... If you have observed the source with multiple source/reference cycles you will want to scan-average the quotient spectra together. ASAP> av = average_time(q) . ... The default is to use integration time weighting. The alternative is to use none, variance , Tsys weighting or Tsys & integration time. ASAP> av = average_time(q, weight='tintsys') . ... ASAP> msk = scans.create_mask([200,400],[600,800]) ASAP> av = average_time(scans, mask=msk, weight='var') . ...

STScI Preprint #1193 . Authors: Daniel Schaerer 1 , William D. Vacca 2 3 Using the latest stellar evolution models, theoretical stellar spectra, and a compilation of observed emission line strengths from Wolf-Rayet (WR) stars, we construct evolutionary synthesis models for young starbursts. ... Our models predict that nebular He II 4686 emission from a low-metallicity starburst should be associated with the presence of WC/WO stars and/or hot WN stars evolving to become WC/WO stars. ...

... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

... Posts tagged ?component separation? ... I happened to observe a surge of principle component analysis (PCA) and independent component analysis (ICA) applications in astronomy. The PCA and ICA is used for separating mixed components with some assumptions. ... Such assumptions allow to set dissimilarity measures and algorithms work toward maximize them. ... ArXiv] component separation methods? Tags: component separation , ICA , maximum entropy , PCA . ... 2 Comments . ... Entries RSS . ...

THE PARAMETERS INVOLVED IN HAPKE'S MODEL FOR ESTIMATION OF THE COMPOSITION OF THE EJECTA LUNAR TERRAINS. ... In the previous papers we were estimated the surface roughness of the ejecta lunar terrains by means comparison of the local phase function and the average integrated lunar indicatrix. ... The Hapke's theoretical model of the lunar surface reflection. ... For THE PARAMETERS INVOLVED IN HAPKE'S MODEL: S.G. Pugacheva, V.V. Shevchenko a low-albedo lunar surface parameter Bo = 1. ...

Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...

... There is an opportunity to perform O-C calculations for objects which are absent in the data base of the package. Such objects can be described by orbital elements or by initial coordinates and velocities. ... On pressing Edit file button user has a possibility to look through the list of object elements or their coordinates and velocities to add or to change it. ... For example, the designations of objects in the list can occupy the last position in each line. ...

... Science User Portal . ... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... Travel to E-ELT Armazones . ... Survey Telescopes . ... Star Clusters . ... Stars@ESO . ... ESO Science Newsletter . ... ESO 3.6-metre telescope . ... MPG/ESO 2.2-metre telescope . ... Observed separations between the primary star GQ Lupi and its companion, as deduced from the images taken with HST in 1999 (left), Subaru in 2002 (middle) and NACO on the VLT in 2004 (right). ...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

spaceweb@oulu.fi - last update: 20 September 1998, 2020 UT (RR) . Traveling Convection Vortex (TCV) is a name given to a specific type of daytime magnetic impulsive events observed by high-latitude ground-based magnetometer arrays. Since the most likely source for TCVs is the solar wind , they are considered to be important processes in transfering energy from the solar wind into the magnetosphere . ... For example, one AMPTE Lithium release in the solar wind caused a TCV event . ...

... Galaxies 99 Cosmic background with model of cloudy interstellar medium Yu. ... Figure 1: Averaged spectrum of the cosmic background I f in frequency range 0.25 200 MHz for the Galactic poles. ... First interpretation of the cosmic noise background spectrum at broad band frequency range 0.25 200 MHz with a model of the cloudy interstellar medium ISM is presented here. ... Synthesized background spectra I f for regions of the Galactic poles at the frequency range 0.25 200 MHz is presented in Fig. ...

... The Stellar Oscillations Network Group (SONG) seeks to study p-mode (acoustic) oscillations in solar type stars. ... The observation of many solar-like stars will also help us to understand how solar p-modes are excited and damped. ... Naively, the two or three orders of magnitude improvement over this provided by the normal 1 second time resolution of the KPNO CCD cameras should be quite sufficient for such a detection. ... Figure: Non-cadenced data-a free-running observing sequence. ...

IFP gallery SCORPIO (since 2000). Here some data observed on the 6m telescope with IFP installed in the SCORPIO focal reducer are presented. ... Velocity field . Mkn 1157 was observed 1 Sep. 2002 in the Ha emission line. Texp =32x240 sec, seeing 1.5", IFP260. ... This galaxy was observed September, 23 2000 in the Ha emission line, Texp=32x120 sec, seeing 2.5", IFP260. ... PV Cep was observed at the 6m telescope in May, 25 2003 in the [SII] 6716A with IFP501, Texp=36x200 sec, seeing 1.0". ...

... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...

Next: Reduction procedure Up: Extinction and transformation Previous: Strategy . Standard stars can be included in the extinction solution, if one is careful. The problem is that there are usually appreciable ``conformity errors'' due to mismatch between the instrumental and the standard passbands [ 16 ]. ... Thus, it is wrong to assume that the transformation between the instrumental system and the standard system is exact, even if there were no measurement error in either system [ 1 ]. ...

The problem of solar wind data correlation for the observations onboard several spacecraft is very important for three points of view: . ... This problem is studied now in detail by systematic determination of ion flux and ion velocity data correlations by INTERBALL-1 (IKI group), WIND and IMP 8 (both - MIT group). ... Solar wind plasma correlation lengths from IMP 8, WIND and INTERBALL-1. ... Correlation of solar wind observations onboard several spacecraft: INTERBALL-1, IMP 8 and WIND data. ...

... 1s2.2s . ... 462743.56 . ... 701829.38 . ... 1.05e-01 . ... 1.00e+00 . ...

Astronomers at Armagh Observatory observed the partial eclipse of the Sun on 29 March under unusually good conditions. ... The images, taken by astronomer Miruna Popescu, shows the eclipse as seen from the Armagh Observatory at around 11:30 (Summer Time) on 29th March, and the way it was observed by astronomer Apostolos Christou with a small portable telescope equipped with a filter to protect against the Sun's dangerous radiation. ... For more images from Armagh see: Miruna Popescu's Pages . ...

... A1 centered at 2500 angstroms with a width of 1200 angstroms . ... M63 or NGC 5055 is a pleasant spiral galaxy with multiple arms and a bright inner region. The exposure times were 1149 seconds through B1 and 576 seconds through A1. NGC 752 a galactic stellar cluster was observed for 777 seconds through B5 . ... NGC 1365 is a prominent spiral galaxy in the Fornax Cluster. ... The galaxy fits comfortably into one UIT frame and this exposure was for 1360 seconds through A1 and B1. ...