Density mapping with weak lensing and phase information

The available probes of the large scale structure in the Universe have distinct properties: galaxies are a high resolution but biased tracer of mass, while weak lensing avoids such biases but, due to low signal-to-noise ratio, has poor resolution. We investigate reconstructing the projected density field using the complementarity of weak lensing and galaxy positions. We propose a maximum-probability reconstruction of the 2D lensing convergence with a likelihood term for shear data and a prior on the Fourier phases constructed from the galaxy positions. By considering only the phases of the galaxy field, we evade the unknown value of the bias and allow it to be calibrated by lensing on a mode-by-mode basis. By applying this method to a realistic simulated galaxy shear catalogue, we find that a weak prior on phases provides a good quality reconstruction down to scales beyond l=1000, far into the noise domain of the lensing signal alone.Comment: 11 pages, 9 figures, published in MNRA

Ibm Kelompok Wanita Tani Ketela Pohon

Desa Cempaga adalah salah satu desa penghasil ketela pohon terbesar di Kabupaten Buleleng. Di desa ini terdapat 4 (empat) Kelompok Wanita Tani (KWT), namun kegiatan ini hanya pada peserta di KWT Sari Tunjung Mekar dan KWT Gunung Sari. Desa Cempaga banyak menghasilkan ketela pohon (singkong) sebagai bahan pangan sumber karbohidrat. Namun masalahnya keterbatasan kemampuan pengolahan, cita rasa dan penerapan strategi pemasaran yang kurang maksimal. Selain itu ketela pohon hanya diolah menjadi gaplek, sela kukus, lempog, sela meurap, bahkan hanya untuk pakan ternak. Untuk itu diperlukan pemberdayaan masyarakat KWT Desa Cempaga dalam pengolahan ketela pohon agar dimanfaatkan menjadi produk pangan bernilai ekonomi.Metode pelaksanaan pengabdian di KWT Desa Cempaga untuk memberdayakan potensi ketela pohon yang dihasilkan. Kegiatan ini meliputi 1) pelatihan dan praktik langsung untuk menghasilkan berbagai produk ketela pohon yang siap dipasarkan, 2) perbaikan manajemen KWT desa Cempaga melalui struktur organisasi serta tugas tanggungjawabnya, perbaikan pembukuan sederhana, pembekalan strategi pemasaran dan promosi produk ketela pohon, 3) penyediaan sarana dan prasarana melalui pengadaan peralatan dan bahan praktik, 4) pendampingan berupa konsultasi dan bimbingan dalam memproduksi olahan ketela pohon, pembukuan sederhana dan strategi pemasarannya, serta promosi produk KWT desa Cempaga. Pencapaian hasil kegiatan ini adalah 1) Anggota KWT memperoleh pemahaman dan pengalaman untuk diversifikasi olahan ketela pohon, serta pengemasan dan pelabelan produk pangan, 2) Perbaikan manajemen KWT melalui struktur organisasi, pembukuan sederhana dan pemahaman strategi pemasaran dan promosi melalui media sosial (blog), 3) didukung penyediaan sarana dan prasarana kegiatan. Hal lain yang diperoleh KWT adalah adanya peningkatan pemasaran ke warung, toko-toko dan USAha-USAha yang tersebar di pasar tradisional Desa Cempaga. Adanya peningkatan kerja sama antar anggota melalui pembagian tugas dan tanggung jawab. Serta menjalin pola kemitraan dengan Dinas Perindustrian dan Perdagangan Kabupaten Buleleng melalui pameran produk ketela pohon.Luaran dalam kegiatan IbM Kelompok Wanita Tani Desa Cempaga adalah laporan kegiatan, blog promosi produk KWT Desa Cempaga, artikel dan poster

Balinese Traditional Culinary Promotes Food Skills and Its Positive Impact on Tourism Vocational School

The limited number of chefs who have skills in preparing, cooking and serving Balinese traditional cuisine has had an adverse impact on Balinese cultural identity, which is an integral part of tourism in Bali. Tourism Vocational School (TVS) prepares its students to become chefs and equips them with skills required to prepare high-quality food and beverages.  However, TVS does not currently incorporate Balinese culinary skills as part of their education. In order for graduates to have these skills, TVS needs to look into how the local culinary skills are applied and learn more about the traditional culinary skills that exist in Bali. This study aims to provide a basis on how TVS can incorporate Balinese Food Skills into their curriculum so that students are more equip in preparing traditional Balinese cuisine. This research used the Modification of Borg & Gall\u27s (1989) step as the method for achieving its goal

Cross-correlation Weak Lensing of SDSS Galaxy Clusters III: Mass-to-light Ratios

We present measurements of the excess mass-to-light ratio measured aroundMaxBCG galaxy clusters observed in the SDSS. This red sequence cluster sample includes objects from small groups with masses ranging from ~5x10^{12} to ~10^{15} M_{sun}/h. Using cross-correlation weak lensing, we measure the excess mass density profile above the universal mean \Delta \rho(r) = \rho(r) - \bar{\rho} for clusters in bins of richness and optical luminosity. We also measure the excess luminosity density \Delta l(r) = l(r) - \bar{l} measured in the z=0.25 i-band. For both mass and light, we de-project the profiles to produce 3D mass and light profiles over scales from 25 kpc/ to 22 Mpc/h. From these profiles we calculate the cumulative excess mass M(r) and excess light L(r) as a function of separation from the BCG. On small scales, where \rho(r) >> \bar{\rho}, the integrated mass-to-light profile may be interpreted as the cluster mass-to-light ratio. We find the M/L_{200}, the mass-to-light ratio within r_{200}, scales with cluster mass as a power law with index 0.33+/-0.02. On large scales, where \rho(r) ~ \bar{\rho}, the M/L approaches an asymptotic value independent of cluster richness. For small groups, the mean M/L_{200} is much smaller than the asymptotic value, while for large clusters it is consistent with the asymptotic value. This asymptotic value should be proportional to the mean mass-to-light ratio of the universe . We find /b^2_{ml} = 362+/-54 h (statistical). There is additional uncertainty in the overall calibration at the ~10% level. The parameter b_{ml} is primarily a function of the bias of the L <~ L_* galaxies used as light tracers, and should be of order unity. Multiplying by the luminosity density in the same bandpass we find \Omega_m/b^2_{ml} = 0.02+/-0.03, independent of the Hubble parameter.Comment: Third paper in a series; v2.0 incorporates ApJ referee's suggestion

Cosmological Constraints from the SDSS maxBCG Cluster Catalog

We use the abundance and weak lensing mass measurements of the SDSS maxBCG cluster catalog to simultaneously constrain cosmology and the richness--mass relation of the clusters. Assuming a flat \LambdaCDM cosmology, we find \sigma_8(\Omega_m/0.25)^{0.41} = 0.832\pm 0.033 after marginalization over all systematics. In common with previous studies, our error budget is dominated by systematic uncertainties, the primary two being the absolute mass scale of the weak lensing masses of the maxBCG clusters, and uncertainty in the scatter of the richness--mass relation. Our constraints are fully consistent with the WMAP five-year data, and in a joint analysis we find \sigma_8=0.807\pm 0.020 and \Omega_m=0.265\pm 0.016, an improvement of nearly a factor of two relative to WMAP5 alone. Our results are also in excellent agreement with and comparable in precision to the latest cosmological constraints from X-ray cluster abundances. The remarkable consistency among these results demonstrates that cluster abundance constraints are not only tight but also robust, and highlight the power of optically-selected cluster samples to produce precision constraints on cosmological parameters.Comment: comments welcom

Measurement of Galaxy Cluster Sizes, Radial Profiles, and Luminosity Functions from SDSS Photometric Data

Imaging data from the Sloan Digital Sky Survey is used to measure the empirical size-richness relation for a large sample of galaxy clusters. Using population subtraction methods, we determine the radius at which the cluster galaxy number density is 200/Omega_m times the mean galaxy density, without assuming a model for the radial distribution of galaxies in clusters. If these galaxies are unbiased on Mpc scales, this galaxy-density-based R_200 reflects the characteristic radii of clusters. We measure the scaling of this characteristic radius with richness over an order of magnitude in cluster richness, from rich clusters to poor groups. We use this information to examine the radial profiles of galaxies in clusters as a function of cluster richness, finding that the concentration of the galaxy distribution decreases with richness and is systematically lower than the concentrations measured for dark matter profiles in N-body simulations. Using these scaled radii, we investigate the behavior of the cluster luminosity function, and find that it is well matched by a Schechter function for galaxies brighter than M_r = -18 only after the central galaxy has been removed. We find that the luminosity function varies with richness and with distance from the cluster center, underscoring the importance of using an aperture that scales with cluster mass to compare physically equivalent regions of these different systems. We note that the lowest richness systems in our catalog have properties consistent with those expected of the earliest-forming halos; our cluster-finding algorithm, in addition to reliably finding clusters, may be efficient at finding fossil groups.Comment: 17 pages, 12 figures. Accepted for publication in Ap