SkyView Surveys

Energy vs Data Pixel Resolution plot of all SkyView Surveys

(Click for larger image)

Introduction

The table includes:

• The provenance of the data.
• The copyright status of the data.
• The spectral regime of the data.
• Number of surveys, i.e., typically the number of separate frequency bands in SkyView.
• The approximate frequency of the data. In addition to the frequency other indicators of the spectral range may be included (e.g., photon energy, wavelength, band).
• The coverage of the survey on the sky. All-sky indicates that the survey covers substantially the entire sky although there may be small patches not covered.
• Pixel scale. The angular size of the pixels. If only a single value is given then the pixels are assumed square.
• Pixel units. The units in which the intensity at the pixel is given.
• Resolution. A measure of the intrinsic resolution of the image. It may be greater or less than the pixel scale.
• Coordinate system. The native coordinate system of the survey as used in SkyView.
• Equinox. For data in Equatorial or Ecliptic coordinates, the equinox year of the coordinates.
• Projection. The native projection of the data.
• Reference. Reference to material giving further information on the survey.

Radio surveys
GTEE 0035 MHz Radio survey
Bonn 1420 MHz Survey
HI All-Sky Continuum Survey
4850 MHz Survey/GB6
CO Galactic Plane Survey
FIRST
Dickey and Lockman HI map
NVSS
Sydney University Molonglo Sky Survey
VLA Low-frequency Sky Survey
Westerbork Northern Sky Survey

Infrared surveys
Two Micron All Sky Survey (H-Band)
Two Micron All Sky Survey (J-Band)
Two Micron All Sky Survey (K-Band)
Cosmic Background Explorer DIRBE
Cosmic Background Explorer DIRBE Annual Average Map
Cosmic Background Explorer DIRBE Zodi-Subtracted Mission Average
IRAS Sky Survey Atlas: 100 micron
IRAS Sky Survey Atlas: 12 micron
IRAS Sky Survey Atlas: 25 micron
IRAS Sky Survey Atlas: 60 micron
Improved Reprocessing of the IRAS Survey: 100
Improved Reprocessing of the IRAS Survey: 12
Improved Reprocessing of the IRAS Survey: 25
Improved Reprocessing of the IRAS Survey: 60
Schlegel, Finkbeiner and Davis 100 micron survey
Schlegel, Finkbeiner and Davis Dust Survey

Optical surveys
Original Digitized Sky Survey
First Digitized Sky Survey: Blue Plates
First Digitized Sky Survey: Red Plates
2nd Digitized Sky Survey (Blue)
2nd Digitized Sky Survey (Infrared)
2nd Digitized Sky Survey (Red)
H-alpha Full Sky Map
Near-Earth Asteriod Tracking System Archive
Sloan Digitized Sky Survey G-band
Sloan Digitzed Sky Survey I-band
Sloan Digitzed Sky Survey R-band
Sloan Digitzed Sky Survey U-band
Sloan Digitzed Sky Survey Z-band
The Southern H-Alpha Sky Survey Atlas: Continuum
The Southern H-Alpha Sky Survey Atlas: Continuum-Corrected
The Southern H-Alpha Sky Survey Atlas: H-alpha
The Southern H-Alpha Sky Survey Atlas: Smoothed

Ultraviolet surveys
Extreme Ultraviolet Explorer: 83 A
Extreme Ultraviolet Explorer: 171 A
Extreme Ultraviolet Explorer: 405 A
Extreme Ultraviolet Explorer: 555 A
ROSAT Wide Field Camera: F1
ROSAT Wide Field Camera: F2

X-ray surveys
Swift BAT All-Sky Survey: Flux and Significance
GRANAT/SIGMA Flux
GRANAT/SIGMA
HEAO 1A
ROSAT High Resolution Image Pointed Observations Mosaic: Intensity
INTEGRAL/Spectral Imager Galactic Center Survey
PSPC summed pointed observations, 1 degree cutoff, intensity
PSPC summed pointed observations, 2 degree cutoff, counts
PSPC summed pointed observations, 2 degree cutoff, exposure
PSPC summed pointed observations, 2 degree cutoff, intensity
ROSAT All-Sky X-ray Survey Broad Band
ROSAT All-Sky X-ray Survey Hard Band
ROSAT All-Sky X-ray Survey Soft Band
ROSAT All-Sky X-ray Background Survey: Bands 1
ROSAT All-Sky X-ray Background Survey: Bands 2
ROSAT All-Sky X-ray Background Survey: Bands 3
ROSAT All-Sky X-ray Background Survey: Bands 4
ROSAT All-Sky X-ray Background Survey: Bands 5
ROSAT All-Sky X-ray Background Survey: Bands 6
ROSAT All-Sky X-ray Background Survey: Bands 7
ROSAT All-Sky Broad Band Intensity
ROSAT All-Sky Hard Band Intensity
ROSAT All-Sky Broad Band Intensity
RXTE Allsky 3-20keV Significance
RXTE Allsky 3-8keV Significance
RXTE Allsky 8-20keV Significance

Gamma ray surveys
CGRO Compton Telescope: 3 channel data
Energetic Gamma-Ray Event Telescope: 10 channel data
Energetic Gamma-Ray Event Telescope: Hard
Energetic Gamma-Ray Event Telescope: Soft

Radio surveys

Users should be aware that both the angular resolution and the sensitivity varies from region to region in the velocity-integrated map. The component surveys were integrated individually using clipping or moment masking in order to display nearly all statistically significant emission but little noise above a level of ~1.5 K km/s. See the reference below and the Millimeter-Wave Group site for more details

These FIRST data have been retrieved from the FIRST FTP archive at the Space Telescope Science Institute.

The FIRST survey is included on the SkyView High Resolution Radio Coverage map. This map shows coverage on an Aitoff projection of the sky in equatorial coordinates.

              Robert Becker,                                
              Physics Dept,                               
              University of California,                     
              Davis, CA  95616

The original 287x101 tiles had only 1 pixel overlap. To allow higher order resampling, the data were retiled into two hemisphere files of 1726x600 pixels with an overlap of 10 pixels.

The southernmost tiles were only 287x100 pixels. We assumed that bottom row of these tiles (as compared with the others) was truncated.

Observations for the 1.4 GHz NRAO VLA Sky Survey (NVSS) began in 1993 September and should cover the sky north of -40 deg declination (82% of the celestial sphere) before the end of 1996. The principal data products will be:

1. A set of 2326 continuum map "cubes," each covering 4 deg X 4 deg with three planes containing Stokes I, Q, and U images. These maps were made with a relatively large restoring beam (45 arcsec FWHM) to yield the high surface-brightness sensitivity needed for completeness and photometric accuracy. Their rms brightness fluctuations are about 0.45 mJy/beam = 0.14 K (Stokes I) and 0.29 mJy/beam = 0.09 K (Stokes Q and U). The rms uncertainties in right ascension and declination vary from 0.3 arcsec for strong (S > 30 mJy) point sources to 5 arcsec for the faintest (S = 2.5 mJy) detectable sources.
2. Lists of discrete sources.

The NVSS survey is included on the SkyView High Resolution Radio Coverage map. This map shows coverage on an Aitoff projection of the sky in equatorial coordinates.

The survey was completed in 2007. Please note that the images still contain some telescope artifacts. Images can also be obtained from the SUMSS Postage Stamp Server.

The SUMSS is intended to complement the NRAO-VLA Sky Survey (NVSS) which covered the sky between +90 and -40 deg declination, at a frequency of 1400MHz.

Further information on the survey including links to catalogs derived from the survey is available at the WENSS web site.

The WENSS survey is included on the SkyView High Resolution Radio Coverage map. This map shows coverage on an Aitoff projection of the sky in equatorial coordinates.

Infrared surveys

2MASS images and other data products can be obtained at the NASA/IPAC Infrared Science Archive

2MASS images and other data products can be obtained at the NASA/IPAC Infrared Science Archive

2MASS images and other data products can be obtained at the NASA/IPAC Infrared Science Archive

Detailed descriptions of the DIRBE, the data processing, and the data products are given in an Explanatory Supplement. A Small Source Spectral Energy Distribution Browser can be used to assess the visibility of an unresolved or small extended source in the DIRBE data and see its spectral energy distribution. As noted in section 5.6.6 of the Explanatory Supplement, the DIRBE Time-ordered Data are required to derive definitive point source fluxes.

These maps provide an estimate of the infrared intensity at each pixel and wavelength band based on an interpolation of the observations made at various times at solar elongations close to 90°.

These COBE DIRBE maps are a combination original ten band passes with the following wavelengths:

• Band 1 - 1.25 µm
• Band 2 - 2.2 µm
• Band 3 - 3.5 µm
• Band 4 - 4.9 µm
• Band 5 - 12 µm
• Band 6 - 25 µm
• Band 7 - 60 µm
• Band 8 - 100 µm
• Band 9 - 140 µm
• Band 10 - 240 µm

The default two dimensional array uses Band 8 (100 µm).

The COBE DIRBE/Annual Average Maps (AAM) is the cumulative weighted average of the photometry. This average is calculated using the weighted number of observations from each Weekly Averaged Map ( WtNumObs from the Weekly Averaged Map) as the weight, such that annual_average =sum( weekly_average * weekly_weight )/ sum( weekly_weight )

COBE DIRBE/Zodi-Subtracted Mission Average (ZSMA) Skymap represents the extra-Solar system sky brightness. It is the average residual map that results after the modelled interplanetary dust (IPD) signal is subtracted from each of the DIRBE Weekly Skymaps from the cryogenic mission. Individual weekly residual maps can be reconstructed from the data supplied in the DIRBE Sky and Zodi Atlas (DSZA).

Detailed descriptions of the DIRBE, the data processing, and the data products are given in an Explanatory Supplement. A Small Source Spectral Energy Distribution Browser can be used to assess the visibility of an unresolved or small extended source in the DIRBE data and see its spectral energy distribution. As noted in section 5.6.6 of the Explanatory Supplement, the DIRBE Time-ordered Data are required to derive definitive point source fluxes.

These maps provide an estimate of the infrared intensity at each pixel and wavelength band based on an interpolation of the observations made at various times at solar elongations close to 90°.

These COBE DIRBE maps are a combination original ten band passes with the following wavelengths:

• Band 1 - 1.25 µm
• Band 2 - 2.2 µm
• Band 3 - 3.5 µm
• Band 4 - 4.9 µm
• Band 5 - 12 µm
• Band 6 - 25 µm
• Band 7 - 60 µm
• Band 8 - 100 µm
• Band 9 - 140 µm
• Band 10 - 240 µm

The default two dimensional array uses Band 8 (100 µm).

The COBE DIRBE/Annual Average Maps (AAM) is the cumulative weighted average of the photometry. This average is calculated using the weighted number of observations from each Weekly Averaged Map ( WtNumObs from the Weekly Averaged Map) as the weight, such that annual_average =sum( weekly_average * weekly_weight )/ sum( weekly_weight )

COBE DIRBE/Zodi-Subtracted Mission Average (ZSMA) Skymap represents the extra-Solar system sky brightness. It is the average residual map that results after the modelled interplanetary dust (IPD) signal is subtracted from each of the DIRBE Weekly Skymaps from the cryogenic mission. Individual weekly residual maps can be reconstructed from the data supplied in the DIRBE Sky and Zodi Atlas (DSZA).

Detailed descriptions of the DIRBE, the data processing, and the data products are given in an Explanatory Supplement. A Small Source Spectral Energy Distribution Browser can be used to assess the visibility of an unresolved or small extended source in the DIRBE data and see its spectral energy distribution. As noted in section 5.6.6 of the Explanatory Supplement, the DIRBE Time-ordered Data are required to derive definitive point source fluxes.

These maps provide an estimate of the infrared intensity at each pixel and wavelength band based on an interpolation of the observations made at various times at solar elongations close to 90°.

These COBE DIRBE maps are a combination original ten band passes with the following wavelengths:

• Band 1 - 1.25 µm
• Band 2 - 2.2 µm
• Band 3 - 3.5 µm
• Band 4 - 4.9 µm
• Band 5 - 12 µm
• Band 6 - 25 µm
• Band 7 - 60 µm
• Band 8 - 100 µm
• Band 9 - 140 µm
• Band 10 - 240 µm

The default two dimensional array uses Band 8 (100 µm).

The COBE DIRBE/Annual Average Maps (AAM) is the cumulative weighted average of the photometry. This average is calculated using the weighted number of observations from each Weekly Averaged Map ( WtNumObs from the Weekly Averaged Map) as the weight, such that annual_average =sum( weekly_average * weekly_weight )/ sum( weekly_weight )

COBE DIRBE/Zodi-Subtracted Mission Average (ZSMA) Skymap represents the extra-Solar system sky brightness. It is the average residual map that results after the modelled interplanetary dust (IPD) signal is subtracted from each of the DIRBE Weekly Skymaps from the cryogenic mission. Individual weekly residual maps can be reconstructed from the data supplied in the DIRBE Sky and Zodi Atlas (DSZA).

The data are distributed in sets of 430 maps. Each map covers approximately 12.5x12.5 degrees, and the map centers are offset by 5 degrees so that there is a 2.5 degree overlap. IPAC has processed to a uniform standard so that excellent mosaics of the maps can be made. Users should be cautious of data in saturated regions. Known problems in the analysis mean that data values are unlikely to be correct. Note that IPAC has optimized the processing of these data for features of 5' or more although the resolution of the data is closer to the 1.5' pixel size.

There are occasional pixels in the IRAS maps which are given as NULL values. Unless these are explicitly trapped by user software, these data will appear as large negative values. SkyView ignores these pixels when determining the color scale to display an image.

Essentially the entire sky is covered by the survey. However there are a few regions not surveyed and the data values in these regions are suspect. These are given to users as delivered from IPAC.

The data are distributed in sets of 430 maps. Each map covers approximately 12.5x12.5 degrees, and the map centers are offset by 5 degrees so that there is a 2.5 degree overlap. IPAC has processed to a uniform standard so that excellent mosaics of the maps can be made. Users should be cautious of data in saturated regions. Known problems in the analysis mean that data values are unlikely to be correct. Note that IPAC has optimized the processing of these data for features of 5' or more although the resolution of the data is closer to the 1.5' pixel size.

There are occasional pixels in the IRAS maps which are given as NULL values. Unless these are explicitly trapped by user software, these data will appear as large negative values. SkyView ignores these pixels when determining the color scale to display an image.

Essentially the entire sky is covered by the survey. However there are a few regions not surveyed and the data values in these regions are suspect. These are given to users as delivered from IPAC.

The data are distributed in sets of 430 maps. Each map covers approximately 12.5x12.5 degrees, and the map centers are offset by 5 degrees so that there is a 2.5 degree overlap. IPAC has processed to a uniform standard so that excellent mosaics of the maps can be made. Users should be cautious of data in saturated regions. Known problems in the analysis mean that data values are unlikely to be correct. Note that IPAC has optimized the processing of these data for features of 5' or more although the resolution of the data is closer to the 1.5' pixel size.

There are occasional pixels in the IRAS maps which are given as NULL values. Unless these are explicitly trapped by user software, these data will appear as large negative values. SkyView ignores these pixels when determining the color scale to display an image.

Essentially the entire sky is covered by the survey. However there are a few regions not surveyed and the data values in these regions are suspect. These are given to users as delivered from IPAC.

The data are distributed in sets of 430 maps. Each map covers approximately 12.5x12.5 degrees, and the map centers are offset by 5 degrees so that there is a 2.5 degree overlap. IPAC has processed to a uniform standard so that excellent mosaics of the maps can be made. Users should be cautious of data in saturated regions. Known problems in the analysis mean that data values are unlikely to be correct. Note that IPAC has optimized the processing of these data for features of 5' or more although the resolution of the data is closer to the 1.5' pixel size.

There are occasional pixels in the IRAS maps which are given as NULL values. Unless these are explicitly trapped by user software, these data will appear as large negative values. SkyView ignores these pixels when determining the color scale to display an image.

Essentially the entire sky is covered by the survey. However there are a few regions not surveyed and the data values in these regions are suspect. These are given to users as delivered from IPAC.

More information about the IRIS dataset is available at the IRIS Web site whence most of the preceding description came.

More information about the IRIS dataset is available at the IRIS Web site whence most of the preceding description came.

More information about the IRIS dataset is available at the IRIS Web site whence most of the preceding description came.

More information about the IRIS dataset is available at the IRIS Web site whence most of the preceding description came.

Optical surveys

The following data are included:

Southern hemisphere

SERC Southern Sky Survey and the SERC J Equatorial extension. These are typically deep, 3600s, IIIa-J exposures with a GG395 filter. Also included are 94 short (1200s) V exposures typically at Galactic latitudes below 15°. Special exposures are included in the regions of the Magellenic clouds.

Northern hemisphere

The northern hemisphere is covered by 644 plates from the POSS E survey. A special exposure of the M31 region that is distributed on the CD ROMs is not used in SkyView .

The native projection of these data is described as a high-order polynomial distortion of a gnomonic projection using the same terms as the DSS.

The native projection of these data is described as a high-order polynomial distortion of a gnomonic projection using the same terms as the DSS.

SkyView has a copy of the compressed images which cover the entire sky. In previous versions of SkyView (prior to July 2007), this survey was served as a remote survey and data was retrieved in tiles from the ST ScI web site. Image generation using the local copy should be much faster at the SkyView web site. However data from this survey is not currently cached when it is used in the SkyView-in-a-Jar application so that data will be downloaded from the SkyView web site whenever an image is requested. Future updates to SkyView-in-a-Jar should address this caching issue.

The native projection of these data is described as a high-order polynomial distortion of a gnomonic projection using the same terms as the DSS.

Unlike most SkyView surveys, the NEAT data are extremely irregular in their spatial distribution. SkyView's algorithms for mosaicking images together to form large images are not adequate for the NEAT data, so mosaicking is surpressed. Only data within a single NEAT image will be displayed. The system attempts to find the most recent image within which has a offset in both RA and Dec of less than 0.8 degrees. If no such image is found, then an image with the minimum offset is returned, or the search may fail altogether if there are no nearby plates. The NEAT telescope uses an array of 4 CCDs. The backgrounds of the CCDs may differ significantly.

The NEAT survey covers approximately 30% of the sky. Extreme southern and low-Galactic latitude regions are unsurveyed. Coverage is otherwise particularly dense in the ecliptic plane.

NEAT data consists primarily of groups of three images taken with separations of 20 minutes and almost identical positions. SkyView will normally return the last of a 'triplet'. The SkyMorph site can be used to display an overlay of triplets to look for targets which moved during the interval between images.

A catalog of objects detected in the NEAT/SkyMorph pages is accessible through the SkyMorph pages. 'Light-curves' from all images during which an object was in the NEAT field of view can also be generated.

The NEAT data values are in arbitrary density units. To enhance the display data are transformed such that all pixels below the median values are scaled linearly to values 0-20, while all pixels above the median are shifted (but not scaled) to values greater than 20.

Ultraviolet surveys

• Lexan/Boron filter: peak at 83A (full range 50-180)
• Aluminium/Carbon/Titanium : 171A (160-240)
• Aluminium/Titanium/Antimony: 405A (345-605)
• Tin/SiO: 555A (500-740)

The data currently in SkyView is direct from the Center for EUVE.

• Lexan/Boron filter: peak at 83A (full range 50-180)
• Aluminium/Carbon/Titanium : 171A (160-240)
• Aluminium/Titanium/Antimony: 405A (345-605)
• Tin/SiO: 555A (500-740)

The data currently in SkyView is direct from the Center for EUVE.

• Lexan/Boron filter: peak at 83A (full range 50-180)
• Aluminium/Carbon/Titanium : 171A (160-240)
• Aluminium/Titanium/Antimony: 405A (345-605)
• Tin/SiO: 555A (500-740)

The data currently in SkyView is direct from the Center for EUVE.

• Lexan/Boron filter: peak at 83A (full range 50-180)
• Aluminium/Carbon/Titanium : 171A (160-240)
• Aluminium/Titanium/Antimony: 405A (345-605)
• Tin/SiO: 555A (500-740)

The data currently in SkyView is direct from the Center for EUVE.

X-ray surveys

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given.

The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky.

The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 E^-2.15 photons.cm²/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10^-11 ergs/cm²/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10^-11 ergs/cm²/s.

SIGMA discovered numerious interesting hard X-ray sources including GRS 1758-258, which is located only 40' from bright soft X-ray source GX 5-1. It detected hard X-ray flux from X-ray burster A1742-294, which is very near to bright black hole binary 1E1740.7-2942. SIGMA set an upper limit on the hard X-ray flux of from the central supermassive black hole in our Galaxy.

During the period 1990-1998 SIGMA observed more that one quarter of the sky with sensitivity better than 100 mCrab. The Galactic Center region had the deepest exposure ( approximately 9 million sec), with the sensitivity to a source discovery (S/N > ~ 5) or approximately 10 mCrab.

A list of all detected sources with references to publications on them is presented in the paper of Revnivtsev et al. 2004, Astr. Lett. v.6. In these survey images (40-100 keV) all performed observations are averaged together. Transient sources that were discovered by SIGMA may not visible in the averaged image.

This survey has some features that users should keep in mind. The SIGMA telescope is a complicated instrument and is strongly dominated by the accuracy of the background subtraction. The presence of a very bright source in the field of view of the telescope sometimes can not be fully accounted for and as a result of it some 'ghost' sources can appear. Such features can be seen in the regions near very bright sources like Crab Nebula, Cyg X-1, Nova Per 1992, Nova Mus 1991, Nova Oph 1993, and in the Galactic Center region. In addition to its nominal field of view (~17x17 deg) located around the optical axis of the telescope, SIGMA had another window of relatively high transparency of its shield, approximately 20-30° apart from the optical axis. Becuase of this a very bright sources like Cyg X-1 can cause non zero illumination of the SIGMA detector if they are located approximately 20-30° from the optical axis. The ring-like features caused by this effect, can be seen around Cyg X-1, and Nova Per 1992.

The count rate of detected sources (or upper limits) can be roughly translated into mCrab using the fact that that Crab nebula gives the count rate approximately 2.8e^-3 cnts/s in the units, provided in 'flux' maps

SIGMA discovered numerious interesting hard X-ray sources including GRS 1758-258, which is located only 40' from bright soft X-ray source GX 5-1. It detected hard X-ray flux from X-ray burster A1742-294, which is very near to bright black hole binary 1E1740.7-2942. SIGMA set an upper limit on the hard X-ray flux of from the central supermassive black hole in our Galaxy.

During the period 1990-1998 SIGMA observed more that one quarter of the sky with sensitivity better than 100 mCrab. The Galactic Center region had the deepest exposure ( approximately 9 million sec), with the sensitivity to a source discovery (S/N > ~ 5) or approximately 10 mCrab.

A list of all detected sources with references to publications on them is presented in the paper of Revnivtsev et al. 2004, Astr. Lett. v.6. In these survey images (40-100 keV) all performed observations are averaged together. Transient sources that were discovered by SIGMA may not visible in the averaged image.

This survey has some features that users should keep in mind. The SIGMA telescope is a complicated instrument and is strongly dominated by the accuracy of the background subtraction. The presence of a very bright source in the field of view of the telescope sometimes can not be fully accounted for and as a result of it some 'ghost' sources can appear. Such features can be seen in the regions near very bright sources like Crab Nebula, Cyg X-1, Nova Per 1992, Nova Mus 1991, Nova Oph 1993, and in the Galactic Center region. In addition to its nominal field of view (~17x17 deg) located around the optical axis of the telescope, SIGMA had another window of relatively high transparency of its shield, approximately 20-30° apart from the optical axis. Becuase of this a very bright sources like Cyg X-1 can cause non zero illumination of the SIGMA detector if they are located approximately 20-30° from the optical axis. The ring-like features caused by this effect, can be seen around Cyg X-1, and Nova Per 1992.

The count rate of detected sources (or upper limits) can be roughly translated into mCrab using the fact that that Crab nebula gives the count rate approximately 2.8e^-3 cnts/s in the units, provided in 'flux' maps

See Allen, Jahoda, and Whitlock (1994) for full details about the available maps, their processing, and methods for converting the map intensities into familiar physical units.

The SPI significance map is based on the public GCDE data and uses data in the 20 - 40 keV energy range. The analysis of the data was done using the SPIROS software (Skinner & Connell 2003, A&A, 411, L123). This software uses the 'Iterative Removal of Sources' technique in order to find the most significant sources. In the output significance map the sources found in this process are put on top of the residual map as points with a FWHM of 1 degree.

Current data respresent the combination of all public observations as of September 1, 2004.

The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (e.g., to do statistical analysis).

The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5°x2.5° with a minimum overlap of 0.25°. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned.

Detailed information regarding the creation of the ROSAT suveys can be found in the ROSAT PSPC Generation Document.

The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (e.g., to do statistical analysis).

The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5°x2.5° with a minimum overlap of 0.25°. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned.

Detailed information regarding the creation of the ROSAT suveys can be found in the ROSAT PSPC Generation Document.

The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (e.g., to do statistical analysis).

The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5°x2.5° with a minimum overlap of 0.25°. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned.

Detailed information regarding the creation of the ROSAT suveys can be found in the ROSAT PSPC Generation Document.

The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (e.g., to do statistical analysis).

The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5°x2.5° with a minimum overlap of 0.25°. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned.

Detailed information regarding the creation of the ROSAT suveys can be found in the ROSAT PSPC Generation Document.

SkyView also has two other sets of surveys derived from the RASS data with substantially higher resolution. The surveys whose names begin with RASS3 are counts maps with 45" pixels. The RASS or RASSInt surveys are intensity maps generated by dividing the counts maps with the exposure maps provided by MPE.

SkyView also has two other sets of surveys derived from the RASS data with substantially higher resolution. The surveys whose names begin with RASS3 are counts maps with 45" pixels. The RASS or RASSInt surveys are intensity maps generated by dividing the counts maps with the exposure maps provided by MPE.

SkyView also has two other sets of surveys derived from the RASS data with substantially higher resolution. The surveys whose names begin with RASS3 are counts maps with 45" pixels. The RASS or RASSInt surveys are intensity maps generated by dividing the counts maps with the exposure maps provided by MPE.

SkyView has three sets of surveys derived from the RASS data. The surveys whose names begin with RASS3 are counts maps. The surveys with the names RASS or RASSINT are intensity images. These are simply the ratios of the counts maps and the exposure images produced by MPE. Both the counts maps and the intensity images have 45" pixels. A third set of RASS surveys is available int the surveys labeled RASS(.25|.75|1.5)keV. These are lower resolution intensity surveys (40.5' pixels) wiprith where point sources have been removed. They give the best sense of the background X-ray flux.

For the full-resolution RASS3 counts surveys data are organized in 1378 RASS3 fields each 6.4° x 6.4° covering the whole sky. Neighboring fields overlap by at least 0.23°.

Three bands are available through SkyView

• broad band (0.1-2.4 keV)
• hard band (0.5-2.0 keV)
• soft band (0.1-0.4 keV)

SkyView has three sets of surveys derived from the RASS data. The surveys whose names begin with RASS3 are counts maps. The surveys with the names RASS or RASSINT are intensity images. These are simply the ratios of the counts maps and the exposure images produced by MPE. Both the counts maps and the intensity images have 45" pixels. A third set of RASS surveys is available int the surveys labeled RASS(.25|.75|1.5)keV. These are lower resolution intensity surveys (40.5' pixels) wiprith where point sources have been removed. They give the best sense of the background X-ray flux.

For the full-resolution RASS3 counts surveys data are organized in 1378 RASS3 fields each 6.4° x 6.4° covering the whole sky. Neighboring fields overlap by at least 0.23°.

Three bands are available through SkyView

• broad band (0.1-2.4 keV)
• hard band (0.5-2.0 keV)
• soft band (0.1-0.4 keV)

SkyView has three sets of surveys derived from the RASS data. The surveys whose names begin with RASS3 are counts maps. The surveys with the names RASS or RASSINT are intensity images. These are simply the ratios of the counts maps and the exposure images produced by MPE. Both the counts maps and the intensity images have 45" pixels. A third set of RASS surveys is available int the surveys labeled RASS(.25|.75|1.5)keV. These are lower resolution intensity surveys (40.5' pixels) wiprith where point sources have been removed. They give the best sense of the background X-ray flux.

For the full-resolution RASS3 counts surveys data are organized in 1378 RASS3 fields each 6.4° x 6.4° covering the whole sky. Neighboring fields overlap by at least 0.23°.

Three bands are available through SkyView

• broad band (0.1-2.4 keV)
• hard band (0.5-2.0 keV)
• soft band (0.1-0.4 keV)

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

The seven maps correspond to ranges in the pulse height analysis of the photons detected. Since the energy resolution of the PSPC is poor, there is consider overlap between adjacent bands.

The energy range for the bands corresponds to:

Band	Energy range (keV)
Band 1	0.11 - 0.284
Band 2	0.14 - 0.284
Band 3	0.2 - 0.83
Band 4	0.44 - 1.01
Band 5	0.56 - 1.21
Band 6	0.73 - 1.56
Band 7	1.05 - 2.04

Note the substantial overlap between bands. Each photon detected is assigned to a band based on the pulse height analysis for that photon, but the energy resolution of the detectors is relatively poor. Also note that Band 3 was not included in the reference paper due to poor statistics and background modeling.

SkyView has several other sets of surveys derived from ROSAT data with substantially higher resolution and which include point sources. The RASS surveys are derived from the RASS all sky survey. These include count and intensity maps. The PSPC maps are dervived from the PSPC pointed observations which were combined by SkyView. The HRI survey is derived from a similar mosaicking of all HRI observations.

SkyView has three sets of surveys derived from the RASS data. The surveys whose names begin with RASS3 are counts maps. The surveys with the names RASS or RASSINT are intensity images. These are simply the ratios of the counts maps and the exposure images produced by MPE. Both the counts maps and the intensity images have 45" pixels. A third set of RASS surveys is available int the surveys labeled RASS(.25|.75|1.5)keV. These are lower resolution intensity surveys (40.5' pixels) wiprith where point sources have been removed. They give the best sense of the background X-ray flux.

For the full-resolution RASS intensity surveys data are organized in 1378 RASS fields each 6.4° x 6.4° covering the whole sky. Neighboring fields overlap by at least 0.23°.

Three bands are available through SkyView

• broad band (0.1-2.4 keV)
• hard band (0.5-2.0 keV)
• soft band (0.1-0.4 keV)

SkyView has three sets of surveys derived from the RASS data. The surveys whose names begin with RASS3 are counts maps. The surveys with the names RASS or RASSINT are intensity images. These are simply the ratios of the counts maps and the exposure images produced by MPE. Both the counts maps and the intensity images have 45" pixels. A third set of RASS surveys is available int the surveys labeled RASS(.25|.75|1.5)keV. These are lower resolution intensity surveys (40.5' pixels) wiprith where point sources have been removed. They give the best sense of the background X-ray flux.

For the full-resolution RASS intensity surveys data are organized in 1378 RASS fields each 6.4° x 6.4° covering the whole sky. Neighboring fields overlap by at least 0.23°.

Three bands are available through SkyView

• broad band (0.1-2.4 keV)
• hard band (0.5-2.0 keV)
• soft band (0.1-0.4 keV)

SkyView has three sets of surveys derived from the RASS data. The surveys whose names begin with RASS3 are counts maps. The surveys with the names RASS or RASSINT are intensity images. These are simply the ratios of the counts maps and the exposure images produced by MPE. Both the counts maps and the intensity images have 45" pixels. A third set of RASS surveys is available int the surveys labeled RASS(.25|.75|1.5)keV. These are lower resolution intensity surveys (40.5' pixels) wiprith where point sources have been removed. They give the best sense of the background X-ray flux.

For the full-resolution RASS intensity surveys data are organized in 1378 RASS fields each 6.4° x 6.4° covering the whole sky. Neighboring fields overlap by at least 0.23°.

Three bands are available through SkyView

• broad band (0.1-2.4 keV)
• hard band (0.5-2.0 keV)
• soft band (0.1-0.4 keV)

We have utilized the slew parts of all RXTE/PCA observations performed from April 15, 1996-July 16, 2002 which amounts in total to approximately 50,000 observations. The exposure time at a given point in the map is typically between 200-500 seconds. The observational period before April 15, 1996 (High Voltage Epochs 1 and 2) was excluded from the analysis because during that time the PCA had significantly different gain and dependence of the effective area on energy. The data reduction was done using standard tools of the LHEASOFT with a set of packages written by M. Revnivtsev (HEAD/IKI, Moscow; MPA, Garching).

The survey has several features. It has strongly different exposure times at different points on the sky that lead to strong variability of the statistical noise on images. Because of that the only meaningful representation of images is the map in units of statistical significance. After the detection of a source flux can be determined from the map in the 'flux' units. Map resolution is determined mainly by the slew rate of the RXTE (<0.05-0.1°/sec) and the time resolution of used data (16 sec, Std2 mode of the PCA). Sources can be detected down to the level of ~6e^-12 erg/s/cm², but at this level the confusion starts to play an important role. Details of the survey are presented in the paper of Revnivtsev et al. (2004).

We have utilized the slew parts of all RXTE/PCA observations performed from April 15, 1996-July 16, 2002 which amounts in total to approximately 50,000 observations. The exposure time at a given point in the map is typically between 200-500 seconds. The observational period before April 15, 1996 (High Voltage Epochs 1 and 2) was excluded from the analysis because during that time the PCA had significantly different gain and dependence of the effective area on energy. The data reduction was done using standard tools of the LHEASOFT with a set of packages written by M. Revnivtsev (HEAD/IKI, Moscow; MPA, Garching).

The survey has several features. It has strongly different exposure times at different points on the sky that lead to strong variability of the statistical noise on images. Because of that the only meaningful representation of images is the map in units of statistical significance. After the detection of a source flux can be determined from the map in the 'flux' units. Map resolution is determined mainly by the slew rate of the RXTE (<0.05-0.1°/sec) and the time resolution of used data (16 sec, Std2 mode of the PCA). Sources can be detected down to the level of ~6e^-12 erg/s/cm², but at this level the confusion starts to play an important role. Details of the survey are presented in the paper of Revnivtsev et al. (2004).

We have utilized the slew parts of all RXTE/PCA observations performed from April 15, 1996-July 16, 2002 which amounts in total to approximately 50,000 observations. The exposure time at a given point in the map is typically between 200-500 seconds. The observational period before April 15, 1996 (High Voltage Epochs 1 and 2) was excluded from the analysis because during that time the PCA had significantly different gain and dependence of the effective area on energy. The data reduction was done using standard tools of the LHEASOFT with a set of packages written by M. Revnivtsev (HEAD/IKI, Moscow; MPA, Garching).

The survey has several features. It has strongly different exposure times at different points on the sky that lead to strong variability of the statistical noise on images. Because of that the only meaningful representation of images is the map in units of statistical significance. After the detection of a source flux can be determined from the map in the 'flux' units. Map resolution is determined mainly by the slew rate of the RXTE (<0.05-0.1°/sec) and the time resolution of used data (16 sec, Std2 mode of the PCA). Sources can be detected down to the level of ~6e^-12 erg/s/cm², but at this level the confusion starts to play an important role. Details of the survey are presented in the paper of Revnivtsev et al. (2004).

Gamma ray surveys

The maps were originally generated by the CompTel Instrument Team as three separate maps in the bands:

• 1-3 MeV
• 3-10 MeV
• 10-30 MeV

All CompTel observations from phases 1, 2 and 3 were included in the maps (May 1991 through October 1994). These maps were combined into a single 3-D map at SkyView

The EGRET 3D map is comprised of ten channels with the following energy ranges:

• Channel 1 30-50 MeV
• Channel 2 50-70 MeV
• Channel 3 70-100 MeV
• Channel 4 100-150 MeV
• Channel 5 150-300 MeV
• Channel 6 300-500 MeV
• Channel 7 500-1000 MeV
• Channel 8 1000-2000 MeV
• Channel 9 2000-4000 MeV
• Channel 10 4000-10000 MeV

The default two dimensional image for the EGRET 3D survey is an average of Channels 4 - 10 (energies greater than 100 MeV).

The EGRET 3D map is comprised of ten channels with the following energy ranges:

• Channel 1 30-50 MeV
• Channel 2 50-70 MeV
• Channel 3 70-100 MeV
• Channel 4 100-150 MeV
• Channel 5 150-300 MeV
• Channel 6 300-500 MeV
• Channel 7 500-1000 MeV
• Channel 8 1000-2000 MeV
• Channel 9 2000-4000 MeV
• Channel 10 4000-10000 MeV

The default two dimensional image for the EGRET 3D survey is an average of Channels 4 - 10 (energies greater than 100 MeV).

The EGRET 3D map is comprised of ten channels with the following energy ranges:

• Channel 1 30-50 MeV
• Channel 2 50-70 MeV
• Channel 3 70-100 MeV
• Channel 4 100-150 MeV
• Channel 5 150-300 MeV
• Channel 6 300-500 MeV
• Channel 7 500-1000 MeV
• Channel 8 1000-2000 MeV
• Channel 9 2000-4000 MeV
• Channel 10 4000-10000 MeV

The default two dimensional image for the EGRET 3D survey is an average of Channels 4 - 10 (energies greater than 100 MeV).

-------------- Other surveys --------------

Galaxy Explorer All Sky Survey: Near UV

The SkyView GALEX surveys mosaic the intensity images of All-Sky Survey images. For a given pixel only the nearest image is used. Since a given GALEX observation is circular, this maximizes the coverage compared with default image finding algorithms which use the distance from edge of the image.

The SkyView GALEX surveys mosaic the intensity images of All-Sky Survey images. For a given pixel only the nearest image is used. Since a given GALEX observation is circular, this maximizes the coverage compared with default image finding algorithms which use the distance from edge of the image.