude relation is delayed in lower density environments. Therefore, we may suggest that the evolution of galaxies took place earliest in massive galaxies and in high-density regions, and it is delayed in less massive galaxies and in lower density regions. Further studies are, however, obviously needed to confirm the observed trends and establish the 'down-sizing' picture.
9208829
A New Measure for Weak-Lensing Flexion
We study the possibility of using the octopole moment of gravitationally lensed images as a direct measure of the third-order weak gravitational lensing effect, or the gravitational flexion. It turns out that there is a natural relation between flexion and certain combinations of octopole/higher multipole moments that we call the higher order lensing image's characteristics (HOLICs). This will allow one to measure directly flexion from observable octopole and higher multipole moments of background images. We show based on simulated observations how the use of HOLICs can improve the accuracy and resolution of a reconstructed mass map, in which we assume Gaussian uncertainties in the shape measurements estimated using deep i'-band data of blank fields observed with Suprime-Cam on the Subaru telescope.
118543928
Detailed cluster mass and light profiles of A1703, A370 and RXJ1347−11 from deep Subaru imaging*
Weak lensing work can be badly compromised by unlensed foreground and cluster members which dilute the true lensing signal. We show how the lensing amplitude in multicolour space can be harnessed to securely separate cluster members from the foreground and background populations for three massive clusters, A1703 (z= 0.258), A370 (z= 0.375) and RXJ1347−11 (z= 0.451) imaged with Subaru. The luminosity functions of these clusters when corrected for dilution show similar faint-end slopes, α≃− 1.0, with no marked faint-end upturn to our limit of MR≃− 15.0, and only a mild radial gradient. In each case, the radial profile of the mass-to-light ratio (M/L) peaks at intermediate radius, ≃ 0.2rvir, at a level of 300–500(M/LR)⊙, and then falls steadily towards ∼ 100(M/LR)⊙ at the virial radius, similar to the mean field level. This behaviour is likely due to the relative paucity of central late-type galaxies, whereas for the E/S0 sequence only a mild radial decline in M/L is found for each cluster. We discuss this behaviour in the context of detailed simulations where predictions for tidal stripping may now be tested accurately with observations.
8691447
Star Formation and AGN Activity in Galaxies Classified Using the 1.6 μm Bump and PAH Features at z = 0.4–2
We studied the star-formation and AGN activity of massive galaxies in the redshift range z = 0.4-2, which were detected in a deep survey field using the AKARI InfraRed (IR) astronomical satellite and Subaru telescope toward the North Ecliptic Pole (NEP). The AKARI/IRC Mid-InfraRed (MIR) multiband photometry was used to trace the star-forming activities with Polycyclic Aromatic Hydrocarbon (PAH) emission, which is effective not only to distinguish between star-forming and AGN galaxies, but also to estimate the Star Formation Rate (SFR) with converting its flux to the total emitting IR (TIR) luminosity. In combination with the analyses of the stellar components, we studied the MIR SED features of star-forming and AGN-harboring galaxies, which we summarize below: (1) The rest-frame 7.7-μm and 5-μm luminosities are good tracers of star-forming and AGN activities from their PAH and dusty tori emissions, respectively. (2) For dusty star-forming galaxies without AGN, their SFR shows a correlation that is nearly proportional to their stellar mass, and their specific SFR (sSFR) per unit stellar mass increases with redshift. Extinctions estimated from their TIR luminosities are larger than those from their optical SED fittings, which may be caused by geometric variations of dust in them. (3) Even for dusty star-forming galaxies with AGN, SFRs can be derived from their TIR luminosities with subtraction of the obscured AGN contribution, which indicates that their SFRs were possibly quenched around z ≃ 0.8 compared with those without AGN. (4) The AGN activity from their rest-frame 5-μm luminosity suggests that their Super Massive Black Holes (SMBHs) could already have grown to ≃ 3 × 10 8 M ⊙ in most massive galaxies with 10 11 M ⊙ at z > 1.2, and the mass relation between SMBHs and their host galaxies has already become established by z ≃ 1-2.
119187768
Uncertainty Relation and Probability Numerical Illustration
The uncertainty relation and the probability interpretation of quantum mechanics are intrinsically connected, as is evidenced by the evaluation of standard deviations. It is thus natural to ask if one can associate a very small uncertainty product of suitably sampled events with a very small probability. We have shown elsewhere that some examples of the evasion of the uncertainty relation noted in the past are in fact understood in this way. We here numerically illustrate that a very small uncertainty product is realized if one performs a suitable sampling of measured data that occur with a very small probability. We introduce a notion of cyclic measurements. It is also shown that our analysis is consistent with the Landau-Pollak-type uncertainty relation. It is suggested that the present analysis may help reconcile the contradicting views about the “standard quantum limit” in the detection of gravitational waves. Subject Index: 002, 060, 064
6921270
Ward Identities in the derivation of Hawking radiation from Anomalies
Robinson and Wilczek suggested a new method of deriving Hawking radiation by the consideration of anomalies. The basic idea of their approach is that the flux of Hawking radiation is determined by anomaly cancellation conditions in the Schwarzschild black hole (BH) background. Iso et al. extended the method to a charged Reissner-Nordstroem BH and a rotating Kerr BH, and they showed that the flux of Hawking radiation can also be determined by anomaly cancellation conditions and regularity conditions of currents at the horizon. Their formulation gives the correct Hawking flux for all the cases at infinity and thus provides a new attractive method of understanding Hawking radiation. We present some arguments clarifying for this derivation. We show that the Ward identities and boundary conditions for covariant currents without referring to the Wess-Zumino terms and the effective action are sufficient to derive Hawking radiation. Our method, which does not use step functions, thus simplifies some of the technical aspects of the original formulation.
8012861
HAWKING RADIATION FROM KERR–NEWMAN BLACK HOLE AND TUNNELING MECHANISM
We present the derivation of Hawking radiation by using the tunneling mechanism in a rotating and charged black hole background. We show that the four-dimensional Kerr–Newman metric, which has a spherically nonsymmetric geometry, becomes an effectively two-dimensional spherically symmetric metric by using the technique of the dimensional reduction near the horizon. We can thus readily apply the tunneling mechanism to the nonspherical Kerr and Kerr–Newman metric.
119239099
Recent Attempts in the Analysis of Black Hole Radiation
In this thesis, we first present a brief review of black hole radiation which is commonly called Hawking radiation. The existence of Hawking radiation by itself is well established by now because the same result is derived by several different methods. On the other hand, there remain several aspects of the effect which have yet to be clarified. We clarify some arguments in previous works on the subject and then attempt to present the more satisfactory derivations of Hawking radiation. To be specific, we examine the analyses in the two recent derivations of Hawking radiation which are based on anomalies and tunneling; both of these derivations were initiated by Wilczek and his collaborators. We then present a simple derivation based on anomalies by emphasizing a systematic use of covariant currents and covariant anomalies combined with boundary conditions which have clear physical meaning. We also extend a variant of the tunneling method proposed by Banerjee and Majhi to a Kerr-Newman black hole by using the technique of the dimensional reduction near the horizon. We directly derive the black body spectrum for a Kerr-Newman black hole on the basis of the tunneling mechanism.We directly derive the black body spectrum for a Kerr-Newman black hole on the basis of the tunneling mechanism.
118634145
Hawking radiation as tunneling from squashed Kaluza-Klein black hole
We discuss Hawking radiation from a five-dimensional squashed Kaluza-Klein black hole on the basis of the tunneling mechanism. A simple method, which was recently suggested by Umetsu, may be used to extend the original derivation by Parikh and Wilczek to various black holes. That is, we use the two-dimensional effective metric, which is obtained by the dimensional reduction near the horizon, as the background metric. Using the same method, we derive both the desired result of the Hawking temperature and the effect of the backreaction associated with the radiation in the squashed Kaluza-Klein black hole background.