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Data Products (data + products)
Selected AbstractsHST experience in data managementASTRONOMISCHE NACHRICHTEN, Issue 6-8 2004R. Albrecht Abstract The data generated by the Hubble Space Telescope pose a series of special requirements for the analysis process. The Hubble Space Telescope (HST) is being operated in a semi-autonomous, pre-programmed manner, executing a queue of observing requests. Calibration is being done "institutionally", i.e. not in response to individual observing programs, but in the same manner for all users. Data products are being generated for the observers, and they are ingested in the HST science data archives, to make them available for further exploitation through the Virtual Observatory. Added value products can be generated by combining data from different programs. Interactive analysis tools are being supplied to support users in the optimum exploitation of the data. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] ICOADS release 2.1 data and productsINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2005Steven J. Worley Abstract The International Comprehensive Ocean,Atmosphere Data Set (ICOADS), release 2.1 (1784,2002), is the largest available set of in situ marine observations. Observations from ships include instrument measurements and visual estimates, and data from moored and drifting buoys are exclusively instrumental. The ICOADS collection is constructed from many diverse data sources, and made inhomogeneous by the changes in observing systems and recording practices used throughout the period of record, which is over two centuries. Nevertheless, it is a key reference data set that documents the long-term environmental state, provides input to a variety of critical climate and other research applications, and serves as a basis for many associated products and analyses. The observational database is augmented with higher level ICOADS data products. The observed data are synthesized to products by computing statistical summaries, on a monthly basis, for samples within 2° latitude × 2° longitude and 1° × 1° boxes beginning in 1800 and 1960 respectively. For each resolution the summaries are computed using two different data mixtures and quality control criteria. This partially controls and contrasts the effects of changing observing systems and accounts for periods with greater climate variability. The ICOADS observations and products are freely distributed worldwide. The standard ICOADS release is supplemented in several ways; additional summaries are produced using experimental quality control, additional observations are made available in advance of their formal blending into a release, and metadata that define recent ships' physical characteristics and instruments are available. Copyright © 2005 Royal Meteorological Society [source] Star formation in close pairs selected from the Sloan Digital Sky SurveyMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2004B. Nikolic ABSTRACT The effect of galaxy interactions on star formation has been investigated using Data Release One of the Sloan Digital Sky Survey (SDSS). Both the imaging and spectroscopy data products have been used to construct a catalogue of nearest companions to a volume-limited (0.03 < z < 0.1) sample of galaxies drawn from the main galaxy sample of SDSS. Of the 13 973 galaxies in the volume-limited sample, we have identified 12 492 systems with companions at projected separations less than 300 kpc. Star formation rates for the volume-limited sample have been calculated from extinction and aperture corrected H, luminosities and, where available, IRAS data. Specific star formation rates were calculated by estimating galaxy masses from z -band luminosities, and r -band concentration indices were used as an indicator of morphological class. The mean specific star formation rate is significantly enhanced for projected separations less than 30 kpc. For late-type galaxies, the correlation extends out to projected separations of 300 kpc and is most pronounced in actively star-forming systems. The specific star formation rate is observed to decrease with increasing recessional velocity difference, but the magnitude of this effect is small compared to that associated with the projected separation. We also observe a tight relationship between the concentration index and pair separation; the mean concentration index is largest for pairs with separations of approximately 75 kpc and declines rapidly for separations smaller than this. This is interpreted as being due to the presence of tidally triggered nuclear starbursts in close pairs. Further, we find no dependence of star formation enhancement on the morphological type or mass of the companion galaxy. [source] New constraints from the H, line for the temperature of the transiting planet host star OGLE-TR-10,ASTRONOMISCHE NACHRICHTEN, Issue 6 2008M. Ammler-von Eiff Abstract The spectroscopic analysis of systems with transiting planets gives strong constraints on planetary masses and radii as well as the chemical composition of the systems. The properties of the system OGLE-TR-10 are not well-constrained, partly due to the discrepancy of previous measurements of the effective temperature of the host star. This work, which is fully independent from previous works in terms of data reduction and analysis, uses the H, profile in order to get an additional constraint on the effective temperature. We take previously published UVES observations which have the highest available signal-to-noise ratio for OGLE-TR-10. A proper normalization to the relative continuum is done using intermediate data products of the reduction pipeline of the UVES spectrograph. The effective temperature then is determined by fitting synthetic H, profiles to the observed spectrum. With a result of Teff = 6020 ± 140 K, the H, profile clearly favours one of the previous measurements. The H, line is further consistent with dwarf-like surface gravities as well as solar and super-solar metallicities previously derived for OGLE-TR-10. The H, line could not be used to its full potential, partly because of the varying shape of the UVES échelle orders after flat field correction. We suggest to improve this feature when constructing future spectrographs. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Helioseismology program for the PICARD satellite,ASTRONOMISCHE NACHRICHTEN, Issue 5 2008T. Corbard Abstract The PICARD mission is a CNES micro-satellite to be launched in 2009. Its goal is to better understand the Sun and the potential impact of its activity on earth climate by measuring simultaneously the solar total and spectral irradiance, diameter, shape and oscillations. We present the scientific objectives, instrumental requirements and data products of the helioseismology program of PICARD which aims to observe the low to medium l p-mode oscillations in intensity and search for g-mode oscillation signatures at the limb. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The VLA Low-frequency Sky SurveyASTRONOMISCHE NACHRICHTEN, Issue 2-3 2006A. S. Cohen Abstract We present an overview of the ongoing VLA Low-frequency Sky Survey (VLSS, formerly known as 4MASS). The VLSS will map an area of 9.1 sr covering the entire sky above a declination of ,30 degrees (or 75% of the full sky), at a frequency of 74 MHz (4 meter wavelength) with an unprecedented combination of sensitivity and resolution at this low frequency. The observational challenges at this wavelength include radio frequency interference (RFI), ionospheric phase distortions and a large field of view filled with sources. These challenges have been surmounted by a variety of new algorithms. The principle data products from the survey will be a set of publicly available images along with a source catalog of approximately 80 000 objects. Thus we will create an online virtual observatory at this previously unexplored frequency which will complement other major surveys at higher frequencies such as the NVSS. The most efficient way currently know to search for high redshift radio galaxies is to select ultra steep spectrum sources from low frequency surveys. The VLSS represents an excellent opportunity to pursue this method with its unique combination of large sky coverage and very low frequency, which may be especially useful for finding objects at z > 5. The observations are now roughly 50% complete, and we expect to complete most of the rest by late 2005. Current data products and more information are available on our website (URL http://lwa.nrl.navy.mil/VLSS). Basic research in radio astronomy at the Naval Research Laboratory is supported by the office of Naval Research. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||