1507.00725
Prime focus spectrograph for the Subaru telescope: massively multiplexed optical and near-infrared fiber spectrograph
Sugai, et al
PFS is an optical/NIR multi fiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter FoV at Subaru 8.2m telescope. Wavelength coverage 0.38um to 1.26um, with a resolving power of 3000, simultaneously strengthens its ability to target 3 main survey programs: Cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode with a resolving power of 5000 for 0.71 um to 0.89 um will also be available by simply exchanging dispersers. Highlight some of the technological aspects of the design. To transform the telescope focal ratio, a broad-band coated microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of the cable system, optimizing overall throughput; a fiber with low focal ratio degradation is selected for the fiber-ositioner and fiber-slit components, minimizing the effects of fiber movements and fiber bending. Fiber positioning will be performed by a positioned consisting of 2 stages of piezo-electric rotary motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by iteratively measuring and then adjusting the positions of the motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by interactively measuring and then adjusting the positions of the motors. Target light reaches one of the four identical fast-Schmidt spectrograph modes, each with 3 arms. The PFS project has passed several project-wide design review and is now in the construction phase.
1507.00726
First discoveries of z~6 quasars with the Kilo Degree Survey and VISTA Kil-Degree Infrared Galaxy survey
Venemans, Kleijn, et al
As the title says. First of the KiDS papers.
1507.00731
Towards a census of super-compact massive galaxies in the Kilo Degree Survey
Tortora, et al
Complete census of the most compact galaxies in the Universe. 2nd of the KiDS papers.
1507.00733
Strong lens search in the ESO public survey KiDS
Napolitano, et al
Systematic search of strong lens candidates. 3rd of the KiDS papers.
1507.00734
Charing unexplored dwarf galaxy territory with RR Lyrae
Baker, Willman
Observational bias against finding MW dwarf galaxies at low Galactic latitudes (b<20 deg) and at low surface brightnesses (fainter than 29 mag arcsec^-2 in V-band) currently limits the understanding of the faintest limits of the galaxy LF. This paper is a proof-of-concept what groups of two or more RR Lyrae stars reveal MW dwarf galaxies at d>50 kpc in these unmined regions of parameter space, with only modest contamination from interloper groups when large halo structures are excluded. For example, a FoF search with a linking length of 500 pc could reveal dwarf galaxies more luminous than M_V=-3.2 mag and with surface brightnesses as faint as 31 mag arcsec^-2 (or even fainter, depending on RR Lyrae specific frequency). Although existing public RR Lyrae catalog are highly incomplete at d>50 kpc and/or include <1% of the MW halo's volume, FoF search reveals two known dwarfs (Bootes I and Sextans) and two dwarf candidate groups possibly worthy of Follow-up. PanSTARRS 1 may catalog RR Lyrae to 100 kpc which would include ~15% of predicted MW dwarf galaxies. Groups of PS1 RR Lyrae should therefore reveal very low surface brightness and low Galactic latitude dwarfs within its footprint, if they exist. With sensitivity to RR Lyrae to d>600 kpc, LSST is the only planned survey that will be both wide-field and deep enough to use RR Lyrae to definitively measure the MW's dwarf galaxy census to extremely low surface brightnesses, and through the Galactic plane.
1507.00735
Dark matter halo properties of GAMA galaxy groups from 100 squarae degrees of KiDS weak lensing data
Viola, Cacciato, Brower, Kuijken, et al
Use ~1400 GAMA groups (of galaxies) and KiDS lenses: detect a highly significant signal (S/N~120), allowing studies of DM halo properties over 1.5 order of magnitude in mass, from Me13 to 1e14.5 Msun/h. Interpret the results for various subsamples of groups using a halo model framework which accounts for the miscentering of the BCG (used as the tracer of the group center) with respect to the center of the group's DM halo. Find that the density profiles of the haloes are well described by an NFW profile with concentrations that agree with predictions from numerical simulations. In addition, constrain scaling relations between the mass and a number of observable group properties. Find that the mass scales with the total r-band luminosity as a power-law with sleep 1.16±0.13 (1-sigma) and with the group velocity dispersion ad a power-law with slope 1.89±0.27 (1-sigma). Finally, demonstrate the potential of WL studies of groups to discriminate between models of baryonic feedback at group scales by comparing the results with the predictions from the COSMO-OWLS project, urging out models without AGN feedback.
1507.00736
Galaxy evolution within the Kilo-Degree Survey
Tortora, et al
More KiDS papers. Conference proceedings.
1507.00737
The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data
Sifón, et al
Use the first 100 sq. deg. of overlap between KiDS and GAMA survey to determine the galaxy halo mass of ~10k spectroscopically-confirmed satellite galaxies in massive (M>1e13 Msun/h) galaxy groups. Separating the sample as a function of projected distance to the group center, jointly model the satellites and their host groups with NFW density profiles, fully accounting for the data covariance. The probed satellite galaxies i these groups have total masses Msub~1e11.7-12.2 Msun/h consistent across group-centric distance within the error bars. Given their typical stellar masses, M*~1e10.5, such total masses imply stellar mass fractions of M*/Msub~0.04/h. The average sub halo hosting these satellite galaxies has a mass Msub~0.015Mhost independent of host halo mass, in broad agreement with the expectations of structure formation in a LCDM universe.
1507.00738
Gravitational lensing analysis of the Kilo Degree Survey
Kuijken, Heymans, et al
KiDS: multi-band imaging survey for WL and photo-z, using VLT OmegaCAM, in 4 filters similar to the SDSS ugri bands. Deep r-band observations with limiting mag of 24.9, and 0.7" median seeing. Initial KiDS observations have concentrated on the GAMA regions near the celestial equator, where extensive, highly complete redshift catalogues are available. A total of 101 survey tiles, one square degree each, form the basis of the first set of lensing analysis, which focus on measurements of halo properties of GAMA galaxies. 9 galaxies per square arc minute enter the lensing analysis, for an effective inverse shear variance of 69 per square arc minute. Accounting for the shape measurement weight, the median redshift of the sources is 0.53. KiDS data processing follows two parallel tracks, one optimized for galaxy shape measurement (for weak lensing), and one for accurate matched-aperture photometry in 4 bands (for photometric redshifts). This technical paper describes how the lensing and photometric redshift catalogues have been produced (including an extensive description of the Gaussian Aperture and Photometry pipeline), summarizes the data quality, and presents extensive tests for systemsatic errors that might affect the lensing analysis. Also provide first demonstrations of the suitability of the data for cosmological measurements, and explain how the shear catalogues were blinded to prevent confirmation bias in the scientific analyses. The KiDS shear and photometric redshift catalogues, presented in this paper, are released to the community through kids.str.leidenuniv.nl.
1507.00742
The first and second data releases of the Kilo-Degree Survey
de Jong, et al
KiDS on VLT OmegaCAM; will image 1500 square degrees in ugri filters, and together with its NIR counterpart VIKING, will produce deep photometry in 9 bands. Designed for WL shape and photo-z measurements, the core science driver of the survey is mapping the large-scale matter distribution in the Universe back to a z of ~0.5. Secondary science cases are manifold, covering topics such as galaxy evolution, MW structure, and the detection of high-z clusters and quasars. KiDS is an ESO Public Survey and dedicated to serving the astronomical community with high-quality data products derived from the survey data, as well as with calibration data. Public data releases will be made on a yearly basis, the first two of which are presented here. For a total of 148 survey tiles (~160 sq. deg) astrometrically and photometrically calibrated, coadded ugri images have been released, accompanied by weight maps, masks, source lists, and a multi-band source catalog. A dedicated pipeline and data management system based on the Astro-WISE software system, combined with newly developed masking and source classification software, is used for the data production of the data products described here. The achieved data quality and early science projects based on the data products in the first two data releases are reviewed in order to validate the survey data. Early scientific results include the detection of 9 high-z QSOs, fifteen candidate strong gravitational lenses, high-quality photometric redshifts and galaxy structural parameters for hundreds of thousands of galaxies.
1507.00743
Searching for galaxy clusters in the VST-KiDS survey
Radovich, et al
Present the methods and first results for the search for galaxy clusters in KiDS; preliminary results obtained over small area (7 sq deg). Conference proceedings.
1507.00754
Machine learning based photometric redshifts for the KiDS ESO DR2 galaxies
Cavuoti, et al
Estimated zphot for >1.1e6 galaxies of KiDS DR2, obtained using Multi Layer Perceptron with Quasi Newton Algorithm (MLPQNA) model, provided within the framework of DAta Mining and Exploration Web Application REsource (DAMEWARE). These photometric redshifts are based on a spectroscopic knowledge base which was obtained by merging spectroscopic datasets from GAMA DR2 and SDSS-III DR9. The overall 1 sigma uncertainty on Delta z = (zspec-zphot)/(1+zspec) is ~0.03, with a very small average bias of ~0.001, and NMAD of ~0.02 and a fraction of catastrophic outliers (|Delta z| > 0.15) of ~0.4%
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