Suman Bhattacharya

A DIRECT MEASUREMENT OF THE LINEAR BIAS OF MID-INFRARED-SELECTED QUASARS AT z ≈ 1 USING COSMIC MICROWAVE BACKGROUND LENSING

We measure the cross-power spectrum of the projected mass density as traced by the convergence of the cosmic microwave background lensing field from the South Pole Telescope (SPT) and a sample of Type 1 and 2 (unobscured and obscured) quasars at 〈z〉 ~ 1 selected with the Wide-field Infrared Survey Explorer, over 2500 deg^2. The cross-power spectrum is detected at ≈7σ, and we measure a linear bias b = 1.61 ± 0.22, consistent with clustering analyses. Using an independent lensing map, derived from Planck observations, to measure the cross-spectrum, we find excellent agreement with the SPT analysis. The bias of the combined sample of Type 1 and 2 quasars determined in this work is similar to that previously determined for Type 1 quasars alone; we conclude that obscured and unobscured quasars trace the matter field in a similar way. This result has implications for our understanding of quasar unification and evolution schemes.

A Cosmic Microwave Background Lensing Mass Map and Its Correlation with the Cosmic Infrared Background

We use a temperature map of the cosmic microwave background (CMB) obtained using the South Pole Telescope at 150 GHz to construct a map of the gravitational convergence to z ~ 1100, revealing the fluctuations in the projected mass density. This map shows individual features that are significant at the ~4σ level, providing the first image of CMB lensing convergence. We cross-correlate this map with Herschel/SPIRE maps covering 90 deg2 at wavelengths of 500, 350, and 250 μm. We show that these submillimeter (submm) wavelength maps are strongly correlated with the lensing convergence map, with detection significances in each of the three submm bands ranging from 6.7σ to 8.8σ. We fit the measurement of the cross power spectrum assuming a simple constant bias model and infer bias factors of b = 1.3-1.8, with a statistical uncertainty of 15%, depending on the assumed model for the redshift distribution of the dusty galaxies that are contributing to the Herschel/SPIRE maps.

COSMIC EMULATION: THE CONCENTRATION-MASS RELATION FOR wCDM UNIVERSES

The concentration-mass relation for dark matter-dominated halos is one of the essential results expected from a theory of structure formation. We present a simple prediction scheme, a cosmic emulator, for the concentration-mass (c-M) relation as a function of cosmological parameters for wCDM models. The emulator is constructed from 37 individual models, with three nested N-body gravity-only simulations carried out for each model. The mass range covered by the emulator is 2 × 1012 M ☉ < M < 1015 M ☉ with a corresponding redshift range of z = 0-1. Over this range of mass and redshift, as well as the variation of cosmological parameters studied, the mean halo concentration varies from c ~ 2 to c ~ 8. The distribution of the concentration at fixed mass is Gaussian with a standard deviation of one-third of the mean value, almost independent of cosmology, mass, and redshift over the ranges probed by the simulations. We compare results from the emulator with previously derived heuristic analytic fits for the c-M relation, finding that they underestimate the halo concentration at high masses. Using the emulator to investigate the cosmology dependence of the c-M relation over the currently allowable range of values, we find—not surprisingly—that σ8 and ω m influence it considerably, but also that the dark energy equation-of-state parameter w has a substantial effect. In general, the concentration of lower-mass halos is more sensitive to changes in cosmological parameters as compared to cluster mass halos. The c-M emulator is publicly available from http://www.hep.anl.gov/cosmology/CosmicEmu.

Bispectrum of the Sunyaev-Zel'dovich Effect

We perform a detailed study of the bispectrum of the Sunyaev-Zel’dovich effect. Using an analytical model for the pressure profiles of the intracluster medium, we demonstrate the SZ bispectrum to be a sensitive probe of the amplitude of the matter power spectrum parameter σ8. We find that the bispectrum amplitude scales as BtSZ ∝ σ 11−12 8 , compared to that of the power spectrum, which scales as AtSZ ∝ σ 7−9 8 . We show that the SZ bispectrum is principally sourced by massive clusters at redshifts around z ∼ 0.4, which have been well-studied observationally. This is in contrast to the SZ power spectrum, which receives a significant contribution from less-well understood low-mass and highredshift groups and clusters. Therefore, the amplitude of the bispectrum at l ∼ 3000 is less sensitive to astrophysical uncertainties than the SZ power spectrum. We show that current high resolution CMB experiments should be able to detect the SZ bispectrum amplitude with high significance, in part due to the low contamination from extra-galactic foregrounds. A combination of the SZ bispectrum and the power spectrum can sharpen the measurements of thermal and kinetic SZ components and help distinguish cosmological and astrophysical information from high-resolution CMB maps. Subject headings: cosmology: dark matter — galaxies: clusters: general — intergalactic medium

THE MIRA–TITAN UNIVERSE: PRECISION PREDICTIONS FOR DARK ENERGY SURVEYS

Ground and space-based sky surveys enable powerful cosmological probes based on measurements of galaxy properties and the distribution of galaxies in the Universe. These probes include weak lensing, baryon acoustic oscillations, abundance of galaxy clusters, and redshift space distortions; they are essential to improving our knowledge of the nature of dark energy. On the theory and modeling front, large-scale simulations of cosmic structure formation play an important role in interpreting the observations and in the challenging task of extracting cosmological physics at the needed precision. These simulations must cover a parameter range beyond the standard six cosmological parameters and need to be run at high mass and force resolution. One key simulation-based task is the generation of accurate theoretical predictions for observables, via the method of emulation. Using a new sampling technique, we explore an 8-dimensional parameter space including massive neutrinos and a variable dark energy equation of state. We construct trial emulators using two surrogate models (the linear power spectrum and an approximate halo mass function). The new sampling method allows us to build precision emulators from just 26 cosmological models and to increase the emulator accuracy by adding new sets of simulations in a prescribed way. This allows emulator fidelity to be systematically improved as new observational data becomes available and higher accuracy is required. Finally, using one LCDM cosmology as an example, we study the demands imposed on a simulation campaign to achieve the required statistics and accuracy when building emulators for dark energy investigations.

The control of hyperglycemia by a novel trypsin resistant oral insulin preparation in alloxan induced type I diabetic mice.

A trypsin resistant oral insulin preparation was made by incubating insulin for 2 h at 23 °C with previously boiled cow milk at 100 °C that was coagulated with 0.6 M acetic acid. The precipitate was resuspended in the same volume of milk. The immunoblot analysis of the suspended proteins treated with 200 ng of trypsin/ml for 3 h demonstrated that the 80.1% of the insulin in the suspension survived the proteolytic degradation compared to 0% of the hormone survived in the control. The feeding of 0.4 ml (0.08 unit of insulin) of the resuspended proteins followed by 0.2 ml of the same protein to alloxan induced diabetic mice maximally decreased the blood glucose level from 508 ± 10 mg/dl to 130 ± 10 mg/dl in 7 h with simultaneous increase of the basal plasma concentration of insulin from 3 ± 1.1 μunits/ml to 18 ± 1.5 μunits/ml. In control experiment the absence of insulin in the identical milk suspension produced no hypoglycemic effect suggesting milk was not responsible for the hypoglycemic effect of milk-insulin complex. Coming out of insulin-casein complex from the intestinal gut to the circulation was spontaneous and facilitated diffusion transportation which was found from Gibbs free energy reaction.

Extra pancreatic synthesis of insulin

It is currently believed that insulin, an essential hormone for carbohydrate metabolism, is produced only in the pancreas. Many investigators on the other hand had reported that various cells in different organs of the body beside pancreas are also capable of synthesizing insulin. This hormone not only has a critical role in the carbohydrate metabolism, but the protein is also reported to prevent the atherosclerosis and hypertension. The multifunctional synthesis of the protein in different cells in various organs is presented in the review. Insulin was reported to be synthesized in the liver, brain, thymus, adipocytes, gastrointestinal tract, bone marrow and in the leukocytes. Insulin synthesis was confirmed by cDNA analysis, amino acid sequence and by bioassay of the hormone. Liver was found to synthesize insulin, and glucose was found to stimulate NO synthesis in the liver and NO thus produced stimulated insulin and Glut-4 synthesis in the liver. Insulin synthesis occurs not only in human but also all animals. The lymphocytes and the leucocytes in the circulation were found to synthesize insulin. It is possible that synthesis of insulin in leucocytes could be involved for the ready supply of insulin in the prevention of thrombosis in platelets which did not produce any insulin. The synthesis of insulin in different organs in many different animals has also been reported. It was concluded that the synthesis of insulin in different cells was essential to maintain the cellular integrity from carbohydrate derived energy for all living organisms.