- ID:
- ivo://nasa.heasarc/swbat105m
- Title:
- Swift-BAT 105-Month All-Sky Hard X-Ray Survey
- Short Name:
- SWBAT105M
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The catalog includes hard X-ray sources detected in the first 105-months of observations with the Burst Alert Telescope (BAT) coded-mask imager on board the Swift observatory. The 105-month Swift-BAT survey is a uniform hard X-ray all-sky survey with a sensitivity of 8.40x10<sup>-12</sup>erg/s/cm<sup>2</sup> over 90% of the sky and 7.24x10<sup>-12</sup>erg/s/cm<sup>2</sup> over 50% of the sky in the 14-195 keV band. The Swift-BAT 105-month catalog provides 1632 (422 new detections) hard X-ray sources in the 14-195 keV band above the 4.8 sigma significance level. Adding to the previously known hard X-ray sources, 34% (144/422) of the new detections are identified as Seyfert active galactic nuclei (AGNs) in nearby galaxies (z<0.2). The majority of the remaining identified sources are X-ray binaries (7%, 31) and blazars/BL Lac objects (10%, 43). As part of this new edition of the Swift-BAT catalog, the authors release eight-channel spectra and monthly sampled light curves for each object in the online journal and at the <a href="https://swift.gsfc.nasa.gov/results/bs105mon/">Swift-BAT 105-month website</a>. The data reduction, analysis, and catalog generation of the Swift-BAT 105-month survey (between 2004 December and 2013 August) are conducted following the same procedures as in the Swift-BAT 70-month survey (Baumgartner+ 2013, J/ApJS/207/19). The catalog includes 1632 hard X-ray sources detected across the entire sky. Of these 1632 sources, 422 are new detections with respect to the 70-month catalog, and 320 are reported as hard X-ray sources for the first time. The Swift-BAT 105-month survey catalog contains 947 non-beamed AGNs detected in the hard X-ray band. The authors inspected soft X-ray images provided by Swift-XRT (3-10keV), Chandra (2-10keV), ASCA (2-10keV), and XMM-Newton (4-10keV) for the newly detected sources when available using 15 arcmin of matching radius. See section 2.1 of the paper for further explanations. This table was created by the HEASARC in March 2020 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/235/4">CDS Catalog J/ApJS/235/4</a> file table3.dat. This is a service provided by NASA HEASARC .
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Search Results
- 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:
- 09 May 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/swbatsfxt
- Title:
- Swift BAT 100-Month Supergiant Fast X-Ray Transient Catalog
- Short Name:
- SWBATSFXT
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Supergiant Fast X-ray Transients (SFXTs) are High Mass X-ray Binaries (HMXBs) that are defined by their hard X-ray flaring behavior. During such flares they reach peak luminosities of 10<sup>36</sup> - 10<sup>37</sup> erg/s for a few hours (in the hard X-ray), i.e., much shorter timescales than those characterizing Be/X-ray binaries. The authors have investigated the characteristics of bright flares (detections in excess of 5 sigma) for a sample of SFXTs and their relation to the orbital phase. They have retrieved all Swift/BAT Transient Monitor light curves, and collected all detections in excess of 5 sigma from both daily- and orbital-averaged light curves in the time range from 2005 February 12 to 2013 May 31 (MJD 53413 - 56443). The authors also considered all on-board detections as recorded in the same time span and selected those within 4 arcminutes of each source in their sample and in excess of 5 sigma. This table contains the catalog of over a thousand Burst Alert Telescope (BAT) flares from 11 SFXTs, down to 15-150 keV fluxes of ~6 x 10<sup>-10</sup>erg/cm<sup>2</sup>/s (daily timescale) and ~1.5 x 10<sup>-9</sup>erg/cm<sup>2</sup>/s (orbital timescale, averaging ~800s) and spanning 100 months. The great majority of these flares are unpublished. This population is characterized by short (a few hundred seconds) and relatively bright (in excess of 100 milliCrab, 15-50 keV) events. In the hard X-ray, these flares last in general much less than a day. Clustering of hard X-ray flares can be used to indirectly measure the length of an outburst, even when the low-level emission is not detected. In their paper, the authors construct the distributions of flares, of their significance (in terms of sigma) and their flux as a function of orbital phase, to infer the properties of these binary systems. In particular, they observe a trend of clustering of flares at some phases as P_orb increases, as consistent with a progression from tight, circular or mildly eccentric orbits at short periods, to wider and more eccentric orbits at longer orbital periods. Finally, the authors estimate the expected number of flares for a given source for their limiting flux and provide the recipe for calculating them for the limiting flux of future hard X-ray observatories. The BAT observes 88% of the sky daily, on average, so it is ideally suited to detect flaring in hard X-ray sources. Since 2005-02-12, the BAT Transient Monitor (Krimm et al. 2013, ApJS, 209, 14) has been providing near real-time light curves in the 15-50 keV energy range of more than 900 sources with a mean variance for one-day mosaics of 5.3 milliCrab. Several flares from SFXTs are regularly caught every year by the BAT Transient Monitor (BATTM). The catalog contains a total of 1117 flares from 11 SFXT sources (the only other confirmed SFXT, IGR J11215-5952, never triggered the BAT: see Section 2.2 of the reference paper for more information about this source). They are divided into 46 BAT triggers (bat_subsample_flag = 'T', 43 in outbursts), 126 daily-averaged BATTM light curves (bat_subsample_flag = 'D'), 267 orbital-averaged BATTM light curves (bat_subsample_flag = 'O'), and 678 on-board detections (bat_subsample_flag = 'B'). For each flare, the time of the occurrence, duration, flux, and significance are reported. Given the cut in sigma applied to the available BATTM and on-board detections, this catalog is a flux-limited sample of flares. Assuming a Crab-like spectrum (power-law of photon index 2.15), 5 sigma detections for one day and an average orbit typically correspond to fluxes of 5.98 x 10<sup>-10</sup> and 1.46 x 10<sup>-9</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, respectively, in the 15-150 keV band (or 3.38 x 10<sup>-10</sup> and 8.24 x 10<sup>-10</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the 15-50 keV band). This table was created by the HEASARC in August 2015 based on the union of <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/562/A2">CDS Catalog J/A+A/562/A2</a> files sample.dat (the properties of the confirmed SFXTs) and table4.dat (the catalog of the 1117 flares detected by the Swift BAT from 11 of the 12 confirmed SFXTs). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/swbatagn60
- Title:
- Swift BAT 60-Month Survey of Active Galactic Nuclei Catalog
- Short Name:
- SWBATAGN60
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Surveys above 10 keV represent one of the best resources to provide an unbiased census of the population of active galactic nuclei (AGNs). The authors present the results of 60 months of observation from 2005 March to 2010 March of the hard X-ray sky with the Swift Burst Alert Telescope (BAT). In this time frame, BAT detected (in the 15 - 55 keV band) 720 sources with a signal-to-noise ratio of >= 5 sigma in an all-sky survey, of which 428 are associated with AGNs, most of which are nearby. This sample has negligible incompleteness and statistics which are a factor of ~ 2 larger over similarly complete sets of AGNs. The sample contains (at least) 15 bona fide Compton-thick AGNs and 3 likely candidates. Compton-thick AGNs represent ~ 5% of AGN samples detected above 15 keV. The authors use the BAT data set to refine the determination of the log N - log S of AGNs which is extremely important, now that NuSTAR prepares for launch, toward assessing the AGN contribution to the cosmic X-ray background. The authors show that the log N - log S of AGNs selected above 10 keV is now established to ~ 10% precision. They derive the luminosity function of Compton-thick AGNs and measure a space density of 7.9 (+4.1, -2.9) x 10<sup>-5</sup> Mpc<sup>-3</sup> for objects with a de-absorbed luminosity larger than 2 x 10<sup>42</sup> erg s<sup>-1</sup>. As the BAT AGNs are all mostly local, they allow us to investigate the spatial distribution of AGNs in the nearby universe regardless of absorption. The authors find concentrations of AGNs that coincide spatially with the largest congregations of matter in the local (<= 85 Mpc) universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions. This table was created by the HEASARC in May 2012, based on an electronic version of Table 1 from the referenced paper, which was obtained from the ApJ website. This is a service provided by NASA HEASARC .
21235. Swift BAT survey of AGNs
- ID:
- ivo://CDS.VizieR/J/ApJ/681/113
- Title:
- Swift BAT survey of AGNs
- Short Name:
- J/ApJ/681/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the analysis of the first 9 months of data of the Swift BAT (Burst Alert Telescope) survey of AGNs in the 14-195keV band. Using archival X-ray data or follow-up Swift X-ray telescope (XRT) observations, we have identified 129 (103 AGNs) of 130 objects detected at |b|>15{deg} and with significance >4.8{sigma}. One source remains unidentified. These same X-ray data have allowed measurement of the X-ray properties of the objects.
21236. Swift-BAT survey of AGNs
- ID:
- ivo://CDS.VizieR/J/ApJ/728/58
- Title:
- Swift-BAT survey of AGNs
- Short Name:
- J/ApJ/728/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive and analyze the active galactic nuclei (AGNs) absorption distribution using a complete sample of AGNs detected by Swift-BAT in the first three years of the survey. The fraction of Compton-thick AGNs represents only 4.6% of the total AGN population detected by Swift-BAT. However, we show that once corrected for the bias against the detection of very absorbed sources the real intrinsic fraction of Compton-thick AGNs is 20^+9^_-6_%. We proved for the first time (also in the Burst Alert Telescope (BAT) band) that the anti-correlation of the fraction of absorbed AGNs and luminosity is tightly connected to the different behavior of the X-ray luminosity functions (XLFs) of absorbed and unabsorbed AGNs. This points toward a difference between the two subsamples of objects with absorbed AGNs being, on average, intrinsically less luminous than unobscured ones. Moreover, the XLFs show that the fraction of obscured AGNs might also decrease at very low luminosity.
- ID:
- ivo://CDS.VizieR/J/ApJ/721/1843
- Title:
- Swift-BAT survey of Galactic sources
- Short Name:
- J/ApJ/721/1843
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the populations of X-ray sources in the Milky Way in the 15-55keV band using a deep survey with the BAT instrument aboard the Swift observatory. We present the log N-log S distributions of the various source types and we analyze their variability and spectra. For the low-mass X-ray binaries (LMXBs) and the high-mass X-ray binaries (HMXBs), we derive the luminosity functions to a limiting luminosity of L_X_~7x10^34^erg/s. Our results confirm the previously found flattening of the LMXB luminosity function below a luminosity of L_X_~10^37^erg/s. The luminosity function of the HMXBs is found to be significantly flatter in the 15-55keV band than in the 2-10keV band. From the luminosity functions we estimate the ratios of the hard X-ray luminosity from HMXBs to the star formation rate, and the LMXB luminosity to the stellar mass. We use these to estimate the X-ray emissivity in the local universe from X-ray binaries and show that it constitutes only a small fraction of the hard X-ray background.
- ID:
- ivo://nasa.heasarc/swbatmontr
- Title:
- Swift BAT Transient Monitoring Catalog
- Short Name:
- SWBATMONTR
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The SWBATMONTR database table records high-level information of the lightcurves from the sources monitored with the Burst Alert Telescope (BAT) on board of Swift. The Swift/BAT Monitoring Program is aimed at (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of lightcurves of more than 1000 sources spanning the entire Swift lifetime. 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 BAT monitoring the sky in the field of view and provides alerts when detecting a burst of flux coming from a source in the field of view. The BAT monitoring lightcurves are generated by the BAT team over the course of the Swift mission. The HEASARC ingests these data in the archive and generates this database table by collecting high-level information from the data. The lightcurves are renamed to use a consistent naming convention, and the FITS header is updated by adding standard FITS keywords. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJ/765/L26
- Title:
- Swift/BAT ultra-hard X-ray data from GOALS LIRGs
- Short Name:
- J/ApJ/765/L26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first analysis of the all-sky Swift Burst Alert Telescope (BAT) ultra-hard X-ray (14-195keV) data for a targeted list of objects. We find that the BAT data can be studied at three-times-fainter limits than in previous blind detection catalogs based on prior knowledge of source positions and using smaller energy ranges for source detection. We determine the active galactic nucleus (AGN) fraction in 134 nearby (z<0.05) luminous infrared galaxies (LIRGs) from the GOALS sample. We find that LIRGs have a higher detection frequency than galaxies matched in stellar mass and redshift at 14-195keV and 24-35keV. In agreement with work at other wavelengths, the AGN detection fraction increases strongly at high IR luminosity with half of the high-luminosity LIRGs (50%, 6/12, logL_IR_/L_{sun}_>11.8) detected. The BAT AGN classification shows 97% (37/38) agreement with Chandra and XMM-Newton AGN classification using hardness ratios or detection of an iron K{alpha} line. This confirms our statistical analysis and supports the use of the Swift/BAT all-sky survey to study fainter populations of any category of sources in the ultra-hard X-ray band. BAT AGNs in LIRGs tend to show higher column densities with 40%+/-9% showing 14-195 keV/2-10 keV hardness flux ratios suggestive of high or Compton-thick column densities (logN_H_>24/cm2), compared to only 12%+/-5% of non-LIRG BAT AGNs. We also find that using specific energy ranges of the BAT detector can yield additional sources over total band detections with 24% (5/21) of detections in LIRGs at 24-35keV not detected at 14-195keV.
- ID:
- ivo://CDS.VizieR/J/ApJ/864/84
- Title:
- Swift follow-up obs. of the TXS 0506+056 blazar
- Short Name:
- J/ApJ/864/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detection of the IceCube-170922A neutrino coincident with the flaring blazar TXS 0506+056, the first and only ~3{sigma} high-energy neutrino source association to date, offers a potential breakthrough in our understanding of high-energy cosmic particles and blazar physics. We present a comprehensive analysis of TXS 0506+056 during its flaring state, using newly collected Swift, NuSTAR, and X-shooter data with Fermi observations and numerical models to constrain the blazar's particle acceleration processes and multimessenger (electromagnetic (EM) and high-energy neutrino) emissions. Accounting properly for EM cascades in the emission region, we find a physically consistent picture only within a hybrid leptonic scenario, with {gamma}-rays produced by external inverse-Compton processes and high-energy neutrinos via a radiatively subdominant hadronic component. We derive robust constraints on the blazar's neutrino and cosmic-ray emissions and demonstrate that, because of cascade effects, the 0.1-100keV emissions of TXS 0506+056 serve as a better probe of its hadronic acceleration and high-energy neutrino production processes than its GeV-TeV emissions. If the IceCube neutrino association holds, physical conditions in the TXS 0506+056 jet must be close to optimal for high-energy neutrino production, and are not favorable for ultrahigh-energy cosmic-ray acceleration. Alternatively, the challenges we identify in generating a significant rate of IceCube neutrino detections from TXS 0506+056 may disfavor single-zone models, in which {gamma}-rays and high-energy neutrinos are produced in a single emission region. In concert with continued operations of the high-energy neutrino observatories, we advocate regular X-ray monitoring of TXS 0506+056 and other blazars in order to test single-zone blazar emission models, clarify the nature and extent of their hadronic acceleration processes, and carry out the most sensitive possible search for additional multimessenger sources.
