... Archives . ... Reduced and Processed Data . ... 2 distribution plays an incredibly important role in astronomical data analysis, but it is pretty much a black box to most astronomers. ... Comment ( RSS ) | ... I guess in the typical analysis we call chi2 a ?random variable? that follows the chi2 distribution: . ... where D(i) is the observed data, M(i) is the model predicted data and we ?silently? assume that D(i) is normally distributed and each i measurement is independent. ... Chandra Blog . ...

Next: Code II: Unknown Up: Image Restorations of High Previous: Construction of Algorithms . ... The positions of the designated point sources ( ) must be given as well as initial amplitudes for and . ... The integrated flux of the point sources ( ) plus that of the distributed emission ( ) is constrained to equal that of the observed image ( ). ... This is investigated in Fig. 1 where all emission derives from point sources but only one - the brightest - is designated as such. ...

... Using the central limit theorem, the total noise can be approximated by a Gaussian or normal distribution which has the frequency function : . ... where is the mean intensity of the source. ... In the statistical analysis of the probability distribution of data several estimators based on moments are used. ... For a normal distribution, these moments are and while for a Poisson distribution are and . Besides these moments other estimators are used to describe a distribution e.g. median and mode . ...

... We can investigate projection of this distribution onto the celestial sphere in two ways: in terms of lines of constant SN frequencies per one square degree for all galaxies from the sample (Figure 36 ), and in terms of constant GW amplitudes at a given SN frequency per square degree (Figure 44 ). ... Figure 45: The sky distribution of the total supernova frequency from nearby galaxies in terms of lines of equal frequencies per square degree. ...

... CYGAM FLIGHT IN THE HIGH APOGEE ORBIT? Distribution of the Galaxy diffuse emission with high angular resolution allowing to refine the spatial distribution of the cosmic-ray protons in the Galaxy. More than 1000 compact sources with the fraction of degree location accuracy and continuouse monitoring of their flux time variation. Up to 10 new gamma-ray pulsars emitting in the very high energy range. Several high energy gamma-ray bursts with the fraction of degree localization accuracy. ...

... The task calculates an average RMF over the spatial region used to extract the source spectrum. ... Essentially a grid is placed over the source region and the redistribution parameters calculated at each point. ... By means of command line parameters the averaging may be performed assuming that the flux distribution is that of the point spread function (PSF), a flat uniform distribution or it may be defined explicitly by supplying the task with an image containing the source region. ...

... Summary. ... Subject of my Ph.D. thesis is the analysis and interpretation of the overall gas dynamics in the starburst galaxy NGC 1808, in comparison with other spiral galaxies in a similar evolutionary stage. ... c) nuclear outflow of neutral gas into the halo of the galaxy, . ... We have mapped the 21-cm absorption in the nuclear region of the starburst galaxy NGC 1808 using the VLA AnB-hybrid array with a resolution of approx. 5.2 arcsec (which corresponds to 275 pc). ...

HI Distribution in the Region . of the Supernova Remnant G78.2+2.1 ( 2001 ). ... Based on RATAN-600 21 cm line observations with an angular resolution of 2.4' over a wide range of radial velocities, we analyze the neutral-hydrogen distribution in the region of the supernova remnant (SNR) G78.2+2.1. ... The brightness distribution of H I features at a radial velocity of +10 km/s after an extended background in the region of the Cygnus X radio source and SNR G78.2+2.1 has bee subtracted. ...

2014 May version . ... Green D. A., 2014 , Bulletin of the Astronomical Society of India, 42 , 47-58. ( .pdf , or arXiv.org:1409.0637 ) If you make use of the detailed version of the catalogue, then plaese also cite: . Green D. A., 2014, `A Catalogue of Galactic Supernova Remnants (2014 May version)' , Cavendish Laboratory, Cambridge, United Kingdom (available at "http://www.mrao.cam.ac.uk/surveys/snrs/" ). ... Copyright D. A. Green 2014. 25872nd access to this version of the catalogue. ...

... The remote planet Pluto and its moon Charon orbit the Sun at a mean distance of almost 6,000 million kilometres, or nearly fourty times farther out than the Earth. During a recent investigation by an international group of astronomers [1], the best picture ever of Pluto and Charon [2] was secured with the European Space Agency's Faint Object Camera at the Hubble Space Telescope (HST). ... The new HST image was taken when Charon was near its maximum elongation from Pluto (0.9 arcseconds). ...

11 august 2014/Monday: Arriving, Registration . ... The variation of solar flare coronal X-ray source spatial properties. ... Melnikov V.F., Charikov Yu.E., Kudriavtsev I.V. Directivity of X-ray and gamma-ray emission from different parts of flaring magnetic loops. ... E., Melnikov V.F. Angular characteristics of polarization degree of hard X-ray emission from different parts of flaring magnetic loops. ... The thick target model and analytical calculations of the hard X-ray emission from solar flares. ...

Distribution of the analyzed SEPs with different >100 MeV proton fluxes ( J 100 ) at the microwave flux density plane ' S 9 vs. ... 1) General correspondence takes place between intensities of microwave bursts and proton fluxes - J 100 increases when S 9 and S 15 rise. ... 3) Powerful microwave bursts ( S 9 , S 15 >3000-10000 sfu ) with hard radio spectra ( S 9 < S 15 ) correspond to majority of powerful proton fluxes ( J 100 >10 pfu ). ...

Static Fourier spectrometers are often used for spectral measurements of the ionosphere emissions. There are two main advantages of Fourier spectrometers (FS) - large geometric factor and high spectral resolution; these parameters are two orders better than for grating spectral instruments. ... In scanning Fourier spectrometer optical and electric modulation of signal is used to avoid this problem, for static Fourier spectrometer there are no such ways. ...

Next: Calibration with the ISOPHOT Interactive Analysis (PIA) . ... ISO P HOT I nteractive A nalysis, PIA , is a scientific and calibration data analysis tool for ISOPHOT data reduction. The PIA software was designed both as a tool for use by the instrument team for calibration of the PHT instrument during and after the ISO mission, and as an interactive tool for ISOPHOT data analysis by general observers. ... PIA is entirely based on the Interactive Data Language IDL (IDL92). ...

... For SIMS (Secondary Ion Mass Spectrometry) analysis, a solid surface is bombarded by primary ions of some keV energy. ... The subsequent mass analysis of the emitted ions provides detailed information on the elemental and molecular composition of the surface. ... Extremely short ion pulses with a duration below . ... By rastering a fine-focussed ion beam over the surface, like an electron beam in an electron microprobe, mass resolved secondary ion images (chemical maps) can be obtained...

... arXiv.org . astro-ph . ... We fit the near-infrared to radio spectral energy distributions of 30 luminous and ultra-luminous infrared galaxies with pure starburst models or models that include both starburst and AGN components to determine important physical parameters for this population of objects. In particular we constrain the optical depth towards the luminosity source, the star formation rate, the star formation efficiency and the AGN fraction. ...

... Abstract: We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. ... As a general result, clumpy models are less opaque than the corresponding homogeneous models. ... 0.00 0.15 0.50 0.1 0.5 1.0 2.0 5.0 10.0 0.25 X . ... We have also produced several homogeneous models, to compare to the clumpy models. ... Homogeneous and clumpy models with the same tauV have the same dust mass. ...

Gamma-rays from the GC . M.Chernyakova (DIAS), D.Malyshev (DIAS), F.Aharonian (DIAS, MPIK), R.M.Crocker(MPIK), D.I.Jones(MPIK) 1 10°x10° Count and TS maps (>300 GeV) Gamma-rays from the GC 2 TS maps of the GC at different energies 300 MeV ­ 3GeV 3 GeV ­ 30 GeV 30 GeV ­ 300 GeV Gamma-rays from the GC 3 4 Gamma-rays from the GC Lightcurve 5 Gamma-rays from the GC Source spectrum Model X-ray and low-energy emission come from the central object, probably SMBH accretion disk. ...

At Arecibo we have a variety of optical instruments that we use to study terrestrial airglow emissions. ... As a complement to the airglow instrumentation we also maintain a set of optical instruments, called lidars, used for "active" remote sensing of the atmosphere. That is, we generate our own source signal using lasers and measure the characteristics of the light scattered back from the atmosphere. ... An operations manual for the Optical Laboratories is currently under major revision. ...

... Far from a smooth distribution, Abell 2744 not only has knots of galaxies, but the X-ray emitting hot gas (colored red) in the cluster appears distributed differently than the dark matter. ... An expansive nebula of dust is seen to surround red supergiant star Betegeuse in this remarkable high resolution composite, an infrared VLT image from the European Southern Observatory. ... It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula. ...