Search results for "STARS"
showing 10 items of 798 documents
Broad-band Spectral Evolution of Scorpius X-1 along its Color-Color Diagram
2007
We analyze a large collection of RXTE archive data from April 1997 to August 2003 of the bright X-ray source Scorpius X-1 in order to study the broadband spectral evolution of the source for different values of the inferred mass accretion rate by studying energy spectra from selected regions in the Z-track of its Color-Color Diagram. A two-component model, consisting of a soft thermal component interpreted as thermal emission from an accretion disk and a thermal Comptonization component, is unable to fit the whole 3--200 keV energy spectrum at low accretion rates. Strong residuals in the highest energy band of the spectrum require the addition of a third component that can be fitted with a …
23 GHz VLBI observations of SN 2008ax (Research Note)
2009
We report on phase-referenced 23 GHz Very-Long-Baseline-Interferometry (VLBI) observations of the type IIb supernova SN 2008ax, made with the Very Long Baseline Array (VLBA) on 2 April 2008 (33 days after explosion). These observations resulted in a marginal detection of the supernova. The total flux density recovered from our VLBI image is 0.8 ± 0.3 mJy (one standard deviation). As it appears, the structure may be interpreted as either a core-jet or a double source. However, the supernova structure could be somewhat confused with a possible close by noise peak. In such a case, the recovered flux density would decrease to 0.48 ± 0.12 mJy, compatible with the flux densities measured with the…
Brown Dwarfs in ChaI Dark Cloud
2004
We present the results of a multiband survey for brown dwarfs in the Chamaeleon I dark cloud with the Wide Field Imager (WFI) camera at the ESO/MPG 2.2-m telescope on La Silla (Chile) on 28-May to 03-Jun 1999. The survey has revealed a substantial population of brown dwarfs in this southern star-forming region. Candidates were selected from R, I and H{alpha} imaging observations. We also observed in two medium-band filters, M855 and M915, for spectral type determination. The former filter covers a wavelength range containing spectral features characteristic of M-dwarfs, while the latter lies in a relatively featureless wavelength region for these late-type objects. A correlation was found b…
VCNS II. The IR-excess-selected population
2015
We performed a deep wide-field (6.76 square-degrees) near-infrared survey with the VISTA telescope that covers the entire extent of the Carina nebula complex. Complementing the VISTA near-infrared catalog with Spitzer IRAC mid-infrared photometry improves the situation of the background contamination considerably. We find that a (J-H) versus (Ks-[4.5]) color-color diagram is well suited to tracing the population of YSO-candidates (cYSOs) by their infrared excess. We identify 8781 sources with strong infrared excess, which we consider as cYSOs. This sample is used to investigate the spatial distribution of the cYSOs with a nearest-neighbor analysis. The surface density distribution of cYSOs …
Variability in proto-PNe. II.
2014
We have carried out a detailed observational study of the light, color, and velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS 22223+4327 and 22272+5435. The light curves are based upon our observations from 1994 to 2011, together with published data by Arkhipova and collaborators. They each display four significant periods, with primary periods for IRAS 22223+4327 and 22272+5435 being 90 and 132 days, respectively. For each of them, the ratio of secondary to primary period is 0.95, a value much different from that found in Cepheids, but which may be characteristic of post-asymptotic giant branch (AGB) stars. Fewer significant periods are found in the smaller radia…
Czy intymność, namiętność i zobowiązanie kształtują satysfakcję seksualną seniorów? Wyniki badania eksploracyjnego
2018
Wstęp: Seks stanowi manifestację relacji miłosnej pozwalającą na osiągnięcie pełni miłości. Seks osób starszych bywa jednak często pomijany lub niedoceniany w dyskusjach nad ludzką seksualnością. Aktywność seksualna w wieku senioralnym jest formą wyrażania uczuć i bliskości, ale również wzajemnej lojalności i zaufania. Ma również właściwości prozdrowotne. Badacze twierdzą, że aż 67% osób starszych jest zadowolonych ze swojej aktywności seksualnej. Materiały i metody: W badaniu wzięły udział 83 osoby w wieku 61–81 lat, 33 mężczyzn oraz 55 kobiet. Byli to członkowie Uniwersytetu Trzeciego Wieku oraz różnych kół zainteresowań dla osób starszych. Aktywność seksualną deklarowało 68% kobiet oraz …
Job Creation in Spain: Productivity Growth, Labour Market Reforms or both?
2010
The benefits implied by changing the growth model are at the heart ofthe heated political and economic debate in Spain. Increases in productivity and the reallocation of employment towards more innovative sectors are defended as the panacea for most of the ills afflicting the Spanish economy. In this paper we use a DSGE model with price rigidities, and labour market search frictions a la Mortensen-issarides, to assess the effects of the change in the growth model onunemployment. In so doing, we assume that the vigorous demand shock which has been mostly responsible for recent economic growth in Spain will be successfully substituted by a productivity shock as the main driver of Spain‘s…
Koksnes staru veidošanās parastajā priedē Pinus sylvestris Tomē lāna briestaudzē
2020
Parastā priede ir pasaulē visplašāk izplatītākā un ekonomiski nozīmīga skujkoku suga. Tā veido biomasas pieaugumu, izmantojot pašreizējos asimilātus, tomēr tās augšanai tiek izmantotas arī iepriekš izveidotās rezerves, kas noglabātas koksnes staru veidā. Mainīgos vides, īpaši ekstrēmos apstākļos mainās arī uzkrāto rezervju daudzums, kas var ietekmēt biomasas pieaugumu nākotnē. Koksnes staru izmēri atspoguļo uzkrāto rezervju daudzumu koksnē un pēc tā var spriest par koku reakciju uz meteoroloģiskajiem faktoriem un sociālā statusa nozīmi vienas audzes ietvaros. Par pētījuma vietu izvēlēta saimnieciska parastās priedes audze lāna tipa mežā, Tomē. Pētījumam ievāca urbumus no I un III Krafta kla…
ON THE FON ASTROPLATE PROJECT ACCOMPLISHMENT
2019
The plan of the photographic survey of thenorthern sky (FON) was proposed in 1976 in Golosiiv ob-servatory (now MAO NAS of Ukraine) by I. Kolchinskyand A. Onegina. The final project of the Compiled FONACcatalog (FON Astrographic Catalog) is based on the digitaldata of photographic plates exposed at four observatories.They are MAO NAS of Ukraine (Kyiv, Ukraine), Kitabastronomical observatory (Tashkent, Uzbekistan), Hissarastronomical observatory (Dushanbe, Tajikistan), and Bal-done observatory (Latvia)). The total amount of plates is5700. The result is expected to be the catalog of positionsand B-magnitudes of stars covered the declination areafrom -20 to 90 degrees. The estimated mean epoch…
Flow Behavior of Chain and Star Polymers and Their Mixtures
2018
Star-shaped polymers show a continuous change of properties from flexible linear chains to soft colloids, as the number of arms is increased. To investigate the effect of macromolecular architecture on the flow properties, we employ computer simulations of single chain and star polymers as well as of their mixtures under Poiseuille flow. Hydrodynamic interactions are incorporated through the multi-particle collision dynamics (MPCD) technique, while a bead-spring model is used to describe the polymers. For the ultradilute systems at rest, the polymers are distributed uniformly in the slit channel, with a weak dependence on their number of arms. Once flow is applied, however, we find that the…