Next: References Up: RGS_EFFAREACORR Previous: Ground calibration Contents . EFFAREACORR correction factors are assumed to result from two effects . ... absorption by contamination on the CCD surfaces. that are analysed with a combination of observations of power-law spectra, particularly of Mkn421, and sources assumed to be constant, namely RXJ1856.6-3754 and the Vela PWN, in which the observed changes are due to changes in absorption by the contamination layer. ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... PULSE@Parkes . ... The project does not assume any detailed prior knowledge of pulsar astronomy though students should have studied astronomy as a component of Stage 4 Science (Years 7-8). ...

STIS Instrument Handbook for Cycle 24 . ... Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 24 > Chapter 13: Spectroscopic Reference Material > 13.8 MAMA Spectroscopic Bright Object Limits . ... MAMA Spectroscopic Bright Object Limits . ... For echelle observations, the global limit of 200,000 counts/s over the detector sets the magnitude limits, but you must also assure that your source does not violate the local limit, e.g., if it had a bright emission line. ... 1.61 . ...

The Chi-Square Goodness of Fit Statistic . This statistic enables us to test whether observed frequencies are close to . those we would expect. ... Expected frequencies . ... For example, if we . have an honest die we would expect 1/6 of all cases to show any of . ... So, for example, if we roll a die 60 times we would expect : . ... If we actually roll a die 60 times we wouldn't expect each of the faces . ... times each face actually comes up is the observed frequency for that face. ...

... Searching for Far Out and Wandering Worlds . ... The Real Reality Show: Would aliens be anything like us? ... The SETI Institute is after alien signals. Assuming another world is beaming a 1-million-watt radio signal in our direction, how far away can that source be before the signal is lost in intergalactic noise? ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ...

True Color Image Gallery: Galactic SNR | Magellanic Cloud SNR . ... Radio . ... Radio Images Page . ... Exposure uf . ... Exposure uf Exposure time of unfiltered event file . Exposure f Exposure time of filtered event file . radio pulsar . ... Click left mouse button on hyperlink below to download file . ... Event 2 FITS File . ... AUX file . ... see fit detail page for more about the fit. see chandra spectrum page for region used. Images in Several Energy Bands . ... Radio Images . ...

... The first task assumes the searching for chemical composition and sizes of particles which give the wavelength dependence of the extinction efficiencies close to the observed dependence of . Figure 7: Wavelength dependence of the extinction efficiency factors for homogeneous spherical particles of different sizes consisting of astronomical silicate and amorphous carbon. The dashed segment shows the approximate wavelength dependence of the mean galactic extinction curve at optical wavelengths. ...

... A glance at the article might leave you assuming that the planet was discovered using a large telescope at a remote, high-elevation location or perhaps by a multi- billion dollar observatory in Earth orbit. Reading on, you may be surprised to find that astronomers actually discovered the planet with a small telescope located not too far from the city of Tucson, Arizona. ... Well, don't give up, because you can observe interesting celestial sights near low-elevation big cities. ...

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. ...

IBIS Data Analysis . ... IBIS . ... Flat Fielding - Introduction . The images obtained by IBIS will have intensity variations across the field of view that are not due to the solar image, but rather caused by instrumental effects that alter the observed intensity in each point of the field of view. ... IBIS Flat Fielding Techniques . ... Therefore, it is desirable to obtain the flat field measurements center on a point along the equator near the heliographic center of the solar disk. ...

... THE DETAILS . ... proj> : This is just your project number (i.e. a9999) and it is used both for making the executable file name (a9999.exec) and for knowing the name of your .sls set-up files (assumed to be a9999.sls). start_lst(hh:mm) : The is the LST at which your observations will start. ... You tell the program which .sls file to use for a given observation by the target object's priority number -- a priority of 2 selects the "b" set-up file, while all other priorities select the "a" set-up file...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Figure 1: Dynamic spectrum of Jovian radio emission recorded by Cassini on October 21, 2000 (courtesy of W.S. Kurth, Cassini RPWS Team, University of Iowa). ... We investigate the formation of zebra-like fine spectral structures (consisting of several parallel bands in the dynamic spectrum) in the Jovian broadband kilometric radiation; such radio bursts were observed by Cassini in 2000/2001. ...

Mikhail Medvedev (University of Kansas) HEA- 2007 , IKI, Moscow Missing baryons in inter-cluster gas Afshordi, et al, 2007 , astro-ph/0612700 35% +/- 8% Sample of 260 clusters WMAP SZ 3yr data Compared with 11 simulated clusters Assumed: Universal NFW profile Self-similarity Isothermal gas Possible explanations Observed stellar mass in galaxies: ~ 10% (Lin, et al, ... Simulations indicate that the effect is small (Dolag, et al, 2004) Can account for ~1-2% missing mass at most ...

Next: Comments on Individual Sources Up: Sample Identification Previous: Sample Identification . In Figure 2, we show the spectra of the optical counterparts to 85 of 97 observed X-ray/radio sources. ... Positional information for all 85 sources for which we announce identifications herein are given in Table 3, including information from WGACAT, the PMN and Green Bank surveys, the NVSS and our ATCA survey. ... Of the 85 newly identified sources, 59 are FSRQs, and 22 are BL Lacs. ...

... Previous: Residual Bias Removal in HST NICMOS Images . ... Bias frames taken with CCDs should be homogeneous in intensity. ... Using a large number of bias frames obtained in one specific run, the time-dependent pattern was found to be built up of a fixed one-dimensional periodic function whose phase-shift varies from row to row. It was successfully removed from calibration and science frames through the use of pre- and upscan ``bias'' pixels available in each of these frames. ...

Figure 10. The circles show the thermal defocus corrections that were observed on August 15, 2000. These data were derived by combining the defocus measurements seen in Figure 6 with the thermal measurements of the truss seen in Figure 7. ... I then fit the thermal defocus data given by the circles above using only the thermal time constant and an arbitrary "zero-point" constant as fit parameters. ... M1 corresponds to a thermal time constant of 0.37 hours (22 minutes) for the rods. ...

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. ...

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 ]. ...

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 . ...

... 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. ...