Swift Serendipitous Survey in Deep XRT GRB Fields (SwiftFT)

Swift Serendipitous Survey in Deep XRT GRB Fields (SwiftFT) SWIFTFT ivo://nasa.heasarc/swiftft NASA/GSFC HEASARC Puccetti et al. 2026-04-03 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the SwiftFT catalog of point sources detected by the X-ray Telescope (XRT) on board the Swift satellite in observations centered on gamma-ray bursts (GRBs) during the first four years of operation (Jan 2005 - Dec 2008). Swift is a NASA mission with international participation dedicated to the gamma-ray burst study. It carries three instruments. The BAT is the large field of view instrument and operates in the 10-300 keV energy band; and two narrow field instruments, XRT and UVOT, that operate in the X-ray and UV/optical regime, respectively. The catalog was derived including pointing positions of the 374 fields centered on the GRBs covering a total area of ~32.55 square degrees. Since GRBs are distributed randomly in the sky, the survey covers totally unrelated parts of the sky, and is highly uniform courtesy of the XRT's stable point spread function and small vignetting correction factors. The observations for a particular field were merged together and the source search analysis was restricted to a circular area of 10 arcmin radius centered in the median of the individual observation aim points. The total exposure considering all the fields is of 36.8 Ms, with ~32% of the fields having more than 100 ks exposure time, and ~28% with exposure time in the range 50-100 ks. The catalog was generated by running the detection algorithm in the XIMAGE package version 4.4.1 that locates the point sources using a sliding-cell method. The average background intensity is estimated in several small square boxes uniformly located within the image. The position and intensity of each detected source are calculated in a box whose size maximizes the signal-to-noise ratio. The detect algorithm was run separately in the following three energy bands: 0.3-3 (Soft), 2-10 (Hard), and 0.3-10 (Full) keV. For each detections the three count rates in the soft, hard, and full bands are all corrected for dead times and vignetting using exposure maps and for the PSF. Hardness ratios are calculated using the three energy band and defined as HR = (cH - cS)/(cH + cS) where cS and cH are the count rates in the S(oft) and H(ard) bands, respectively. The catalog was cleaned of spurious and extended sources by visual inspection of all the observations. Count rates in the three bands were converted into flux in the 0.5-10, 0.5-2, and 2-10 keV energy bands, respectively. The flux was estimated using a power law spectrum with photon spectral index of 1.8 and a Galactic NH of 3.3 x 1020 cm-2. Each row in the catalog is a unique source. The detections from the soft, hard, and full bands were merged into a single catalog using a matching radius of 6 arcsec and retaining detection with a significance level of being spurious <= 2 x 10-5 in at least one band. There are 9387 total entries in the catalog. The SWIFTFT acronym honors both the Swift satellite and the memory of Francesca Tamburelli who made numerous crucial contributions to the development of the Swift-XRT data reduction software. This database table was created by the HEASARC in November 2021 based on the electronic version available from the ASI Data Center <a href="https://www.asdc.asi.it/xrtgrbdeep_cat/">https://www.asdc.asi.it/xrtgrbdeep_cat/</a> and published in the Astronomy and Astrophysics Journal. This catalog is also available as the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/528/A122">CDS catalog J/A+A/528/A122</a>. The HEASARC added the source_number parameter, a counter to numerically identify each source in the catalog, as well as Galactic coordinates and changed the source name from SWIFTFTJHHMMSS.s+DDMM.m to SWIFTFT JHHMMSS.s+DDMM.m, adding a space between the catalog prefix and the formatted J2000 coordinates. This is a service provided by NASA HEASARC . 2011A&A...528A.122P https://heasarc.gsfc.nasa.gov/W3Browse/all/swiftft.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=swiftft& GET text/xml 180 99999 true 227.7671 -80.63 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=swiftft GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_swiftft&Action=More+Options&Action=Parameter+Search&ConeAdd=1 SWIFT 0.0166666666666667 X-ray public swiftft Swift Serendipitous Survey in Deep XRT GRB Fields (SwiftFT) error_radius_90 90%-Confidence Radial Position Error degree stat.error;pos double nullable exposure_mapb Exposure from Exposure Map at 1 keV s time.duration;obs.exposure int nullable exposure_mapa Exposure from Exposure Map at 1.5 keV s time.duration;obs.exposure int nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray double nullable flux_0p5_10 0.5-10 keV Source Flux or 90% Upper Limit erg/cm^2/s phot.flux;em.X-ray double nullable dec Declination degree pos.eq.dec;meta.main double nullable snr_0p3_10 0.3-10 keV Signal-to-Noise Ratio stat.snr;em.X-ray double nullable flux_2_10 2-10 keV Source Flux or 90% Upper Limit erg/cm^2/s phot.flux;em.X-ray double nullable count_rate_0p3_10 0.3-10 keV Source Rate or 90% Upper Limit ct/s phot.count;em.X-ray double nullable flux_2_10_error 2-10 keV Source Flux Error; -99 for Upper Limit erg/cm^2/s stat.error;phot.flux;em.X-ray double nullable target_name XRT Field Target Designation meta.id char nullable name IAU-Style Source Designation (SWIFTFT JHHMMSS.s+DDMM.m) meta.id;meta.main char nullable "__row" System index column char nullable y_pixel_pos Y Pixel Position pixel pos.cartesian.y;instr.pixel double nullable probdet_0p3_10 0.3-10 keV Detection Probability stat.fit.goodness double nullable error_radius_68 68%-Confidence Radial Position Error degree stat.error;pos double nullable source_number Unique Numerical Identifier for Each Source in This Catalog meta.id;src int nullable "__y_ra_dec" System unit vector column double nullable "__x_ra_dec" System unit vector column double nullable probdet_0p3_3 0.3-3 keV Detection Probability stat.fit.goodness double nullable count_rate_0p3_10_error 0.3-10 keV Source Rate Error; -99 for Upper Limit ct/s stat.error;phot.count;em.X-ray double nullable count_rate_0p3_3_error 0.3-3 keV Source Rate Error; -99 for Upper Limit ct/s stat.error;phot.count;em.X-ray double nullable count_rate_0p3_3 0.3-3 keV Source Rate or 90% Upper Limit ct/s phot.count;em.X-ray double nullable "__z_ra_dec" System unit vector column double nullable bii Galactic Latitude degree pos.galactic.lat double nullable end_time End Time of the Last Observation That Includes the Source mjd time.end;obs double nullable hardness_ratio_error Hardness Ratio Error stat.error;phot.flux;arith.ratio;em.X-ray double nullable flux_0p5_2 0.5-2 keV Source Flux or 90% Upper Limit erg/cm^2/s phot.flux;em.X-ray double nullable lii Galactic Longitude degree pos.galactic.lon double nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable exposure_mapc Exposure from Exposure Map at 4.5 keV s time.duration;obs.exposure int nullable probdet_2_10 2-10 keV Detection Probability stat.fit.goodness double nullable offaxis Off-Axis from the Center of the Field arcmin pos.angDistance double nullable "time" Start Time of the First Observation That Includes the Source mjd time.start;obs double nullable count_rate_2_10 2-10 keV Source Rate or 90% Upper Limit ct/s phot.count;em.X-ray double nullable exposure Total Exposure Time s time.duration;obs.exposure int nullable galactic_nh Galactic Column Density cm^-2 phys.columnDensity double nullable flux_0p5_2_error 0.5-2 keV Source Flux Error; -99 for Upper Limit erg/cm^2/s stat.error;phot.flux;em.X-ray double nullable flux_0p5_10_error 0.5-10 keV Source Flux Error; -99 for Upper Limit erg/cm^2/s stat.error;phot.flux;em.X-ray double nullable snr_2_10 2-10 keV Signal-to-Noise Ratio stat.snr;em.X-ray double nullable count_rate_2_10_error 2-10 keV Source Rate Error; -99 for Upper Limit ct/s stat.error;phot.count;em.X-ray double nullable snr_0p3_3 0.3-3 keV Signal-to-Noise Ratio stat.snr;em.X-ray double nullable x_pixel_pos X Pixel Position pixel pos.cartesian.x;instr.pixel double nullable