GaBoDS: The Garching-Bonn Deep Survey -- I. Anatomy of galaxy clusters in the background of NGC 300

The Garching-Bonn Deep Survey (GaBoDS) is a virtual 12 square degree cosmic shear and cluster lensing survey, conducted with the [email protected] MPG/ESO telescope at La Silla. It consists of shallow, medium and deep random fields taken in R-band in subarcsecond seeing conditions at high galactic latitude. A substantial amount of the data was taken from the ESO archive, by means of a dedicated ASTROVIRTEL program. In the present work we describe the main characteristics and scientific goals of GaBoDS. Our strategy for mining the ESO data archive is introduced, and we comment on the Wide Field Imager data reduction as well. In the second half of the paper we report on clusters of galaxies found in the background of NGC 300, a random archival field. We use weak gravitational lensing and the red cluster sequence method for the selection of these objects. Two of the clusters found were previously known and already confirmed by spectroscopy. Based on the available data we show that there is significant evidence for substructure in one of the clusters, and an increasing fraction of blue galaxies towards larger cluster radii. Two other mass peaks detected by our weak lensing technique coincide with red clumps of galaxies. We estimate their redshifts and masses.Comment: 20 pages, 16 figures, gzipped. An online postscript version with higher quality figures (3.3 MBytes) can be downloaded from http://www.mpa-garching.mpg.de/~mischa/ngc300/ngc300.ps.gz . Submitted to A&

Histomorphometric Analysis of the Rat Proximal Tibial Metaphysis by “Linear Scanning”

Twenty-four female Sprague-Dawley rats (10 weeks old, 200g BW) were either sham-operated (n = 6) or ovariectomized (ovx). Ovx rats were divided into 3 groups (n = 6 each) : ovx; ovx + 1,25(OH) 2D3; ovx + l,25(OH)2D3 + 1,24,25(OH)3D3. The vitamin D metabolites were fed orally starting the day after surgery. After 7 weeks all rats were sacrificed and the proximal tibiae were processed undecalcified for quantitative histomorphometry. Conventional histomorphometric analysis of the distal zone (\u3e 1 mm from the growth cartilage) of the tibial metaphysis revealed a dramatic loss of cancellous bone mass in ovx rats. Both l,25(OH)2D3 and the combination of l,25(OH)2D3 with l,24,25(OH)3D3 prevented the bone loss in the distal zone in ovx animals. Measurements in the proximal zone (\u3c 1 mm from the growth cartilage) of the tibial metaphysis were performed with a newly developed technique that utilizes the advantages of automatic image analysis, and that we propose to name linear scanning . This method revealed a significantly decreased hard tissue mass at about 100 μm and within 800 to 950 μm distance from the growth plate in ovx rats. However, ovx rats reached normal amounts of hard tissue within 250 to 450 μm from the growth plate. The results obtained by linear scanning suggest that the obvious loss of cancellous bone mass in the distal zone of the tibial metaphysis in growing ovx rats is not a consequence of structural changes in the proximal zone

Implante Simultâneo de um Marcapasso Dupla-Câmara Unipolar e de um Desfibrilador

Vale a pena considerar a possibilidade de implante simultâneo de desfibrilador em um paciente portador de marcapasso unipolar. Este relato de caso mostra que, tomadas algumas precauções, essa associação pode produzir bons resultado

Conformational properties of ethyl- and 2,2,2-trifluoroethyl thionitrites, (CX3CH2SNO, X = H and F)

The simple 2,2,2-trifluoroethyl thionitrite molecule, CF3CH2SNO, has been prepared in good yield for the first time using CF3CH2SH and NOCl in slight excess. The vapor pressure of the red-brown compound CF3CH2SNO follows, in the temperature range between 226 and 268 K, the equation log p = 12.0-3881/T (p/bar, T/K), and its extrapolated boiling point reaches 51 °C. Its structural and conformational properties have been compared with the ethyl thionitrite analogue, CH3CH2SNO. The FTIR spectra of the vapor of both thionitrites show the presence of bands with well-defined contours, allowing for a detailed conformational analysis and vibrational assignment on the basis of a normal coordinate analysis. The conformational space of both thionitrite derivatives has also been studied by using the DFT and MP2(full) level of theory with extended basis sets [6-311+G(2df) and cc-pVTZ]. The overall evaluation of the experimental and theoretical results suggests the existence of a mixture of two conformers at room temperature. The relative abundance of the most stable syn form (N=O double bond syn with respect to the C-S single bond) has been estimated to be ca. 79 and 75% for CF3CH2SNO and CH3CH2SNO, respectively.Centro de Química Inorgánic

Cosmic shear analysis of archival HST/ACS data: I. Comparison of early ACS pure parallel data to the HST/GEMS Survey

This is the first paper of a series describing our measurement of weak lensing by large-scale structure using archival observations from the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). In this work we present results from a pilot study testing the capabilities of the ACS for cosmic shear measurements with early parallel observations and presenting a re-analysis of HST/ACS data from the GEMS survey and the GOODS observations of the Chandra Deep Field South (CDFS). We describe our new correction scheme for the time-dependent ACS PSF based on observations of stellar fields. This is currently the only technique which takes the full time variation of the PSF between individual ACS exposures into account. We estimate that our PSF correction scheme reduces the systematic contribution to the shear correlation functions due to PSF distortions to < 2*10^{-6} for galaxy fields containing at least 10 stars. We perform a number of diagnostic tests indicating that the remaining level of systematics is consistent with zero for the GEMS and GOODS data confirming the success of our PSF correction scheme. For the parallel data we detect a low level of remaining systematics which we interpret to be caused by a lack of sufficient dithering of the data. Combining the shear estimate of the GEMS and GOODS observations using 96 galaxies arcmin^{-2} with the photometric redshift catalogue of the GOODS-MUSIC sample, we determine a local single field estimate for the mass power spectrum normalisation sigma_{8,CDFS}=0.52^{+0.11}_{-0.15} (stat) +/- 0.07 (sys) (68% confidence assuming Gaussian cosmic variance) at fixed Omega_m=0.3 for a LambdaCDM cosmology. We interpret this exceptionally low estimate to be due to a local under-density of the foreground structures in the CDFS.Comment: Version accepted for publication in Astronomy & Astrophysics with 28 pages, 25 figures. A version with full resolution figures can be downloaded from http://www.astro.uni-bonn.de/~schrabba/papers/cosmic_shear_acs1_v2.pd

ARCRAIDER II: Arc search in a sample of non-Abell clusters

We present a search for gravitational arcs in a sample of X-ray luminous, medium redshift clusters of galaxies. The sample of clusters is called ARCRAIDER, is based on the ROSAT Bright Survey (RBS) and fulfills the following criteria: (a) X-ray luminosity Lx>=0.5x10^45erg/s (0.5-2keV band), (b) redshift range 0.1<=z<=0.52, (c) classified as clusters in the RBS, (d) not a member of the Abell catalogue and, finally, (e) visible from the ESO sites La Silla/Paranal (declination \delta<=20deg). In total we found more than 35 (giant) arc/arclet candidates, including a possible radial arc, one galaxy-galaxy lensing event and a possible quasar triple image in 14 of the 21 clusters of galaxies. Hence 66% of the sample members are possible lenses.Comment: Accepted for publication in Astronomy and Astrophysics; 8 pages (excl. Appendix), 6 figures, 9 tables; Please download the high-res images of the appendix from http://astro-staff.uibk.ac.at/~w.kausch/ARCRAIDER_II_images.tar.g

ARCRAIDER I: Detailed optical and X-ray analysis of the cooling flow cluster Z3146

We present a detailed analysis of the medium redshift (z=0.2906) galaxy cluster Z3146 which is part of the ongoing ARCRAIDER project, a systematic search for gravitational arcs in massive clusters of galaxies. The analysis of Z3146 is based on deep optical wide field observations in the B, V and R bands obtained with the [email protected], and shallow archival WFPC2@HST taken with the F606W filter, which are used for strong as well as weak lensing analyses. Additionally we have used publicly available XMM/Newton observations for a detailed X-ray analysis of Z3146. Both methods, lensing and X-ray, were used to determine the dynamical state and to estimate the total mass. We also identified four gravitational arc candidates. We find this cluster to be in a relaxed state, which is confirmed by a large cooling flow with nominal ~1600M_\odot per year, regular galaxy density and light distributions and a regular shape of the weak lensing mass reconstruction. The mass content derived with the different methods agrees well within 25% at r_{200}=1661 h_{70}^{-1}kpc indicating a velocity dispersion of \sigma_v=869^{+124}_{-153}km/s.Comment: accepted by A&A; 23 pages, 28 figures, 6 tables; High resolution version can be found here: http://astro.uibk.ac.at/~w.kausch/Z3146_astroph_hires.pdf.g

Chandra Observations of the QSO Pair Q2345+007: Binary Quasar or Massive Dark Lens?

The components of the wide (7.3") separation quasar pair Q2345+007A,B (z=2.15) have the most strikingly similar optical spectra seen to date (Steidel & Sargent 1991) yet no detected lensing mass, making this system the best candidate known for a massive (1e14 Msun) dark matter lens system. Here we present results from a 65ksec Chandra observation designed to investigate whether it is a binary quasar or a gravitational lens. We find no X-ray evidence for a lensing cluster to a (0.5-2keV) flux limit of 2e-15 cgs, which is consistent with lensing only for a reduced baryon fraction. Using the Chandra X-ray observations of the quasars themselves, together with new and published optical measurements, we use the observed emission properties of the quasars for further tests between the lens and binary hypotheses. Assuming similar line-of-sight absorption to the images, we find that their X-ray continuum slopes are inconsistent (Gamma_A=2.30 and Gamma_B=0.83) as are their X-ray to optical flux ratios. The probability that B suffers absorption sufficient to account for these spectral differences is negligible. We present new optical evidence that the flux ratio of the pair is variable, so the time-delay in a lens scenario could cause some of the discrepancies. However, adequately large variations in overall spectral energy distribution are rare in individual QSOs. All new evidence here weighs strongly toward the binary interpretation. Q2345+007 thus may represent the highest redshift example known of interaction-triggered but as-yet unmerged luminous AGN.Comment: 15 pages, Latex, emulateapj style, including 3 tables and 5 figures. Accepted Feb 1, 2002 for publication in ApJ Main Journal. See also http://hea-www.harvard.edu/~pgreen/Papers.htm

Weighing the Giants - I. Weak-lensing masses for 51 massive galaxy clusters: project overview, data analysis methods and cluster images

This is the first in a series of papers in which we measure accurate weak-lensing masses for 51 of the most X-ray luminous galaxy clusters known at redshifts 0.15<z<0.7, in order to calibrate X-ray and other mass proxies for cosmological cluster experiments. The primary aim is to improve the absolute mass calibration of cluster observables, currently the dominant systematic uncertainty for cluster count experiments. Key elements of this work are the rigorous quantification of systematic uncertainties, high-quality data reduction and photometric calibration, and the "blind" nature of the analysis to avoid confirmation bias. Our target clusters are drawn from RASS X-ray catalogs, and provide a versatile calibration sample for many aspects of cluster cosmology. We have acquired wide-field, high-quality imaging using the Subaru and CFHT telescopes for all 51 clusters, in at least three bands per cluster. For a subset of 27 clusters, we have data in at least five bands, allowing accurate photo-z estimates of lensed galaxies. In this paper, we describe the cluster sample and observations, and detail the processing of the SuprimeCam data to yield high-quality images suitable for robust weak-lensing shape measurements and precision photometry. For each cluster, we present wide-field color optical images and maps of the weak-lensing mass distribution, the optical light distribution, and the X-ray emission, providing insights into the large-scale structure in which the clusters are embedded. We measure the offsets between X-ray centroids and Brightest Cluster Galaxies in the clusters, finding these to be small in general, with a median of 20kpc. For offsets <100kpc, weak-lensing mass measurements centered on the BCGs agree well with values determined relative to the X-ray centroids; miscentering is therefore not a significant source of systematic uncertainty for our mass measurements. [abridged]Comment: 26 pages, 19 figures (Appendix C not included). Accepted after minor revisio