... We demonstrate through numerical simulations that model parameters estimated with our technique are essentially bias-free, even when the average number of counts per bin is 1. ... The IW technique avoids such biases by estimating through successive iterations, where for each iteration, j, , and the best-fit parameters are determined by minimization of . ... In our sample, we find that the minimum values and best-fit parameters converge after about 6 iterations. ...

Some peculiarities of orbits of observed comets. ... Icarus, 2005 Simulation and reality Distribution of anti-perihelia of short-period comets with e 0.9 ( ecliptic coordinates ) Distribution of anti-perihelia of short-period comets with e 0.9 ( ecliptic coordinates ) Distribution of anti-perihelia of long-period comets with 0.9 e 1 ( ecliptic coordinates ) ­ ...

Next: Simulations Up: Maximum Likelihood Estimation of Previous: Introduction . The properties of an ensemble of faint galaxies can be defined by the distribution of the parameters of the models that best fit each individual object. ... The model also includes instrumental parameters, such as the sky background (estimated locally) and amplitude of the noise. ... The probability of the observed value is then computed for each pixel using the adopted error distribution. ...

EPIC MOS response Steve Sembay, R.D. Saxton 10 December 2004 1 CCF components Name of CCF VALDATE EVALDATE Blocks changed XSCS ag EMOS1 REDIST 0043.CCF 1999-12-10 2000-07-15 CCD REDISTRIBUTION-n NO EMOS1 REDIST 0044.CCF 2000-07-15 2000-11-09 CCD REDISTRIBUTION-n NO EMOS1 REDIST 0045.CCF 2000-11-09 2001-04-18 CCD REDISTRIBUTION-n NO EMOS1 REDIST 0046.CCF 2001-04-18 2001-08-18 CCD ... This release contains a new set of CCFs which enable rmfgen to generate the correct rmfs. ...

... Posts tagged ?BEHR? ... A great advantage of Bayesian analysis, they say, is the ability to propagate the posterior. That is, if we derive a posterior probability distribution function for a parameter using one dataset, we can apply that as the prior when a new dataset comes along, and thereby improve our estimates of the parameter and shrink the error bars. ... Suppose you have two data sets, D1 and D2, hypotheses H, and background info (model, etc.) ... Comment . ... 7 Comments . ...

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. ...

... 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. ...

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... Fit Teff, theta and E(B-V) to IUE spectrum and uvby photometry using a grid of helium-rich model flux distributions. models{ . ... simon/models/01980001/19325he90L.s . simon/models/01980001/20325he90L.s . simon/models/01980001/21325he90L.s . simon/models/01980001/22325he90L.s . simon/models/01980001/23325he90L.s . simon/models/01980001/24325he90L.s . simon/models/01980001/25325he90L.s . simon/models/01980001/26325he90L.s . ... IUE data file in "spectrum format 2" . ...

... CentralProcessor 0.11 documentation . TCPSink task sends data via socket to vispublisher which further distributes a selection of data to user clients such as vis and spd. ... Due to the shear amount of data we do not expect that this task can be scaled up to full ASKAP. ... Also note that this task can only be used for a single data stream. ... This section describes the valid parameters. ... The type of the task defined by tasks. name .type should be set to TCPSink . Parameter . Type . ...

Toward a Quantitative Interpretation of MidIR Spectra of Galaxies B. Nikolic (NRAO), P. Alexander (Cambridge), M. Clemens (Padova), D. Ford (Cambridge), G. Cotter (Oxford), M.S. Longair (Cambridge) The Method Starburst99 + Comprehensive dust model + Simple radiative transfer Allows investigation of the effects of starburst age, metallicity, IMF etc. ... Appropriate for midIR models since only UV/optical photons are important in exciting the emission. ...

... We cannot use for this purpose equivalent widths and profiles of HI lines (well known criteria of atmospheric conditions for normal supergiants), since these lines are strongly distorted in the spectrum of IRAS04296 as seen in Fig. ... Figure: Upper: iron abundance FeI (circles) and FeII (crosses) calculated for IRAS04296+3429 with model parameters , and using lines with different excitation potentials EP of a low level; bottom: the same as a function of the equivalent width W . ...

Next: The Newton--Raphson Method. Up: Fitting of Data Previous: Fitting of Data . ... In a linear problem, if the errors on the observations have a gaussian distribution, the ``Maximum Likelihood Principle'' gives you the ``best estimate'' of the parameters as the solution of the so-called ``Least Squares Minimization'' that follows: . ... A certain number of numerical methods have been developed to solve the non--linear least squares problem, four have so far been implemented in MIDAS. ...

... Of the 4 buttons in the bottom part of the configuration screen, three deals with power level adjustments: the 'Power control' button brings up the power control window where You can adjust the power levels of the different parts of the IF/LO system, the 'Power levels' button brings up the power level monitoring window (which also can be run outside CIMA as the 'powerwin' program), and the 'Adjust Mock power' button which adjusts the power levels on the Mock spectrometer (but nowhere else). ...

Astronomy Picture of the Day . ... 31.05.2015 . ... Credit Copyright: High-Z Supernova Search Team , HST , NASA Explanation: Long ago, far away, a star exploded. Supernova 1994D , visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526 . Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae . ... Publications with keywords: supernova - cosmology . ... A Supernova through Galaxy Dust . ...

Probing weak NeVIII absorption with `agnostic stacking' of COS data Stephan Frank (OSU), Matthew Pieri (LAM), Charles Danforth (Colorado), and Smita Mathur (OSU) IGM@50 Abbazio di Spineto, Italy 2015 Abstract Utilising the largest available high-quality COS dataset towards quasars at redshifts z>0.7, we probe weak NeVIII absorbers to an unprecedented low column density limit (log N > 12.3) via a new method (`agnostic stacking'). ... 2 An example of fitting the non-NeVIII absorption. ...

PHOTOMETRIC SEARCH FOR BLACK HOLES IN DORMANT X-RAY TRANSIENTS ґ ґ Aleksander Sadowski1 , Janusz Ziolkowski2 , and Krzysztof Belczynski3 ё Astronomical Observatory of Warsaw University, Al. ... Such definition means that our statistics for the number of expected BH X-ray binaries include both transient and persistent systems. ... If this value is 2 M , then, according to our calculations, Galaxy contains some 15 000 to 40 000 of BH X-ray binaries (and some 30 000 to 250 000 of NS X-ray binaries). ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2015 May 31 . Supernova 1994D and the Unexpected Universe . Image Credit: High-Z Supernova Search Team , HST , NASA . Explanation: Long ago, far away, a star exploded. ... Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae . ... About APOD | ...

. N OTE: . Only clusters with R<60 kpc were used to compute the spatial parameters and metallicity gradients for all subsystems except the corona. The numbers in parantheses give the number of clusters for which the corresponding parameter is known. The X O scale length of the old halo is strongly distorted by the observed asymmetry of the distribution of the corresponding clusters projected onto the XY plane ( Fig. 4А ) . discussion in the text | previous table .

... INSTRUMENT: SurveyCam FILTERS: Stromgren uvby, 2" square COMMENTS: remote observations are expected BRIEF SCIENCE JUSTIFICATION: Last decade numerous faint structures at the periphery of regular galaxies, as arcs, tails, or streams, have been discovered (see e.g. Martinez-Delgado et al., ... The broad-band photometry is used for observing the faint structures, but it does not allow to break the age-metallicity degeneracy efficiently. ... The standard Stromgren set is available at APO. ... 2014). ...