Next: Catalog Construction Up: Observations and Analysis Previous: Source Detections . ... It was assumed that the highest signal gives the most likely position of the source. ... Comparing the summed map with the maps from the individual energy ranges, the one which produced the smallest error box was chosen to represent the source position, as long as was greater than 4, a level chosen to reflect a reasonable degree of confidence in the detection. ...

True Color Image Gallery: Galactic SNR | Magellanic Cloud SNR . ... Description: large, diffuse, X-ray and radio brighter in northern half . Radio . ... Radio Images Page . ... Exposure uf . ... Exposure uf Exposure time of unfiltered event file . Exposure f Exposure time of filtered event file . ... Event 2 FITS File . ... AUX file . ... 0.3 - 10.0 . ... see fit detail page for more about the fit. see chandra spectrum page for region used. ... True Color Image . ... Radio Images . ...

... Meta Index / Home Page This section documents warnings and errors generated by this task (if any). ... The value of the INSTRUME keyword of the event list was not one of the XMM EPIC instruments. noSourcesSelected . ... None of the sources in the input event list passed the filter specified by expression . ... The present error occurs if any value of the integer specified in this column occurs more than once (in the filtered source list). badIdBand . ... The task couldn't work out the source energy....

In this section we present plots which may be used to rapidly estimate signal-to-noise ratio (SNR) for point sources with stellar spectra observed through popular WFPC2 filters. ... One uses these plots as follows: . ... Dotted lines across the top of each plot indicate the onset of saturation. ... We look at Figure B.10 and find this value on the horizontal axis. ... This exposure is well below the saturation lines in the plot, so saturation is not a concern. ... 0.45 Figure B.1: Point Source SNR vs. ...

... Miriad has a couple of tasks available for finding positions of sources (see also cgcurs in Chapter 17 ). ... It fits a 2-D parabola to the image intensities in a 3 by 3 pixel box centred on the brightest pixel in a specified region and reports the fitted location and intensity. ... Input image . ... The quality of your fit can improve significantly by selecting a snug region, and/or using the clip keyword to keep pixel values with little signal (e.g. sidelobes and noise) out of the fitting process....

... Next: The PROS Big Up: Software Systems Previous: Data Reduction Software . ... The srcinten task provides PROS users with a tool to compute count rates for point sources in the ROSAT High Resolution Imager (HRI). ... Corrected upper limits are cited at locations where the count rate falls below the source detection threshold. ... Srcinten is a new PROS task that computes and applies the above correction factors to the net counts in a user-specified aperture. ...

... Luminosity (L) · · · · A source's luminosity is the power that it emits in radiation. ... NB Astronomers often say `flux' when they mean `flux density' · SI units are Wm-2Hz -1 -26 filter · Also used are Jy 10 Wm-2Hz -1 E= РРРF d dA dt Specific Intensity, Surface Brightness (I) · Specific intensity (or surface brightness) is the power received (or emitted) per unit area per unit frequency per unit solid angle. ч F at surface of a spherical source = I · · Specific intensity is independent of distance...

... Solar flare activity is produced by the processes of accumulation and release of energy in an active region. ... In the framework of study of solar active regions, producing powerful flares the researchers from the RATAN-600 radio telescope have detected sources with features in the form of a sharp drop in the intensity of polarized radiation in various parts of the recorded frequency range (2-16GHz), sometimes changing the sign of polarization. ...

Venus in visible light (violet filter) 17k jpg . Venus in visible light 73k gif . image from Pioneer Venus 15k jpg ; 28k jpg ( caption ) . ... UV image from HST WFPC2 (false color) 23k jpg ; 99k gif . ... New Magellan mosaics (5 hemispheres) 13500k tiff ; ( caption ) . ... 7 pancake volcanoes, alpha region 227k gif ; . Lada Regio, 47 deg S, 25 Long, showing mountains and craters 121k gif ; . ... False color IR image of Venus' lower clouds as seen by Galileo 37k jpg 112k gif ( caption ) . ...

Venus in visible light (violet filter) 50k gif ; 25k jpg . ... image from Pioneer Venus 15k jpg ; 28k jpg ( caption ) . ... 7 pancake volcanoes, alpha region 227k gif ; 327k jpg . ... Lada Regio, 47 deg S, 25 Long, showing mountains and craters 121k gif ; 321k jpg . ... Gula Mons and Cunitz crater, flat image of gulacun.gif 250k gif ; 178k jpg . ... Crater Farm, Lavinia Region, small 107k gif ; 147k jpg . ... Central Ovida region, 1 deg s by 83 deg 191k gif ; 531k jpg . ... Pictures .. ... Venus .. ...

... comparison of the system performance for alfa and lbw at OH (.ps) ( .pdf ) (no amps in) . comparison of the system performance for alfa and lbw at OH (.ps) ( .pdf ) (with amps in) . ... On 01apr05 the system performance was measured using the continuum source CTA21 (B0316+162. ... The plots show the comparison of the system performance for alfa and lbw at OH (.ps) ( .pdf ) (no amps installed). ... Black is polA, red is polB. ... G/T alfa)/(G/T lbw) . ... The polB/polA performance ratios are: . ...

... 172 ] Briefly, the count rate at the detector from a source at a redshift z is . ... Figure 55 shows the ``Green functions'' for the double compact binary merging rate   evolution assuming no collapse anisotropy. ... Another way that diverse peculiarities in the - distribution induced by the sources evolution could arise is connected with a possible non-monotonic character of the star formation rate in galaxies. ... 22 ] Figure  56 shows two-dimensional cuts through the parameter space. ...

... Near-IR broad-band imaging of V1318 Cygni reveals the presence of two distinct stellar components oriented north-south, a result recently reported by Aspin et al. ... The distribution of the high density molecular gas traced by the CS J emission is highly concentrated around V1318 and V1686 Cygni, while the total column density of gas traced by the J shows a ridge morphology centered on these sources. ... A molecular outflow has been detected in CO J . ...

... One striking feature is a small source of almost pure H 2 line emission, which is located near one of the compact sources in Orion reported by O'Dell and collaborators (HST-18 = 203-504). ... H-H objects, Proplyds, Orion Bar, H 2 . ... We obtained a series of images across the bright rim of the Orion Bar near the peaks of mm-wave molecular line emission with NICMOS cameras 1-3 (NIC1, NIC2, NIC3) in several filters on 1998 February 18. ... The suggestion of an H-H object does not seem compelling. ...

... Energy . ... Solar Wind . ... Field . ... The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. For some reason the field slows down the flow of heat from the Sun's interior and keeps sunspots slightly cooler than their surroundings. ... Solar Eclipses . ...

... LABORATORY OF RADIO ASTRONOMICAL OBSERVATIONS . Radio sources identification is one of the most important tasks of the current radio astrophysics. ... Optical idetification. ... Optical identifications of subsample of steep spectra radio sources from RC catalog using 6m SAO telescope of SAO RAS: optical observations. ... Astronomy Reports. ... Identification of radio sources with data of various radio catalogs allows one to construct continual spectrum of the object and its radio structure. ...

... Flux Sign Expo . ... 0.13 PHA . ... The map above is movable . ... Original shows mosaics with all data available. Flux map Error map Significance Exposure . Flux and error maps are in mCrab units. All maps are convolved with instrumental point spread function (PSF) which is Gaussian ( =5'). Exposure maps are in ksec. INTEGRAL/IBIS 9-year Galactic Hard X-Ray Survey* , A , Volume 545, id.A27 { NASA ADS | ... 7-year Galactic Bulge map , 2009 . 9-year Galactic survey , 2012 . ...

... Data Reduction FAQ > A number of OmegaCAM filters show vignetting in their central regions. What are the causes for this and what are the dimensions of these features? ... Observing with ESO Telescopes . ... ESO-MIDAS . ... ESO Data . ... ESO HST Image Galleries . ... ESO Data Access Policy . ... ESO Science Newsletter . ... A number of OmegaCAM filters are not monolithic, but consist of four segments (each covering 8 detectors) that have a central cross-shaped support structure. ... Filter . ...

. Comment on J1239-1023 . No image is shown by Dallacasa et al. (1998) as they did not find the VLBI structure at 2.3 and 8.4 GHz prominent, just dominated by a compact region barely resolved in position angle about -45 . In our case the source is well resolved, with a jet pointing to the W-NW direction, in agreement with what is seen in the images at 2.3 and 8.4 GHz from the VLBA Calibrators database. VLBApls home page . Last modified: 16 Oct 2000

Star formation is often best manifested by bright H II regions.These are regions of hydrogen which have been ionized by ultraviolet photons which are emitted from massive stars (typically stars more than 20 times the mass of the Sun). ... A narrowband filter image centered on this wavelength will then readily reveal these H II regions and hence the current sites of star formation in a galaxy, The luminous blobs that can be seen here are all H II regions . ... NGC 3558 Visual . NGC 3558 Infrared . ...