120 research outputs found
Target and (Astro-)WISE technologies - Data federations and its applications
After its first implementation in 2003 the Astro-WISE technology has been
rolled out in several European countries and is used for the production of the
KiDS survey data. In the multi-disciplinary Target initiative this technology,
nicknamed WISE technology, has been further applied to a large number of
projects. Here, we highlight the data handling of other astronomical
applications, such as VLT-MUSE and LOFAR, together with some non-astronomical
applications such as the medical projects Lifelines and GLIMPS, the MONK
handwritten text recognition system, and business applications, by amongst
others, the Target Holding. We describe some of the most important lessons
learned and describe the application of the data-centric WISE type of approach
to the Science Ground Segment of the Euclid satellite.Comment: 9 pages, 5 figures, Proceedngs IAU Symposium No 325 Astroinformatics
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The black hole in IC 1459 from HST observations of the ionized gas disk
The peculiar elliptical galaxy IC 1459 (M_V = -21.19, D = 16.5 Mpc) has a
fast counterrotating stellar core, stellar shells and ripples, a blue nuclear
point source and strong radio core emission. We present results of a detailed
HST study of IC 1459, and in particular its central gas disk, aimed a
constraining the central mass distribution. We obtained WFPC2 narrow-band
imaging centered on the Halpha+[NII] emission lines to determine the flux
distribution of the gas emission at small radii, and we obtained FOS spectra at
six aperture positions along the major axis to sample the gas kinematics. We
construct different dynamical models for the Halpha+[NII] and Hbeta kinematics
that include a supermassive black hole, and in which the stellar mass
distribution is constrained by the observed surface brightness distribution and
ground-based stellar kinematics. All models are consistent with a black hole
mass in the range Mbh=1-4 x 10^8 Msun, and models without a black hole are
always ruled out at high confidence.Comment: 40 pages including 14 figures, Latex; submitted to A
Vascular targeting of solid tumours:a major 'inverse' volume-response relationship following combretastatin A-4 phosphate treatment of rat rhabdomyosarcomas
Uitkomsten Mestinnovaties in een notendop
De minister van LNV heeft Wageningen UR verzocht om inzichtelijk te maken welke technische innovaties er mogelijk zijn die aansluiten bij de ontwikkelingen in de markt om tot een betere mestverwerking te komen. De innovaties zijn gericht op het inbreken van de fosfaatkringloop in Nederland
The HST/ACS Coma Cluster Survey. II. Data Description and Source Catalogs
The Coma cluster was the target of a HST-ACS Treasury program designed for
deep imaging in the F475W and F814W passbands. Although our survey was
interrupted by the ACS instrument failure in 2007, the partially completed
survey still covers ~50% of the core high-density region in Coma. Observations
were performed for 25 fields that extend over a wide range of cluster-centric
radii (~1.75 Mpc) with a total coverage area of 274 arcmin^2. The majority of
the fields are located near the core region of Coma (19/25 pointings) with six
additional fields in the south-west region of the cluster. In this paper we
present reprocessed images and SExtractor source catalogs for our survey
fields, including a detailed description of the methodology used for object
detection and photometry, the subtraction of bright galaxies to measure faint
underlying objects, and the use of simulations to assess the photometric
accuracy and completeness of our catalogs. We also use simulations to perform
aperture corrections for the SExtractor Kron magnitudes based only on the
measured source flux and half-light radius. We have performed photometry for
~73,000 unique objects; one-half of our detections are brighter than the
10-sigma point-source detection limit at F814W=25.8 mag (AB). The slight
majority of objects (60%) are unresolved or only marginally resolved by ACS. We
estimate that Coma members are 5-10% of all source detections, which consist of
a large population of unresolved objects (primarily GCs but also UCDs) and a
wide variety of extended galaxies from a cD galaxy to dwarf LSB galaxies. The
red sequence of Coma member galaxies has a constant slope and dispersion across
9 magnitudes (-21<M_F814W<-13). The initial data release for the HST-ACS Coma
Treasury program was made available to the public in 2008 August. The images
and catalogs described in this study relate to our second data release.Comment: Accepted for publication in ApJS. A high-resolution version is
available at http://archdev.stsci.edu/pub/hlsp/coma/release2/PaperII.pd
A fluorogenic probe for granzyme B enables in-biopsy evaluation and screening of response to anticancer immunotherapies
Immunotherapy promotes the attack of cancer cells by the immune system; however, it is difficult to detect early responses before changes in tumor size occur. Here, we report the rational design of a fluorogenic peptide able to detect picomolar concentrations of active granzyme B as a biomarker of immune-mediated anticancer action. Through a series of chemical iterations and molecular dynamics simulations, we synthesize a library of FRET peptides and identify probe H5 with an optimal fit into granzyme B. We demonstrate that probe H5 enables the real-time detection of T cell-mediated anticancer activity in mouse tumors and in tumors from lung cancer patients. Furthermore, we show image-based phenotypic screens, which reveal that the AKT kinase inhibitor AZD5363 shows immune-mediated anticancer activity. The reactivity of probe H5 may enable the monitoring of early responses to anticancer treatments using tissue biopsies
The nature of nuclear Halpha emission in LINERs
To get insight in the nature of the ionized gas in the nuclear region of
LINERs we have performed a study of HST Halpha imaging of 32 LINERs. The main
conclusion from this analysis is that for the large majority of LINERs (84%) an
unresolved nuclear source has been identified as well as extended emission with
equivalent sizes ranging from few tens till about hundredths of parsecs. Their
morphologies appear not to be homogeneous being basically grouped into three
classes:nuclear outflow candidates (42%), core-halo morphologies (25%) and
nuclear spiral disks (14%). Clumpy structures reminiscent of young stellar
clusters are not a common property on LINERs. The remaining 5 galaxies are too
dusty to allow a clear view of the ionized gas distribution. A size-luminosity
relation has been found between the equivalent radius of the Halpha emission
and the (2-10 keV) X-ray luminosities. Both ionised gas morphologies and the
size-luminosity relation are indistinguishable from those of low luminosity
Seyferts, suggesting the same origin for the NLR of LINERs and Seyferts. Also a
relation between soft X-rays and ionized gas has been suggested for the first
time in LINERs. From multiwavelength data, only 4 out of the 32 LINERs have no
evidences on an AGN nature of theirnuclear sources from multiwavelength data,
but extremely obscured AGNs cannot be discarded out given the Compton thick
signatures of their X-ray emission. For the confirmed AGN LINERs, their Halpha
imaging favour core-halo and outflow morphologies (65% of the cases). Finally,
their calculated Eddington ratios show that our LINER sources radiate at
sub-Eddington regime, with core-halo systems having on average larger Eddington
ratios than outflow candidates.Comment: Accepted for publication in Astronomy and Astrophysic
Identification of a mitotic recombination hotspot on chromosome III of the asexual fungus Aspergillus niger and its possible correlation elevated basal transcription
Genetic recombination is an important tool in strain breeding in many organisms. We studied the possibilities of mitotic recombination in strain breeding of the asexual fungus Aspergillus niger. By identifying genes that complemented mapped auxotrophic mutations, the physical map was compared to the genetic map of chromosome III using the genome sequence. In a program to construct a chromosome III-specific marker strain by selecting mitotic crossing-over in diploids, a mitotic recombination hotspot was identified. Analysis of the mitotic recombination hotspot revealed some physical features, elevated basal transcription and a possible correlation with purine stretches
The first and second data releases of the Kilo-Degree Survey
Context. The Kilo-Degree Survey (KiDS) is an optical wide-field imaging survey carried out with the VLT Survey Telescope and the OmegaCAM camera. KiDS will image 1500 square degrees in four filters (ugri), and together with its near-infrared counterpart VIKING will produce deep photometry in nine bands. Designed for weak lensing shape and photometric redshift measurements, its core science driver is mapping the large-scale matter distribution in the Universe back to a redshift of ~0.5. Secondary science cases include galaxy evolution, Milky Way structure, and the detection of high-redshift clusters and quasars.
Aims. KiDS is an ESO Public Survey and dedicated to serving the astronomical community with high-quality data products derived from the survey data. Public data releases, the first two of which are presented here, are crucial for enabling independent confirmation of the survey’s scientific value. The achieved data quality and initial scientific utilization are reviewed in order to validate the survey data.
Methods. A dedicated pipeline and data management system based on ASTRO-WISE, combined with newly developed masking and source classification tools, is used for the production of the data products described here. Science projects based on these data products and preliminary results are outlined.
Results. For 148 survey tiles (≈160 sq.deg.) stacked ugri images have been released, accompanied by weight maps, masks, source lists, and a multi-band source catalogue. Limiting magnitudes are typically 24.3, 25.1, 24.9, 23.8 (5σ in a 2′′ aperture) in ugri, respectively, and the typical r-band PSF size is less than 0.7′′. The photometry prior to global homogenization is stable at the ~2% (4%) level in gri (u) with some outliers due to non-photometric conditions, while the astrometry shows a typical 2D rms of 0.03′′. Early scientific results include the detection of nine high-z QSOs, fifteen candidate strong gravitational lenses, high-quality photometric redshifts and structural parameters for hundreds of thousands of galaxies
Euclid: Estimation of the impact of correlated readout noise for flux measurements with the euclid NISP instrument
The Euclid satellite, to be launched by ESA in 2022, will be a major instrument for cosmology for the next decades. Euclid is composed of two instruments: the Visible instrument and the Near Infrared Spectrometer and Photometer (NISP). In this work, we estimate the implications of correlated readout noise in the NISP detectors for the final in-flight flux measurements. Considering the multiple accumulated readout mode, for which the UTR (Up The Ramp) exposure frames are averaged in groups, we derive an analytical expression for the noise covariance matrix between groups in the presence of correlated noise. We also characterize the correlated readout noise properties in the NISP engineering-grade detectors using long dark integrations. For this purpose, we assume a (1/f)α-like noise model and fit the model parameters to the data, obtaining typical values of e− Hz−0.5, and . Furthermore, via realistic simulations and using a maximum likelihood flux estimator we derive the bias between the input flux and the recovered one. We find that using our analytical expression for the covariance matrix of the correlated readout noise we diminish this bias by up to a factor of four with respect to the white noise approximation for the covariance matrix. Finally, we conclude that the final bias on the in-flight NISP flux measurements should still be negligible even in the white readout noise approximation, which is taken as a baseline for the Euclid on-board processing to estimate the on-sky flux
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