The silicates that produce the 10 and 18 micron features appear to be broadly similar to terrestrial minerals such as Forsterite and Enstatite. ... Where pre-solar silicate dust grains can be isolated from meteorite material, these also tend to be Mg-rich silicates rather than Fe-rich silicates. ... It has been suggested that the interstellar silicate grains have a different 10 micron feature profile than what is observed for the silicates around evolved stars. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... The variability of the spectrum of the optical component of the IR-source IRAS01005+7910 was discovered for the first time in the BTA spectra [1]. ... The spectral features include absorptions that form in near-photospheric layers, narrow envelope emissions, and emission-absorption profiles that form in photosphere-to-envelope transition layers (the wind). ... Discovery of spectral variation in the optical counterpart of IRAS01005+7910. ... Dashed line - envelope curve of all the SiII 5979 profiles ...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... In this first example, we allow an object to fall onto a small radar unit . The resulting Time-Frequency distribution is shown as a contour plot in Fig. 8 (a). Figure: FIGURE GOES SOMEWHERE IN THIS GENERAL VICINITY . ... Its density plot appears as an image in Fig. ... The response has a very high peak, as evidenced from Fig. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2013 October 14 . High Noon Analemma Over Azerbaijan . Image Credit Copyright: Tun Tezel ( TWAN ) . Explanation: Is the Sun always straight up at noontime? ... Pictured above is one such high noon analemma -- a series of pictures always taken at exactly noontime over the course of a year. ... About APOD | ...

Next: A New IRAF Catalog Access Tool for Astrometry . Up: Iraf Packages . ... Twofitlines is a tool developed within IRAF, optimized to be used with data containing multiple spectra along the spatial axis of the detector. A given spectral feature can be decomposed in one or several Gaussian components. ... A given spectral feature can be modeled using one or more components (currently only Gaussian profiles are available), . ... Close spectral features could be modeled simultaneously. ...

Next: Radial velocity of the Up: Optical spectrum of IRAS04296 Previous: Observations and spectra reduction . ... However, molecular emission features are only very rarely observed in the optical spectra of PPNe. ... On the other hand, it is well known that cometary nuclei spectra show prominent Swan band emission. In both spectra of IRAS04296 we have discovered strong emission in the (0;0) and (0;1) bands of the Swan system of the molecule. ... Now consider the case of IRAS04296. ...

... A concrete application is displayed step by step by the command: TUTORIAL/CLOUD . The data used for this example are CaII absorption features observed in the spectrum of SN 1986g in NGC 5128 (observer: S. d'Odorico, instrument: CASPEC). ... Sampling is 0.05? per pixel and the measured instrumental resolution, 17km/s. The final cloud model consists of 12 absorption doublets. The corresponding image includes both components K and H and has been convolved by a gaussian PSF of 0.22? (17km/s) FWHM. ...

Statistical methods and HI in the Magellanic Bridge Erik Muller ATNF Preamble Using numerical simulations to assist in the interpretation of observational data. ... Numerical simulations of the Mag. ... Some statistical methods for HI · Spatial Power spectrum (SPS) · Spectral Correlation Function (SCF) The Magellanic System. ... N-Body Numerical simulations High velocity spur SMC LMC SMC Wing Peak intensity, RA-Vel [K] (Bruns 2003 ­ Parkes data only) Some conclusions from SPS 1. ...

... While Sfit accepts input from "stdio", it is more natural to save/edit commands in a file (eg "solve_input.sfit") and run the code simply by entering > Sfit solve_input.sfit [linelist] . ... The model grid (3.4MB) produced by Example 1 and a selection of input spectra ( f008 f036 f068 f304 f354 ), together with SFIT output files are also given in this folder . ... The model grid (2.8MB) produced by Example 3 and an input spectrum together with SFIT output files are also given in this folder . ...

XMM-Newton CCF Release Note XMM- CCF -REL-171 RGS Instrumental Flourine Absorption A.M.T. Pollock June 24, 2004 1 CCF components Name of CCF VALDATE List of Blocks changed XSCS ag RGS1 EXAFS 0004 1999-01-01T00:00:00 MgF2-P-CCD1 NO MgF2-P-CCD2 MgF2-P-CCD3 MgF2-P-CCD4 MgF2-P-CCD5 MgF2-P-CCD6 MgF2-P-CCD7 MgF2-P-CCD8 MgF2 ... Identical RGS1 and RGS2 data were analysed with response matrices with and without improved instrumental absorption by MgF 2 provided by the new RGS EXAFS CCFs. ...

These are very prominent absorption lines is most all galaxies. ... These pair of absorption lines will appear in all the spectra and they should be your principle source for determining the redshift. ... When this applet opens you will see an iconic representation of galaxies in the left hand side of the applet and a target area in the right side of the applet. ... Note: What you are doing in this excercise is identical to what Hubble did in the 1920's and you are using the same galaxies. ...

... Archive for May 2009 . ... As discussed in systematic errors, astronomers, like physicists, show their error components in two additive terms; statistical error + systematic error. ... Continue reading ?[ ... Tags: additive , bias , law of total variance , MADS , mathematical statistics , mean integrated square error , mean square error , MISE , mse , probability theory , variance . Category: Algorithms , Data Processing , Jargon , News , Stat , Uncertainty | Comment . ... Category: Misc | ...

... A rare type of galaxy known as a Polar Ring, NGC 4650A is composed of an old central group of stars and a young ring of stars rotating farther out. ... Dust usually shows its presence by blocking out light emitted from stars or nebulae behind it, sometimes creating the illusion of a horse's head or a sombrero hat. ... Moon Occults Saturn . ... On September 18, 1997, many stargazers in the U. S. were able to watch a lovely early morning lunar occultation as a bright Moon passed in front of Saturn. ...

... Data Reduction FAQ > The reduced science spectrum displayed in the Reflex window appears good but when I try to plot it, it is quite different. How can I get it? ... Observing with ESO Telescopes . ... ESO-MIDAS . ... Reflex . ... ESO Data . ... ESO HST Image Galleries . ... ESO Data Access Policy . ... ESO Science Newsletter . ... ESO Annual Reports . ... Seminars at ESO Santiago . ... Seminars at ESO Garching . ... ESO Telescope Bibliography . ... Last Update: 01.04.14 ESO . ...

Classroom Activity: Making a Rainbow . ... When white light from the Sun or a light bulb passes through a prism, the light splits into its component wavelengths. ... Red, blue, green colored filters - if possible, cut 1x4-inch pieces of the filters for each student . ... Many students have the misconception that filters somehow dye the light a certain color. ... Younger students can draw the rainbow and make up a mnemonic for remembering the order of the colors (such as, ROY G. BIV). ...

Next: Ejectors in Massive Binary Previous: Artificial Galaxy: Full Matrix . The first version of the Scenario Machine was aimed especially at the simulation of massive binary star evolution. ... First, there is a large class of intermediate mass binaries (say, consisting initially of 8 + 5 solar masses) that can also produce NS and thus lead to the formation of a bright X-ray source. ... Next: Ejectors in Massive Binary Previous: Artificial Galaxy: Full Matrix Mike E. Prokhorov . ...

The idea of component-oriented programming is that in the course of implementation of various software projects a programmer (or a programmers team) accumulates a library of reused software fragments that are used in different projects. ... To solve such problems there are some special syntax means in Actor Prolog that support component-oriented programming. ... A package in Actor Prolog is a set of classes linked by implication. ... Actor Prolog supports visual component-oriented programming. ...

... Bojan Nikolic web pages (r. 329) . ... SCons user manual http://www.scons.org/doc/1.2.0/HTML/scons-user/book1.html . SCons man page (on web at http://www.scons.org/doc/HTML/scons-man.html , or man scons ) . ... SCons is a tool to build compile source code into (closer-to) executable format. ... Curiously, the shared-library SCons builder will accept multiple identical sources and pass them all to the linker, which will normally lead to ?multiple definition? errors. ... Introduction to SCons . ...