- ID:
- ivo://nasa.heasarc/skyview/sdss
- Title:
- Sloan Digital Sky Survey g-band
- Short Name:
- SDSS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Sloan Digital Sky Survey is the deepest large scale survey of the sky currently available. SkyView dynamically queries the SDSS archive (currently release DR9) to retrieve information and resample it into the user requested frame. Further information on the SDSS and many additional services are available at the <a href="https://www.sdss.org">SDSS website</a>. Provenance: Sloan Digital Sky Survey Team. This is a service of NASA HEASARC.
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- ID:
- ivo://nasa.heasarc/skyview/sdssdr7
- Title:
- Sloan Digital Sky Survey g-band DR7
- Short Name:
- SDSSDR7
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Sloan Digital Sky Survey is the deepest large scale survey of the sky currently available. SkyView dynamically queries the SDSS archive to retrieve information and resample it into the user requested frame. Further information on the SDSS and many additional services are available at the <a href="https://www.sdss.org/">SDSS website</a>. Provenance: Sloan Digital Sky Survey Team. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/goods-isaac-h
- Title:
- Southern GOODS Field: VLT ISAAC Observations, H band
- Short Name:
- GOODS ISAAC H
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- As part of the Great Observatories Origins Deep Survey (GOODS), near-infrared imaging observations of the Chandra Deep Field South (CDF-S) were carried out in J, H, Ks bands, using the ISAAC instrument mounted at the Antu Unit Telescope of the VLT at ESO's Cerro Paranal Observatory, Chile. <p> These data were obtained as part of the ESO Large Programme 168.A-0485 (PI: C. Cesarsky). Data covering four ISAAC fields in J and Ks bands were also drawn from the ESO programmes 64.O-0643, 66.A-0572 and 68.A-0544 (PI: E.Giallongo), which were part of the previous data releases. <p> This data release covers 172.4, 159.6, and 173.1 arcmin2 of the GOODS/CDF-S region in J, H and Ks respectively. More than 50% of the images reach a 5-sigma depth for point sources of at least 25.2 mag (J), 24.7 mag (H and Ks) in the AB system ("median depth"). <p> This final GOODS/ISAAC data release accumulates observational data which have been acquired in 12814 science integrations between October 1999 and January 2007 totaling 1.3 Msec integration time. [Above adapted from reference website.] <p> <i> SkyView</i> uses the mosaic files provided in this delivery. The Version 1.5 mosaic is used for the KS band. Provenance: Data downloaded from VLT archive. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/goods-vimos-r
- Title:
- Southern GOODS Field: VLT VIMOS Observations, R band
- Short Name:
- GOODS VIMOS R
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- As part of the Great Observatories Origins Deep Survey (GOODS), deep imaging in the Chandra Deep Field South (CDF-S) has been carried out, using the VIMOS instrument mounted at the Melipal Unit Telescope of the VLT at ESO's Cerro Paranal Observatory, Chile. <p> This data release contains the coadded images in U band from the ESO large programme 168.A-0485 (P.I. C. Cesarsky) which have been obtained in service mode observations between August 2004 and fall 2006. The 1-sigma depth for VIMOS U band in the area covered by the GOODS-ACS observations is ~30 AB (within an aperture of 1" radius, ranging from 29.5 and 30.2 AB). The PSF of the VIMOS U band mosaic is ~0.8" FWHM, but varies over the field. <p> Also included in this data release is a coadded image in R band obtained from data retrieved from the ESO archive. Due to the different observing strategies adopted in the programmes the resulting coverage of the GOODS-ACS area is more complex than for the U band. The depth of the VIMOS R band mosaic over the ACS area ranges from ~28 AB to 29 AB (1-sigma, 1" aperture radius). The PSF of the VIMOS R band mosaic is ~0".7 FWHM and varies over the field. [Adapted from reference website.] Provenance: Data downloaded from VLT archive. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/goodsirac-1
- Title:
- Spitzer IRAC GOODS 3\.6 micron data, channel 1
- Short Name:
- GOODSIRAC 1
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Spitzer IRAC medium infrared observations taken in all four IRAC channels in both the north and south GOODS fields. Provenance: IRAC Goods Team, IRSA data center. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/goodsmips
- Title:
- Spitzer MIPS GOODS 24 Micron Data
- Short Name:
- GOODSMIPS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Spitzer MIPS observations of the GOODS North and South fields in the 24 micron channel. Provenance: IRSA, GOODS team. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/bat-flux-1
- Title:
- Swift BAT 70 Month All-Sky Survey: 14\-20 keV: flux
- Short Name:
- BAT-flux-1
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This BAT Hard X-ray Survey data is the 70-month survey product of the BAT instrument on the Swift observatory. Swift/BAT is a wide field-of-view (70x100 degrees) hard X-ray imager consisting of a coded mask and a large array of CdZnTe detectors (with an effective area of ~ 5000 cm<sup>2</sup>). <p> BAT is sensitive in the energy range 14-195 keV. The data are divided into 8 energy bands <table border> <tr><th>Band<th>Energy (keV)<th>Frequency (EHz) </tr> <tr><td>1<td> 14-20 <td> 3.38-4.84</tr> <tr><td>2<td> 20-24 <td> 4.84-5.80</tr> <tr><td>3<td> 24-35 <td> 5.80-8.46</tr> <tr><td>4<td> 35-50 <td> 8.46-12.1</tr> <tr><td>5<td> 50-75 <td> 12.1-18.1</tr> <tr><td>6<td> 75-100 <td> 18.1-24.2</tr> <tr><td>7<td> 100-150<td> 24.2-36.3</tr> <tr><td>8<td> 150-195<td> 36.3-47.2</tr> <tr><td>Sum (SNR only)<td>14-195<td> 3.38-47.2</tr> </table> Each band is represented as as two separate surveys, a signal-to-noise (SNR) map and a flux map. (e.g., BAT-snr-1 or BAT SNR 1 or BAT SNR 14-20, or BAT-Flux-1, ...). An additional summed survey, BAT-SNR-SUM or BAT SNR SUM or BAT SNR 14-195, is also available, but there is no summed flux survey. In our Web interface only the SNR surveys are shown in the Web form. Users can get flux maps corresponding to a given SNR image from the results pages. The batch interfaces may directly query any of the surveys since the user chooses the names explicitly rather than from a selection box. <p> The values displayed in the significance maps are the local signal to noise ratio in each pixel. The noise in these coded-mask images follows a Gaussian distribution with center at zero and a characteristic width (sigma) of 1.0. The noise is calculated locally for each pixel by measuring the RMS value of all pixel values in an annulus around each pixel and hence includs both statistical and systematic components. Known sources are excluded from the annuli. <p> The signal in each pixel is taken from the flux maps. <p> The flux values are in the native BAT survey units of counts/sec/detector. The detector is an individual piece of CZT in the BAT array with an area of 1.6 x 10<sup>-7</sup>m<sup>2</sub>. <p> While the Swift mission is primarily designed to follow gamma-ray bursts, the random distribution of bursts in the sky means that these survey's sky coverage is relatively uniform with the exposure at any point varying between about 6 to 16 megaseconds. The survey limits for source detection are about 10<sup>-11</sup> ergs/s/cm<sup>2</sup> over about half the sky and 1.3x10<sup>-11</sup> ergs/s/cm<sup>2</sup> over 90%. <p> These data replace the 9-month BAT datasets which we have retired. If you wish access to the older data please let us know. Note that for the 9-month data we provided access through the web page to the flux data and gave links to the signal-to-noise maps. Since the existence of sources is most easily seen in the SNR maps, we decided to invert that for this release. <p> For the 8 band data, the source data were provided by the BAT team as 6 FITS files. Each of these contained the 8 bands in separate image extensions for a region centered at l=0,b=+/-90 or l=0,90,180,270,b=0, the centers of 6 cubic facets. However these data are not the classical cube-faced projections, e.g., as used in COBE data. The data on the facets overlap, so that this is just a convenient way to tile the sky. <i>SkyView</i> separated each of the FITS image extensions into a separate file, but no other modifications were made to the data. The summed image was provided as six separate files. Provenance: NASA BAT Team. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/swiftuvot
- Title:
- Swift UVOT Combined V Intensity Images
- Short Name:
- SWIFTUVOT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Swift UVOT instrument is a 30 cm modified Ritchey-Chretien reflecting telescope launched on board the Swift satellite on November 20, 2004. The range of optical and UV filters can accomodate wavebands between 1700 and 6500 Angstroms. A full field image covers 17x17 arcminutes and at maximum spatial sampling is imaged onto 2048x2048 0.5" pixels. A 1000 second observation can detect point sources to m=22.3 when no filter is used. The Swift Serendipitous Source Catalog (Page et al., 2015) detects sources down to m=23-26 for the six filters in very deep observations, but the typical limits are substantially brighter (~20-23 magnitude). <p> These surveys are mosaics of all Swift UVOT observations released between the start of the mission and July 2017. Data were extracted from the HEASARC archive from the UVOT products directory. Mosaics are provided in six filters and also with no filter, i.e., WHITE. The table below gives the number of observations and bandpasses for each of the filters. For each UVOT observation standard processing generates a counts and exposure file as a single multi-extension FITS file with a separate extension for each filter. To aid processing, these extensions were copied into separate files in directory trees for each filter. Four observations in which the exposure and counts maps did not agree on the filters used were omitted from the processing. <p> Some observations were recorded with 0.5" pixels while others were binned to 1". All 0.5" observations (typically fewer than 10%) were rebinned to the larger pixels for the counts maps since the counts data scales with the pixel size. Since the exposure values are intensive and do not vary significantly based upon the resolution, these data were not generally rebinned unless it was needed to ensure that Order 9 Hips data were produced. <p> The CDS Hipsgen software was used to generate Order 9 HiPS data (~0.8" pixels) for both the Counts and Exposure images. The HiPS (Hierarchical Progressive Survey VO standard) supports multi-resolution mosaics. Any quantitative use of these images should note that the rebinning increases the total counts by a factor of ~(1.0/0.8)^2 ~ 1.56. This software uses a bilinear interpolation to generate HEALPix tiles of an appropriate order (18 in this case). <i>SkyView</i> developed software was used to divide the level 9 counts maps tiles by the corresponding exposure maps to create intensity tiles. Pixels where the exposure was less than 5 seconds were left as NaNs. The lower order (8 to 3) order intensity tiles were then generated by averaging 2x2 sets of the higher order maps treating any missing maps or pixels as NaNs. A HiPS all-sky image was generated by averaged the Order 3 tiles. <p> Only the Intensity HIPS files are presented in the SkyView web page directly, but intensity, counts and exposure maps are available for all seven filters. Note that unlike the XRT HiPS data, the exposure and counts maps have not been clipped. I.e., the source FITS files have been aligned with the coordinate system and thus contain large numbers of unexposed pixels with 0 values. These 0's are simply propogated to HiPS tiles. NaNs are returned in regions which lie outside any of the original source images. For the Intensity map, any pixel for which the exposure was less than 5s is returned as a NaN. <table border> <tr><th align=center>Filter</th><th>Count</th><th>Central Wavelength (&#8491;;)</th><th>Bandpass (&#8491;;)</th><th>Central Frequency(THz)</th><th>Bandpass (THz)</th><th>Coverage</th></tr> <tr><th align=center>WHITE</th><td align='center'>3,000</td><td align='center'>3600</td><td align='center'>1600-6000</td><td align='center'>832</td><td align='center'>500-1874</td> <td>0.0017</td></tr> <tr><th align=center>V</th><td align='center'>30,557</td><td align='center'>5468</td><td align='center'>5083-5852</td>< <td align='center'>548</td><td align='center'>512-590</td> <td>0.0171</td></tr> <tr><th align=center>B</th><td align='center'>28,347</td><td align='center'>4392</td><td align='center'>3904-4880</td> <td align='center'>683</td><td align='center'>614-768</td> <td>0.0112<td></tr> <tr><th align=center>U</th><td align='center'>49,954</td><td align='center'>3465</td><td align='center'>3072-3875</td> <td align='center'>865</td><td align='center'>774-975</td> <td>0.0287</td></tr> <tr><th align=center>UVW1</th><td align='center'>60,690</td><td align='center'>2600</td><td align='center'>2253-2946</td> <td align='center'>1154</td><td align='center'>1017-1330</td><td>0.0277</td></tr> <tr><th align=center>UVM2</th><td align='center'>56,977</td><td align='center'>2246</td><td align='center'>1997-2495</td> <td align='center'>1334</td><td align='center'>1201-1501</td>>td>0.0314</td></tr> <tr><th align=center>UVW2</th><td align='center'>54,590</td><td align='center'>1928</td><td align='center'>1600-2256</td> <td align='center'>1554</td><td align='center'>1328-1874</td><td>0.0260</td></tr> </table> <strong>Observation counts and bandpasses for UVOT Filters</strong> <p> Provenance: Data generated from public images at HEASARC archive. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/swiftxrt
- Title:
- Swift XRT Combined Intensity Images
- Short Name:
- SWIFTXRT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Swift XRT (<a href="https://ads.harvard.edu/abs/2005SSRv..120..165B">Burrows et al 2005, SSRv, 120, 165</a>) is a sensitive, broad-band (0.2 - 10 keV) X-ray imager with an effective area of about 125 cm**2 at 1.5 keV. The 600 x 600 pixel CCD at the focus provides a 23.6' x 23.6' field of view with a pixel scale of 2.36". The point spread function is 18" (HPD) at 1.5 keV. <p> These XRT surveys represent the data from the first 12.5 years of Swift X-ray observations. They include all data taken in photon counting mode. A total of just over 8% of the sky has some non-zero exposure. The fraction of sky exposed as a function of the exposure is given in the following table: <table border> <tr><th>Exposure</th><td>>0</td> <td>10</td> <td>30</td> <td>100</td> <td>300</td> <td>1000</td> <td>3000</td> <td>1000</td> <td>30000</td> <td>100000</td><td>300000</td></tr> <tr><th>Coverage</th> <td> 8.42 </td><td> 8.37 </td><td> 8.29 </td><td> 7.67 </td><td> 7.29 </td><td> 5.68 </td> <td> 3.40 </td><td> 1.26 </td><td> 0.35 </td><td> 0.044 </td><td> 0.00118</td></th> </table> The individual exposure and counts maps have been combined into a Hierarchical Progressive Survey (HiPS) where the data are stored in tiles in the HEALPix projection at a number of different resulutions. The highest resolution pixels (HEALPix order 17) have a size of roughly 1.6". Data are also stored at lower resolutions at factors of 1/2, 1/4, 1/8, 1/16, and 1/32, and in an all sky image with a resolution 1/256 of the higest resolution. An intensity map has been created as the ratio of the counts and exposure maps. <p> These surveys combine the basic count and exposure maps provided as standard products in the Swift XRT archive in obsid/xrt/products/*xpc_(sk|ex).img.gz. The surveys were created as follows: <ul> <li>All of the exposure maps available in the archive in mid-May 2017 were combined using the CDS-developed Hipsgen tool. This includes 129,063 observations for which both count and exposure files were found in PC mode. Three exposures where there was a counts map but no exposure map were ignored. A few exposure files had more than one exposure extension. 1,082 files had two extensions and 1 file had 3 extensions. The 1084 HDUs in extensions were extracted as separate files and included in the total exposure. The value of 0 was given to the Hipsgen software as the null value for the FITS files. This caused the CDS software to treat such pixels as missing rather than 0 exposure. <li> The counts data was extracted from the counts maps for each observation using <i>SkyView</i> developed software. For any pixel in which a count was recorded, the corresponding exposure file was checked and if there was any exposure (in any of the associated extensions), then the count was retained. If there was no exposure in any of the extensions of the corresponding exposure file, the counts in the pixel were omitted. Once a count was accepted, the overlap between the counts map pixel and the pixels of the corresponding HiPS tile (or tiles) was computed. Each count was then assigned entirely to a single pixel in the HiPS tile randomly but with the destination pixel probabilities weighted by area of the overlap. Thus if several pixels were found in a given counts map pixel they might be assigned to different pixels in the output image. The HiPS pixels (~1.6") used were of substantially higher resolution than the XRT resolution of 18" and somewhat higher than the counts map resolution of 2.36". <p> A total of 183,750,428 photons were extracted from the counts maps while 15,226 were rejected as being from pixels with 0 exposure. There were 501 pixels which required special treatment as straddling the boundaries of the HEALPix projection. <li> The resulting counts tiles were then clipped using the exposure tiles that had been previously generated. Basically this transferred the coverage of the exposure tiles to the counts tiles. Any counts pixel where the corresponding exposure pixel was a NaN was changed to a NaN to indicate that there was no coverage in this region. <p> During the clipping process 137,730 HiPS level 8 were clipped (of 786,432 over the entire sky). There were 12,236 tiles for which there was some exposure but no counts found. During the clipping process 2 photons were found on pixels where there was no corresponding exposure in the exposure tiles. This can happen when the pixel assignment process noted above shifts a photon just outside the exposed region but should be -- as it was -- rare. These photons were deleted. <li> After creating the clipped level 8 counts maps, level 7 to 3 tiles and an all sky map where generated by averaging pixels 2x2 to decrease each level. When adding the four pixels in the level N map together only pixels whose value was not NaN were considered. <li> Finally an intensity map was created by dividing the counts tiles by the exposure tiles. To eliminate gross fluctuations due to rare counts in regions with very low exposure, only regions with exposure > 1 second were retained. A total of 30 photons were deleted due to this criterion. </ul> <p> Note that while any sampler may in principle be used with these data, the Spline sampler may give unexpected results. The spline computation propogates NaNs thought the image and means that even occasional NaNs can corrupt the output image completely. NaNs are very common in this dataset. Also, if the region straddles a boundary in the HEALPix projection, the size of the requested input region is likely to exceed memory limits since the HiPS data are considered a single very large image. Provenance: Data generated from public images at HEASARC archive. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/sumss
- Title:
- Sydney University Molonglo Sky Survey
- Short Name:
- SUMSS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Sydney University Molonglo Sky Survey (SUMSS) is a deep radio survey at 843 MHz of the entire sky south of declination -30&#176;;, made using the Molonglo Observatory Synthesis Telescope (<a href="https://www.physics.usyd.edu.au/astrop/most/"> MOST </a>), located near Canberra, Australia. The images from the SUMSS are produced as 4 x 4 degree mosaics of up to seventeen individual observations, to ensure even sensitivity across the sky. The mosaics slightly overlap each other. Data were last updated on January 28, 2015. <p> Images can also be obtained from the <a href="https://www.astrop.physics.usyd.edu.au/cgi-bin/postage.pl">SUMSS Postage Stamp Server</a>. <p> 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. <p> Provenance: The SUMSS project team, University of Sydney. This is a service of NASA HEASARC.
