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401. Swift Gamma-ray Urgent Archiver for Novel Opportunities (GUANO) Events
ID:
ivo://nasa.heasarc/swiftguano
Title:
Swift Gamma-ray Urgent Archiver for Novel Opportunities (GUANO) Events
Short Name:
SWIFTGUANO
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
The Swift Observatory provides event-level data from the Burst Alert Telescope (BAT) on demand in response to transients detected by other observatories/instruments. This capability, named "Gamma-ray Urgent Archiver for Novel Opportunities" (GUANO), was introduced in 2020. In normal operations, BAT records the arrival time (to 100-microsecond accuracy), location (in detector coordinates), and energy (in one of 80 bins from 15 to 350 keV) for each individual count that strikes the detector. These data, referred as event-by-event (or event), because of the large effective area of the BAT, produces a large data volume that cannot all be stored onboard or telemetered to the ground. For this reason, the BAT has relied on the performance of its onboard real-time detection algorithms, and only preserves event data and telemeters them to the ground around the time of events that trigger these onboard algorithms. The GUANO implementation allows to download BAT event data that did not trigger on board. Upon receiving an alert from different observatories, an autonomous spacecraft-commanding pipeline requests to download from the Swift satellite the BAT event data around the time of the GUANO event with a time window, typically around 200 seconds. The satellite does not slew; therefore, only BAT event data are available for the GUANO event and these data are tagged with a sequence number associated with the ongoing observation containing the GUANO time window. This table records the times of the GUANO events from different observatories from which Swift was able to download the BAT event data together with the directory and file names where the event are located in the archive. There is one record for each trigger by an external observatory that requested BAT event data; therefore, it is possible that multiple records are associated with the same event. This contents of this database table are generated at the Swift processing site. During operation, it is updated for any new GUANO trigger. These updates are then delivered to the HEASARC and ingested into the HEASARC database in a timely fashion. Note that some parameters (specifically, the galactic coordinates) have been added and are populated by the HEASARC. This is a service provided by NASA HEASARC .
402. Swift Master Catalog
ID:
ivo://nasa.heasarc/swiftmastr
Title:
Swift Master Catalog
Short Name:
Swift
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table records high-level information for each Swift observation and provides access to the data archive. Each record is associated with a single observation that contains data from all instruments on board Swift. The BAT is the large field of view instrument and operates in the 10-300 keV energy band. The narrow field instruments, XRT and UVOT, operate in the X-ray and UV/optical regime, respectively. An observation is defined as a collection of snapshots, where a snapshot is defined as the time spent observing the same position continuously. Because of observing constraints, the length of a snapshot can be shorter than a single orbit and it can be interrupted because the satellite will point in a different direction of the sky or because the time allocated to that observation ends. The typical Swift observing strategy for a Gamma Ray Burst (GRB) and/or afterglow, consists of a serious of observations aimed at following the GRB and its afterglow evolution. This strategy is achieved with two different type of observations named Automatic Targets and Pre-Planned Targets. The Automatic Target is initiated on board soon after an event is triggered by the BAT. The Figure of Merit (FOM) algorithm, part of the observatory's autonomy, decides if it is worth requesting a slew maneuver to point the narrow field instruments (NFI) on Swift, XRT and UVOT, in the direction of the trigger. If the conditions to slew to the new position are satisfied, the Automatic Target observation takes place; all the instruments have a pre-set standard configuration of operating modes and filters and about 20000 seconds on source will be collected. The Pre-Planned Target observations instead are initiated from the ground once the trigger is known. These observations are planned on ground and uploaded onto the spacecraft. This database table is generated at the Swift processing site. During operation, it is updated on daily basis. This is a service provided by NASA HEASARC .
403. Swift TDRSS Messages
ID:
ivo://nasa.heasarc/swifttdrss
Title:
Swift TDRSS Messages
Short Name:
SWIFTTDRSS
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
This database table is derived from the Swift TDRSS messages sent on ground soon after a BAT trigger occurs on-board. For each trigger there are associated up to 14 messages, however not all are always generated and sent on ground. The messages are generated on board by the BAT, XRT and UVOT instruments and the Figure of Merit part of the observatory's autonomy. The BAT and XRT can each have five different message types. The UVOT and FOM can each have two different message types. These TDRSS messages are the results of the on-board data processing of the three instruments and some contain data products. They are first distributed via the GCN and later archived. The BAT messages are: alert, 'ack' containing the position, or 'nack' if the position could not be calculated, a lightcurve and scaled map. The XRT messages are: centroid containing the position, an image (if the position has been calculated), centroid error if the position could not be calculated, spectra in Low Rate Photodiode and Windowed Timing modes, a lightcurve. The UVOT messages are: finding chart containing star positions and a subimage centered on the XRT position. The FOM messages are used to indicate if the FOM will or will not observe the new target and if the spacecraft will (or will not) request a slew for the new target. The parameters in this database table are a collection of high level information taken from the following messages : the BAT alert, 'ack' or 'nack' message, the FOM messages, the XRT position and image. If the information is not available the fields are left blank. All messages are provided as data products within this database table. This database table is generated at the Swift processing site. During operation, it is updated on daily basis. This is a service provided by NASA HEASARC .
404. Swift UVOT Combined V Intensity Images
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 (&amp;#8491;;)</th><th>Bandpass (&amp;#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.
405. Swift UVOT Instrument Log
ID:
ivo://nasa.heasarc/swiftuvlog
Title:
Swift UVOT Instrument Log
Short Name:
SwiftUVOT
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
The UVOT runs only one type of configuration filter/mode/window in a given time interval. This database table, therefore, contains for a given time interval a single record that describes one configuration. This database table is generated by the Swift Data Center. During operation, it is updated on daily basis. This is a service provided by NASA HEASARC .
406. Swift XRT Combined Intensity Images
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>&gt;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.
407. Swift XRT Instrument Log
ID:
ivo://nasa.heasarc/swiftxrlog
Title:
Swift XRT Instrument Log
Short Name:
SwiftXRT
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
The XRT runs only one type of configuration mode/window in a given time interval. The table therefore contains for a given time interval a single record that describes one configuration. A new record is generated when the following is changing within an observation: new operating mode , new pointing mode, or new window configuration. This database table is generated by the Swift Data Center. During operation, it is updated on daily basis. This is a service provided by NASA HEASARC .
408. Sydney University Molonglo Sky Survey
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&amp;#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.
409. TAP VizieR query engine
ID:
ivo://CDS.VizieR/ObsTAP
Title:
TAP VizieR query engine
Short Name:
VizieR ObsTAP
Date:
12 Jun 2019 18:00:00
Publisher:
CDS VizieR service
Description:
This service provides ObsTAP access to VizieR spectra, time-series and images.
410. The Extended IRAS Galaxy Atlas
ID:
ivo://irsa.ipac/IRAS/Images/EIGA
Title:
The Extended IRAS Galaxy Atlas
Short Name:
EIGA
Date:
31 Mar 2023 23:00:00
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The Extended IRAS Galaxy Atlas (EIGA) is an extension of the original IRAS Galaxy Atlas (IGA) to b = 6.7 deg.. High resolution images at 60 microns and 100 microns have been produced to match the latitude coverage of radio continuum observations obtained as part of the Canadian Galactic Plane Survey (CGPS). Also associated with the EIGA and IGA is the Mid-Infrared Galaxy Atlas (MIGA).

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