The Hyper Suprime-Cam software pipeline Bosch, James; Armstrong, Robert; Bickerton, Steven ...
Publications of the Astronomical Society of Japan,
01/2018, Letnik:
70, Številka:
SP1
Journal Article
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Abstract
In this paper, we describe the optical imaging data processing pipeline developed for the Subaru Telescope’s Hyper Suprime-Cam (HSC) instrument. The HSC Pipeline builds on the prototype ...pipeline being developed by the Large Synoptic Survey Telescope’s Data Management system, adding customizations for HSC, large-scale processing capabilities, and novel algorithms that have since been reincorporated into the LSST codebase. While designed primarily to reduce HSC Subaru Strategic Program (SSP) data, it is also the recommended pipeline for reducing general-observer HSC data. The HSC pipeline includes high-level processing steps that generate coadded images and science-ready catalogs as well as low-level detrending and image characterizations.
Abstract
We have developed an automated quick data analysis system for data quality assurance (QA) for Hyper Suprime-Cam (HSC). The system was commissioned in 2012–2014, and has been offered for ...general observations, including the HSC Subaru Strategic Program, since 2014 March. The system provides observers with data quality information, such as seeing, sky background level, and sky transparency, based on quick analysis as data are acquired. Quick-look images and validation of image focus are also provided through an interactive web application. The system is responsible for the automatic extraction of QA information from acquired raw data into a database, to assist with observation planning, assess progress of all observing programs, and monitor long-term efficiency variations of the instrument and telescope. Enhancements of the system are being planned to facilitate final data analysis, to improve the HSC archive, and to provide legacy products for astronomical communities.
ABSTRACT We improve the ellipticity of re-smeared artificial image (ERA) method of point-spread function (PSF) correction in a weak lensing shear analysis in order to treat the realistic shape of ...galaxies and the PSF. This is done by re-smearing the PSF and the observed galaxy image using a re-smearing function (RSF) and allows us to use a new PSF with a simple shape and to correct the PSF effect without any approximations or assumptions. We perform a numerical test to show that the method applied for galaxies and PSF with some complicated shapes can correct the PSF effect with a systematic error of less than 0.1%. We also apply the ERA method for real data of the Abell 1689 cluster to confirm that it is able to detect the systematic weak lensing shear pattern. The ERA method requires less than 0.1 or 1 s to correct the PSF for each object in a numerical test and a real data analysis, respectively.
Abstract
We present an optically-selected cluster catalog from the Hyper Suprime-Cam (HSC) Subaru Strategic Program. The HSC images are sufficiently deep to detect cluster member galaxies down to ...M* ∼ 1010.2 M⊙ even at z ∼ 1, allowing a reliable cluster detection at such high redshifts. We apply the CAMIRA algorithm to the HSC Wide S16A dataset covering ∼232 deg2 to construct a catalog of 1921 clusters at redshift 0.1 < z < 1.1 and richness ${\skew7\hat{N}}_{\rm mem}>15$ that roughly corresponds to M200m ≳ 1014 h−1 M⊙. We confirm good cluster photometric redshift performance, with the bias and the scatter in Δz/(1 + z) being better than 0.005 and 0.01, respectively, over most of the redshift range. We compare our cluster catalog with large X-ray cluster catalogs from the XXL and XMM-LSS (the XMM Large Scale Structure) surveys and find good correlation between richness and X-ray properties.We also study the mis-centering effect from the distribution of offsets between optical and X-ray cluster centers. We confirm the high (>0.9) completeness and purity for high-mass clusters by analyzing mock galaxy catalogs.
We developed a new method that uses ellipticity defined by 0th order moments (0th-ellipticity) for weak gravitational lensing shear analysis. Although there is a strong correlation between the ...ellipticity calculated using this approach and the usual ellipticity defined by the 2nd order moment, the ellipticity calculated here has a higher signal-to-noise ratio because it is weighted to the central region of the image. These results were confirmed using data for Abell 1689 from the Subaru telescope. For shear analysis, we adopted the ellipticity of re-smeared artificial image method for point spread function correction, and we tested the precision of this 0th-ellipticity with simple simulation, then we obtained the same level of precision with the results of ellipticity defined by quadrupole moments. Thus, we can expect that weak lensing analysis using 0 shear will be improved in proportion to the statistical error.
Highly accurate weak lensing analysis is urgently required for planned cosmic shear observations. For this purpose we have eliminated various systematic noises in the measurement. The point-spread ...function (PSF) effect is one of them. A perturbative approach for correcting the PSF effect on the observed image ellipticities has been previously employed. Here we propose a new non-perturbative approach for PSF correction that avoids the systematic error associated with the perturbative approach. The new method uses an artificial image for measuring shear which has the same ellipticity as the lensed image. This is done by re-smearing the observed galaxy images and observed star images (PSF) with an additional smearing function to obtain the original lensed galaxy images. We tested the new method with simple simulated objects that have Gaussian or Sersic profiles smeared by a Gaussian PSF with sufficiently large size to neglect pixelization. Under the condition of no pixel noise, it is confirmed that the new method has no systematic error even if the PSF is large and has a high ellipticity.
In this paper, we propose an efficient method for human dense avoidance based on a coverage control. Our motivation is to avoid crowding in public facilities such as stations and government offices, ...and human dense in the current situation of COVID‐19 from system and control theory. In this paper, humans and robots are modeled as heterogeneous and homogeneous agents, respectively, which make decisions based on their local information. We suppose a dense situation caused by the rendezvous among humans due to their own inherent dynamics. As a main result, we propose a coverage control for a distributed movement of multiple humans. We also characterize the stationary point analytically in terms of the gains that describe a strength of the interconnection of the agents, and the centers of the Voronoi regions related to the agents. Moreover, we verify the meaning of the characterization from an engineering viewpoint of the dense avoidance. Finally, we show the efficiency of the method based on a numerical simulation.
Multi-spectral filter array composed of a wavy alternating dielectric multilayer was integrated on a CMOS image sensor of the Raspberry Pi HQ Camera. The filter array consists of 16-channel ...elementary filters exhibiting pseudo-random transmission characteristics. Each filter covers
20
×
20
CMOS pixels. The incoming spectrum is encoded as a set of 16 grayscale intensities and passed to principal component analysis (PCA) to classify the states of the target spectral characteristic. Preliminary demonstration for blood flow state identification in human peripheral revealed proposed device’s potential ability as a real-time monitoring tool in the near infrared.
We have developed a method for measuring higher order weak-lensing distortions of faint background galaxies, namely, the weak gravitational flexion, by fully extending the Kaiser, Squires, and ...Broadhurst method to include higher order lensing image characteristics (HOLICs) introduced by Okura, Umetsu, and Futamase. We take into account explicitly the weight function in calculations of noisy shape moments and the effect of higher order point-spread function (PSF) anisotropy, as well as isotropic PSF smearing. Our HOLICs formalism allows accurate measurements of flexion from practical observational data in the presence of a noncircular, anisotropic PSF. We test our method using mock observations of simulated galaxy images and actual, ground-based Subaru observations of the massive galaxy cluster A1689. From the high-precision measurements of the spin-1 first flexion, we obtain a high-resolution mass map in the central region of A1689. The reconstructed mass map shows a bimodal feature in the central image region of the cluster. The major, pronounced peak is associated with the brightest cluster galaxy and central cluster members, while the secondary mass peak is associated with a local concentration of bright galaxies. The refined, high- resolution mass map of A1689 demonstrates the power of the generalized weak- lensing analysis techniques for quantitative and accurate measurements of the weak gravitational lensing signal.
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