The New Contact Binary GSC 2414-0797

Original article can be found at: http://www.konkoly.hu/ibvs/GSC 2414-0797 has a contact binary star type light curve, a 0.4 magnitude brightness variation with a period 0.3406 days.Peer reviewe

A New Distance Correlation Metric and Bagging Method for NARX Model Estimation

System identification is a challenging and interesting engineering problem that has been studied for decades. In particular, the NARMAX methodology has been extensively used with interesting results. Such methodology identifies a deterministic parsimonious model by ranking a set of candidate terms using a linear dependency metric with respect to the output. Other metrics have been used that identify nonlinear dependencies, like the mutual information, but they are hard to interpret. In this work, the distance correlation metric is implemented together with the bagging method. These two implementations enhance the performance of the NARMAX methodology providing interpretability of nonlinear dependencies and uncertainty measures in the model identified. A comparison of the new BOFR-dCor (Bagging Orthogonal Forward Regression using distance Correlation) algorithm is done with respect to the traditional OFR (Orthogonal Forward Regression) algorithm and the OFR-MI (Orthogonal Forward Regression using Mutual Information) algorithm showing interesting results that improve interpretability and uncertainty analysis

Near-infrared colors of minor planets recovered from VISTA - VHS survey (MOVIS)

The Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE) provide information about the surface composition of about 100,000 minor planets. The resulting visible colors and albedos enabled us to group them in several major classes, which are a simplified view of the diversity shown by the few existing spectra. We performed a serendipitous search in VISTA-VHS observations using a pipeline developed to retrieve and process the data that corresponds to solar system objects (SSo). The colors and the magnitudes of the minor planets observed by the VISTA survey are compiled into three catalogs that are available online: the detections catalog (MOVIS-D), the magnitudes catalog (MOVIS-M), and the colors catalog (MOVIS-C). They were built using the third data release of the survey (VISTA VHS-DR3). A total of 39,947 objects were detected, including 52 NEAs, 325 Mars Crossers, 515 Hungaria asteroids, 38,428 main-belt asteroids, 146 Cybele asteroids, 147 Hilda asteroids, 270 Trojans, 13 comets, 12 Kuiper Belt objects and Neptune with its four satellites. The colors found for asteroids with known spectral properties reveal well-defined patterns corresponding to different mineralogies. The distributions of MOVIS-C data in color-color plots shows clusters identified with different taxonomic types. All the diagrams that use (Y-J) color separate the spectral classes more effectively than the (J-H) and (H-Ks) plots used until now: even for large color errors (<0.1), the plots (Y-J) vs (Y-Ks) and (Y-J) vs (J-Ks) provide the separation between S-complex and C-complex. The end members A, D, R, and V-types occupy well-defined regions.Comment: 19 pages, 16 figure

Discovery of three z>6.5 quasars in the VISTA Kilo-degree Infrared Galaxy (VIKING) survey

Studying quasars at the highest redshifts can constrain models of galaxy and black hole formation, and it also probes the intergalactic medium in the early universe. Optical surveys have to date discovered more than 60 quasars up to z~6.4, a limit set by the use of the z-band and CCD detectors. Only one z>6.4 quasar has been discovered, namely the z=7.08 quasar ULAS J1120+0641, using near-infrared imaging. Here we report the discovery of three new z>6.4 quasars in 332 square degrees of the Visible and Infrared Survey Telescope for Astronomy Kilo-degree Infrared Galaxy (VIKING) survey, thus extending the number from 1 to 4. The newly discovered quasars have redshifts of z=6.60, 6.75, and 6.89. The absolute magnitudes are between -26.0 and -25.5, 0.6-1.1 mag fainter than ULAS J1120+0641. Near-infrared spectroscopy revealed the MgII emission line in all three objects. The quasars are powered by black holes with masses of ~(1-2)x10^9 M_sun. In our probed redshift range of 6.44<z<7.44 we can set a lower limit on the space density of supermassive black holes of \rho(M_BH>10^9 M_sun) > 1.1x10^(-9) Mpc^(-3). The discovery of three quasars in our survey area is consistent with the z=6 quasar luminosity function when extrapolated to z~7. We do not find evidence for a steeper decline in the space density of quasars with increasing redshift from z=6 to z=7.Comment: 14 pages, 9 figures. Published in Ap

The ELAIS deep X-ray survey - I. Chandra source catalogue and first results

We present an analysis of two deep (75 ks) Chandra observations of the European Large Area Infrared Space Observatory (ISO) Survey (ELAIS) fields N1 and N2 as the first results from the ELAIS deep X-ray survey. This survey is being conducted in well-studied regions with extensive multiwavelength coverage. Here we present the Chandra source catalogues along with an analysis of source counts, hardness ratios and optical classifications. A total of 233 X-ray point sources are detected in addition to two soft extended sources, which are found to be associated with galaxy clusters. An overdensity of sources is found in N1 with 30 per cent more sources than N2, which we attribute to large-scale structure. A similar variance is seen between other deep Chandra surveys. The source count statistics reveal an increasing fraction of hard sources at fainter fluxes. The number of galaxy-like counterparts also increases dramatically towards fainter fluxes, consistent with the emergence of a large population of obscured sources

Necesidad de calefacción en la región centro oeste del país, según la dirección de los vientos

Se determina para siete localidades del centro oeste del país las necesidades de calefacción en función de las direcciones de los vientos y las calmas para los meses de abril a setiembre, a partir de los datos climáticos de la década 1981-1990 generados por el Servicio Meteorológico Nacional. Se emplean para los cálculos dos procedimientos: Mediante uno de éstos, se calculan los grados días de calefacción , GDC y el otro empleando el programa Psicro, que permite chequear los resultados obtenidos.Tema: Uso racional de la energía.Asociación Argentina de Energía Sola

Necesidad de calefacción en la región centro oeste del país, según la dirección de los vientos

Se determina para siete localidades del centro oeste del país las necesidades de calefacción en función de las direcciones de los vientos y las calmas para los meses de abril a setiembre, a partir de los datos climáticos de la década 1981-1990 generados por el Servicio Meteorológico Nacional. Se emplean para los cálculos dos procedimientos: Mediante uno de éstos, se calculan los grados días de calefacción , GDC y el otro empleando el programa Psicro, que permite chequear los resultados obtenidos.Tema: Uso racional de la energía.Asociación Argentina de Energía Sola

Necesidad de calefacción en la región centro oeste del país, según la dirección de los vientos

Se determina para siete localidades del centro oeste del país las necesidades de calefacción en función de las direcciones de los vientos y las calmas para los meses de abril a setiembre, a partir de los datos climáticos de la década 1981-1990 generados por el Servicio Meteorológico Nacional. Se emplean para los cálculos dos procedimientos: Mediante uno de éstos, se calculan los grados días de calefacción , GDC y el otro empleando el programa Psicro, que permite chequear los resultados obtenidos.Tema: Uso racional de la energía.Asociación Argentina de Energía Sola