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LSXPS Catalogue: On-line Documentation

Search | Transients | Catalogue paper | Table descriptions | Download catalogue files | Upper limit server | Recent changes.

On this page:

  1. Summary / Quick-start information.
  2. Access & Usage.
  3. Transient detection.
  4. Catalogue completeness and purity.
  5. Notes on terminology.
  6. Catalogue contents.

Other documentation:

False alarm rate as a function of exposure time and flag

Fig. 1 The solid line shows the sky coverage (corrected for overlaps) of LSXPS. The histograms show the distribution of dataset exposures (observations in blue, stacks in red). This plot is automatically updated whever dataset are added to LSXPS.

Summary / Quick-start information

Data included2005-01-01 — working…
(working…)
Sky coverageworking…
Detectionsworking…
Unique sourcesworking…
Variable sources2working…
Uncatalogued sources2working…
False positive rateFlag=Good0.3%
Flag=Good/Reasonable1%
Flag=Good/Reasonable/Poor<10%

Table 1. Summary details of the 2SXPS catalogue.
1‘Variable’ sources are those which are variable with at least 3-σ confidence in at least one band or hardness ratio.
2Sources counted as ‘Uncatalogued’ here may have matches USNO-B1 or 2MASS, as the rate of spurious matches to those catalogues is very high.

The LSXPS catalogue covers square degrees on the sky and contains position, fluxes, spectral details and variability information for X-ray point sources detected in observations with the Swift X-ray Telescope between 2005-01-01 and . Each source has a detection flag which indicates how likely it is to be a real astrophysical object. Table 1 shows summary information for the catalogue, and is automatically updated. Fig. 1 shows the latest details of the sky coverage.

Full details of how the catalogue was constructed are given in Evans et al (2023). The underlying source detection process is almost identical to that of 2SXPS but the unique feature of this catalogue is that it is living: it is updated in nearly real-time and transient searches are carried out on each dataset as it is received.

On this web page we give some summary details of the catalogue; how to access, use and cite it; a demonstration of its quality and performance; and finally details of the catalogue contents. Other pages provide details about the LSXPS website and the upper-limit server..

When Searching the catalogue you can select a pre-defined subset of the full catalogue to search, for greater purity (but reduced completeness). There are two such samples, as defined in Table 2

SampleSourcesDatasets
All All sources. All datasets.
Clean Sources with a detection flag of 0 or 1, a field flag of 0 or 1, and none of the ‘OpticalLoadingWarning,’ ‘StrayLightWarning’ and ‘NearBrightSourceWarning’ warnings set. Datasets with a field flag of 0 or 1.
Ultra-clean A subset of clean sources with detection and field flags of 0. Datasets with detection flag of 0.

Table 2. Definitions of the pre-defined subsets that can be selected.

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Data Access and Usage

The catalogue can be queried through the search interface, and accessed extensively through the swifttools.ukssdc Python module (available in swiftools v3.0 onwards). You can also or download the latest table files.

Not all columns contain values for each entry in the tables, for example, in the Sources table, only sources for which a spectral fit exists have entries in the Fitted* fields. In the CSV files, such empty entries are literally empty; in the FITS and SQL files these entries are NULL.

If you use data from this catalogue in your work, including data obtained via the API, please cite Evans et al. (2023) and in the acknowledgements section of your publication, please state:

This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester.

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Transient detection

In order to determine whether an object found in a new XRT dataset is a transient, two steps are taken. The first is to determine if it is a catalogued X-ray source, the second is to determine whether its measured flux is above historical upper limits (more details are in Section 4 of the LSXPS paper). The set of catalogues against which we check to see if the source is known may evolve. The current set is:

If the source is not catalogued, then the upper limits against which we compare are, at the present time:

For the first two entries, the upper limits are found using the ESA HILIGT service.

Transients have to be manually classified by XRT team members before they are released on the public web pages. They can have the following classifications:

Outburst
If the light curve shows historical detections of the source (from the forced photometry) but at a flux level below that of the new observation, the source is likely an outburst rather than a transient.
Low significance
The Eddington bias causes objects detected close to the sensitivity limit to be preferentially recorded with count-rates significantly above their true value; this can result in sources which are in reality below the historical upper limit (i.e.\ not transients) to be misclassified as transients. We are not able to say a-priori whether a given source is affected by this bias, although in the 1SXPS paper (section 6.2 and fig.~10), we showed that SXPS sources with fewer than 30 counts are affected by this bias. Sources whose peak count-rate is <3 σ above the 3-σ upper limit and which have fewer than 30 counts in the detection are usually classed as low significance.
Needs follow up
This is somewhat of a catch-all category, where the source does not obviously fall into either category above, but there is some doubt as to its nature and further observations are felt necessary before it can be definitively identified as a transient.
Confirmed transient
The object is definitely a new transient.

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Completeness and purity

The source detection system employed by LSXPS is almost identical to that of 2SXPS. As a result, we did not need to recharacterise its performance. The performance of the 2SXPS source detection system was done using an extensive set of simulations. This is described in detail in Section 7 of Evans et al. (2020). We simulated fields for a range of exposure times and background levels, chosen to reflect the range of such values in 2SXPS. Simulations did not include artifacts such as stray light, hot pixels, bright Earth or diffuse sources; however, our screening process is designed to identify and flag 2SXPS sources affected by such phenomena. We ran the 2SXPS source detection algorithm on the simulated images, and so by comparing the set of detected sources with the input list of simulated sources, we can measure both the completeness of our detection system and its purity.

Each detection is assigned a flag based on various statistical tests. These flags were calibrated (via the simulations) such that the fraction of spurious sources was 0.3% (i.e. equivalent to a Gaussian 3-σ significance) for Good, 1% when Good and Reasonable sources are considered, and up to 10% when the Poor sources are also included. Fig. 2 shows the false positive rate obtained from the simulations as a function of exposure time, validating the purity claims made here. Fig. 3 shows the fraction of simulated sources recovered as a function of flux and exposure time, i.e. the completeness of our algorithm.

False alarm rate as a function of exposure time and flag

Fig. 2 False positive rate as a function of exposure time and flag. The green points refer to Good sources, blue points are Good and Reasonable and red shows all sources.

False alarm rate as a function of exposure time and flag

Fig. 3 The completeness of 2SXPS. The dotted, solid and dash-dot lines show the flux at which 10%, 50% and 90% of the simulated sources were recovered, respectively. Colours are as in Fig. 1.

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Notes on terminology

There are various phrases and labels used within the LSXPS catalogue which it is important users properly understand, especially since the meanings of these labels may differ from those used in other catalogues. Several key pairs of labels are described here.

Datasets: observations and stacked images (and snapshots)

Swift data are organised into observations, each of which has a unique 11-digit obsID. An observation generally contains all observations of a given location within a UT day, and may consist of multiple snapshots, taken on different spacecraft orbits, as described on this page. The basic datasets from which 2SXPS was created are the observations.

Many locations on the sky are observed repeatedly by Swift, for example, to monitor the evolution of a specific source, and so we also combined overlapping observations to give a single dataset of greater exposure, allowing fainter sources to be detected. We call these datasets stacked images. Some observations have only partial overlap, and one can make long ‘chains’ of overlapping observations covering large spatial areas. We defined a maximum stacked image size of 2,700 pixels (~106′) to a side and then created stacked images such that every overlap of observations is in at least one stack. Thus, multiple stacked images can overlap, and an observation can contribute to multiple stacked images; but the maximum exposure at any given sky is reached for every location Swift has observed.

Within each dataset (observation or stacked image), source detection and PSF fitting is carried out on each of the four bands independently of each other. Note that this is not the same approach as the XMM catalogues, in which the energy bands are handled simultaneously.

There is a third natural timescale to consider for Swift data. The satellite is in a low-Earth orbit and due to its Earth-limb avoidance constraints, the longest window of continuous visibility for any point on the sky is around 2.7 ks. Thus if an observation is required which is longer than this (or in which multiple exposures are desired within a UT day, for science reasons) the observation will comprise a number of separate exposures, known as ‘snapshots’. Each snapshot is a continuous exposure in a single pointing direction. We do not carry out source detection on individual snapshots, however light curves are built with per-snapshot binning (as well as per-observation binning) and variability calculations are also carried out on this timescale.

Detections and sources; and aliases

In the creation of LSXPS, source detection was carried out on every dataset and every energy band independently (as noted above, this differs from the XMM approach). Thus, for many sources there are multiple detections, in the different energy bands and in different datasets covering the source location. Details of these are all listed in the ‘Detections’ table available for download, and are given in the relevant parts of the different web pages.

These separate detections were then rationalised into a single list of unique source in two steps. First, detections across different bands but within the same dataset were combined. For this stage, only the statistical errors on the source positions, as deduced from the PSF fit, were used to determine whether two detections corresponded to the same underlying source. This is because, since all detections at this point are from the same dataset, the astrometric system is the same for all sources and so its uncertainty is irrelevant. Then the lists of unique soures per dataset were combined to create the final source list; at this stage the astrometric uncertainty associated with the datasets was taken into account.

The process of merging detections was not perfect. Occasionally the statistical uncertainties were underestimated and also the astrometric uncertainty appears to have a broad tail. As a result of this a small number of sources exist for which multiple detections were not correctly merged, and instead the catalogue contains two distinct sources which really are the same object. Based on an inspection of the distribution of source separations in the catalogue, we therefore identified any sources which lie within 20″ of each other and are not detected in the same dataset, and labelled these as possible aliases of each other. It is vital to note that not everything so labelled is really an alias; in some cases they are genuinely distinct sources which are close together. In other cases, particularly where one of the sources is very bright; the nearby sources are spurious detections in the PSF wings; this is not the same as an alias. In the case of genuine aliases, the available light curves of the sources will be incomplete and incorrect. That is, if a source is incorrectly identified as being two sources, called source A and source B, then the light curve of source A will not contain values derived from the blind detections that were assigned to source B, and furthermore the bins from those datasets where the source was called source B will have been deduced (for source A) based on the background map with the PSF model of source B present! Therefore, in the light curve section of the source pages, an option is given to consolidate across aliases of the source. Using this you can select which sources are genuine aliases, and the correct light curve will then be produced.

Blind and non-blind (retrospective) detections

The sources present in LSXPS were detected via a blind search. That is, no a-priori knowledge of the possible existence of sources was used to deduce whether or not a given set of photons corresponded to the detection of a point source. However, once the list of sources had been produced, a retrospective check was carried out on those datasets in which the source was located, but had not been detected by the blind search. In this case the existence of a source at the specific location was assumed a-priori, and the count-rate of the source inferred based on the number of source and background events at the source's location. If this count-rate was above zero, with 99.7% confidence (i.e 3-σ), the source was deemed to have been present and thus detected in that dataset. The detections database table only lists the blind detections; sources identified as detected in this non-blind, retrospective analysis were not added to the table, however in the light curve analysis they are marked as being detected in those datasets. When viewing the light curves you have the option of whether non-detections should be shown as 3-σ upper limits, or datapoints with 1-σ error-bars, and you can specify this separately for bins in which the source was not detected in any way, and those in which there was no blind detetion, but in which the targeted analysis yields a non-zero count rate.

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Catalogue Contents

There are four tables available for download:

Sources
This is the main catalogue table. This contains the details of the unique sources in the catalogue.
Datasets
This contains details of the individual datasets (observations and stacked images) of which the catalogue is composed.
Detections
This contains details of the individual detections in each dataset and energy band, of the sources.
Cross correlations
This contains details of sources from external catalogues which are positionally coincident with 2SXPS sources.

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Sources Table

The Sources table is the main catalogue table, and gives details of each unique source identified in the catalogue. There are 230 columns in this table in total, so for ease of consideration we have grouped them into the following categories:

Identifiers

LSXPS_ID
Numerical unique source identifier within LSXPS.
IAUName
IAU-format name, LSXPS JHHMMSS.s+-ddmmsss

[Hide identifier columns | Back to Sources table | Back to top | LSXPS index]

Position information

RA
Right Ascension (J2000) in decminal degrees.
Decl
Declination (J2000) in decimal degrees.
Err90
Position uncertainty, 90% confidence, radial, assumed to be Rayleigh-distributed.
AstromType
Provenance of the astrometry used to derive the source position.
  • 0: Astrometry from the Swift star trackers.
  • 1: Astrometry from rectification with 2MASS.
l
Galactic longitude.
b
Galactic latitude.
MeanOffAxisAngle
The mean angular distance of the source from the XRT boresight in all observations within which the source was detected (arcmin).
NearestNeighbour
The distance (in arcseconds) to the closest LSXPS source to this one.
NearestOKNeighbour
The distance (in arcseconds) to the closest LSXPS source to this one which is ranked Good or Reasonable and has no other DetFlag bits set.
NearestNeighbour_ID
The LSXPS_ID of the closest LSXPS source to this one.
NearestOKNeighbour_ID
The LSXPS_ID of the closest LSXPS source to this one which is ranked Good or Reasonable and has no other DetFlag bits set.
HPPIX
The Healpix pixel containing the source (NSIDE=128, ordering=RING).

[Hide position columns | Back to Sources table | Back to top | LSXPS index]

Exposure information

Exposure
The total exposure at the source location in the catalogue.
FirstObsDate
The UTC date & time of the start of the first observation in LSXPS which covered the source location.
LastObsDate
The UTC date & time of the end of the last observation in LSXPS which covered the source location.
FirstObsMET
The time of the start of the first observation in LSXPS which covered the source location, in Swift Mission Elapsed Time.
LastObsMET
The time of the end of the last observation in LSXPS which covered the source location in, Swift Mission Elapsed Time.
FirstDetDate
The UTC date & time of the start of the first observation in LSXPS in which the source count rate is inconsisent with 0 at the 3-sigma level.
LastDetDate
The UTC date & time of the end of the last observation in LSXPS in which the source count rate is inconsisent with 0 at the 3-sigma level.
FirstDetMET
The time of the start of the first observation in LSXPS in which the source count rate is inconsisent with 0 at the 3-sigma level, in Swift Mission Elapsed Time.
LastDetMET
The time of the end of the last observation in LSXPS in which the source count rate is inconsisent with 0 at the 3-sigma level, in Swift Mission Elapsed Time.
FirstBlindDetDate
The UTC date & time of the start of the first observation in LSXPS in which the source is detected in the blind search.
LastBlindDetDate
The UTC date & time of the end of the last observation in LSXPS in which the source is detected in the blind search.
FirstBlindDetMET
The time of the start of the first observation in LSXPS in which the source is detected in the blind search, in Swift Mission Elapsed Time.
LastBlindDetMET
The time of the end of the last observation in LSXPS in which the source is detected in the blind search, in Swift Mission Elapsed Time.
NumObs
The number of observations covering the position of this source.
NumBlindDetObs
The number of observations in which this source was found in a blind search.
NumDetObs
The number of observations in which this source is detected.
BestDetectionID
The ID of the 'best' detection, (cf the detections table).
NonBlindDet_band0
Whether the count-rate in the 0.3-10 keV band is inconsistent with 0 at the 3-sigma level.
NonBlindDet_band1
Whether the count-rate in the 0.3-1 keV band is inconsistent with 0 at the 3-sigma level.
NonBlindDet_band2
Whether the count-rate in the 1-2 keV band is inconsistent with 0 at the 3-sigma level.
NonBlindDet_band3
Whether the count-rate in the 2-10 keV band is inconsistent with 0 at the 3-sigma level.

[Hide exposure columns | Back to Sources table | Back to top | LSXPS index]

Flag information

DetFlag
The best detection flag from all detections of the source. The basic values are 0, 1, or 2, meaning Good, Reasonable or Poor respectively. Higher values mean that an extra warning is associated with the source. This warning is bitwise, defined as follows:
BitValueDescription
2 4 The source position is consistent with that of a known extended source.
3 8 The source is likely an alias of a badly-fitted piled up source.
4 16 The source lies in a region marked as contaminated during the visual screening.
Fieldflag
The best field flag from all detections of the source. This is a bitwise flag with the following values:
BitValueDescription
0 1 Field contains stray light.
1 2 Field contains diffuse emission or artifacts.
2 4 Field contains stray light that could not be adequately modelled.
3 8 Field contains a bright, piled up source which was not properly fitted in some bands.
DetFlag_band0
The final detection flag the 0.3-10 keV band.
DetFlag_band1
The final detection flag the 0.3-1 keV band.
DetFlag_band2
The final detection flag in the 1-2 keV band.
DetFlag_band3
The final detection flag in the 2-10 keV band.
OpticalLoadingWarning
The worst optical loading warning from all detections of this source. If this is 0 there is no warning, otherwise there is a nearby optical source brighter than the level at which optical loading becomes a concern; the value indicates how many magnitudes brighter than that level the source is.
StrayLightWarning
Whether any detection of this source occurred within fitted stray light rings.
NearBrightSourceWarning
Whether any detection of this source occurred within the PSF wings of a bright object.
IsPotentialAlias
Whether this source is potentially an alias (i.e. duplicate) of another source.

[Hide flag columns | Back to Sources table | Back to top | LSXPS index]

State information

WhenAdded
The date at which this source was added to LSXPS.
StillDetected
Whether the source was detected in the most recent observation of its location (1=yes; 0=no, but last upper limit unconstraining; -1 = no, and upper limit below last detection).
ProcessedStatus
A bit-wise flag describing the processing status of the source data.
WhenModified
The date at which this source was last analysed.

[Hide flag columns | Back to Sources table | Back to top | LSXPS index]

Count-rate information

Rate_band0
The mean count-rate in the 0.3-10 keV band.
Rate_band0_pos
The 1-sigma positive uncertainty on the mean count-rate in the 0.3-10 keV band.
Rate_band0_neg
The 1-sigma negative uncertainty on the mean count-rate in the 0.3-10 keV band.
HR1
The aggregate HR1 hardness ratio of the source.
HR1_pos
The 1-sigma positive uncertainty on the aggregate HR1 hardness ratio of the source.
HR1_neg
The 1-sigma negative uncertainty on the aggregate HR1 hardness ratio of the source.
HR2
The aggregate HR2 hardness ratio of the source.
HR2_pos
The 1-sigma positive uncertainty on the aggregate HR2 hardness ratio of the source.
HR2_neg
The 1-sigma negative uncertainty on the aggregate HR2 hardness ratio of the source.
Rate_band1
The mean count-rate in the 0.3-1 keV band.
Rate_band1_pos
The 1-sigma positive uncertainty on the mean count-rate in the 0.3-1 keV band.
Rate_band1_neg
The 1-sigma negative uncertainty on the mean count-rate in the 0.3-1 keV band.
Rate_band2
The mean count-rate in the 1-2 keV band.
Rate_band2_pos
The 1-sigma positive uncertainty on the mean count-rate in the 1-2 keV band.
Rate_band2_neg
The 1-sigma negative uncertainty on the mean count-rate in the 1-2 keV band.
Rate_band3
The mean count-rate in the 2-10 keV band.
Rate_band3_pos
The 1-sigma positive uncertainty on the mean count-rate in the 2-10 keV band.
Rate_band3_neg
The 1-sigma negative uncertainty on the mean count-rate in the 2-10 keV band.
Counts_band0
The total number of counts in the source region in the 0.3-10 keV band.
Counts_band1
The total number of counts in the source region in the 0.3-1 keV band.
Counts_band2
The total number of counts in the source region in the 1-2 keV band.
Counts_band3
The total number of counts in the source region in the 2-10 keV band.
BgCounts_band0
The total number of background counts expected in the source region in the 0.3-10 keV band.
BgCounts_band1
The total number of background counts expected in the source region in the 0.3-1 keV band.
BgCounts_band2
The total number of background counts expected in the source region in the 1-2 keV band.
BgCounts_band3
The total number of background counts expected in the source region in the 2-10 keV band.
RateCF_band0
The PSF correction factor in the 0.3-10 keV band.
RateCF_band1
The PSF correction factor in the 0.3-1 keV band.
RateCF_band2
The PSF correction factor in the 1-2 keV band.
RateCF_band3
The PSF correction factor in the 2-10 keV band.
UL_band0
The 3-sigma upper confidence limit on the count-rate in the 0.3-10 keV band.
UL_band1
The 3-sigma upper confidence limit on the count-rate in the 0.3-1 keV band.
UL_band2
The 3-sigma upper confidence limit on the count-rate in the 1-2 keV band.
UL_band3
The 3-sigma upper confidence limit on the count-rate in the 2-10 keV band.
PeakRate_band0
The peak count-rate in the 0.3-10 keV band.
PeakRate_band0_pos
The 1-sigma positive uncertainty on the peak count-rate in the 0.3-10 keV band.
PeakRate_band0_neg
The 1-sigma negative uncertainty on the peak count-rate in the 0.3-10 keV band.
PeakRate_band1
The peak count-rate in the 0.3-1 keV band.
PeakRate_band1_pos
The 1-sigma positive uncertainty on the peak count-rate in the 0.3-1 keV band.
PeakRate_band1_neg
The 1-sigma negative uncertainty on the peak count-rate in the 0.3-1 keV band.
PeakRate_band2
The peak count-rate in the 1-2 keV band.
PeakRate_band2_pos
The 1-sigma positive uncertainty on the peak count-rate in the 1-2 keV band.
PeakRate_band2_neg
The 1-sigma negative uncertainty on the peak count-rate in the 1-2 keV band.
PeakRate_band3
The peak count-rate in the 2-10 keV band.
PeakRate_band3_pos
The 1-sigma positive uncertainty on the peak count-rate in the 2-10 keV band.
PeakRate_band3_neg
The 1-sigma negative uncertainty on the peak count-rate in the 2-10 keV band.

[Hide count-rate columns | Back to Sources table | Back to top | LSXPS index]

Variability information

PvarPchiSnapshot_band0
The probability that the source count-rate in the 0.3-10 keV band does not vary between snapshots.
PvarPchiSnapshot_band1
The probability that the source count-rate in the 0.3-1 keV band does not vary between snapshots.
PvarPchiSnapshot_band2
The probability that the source count-rate in the 1-2 keV band does not vary between snapshots.
PvarPchiSnapshot_band3
The probability that the source count-rate in the 2-10 keV band does not vary between snapshots.
PvarPchiSnapshot_HR1
The probability that the source HR1 hardness ratio does not vary between snapshots.
PvarPchiSnapshot_HR2
The probability that the source HR2 hardness ratio does not vary between snapshots.
PvarPchiObsID_band0
The probability that the source count-rate in the 0.3-10 keV band does not vary between observations.
PvarPchiObsID_band1
The probability that the source count-rate in the 0.3-1 keV band does not vary between observations.
PvarPchiObsID_band2
The probability that the source count-rate in the 1-2 keV band does not vary between observations.
PvarPchiObsID_band3
The probability that the source count-rate in the 2-10 keV band does not vary between observations.
PvarPchiObsID_HR1
The probability that the source HR1 hardness ratio does not vary between observations.
PvarPchiObsID_HR2
The probability that the source HR2 hardness ratio does not vary between observations.

[Hide variability columns | Back to Sources table | Back to top | LSXPS index]

Spectral/Flux information

GalacticNH
The Galactic absorption column density (in cm-2) in the direction of the source, determined from Willingale et al. (2013).
WhichPow
Which of the available estimates of the power-law spectral ECF and fluxes is given in the summary fields:
ValueSource of spectral information
0 Fixed spectrum: power-law with Γ=1.7 and NH is GalacticNH.
1 Power-law spectral values derived from the hardness ratios.
2 Power-law spectral values taken from a fit to a custom-built spectrum.
WhichAPEC
Which of the available estimates of the APEC spectral ECF and fluxes is given in the summary fields:
ValueSource of spectral information
0 Fixed spectrum: APEC with kT=1 keV and NH is GalacticNH.
1 APEC spectral values derived from the hardness ratios.
2 APEC spectral values taken from a fit to a custom-built spectrum.
GalacticNH
The Galactic absorption column in the direction of the source, from Willingale et al (2013), in cm^-2.
WhichPow
Which method of determining the spectral properties assuming a power-law was used: 0=Canned spectrum, 1=Interpolated from the HR, 2=Spectrum constructed and fitted.
WhichAPEC
Which method of determining the spectral properties assuming an APEC was used: 0=Canned spectrum, 1=Interpolated from the HR, 2=Spectrum constructed and fitted.
PowECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming a power-law spectrum.
PowECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming a power-law spectrum.
PowFlux
The mean 0.3-10 keV observed flux assuming a power-law spectrum.
PowFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming a power-law spectrum.
PowFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming a power-law spectrum.
PowUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming a power-law spectrum.
PowUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming a power-law spectrum.
PowUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming a power-law spectrum.
APECECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming an APEC spectrum.
APECECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming an APEC spectrum.
APECFlux
The mean 0.3-10 keV observed flux assuming an APEC spectrum.
APECFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming an APEC spectrum.
APECFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming an APEC spectrum.
APECUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming an APEC spectrum.
APECUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming an APEC spectrum.
APECUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming an APEC spectrum.
PowPeakFlux
The peak 0.3-10 keV observed flux assuming a power-law spectrum.
PowPeakFlux_pos
The 1-sigma positive uncertainty on the peak 0.3-10 keV observed flux assuming a power-law spectrum.
PowPeakFlux_neg
The 1-sigma negative uncertainty on the peak 0.3-10 keV observed flux assuming a power-law spectrum.
PowPeakUnabsFlux
The peak 0.3-10 keV unabsorbed flux assuming a power-law spectrum.
PowPeakUnabsFlux_pos
The 1-sigma positive uncertainty on the peak 0.3-10 keV unabsorbed flux assuming a power-law spectrum.
PowPeakUnabsFlux_neg
The 1-sigma negative uncertainty on the peak 0.3-10 keV unabsorbed flux assuming a power-law spectrum.
APECPeakFlux
The peak 0.3-10 keV observed flux assuming an APEC spectrum.
APECPeakFlux_pos
The 1-sigma positive uncertainty on the peak 0.3-10 keV observed flux assuming an APEC spectrum.
APECPeakFlux_neg
The 1-sigma negative uncertainty on the peak 0.3-10 keV observed flux assuming an APEC spectrum.
APECPeakUnabsFlux
The peak 0.3-10 keV unabsorbed flux assuming an APEC spectrum.
APECPeakUnabsFlux_pos
The 1-sigma positive uncertainty on the peak 0.3-10 keV unabsorbed flux assuming an APEC spectrum.
APECPeakUnabsFlux_neg
The 1-sigma negative uncertainty on the peak 0.3-10 keV unabsorbed flux assuming an APEC spectrum.
FixedPowECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming the canned power-law spectrum.
FixedPowECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming the canned power-law spectrum.
FixedPowFlux
The mean 0.3-10 keV observed flux assuming the canned power-law spectrum.
FixedPowFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming the canned power-law spectrum.
FixedPowFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming the canned power-law spectrum.
FixedPowUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming the canned power-law spectrum.
FixedPowUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the canned power-law spectrum.
FixedPowUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the canned power-law spectrum.
FixedAPECECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming the canned APEC spectrum.
FixedAPECECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming the canned APEC spectrum.
FixedAPECFlux
The mean 0.3-10 keV observed flux assuming the canned APEC spectrum.
FixedAPECFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming the canned APEC spectrum.
FixedAPECFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming the canned APEC spectrum.
FixedAPECUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming the canned APEC spectrum.
FixedAPECUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the canned APEC spectrum.
FixedAPECUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the canned APEC spectrum.
InterpPowECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming the power-law spectrum interpolated from the HRs.
InterpPowECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming the power-law spectrum interpolated from the HRs.
InterpPowNH
The hydrogen column density inferred assuming the power-law spectrum interpolated from the HRs.
InterpPowNH_pos
The 1-sigma positive uncertainty on the hydrogen column density inferred assuming the power-law spectrum interpolated from the HRs.
InterpPowNH_neg
The 1-sigma negative uncertainty on the hydrogen column density inferred assuming the power-law spectrum interpolated from the HRs.
InterpPowGamma
The spectral photon index inferred assuming the power-law spectrum interpolated from the HRs.
InterpPowGamma_pos
The 1-sigma positive uncertainty on the spectral photon index inferred assuming the power-law spectrum interpolated from the HRs.
InterpPowGamma_neg
The 1-sigma negative uncertainty on the spectral photon index inferred assuming the power-law spectrum interpolated from the HRs.
InterpPowFlux
The mean 0.3-10 keV observed flux assuming the power-law spectrum interpolated from the HRs.
InterpPowFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming the power-law spectrum interpolated from the HRs.
InterpPowFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming the power-law spectrum interpolated from the HRs.
InterpPowUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming the power-law spectrum interpolated from the HRs.
InterpPowUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the power-law spectrum interpolated from the HRs.
InterpPowUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the power-law spectrum interpolated from the HRs.
InterpAPECECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming the APEC spectrum interpolated from the HRs.
InterpAPECECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming the APEC spectrum interpolated from the HRs.
InterpAPECNH
The hydrogen column density inferred assuming the APEC spectrum interpolated from the HRs.
InterpAPECNH_pos
The 1-sigma positive uncertainty on the hydrogen column density inferred assuming the APEC spectrum interpolated from the HRs.
InterpAPECNH_neg
The 1-sigma negative uncertainty on the hydrogen column density inferred assuming the APEC spectrum interpolated from the HRs.
InterpAPECkT
The temperature inferred assuming the APEC spectrum interpolated from the HRs.
InterpAPECkT_pos
The 1-sigma positive uncertainty on the temperature inferred assuming the APEC spectrum interpolated from the HRs.
InterpAPECkT_neg
The 1-sigma negative uncertainty on the temperature inferred assuming the APEC spectrum interpolated from the HRs.
InterpAPECFlux
The mean 0.3-10 keV observed flux assuming the APEC spectrum interpolated from the HRs.
InterpAPECFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming the APEC spectrum interpolated from the HRs.
InterpAPECFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming the APEC spectrum interpolated from the HRs.
InterpAPECUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming the APEC spectrum interpolated from the HRs.
InterpAPECUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the APEC spectrum interpolated from the HRs.
InterpAPECUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the APEC spectrum interpolated from the HRs.
P_pow
The probability that the HR values of this source could be obtained if the true spectrum is an absorbed power-law.
P_APEC
The probability that the HR values of this source could be obtained if the true spectrum is an APEC.
FittedPowECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowNH
The hydrogen column density inferred assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowNH_pos
The 1-sigma positive uncertainty on the hydrogen column density inferred assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowNH_neg
The 1-sigma negative uncertainty on the hydrogen column density inferred assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowGamma
The spectral photon index inferred assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowGamma_pos
The 1-sigma positive uncertainty on the spectral photon index inferred assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowGamma_neg
The 1-sigma negative uncertainty on the spectral photon index inferred assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowFlux
The mean 0.3-10 keV observed flux assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the power-law spectral model fitted to a custom-built spectrum.
FittedPowCstat
The C-statistic from the power-law spectral fit to the custom-built spectrum.
FittedPowDOF
The number of degrees of freedom in the power-law spectral fit to the custom-built spectrum.
FittedPowReducedChi2
The Churazov-weighted reduced chi^2 from the power-law spectral fit to the custom-built spectrum.
FittedAPECECFO
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV observed flux, assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECECFU
The Energy Conversion Factor from 0.3-10 keV count-rate to 0.3-10 keV unabsorbed flux, assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECNH
The hydrogen column density inferred assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECNH_pos
The 1-sigma positive uncertainty on the hydrogen column density inferred assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECNH_neg
The 1-sigma negative uncertainty on the hydrogen column density inferred assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECkT
The temperature inferred assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECkT_pos
The 1-sigma positive uncertainty on the temperature inferred assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECkT_neg
The 1-sigma negative uncertainty on the temperature inferred assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECFlux
The mean 0.3-10 keV observed flux assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV observed flux assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV observed flux assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECUnabsFlux
The mean 0.3-10 keV unabsorbed flux assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECUnabsFlux_pos
The 1-sigma positive uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECUnabsFlux_neg
The 1-sigma negative uncertainty on the mean 0.3-10 keV unabsorbed flux assuming the APEC spectral model fitted to a custom-built spectrum.
FittedAPECCstat
The C-statistic from the APEC spectral fit to the custom-built spectrum.
FittedAPECDOF
The number of degrees of freedom in the APEC spectral fit to the custom-built spectrum.
FittedAPECReducedChi2
The Churazov-weighted reduced chi^2 from the APEC spectral fit to the custom-built spectrum.
HasSpec
Whether a custom-built spectrum was created for this source.

[Hide spectral/flux columns | Back to Sources table | Back to top | LSXPS index]

Cross-correlation information

NumExternalMatches
The number of external sources found to agree spatially with this one at the 3-sigma level.
NumExternalMatches_slim
The number of external sources found to agree spatially with this one at the 3-sigma level, excluding 2MASS and USNO-B1 matches.
MatchInROSHRI
Whether the source is spatially within 3 sigma of a source in the Rosat HRI catalogue.
MatchIn2RXS
Whether the source is spatially within 3 sigma of a source in the 2RXS catalogue.
MatchIn4XMM_DR10
Whether the source is spatially within 3 sigma of a source in the 3XMM-DR8 catalogue.
MatchIn4XMM_DR10s
Whether the source is spatially within 3 sigma of a source in the 3XMM-DR7s (stacked) catalogue.
MatchInXMMSL2
Whether the source is spatially within 3 sigma of a source in the XMMSL2 catalogue.
MatchInSwiftFT
Whether the source is spatially within 3 sigma of a source in the SwiftFT catalogue.
MatchIn1SWXRT
Whether the source is spatially within 3 sigma of a source in the 1SWXRT catalogue.
MatchInXRTGRB
Whether the source is spatially within 3 sigma of an XRT GRB afterglow.
MatchInSDSS_QSO_DR14
Whether the source is spatially within 3 sigma of a source in the SDSS QSO DR14 catalogue.
MatchIn2MASS
Whether the source is spatially within 3 sigma of a source in the 2MASS catalogue.
MatchInUSNOB1
Whether the source is spatially within 3 sigma of a source in the USNO-B1 catalogue.
MatchIn2CSC
Whether the source is spatially within 3 sigma of a source in the 2CSC catalogue.
MatchIn2SXPS
Whether the source is spatially within 3 sigma of a source in the 2SXPS catalogue.

[Hide cross-correlation columns | Back to Sources table | Back to top | LSXPS index]

Datasets Table

The Datasets table contains information about individual datasets — observations and stacked images — which make up the LSXPS catalogue.

DatasetID
The unique identifier for this dataset.
ObsID
The identifier of the observation or stacked image in which this detection occurred.
DataVersion
The version of this dataset; for stacked images it is the number of times the image has been analysed with extra data; for single observations it is the number of times the original data were processed after data downlink.
IsStackedImage
Whether or not this is a stacked image.
FieldFlag
The warning flag associated with this dataset. This is a bitwise flag with the following values:
BitValueDescription
0 1 Field contains stray light.
1 2 Field contains diffuse emission or artifacts.
2 4 Field contains stray light that could not be adequately modelled.
3 8 Field contains a bright, piled up source which was not properly fitted in some bands.
RA
The Right Ascension (J2000) of the field centre in decimal degrees.
Decl
The declination (J2000) of the field centre in decimal degrees.
l
Galactic longitude of the field centre.
b
Galactic latitude of the field centre.
ImageSize
The side length of the field image in XRT pixels (2.357 arcsec per pixel).
ExposureUsed
The nominal exposure in the dataset, after all screening has been carried out.
StartTime_UTC
The UTC start time of the dataset.
StopTime_UTC
The UTC end time of the dataset.
OriginalExposure
The original nominal exposure in the dataset before screening.
StartTime_MET
The start time of the dataset, in Swift Mission Elapsed Time.
StopTime_MET
The end time of the dataset, in Swift Mission Elapsed Time.
MidTime_MET
The mid-time of the dataset, in Swift Mission Elapsed Time.
MidTime_TDB
The mid-time of the dataset, in Barycentric Dynamical Time.
MidTime_MJD
The mid-time of the dataset, as a Modified Julian Date.
LiveDate
The UTC date at which this dataset became live.
FieldBG_band0
The mean background level in the 0.3-10 keV band.
FieldBG_band1
The mean background level in the 0.3-1 keV band.
FieldBG_band2
The mean background level in the 1-2 keV band.
FieldBG_band3
The mean background level in the 2-10 keV band.
NumSrc_band0
The number of sources detected in this dataset in the 0.3-10 keV band.
NumOK_band0
The number of good or reasonable sources detected in this dataset in the 0.3-10 keV band.
MedianDist_band0
The median distance between sources detected in this dataset in the 0.3-10 keV band.
NumSrc_band1
The number of sources detected in this dataset in the 0.3-1 keV band.
NumOK_band1
The number of good or reasonable sources detected in this dataset in the 0.3-1 keV band.
MedianDist_band1
The median distance between sources detected in this dataset in the 0.3-1 keV band.
NumSrc_band2
The number of sources detected in this dataset in the 1-2 keV band.
NumOK_band2
The number of good or reasonable sources detected in this dataset in the 1-2 keV band.
MedianDist_band2
The median distance between sources detected in this dataset in the 1-2 keV band.
NumSrc_band3
The number of sources detected in this dataset in the 2-10 keV band.
NumOK_band3
The number of good or reasonable sources detected in this dataset in the 2-10 keV band.
MedianDist_band3
The median distance between sources detected in this dataset in the 2-10 keV band.
NumberOfSnapshots
The number of snapshots contributing to this dataset.
AstromError
The 90% confidence radial uncertainty on the XRT-2MASS astrometric correction.
CRVAL1_corr
The CRVAL1 WCS reference value for the dataset derived from the XRT-2MASS astrometric correction.
CRVAL2_corr
The CRVAL2 WCS reference value for the dataset derived from the XRT-2MASS astrometric correction.
CROTA2_corr
The CROTA1 WCS reference value for the dataset derived from the XRT-2MASS astrometric correction.
IsObsoleteStack
Whether this corresponds to a stacked image which has been superseded by a newer version, but which contains a unique detection of a source.

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Detections Table

The Detections table contains details of the specific detections that comprise the catalogue. Each source in the Sources table has at least one entry in this detections table; most sources have multiple entries as they were detected in more than one band or dataset. The information in the detections table relates to the specific detection, not to the unique source as a whole. The fields in this table, and their definitions are given below.

DetectionID
A unique identifier for this detection.
DatasetID
The unique identifier for the dataset in which the detection occurred.
ObsID
The obsID of the observation in which the detection occurred.
ObsSourceID
The ID of the obsSource this detection is part of.
LSXPS_ID
The ID of the LSXPS source of which this is a detection.
SourceNo
The identifier of this source within this obsid and band.
Band
The band in which this detection occurred, as an integer:
ValueBand nameEnergy range
0 Total 0.3— 10 keV
1 Soft 0.3— 1 keV
2 Medium 1— 2 keV
3 Hard 2— 10 keV
CorrectedExposure
The exposure time at the position of the source in this obsID.
ExposureFraction
The fractional exposure at the position of this source, i.e. the exposure divided by the nominal exposure for the field.
OffaxisAngle
The angular distance of the source from the XRT boresight in all observations within which the source was detected (arcmin).
RA
Right Ascension (J2000) in decimal degrees.
RA_pos
The 1-sigma positive uncertainty on the Right Ascension.
RA_neg
The 1-sigma negative uncertainty on the Right Ascension.
Decl
Decliniation (J2000) in decimal degrees.
Decl_pos
The 1-sigma positive uncertainty on the Declination.
Decl_neg
The 1-sigma negative uncertainty on the Declination.
Err90
Position uncertainty, 90% confidence, radial, assumed to be Rayleigh-distributed.
RA_corrected
Right Ascension (J2000) in decimal degrees corrected using XRT-2MASS astrometry.
Decl_corrected
Declination (J2000) in decimal degrees corrected using XRT-2MASS astrometry.
Err90_corrected
Uncertainty on the corrected position, 90% confidence, radial, assumed to be Rayleigh-distributed.
l
Galactic longitude.
b
Galactic latitude.
l_corrected
Galactic longitude corrected using XRT-2MASS astrometry.
b_corrected
Galactic latitude corrected using XRT-2MASS astrometry.
IMG_X
The x position of the object in the SKY image plane.
IMG_Y
The y position of the object in the SKY image plane.
NearestNeighbour
The distance (arcseconds) to the closest detection to this one, in this image.
NearestOKNeighbour
The distance (arcseconds) to the closest Good or Reasonable detection to this one, in this image.
DetFlag
The best detection flag from all detections of the source. The basic values are 0, 1, or 2, meaning Good, Reasonable or Poor respectively. Higher values mean that an extra warning is associated with the source. This warning is bitwise, defined as follows:
BitValueDescription
2 4 The source position is consistent with that of a known extended source.
3 8 The source is likely an alias of a badly-fitted piled up source.
4 16 The source lies in a region marked as contaminated during the visual screening.
OpticalLoadingWarning
Whether this detection is potentially affected by optical loading. If this is 0 there is no catalogue bright optical source nearby, otherwise there is a nearby optical source brighter than the level at which optical loading becomes a concern; the value indicates how many magnitudes brighter than that level the source is.
StrayLightWarning
Whether this detection occurred within fitted stray light rings.
NearBrightSourceWarning
Whether this detection occurred within the PSF wings of a fitted bright source.
MatchesKnownExtended
Whether the position of this source matches a known extended X-ray source.
PileupFitted
Whether the accepted fit included pile up.
SNR
The signal to noise ratio of the detection.
CtsInPSFFit
Number of counts in the image region over which the final PSF fit was performed.
BGRateInPSFFit
Mean count-rate in the background map in the region over which the final PSF fit was performed.
Cstat
The C-statistic value from the PSF fit.
Cstat_nosrc
The C-statistic value derived over the PSF fit region if no source is fitted.
L_src
The log-likelihood value that this detection is not just a background fluctuation.
Cstat_flat
The Cstat value found from a fit assuming a constant increase above the background (i.e. the count excess is flat, not PSF-like).
Lflat
The log-likelihood value that this detection is PSF like, not a flat count increase.
FracPix
The fraction of pixels within the PSF fit region which are exposed.
Pileup_S
The best-fitting S parameter of the pile-up model, if fitted.
Pileup_l
The best-fitting l parameter of the pile-up model, if fitted.
Pileup_c
The best-fitting c parameter of the pile-up model, if fitted.
Pileup_tau
The best-fittingtau parameter of the pile-up model, if fitted.
Cstat_altPileup
The Cstat value found from the unusued fit. i.e. if the piled up model was used, this gives the Cstat from the non-piled-up fit, and vice-versa.
PSF_Fit_Radius
"The radius of the circular region over which PSF fitting was carried out (in image pixels, 2.357"" to a side)".
CellDetect_BoxWidth
"The full width of the cell-detect box in which this source was detected (in image pixels, 2.357"" to a side)".
Rate
The corrected count-rate of this detection (i.e. in the band of this image).
Rate_pos
The 1-sigma positive uncertainty on the count rate.
Rate_neg
The 1-sigma negative uncertainty on the count rate.
CtsInRate
The total number of counts in the region used to extract the count rate.
BGCtsInRate
The total number of counts in the region used to extract the count rate.
Rate_CF
The PSF correction factor for the count rate.
BGRateInRate
The background rate in the region used for count-rate calculation.

[Back to top | LSXPS index]

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ObsSources Table

The ObsSources table contains details of the detections in an individual dataset, merged over all bands.

ObsSourceID
The unique identifier of this ObsSource.
DatasetID
The dataset identifier in which this obsSource was found.
LSXPS_ID
Numerical unique source identifier within LSXPS.
OSNum
The identifier of this obsSource within this dataset.
UsedCorrectedPosition
Whether or not the astrometrically-corrected position of this obsSource should be used.
NearestNeighbour
The distance (in arcseconds) to the closest LSXPS obsSource within this dataset.
NearestOKNeighbour
The distance (in arcseconds) to the closest good or reasonable LSXPS obsSource within this dataset.
Exposure
The exposure time at the position of the obsSource, corrected for vignetting.
HR1
The aggregate HR1 hardness ratio of the obsSource.
HR1_pos
The 1-sigma positive uncertainty on the aggregate HR1 hardness ratio of the obsSource.
HR1_neg
The 1-sigma negative uncertainty on the aggregate HR1 hardness ratio of the obsSource.
HR2
The aggregate HR2 hardness ratio of the obsSource.
HR2_pos
The 1-sigma positive uncertainty on the aggregate HR2 hardness ratio of the obsSource.
HR2_neg
The 1-sigma negative uncertainty on the aggregate HR2 hardness ratio of the obsSource.
BestBand
The energy band corresponding to the best detection of this obsSource in this dataset.
PileupWarning
Whether a pileup warning exists, indicating that the object is very piled up and in some bands there is evidence of pile up not being fitted.
BestDetectionID
The DetectionID of the best detection of this obsSource in this dataset.
IsOrphanSource
Whether this source is one which is only detected in this dataset, and this dataset is deprecated.

Cross Correlations Table

The Cross correlations table contains details of the cross correlation between the LSXPS sources and other catalogues.

LSXPS_ID
The numerical identifier of the LSXPS source.
ExtCat_ID
The catalogued name of the external source.
Catalogue
The catalogue in which the external source was found.
Distance
The distance in arcseconds between the 2SXPS and external source positions.
Ext_RA
The Right Ascension (J2000) in decimal degrees of the external source.
Ext_Decl
The declination (J2000) in decimal degrees of the external source.
Ext_Err90
The 90% confidence radial position error of the external source used for cross correlation. This may have been converted to 90% (assuming Rayleigh statistics) and had a systematic error added if necessary, therefore may differ from the catalogued value.

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Old Stacks Table

The Old Stacks table contains details of the stacked images which have been superseded by newer data.

DatasetID
The unique identifier for this dataset.
DataVersion
The version of this dataset; for stacked images it is the number of times the image has been analysed with extra data; for single observations it is the number of times the original data were processed after data downlink.
LiveDate
The UTC date at which this dataset became live.
ObsID
The identifier of the observation or stacked image in which this detection occurred.
IsObsoleteStack
Whether this corresponds to a stacked image which has been superseded by a newer version, but which contains a unique detection of a source.

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Transients Table

The Transients table contains details of possible transients found in LSXPS analysis.

TransientID
A unique numerical identifier for this transient within this catalogue.
IAUName
The IAU-format name of the transient: SwiftJ HHMMSS.S+ddmmss.
LSXPS_ID
The source identifier within the main LSXPS catalogue.
LSXPSName
The IAU name of this object in the main LSXPS catalogue.
Classification
A numerical code describing how this transient has been classified.
RA
Right Ascension (J2000) in decminal degrees.
Decl
Declination (J2000) in decimal degrees.
Err90
Position uncertainty, 90% confidence, radial, assumed to be Rayleigh-distributed.
l
Galactic longitude.
b
Galactic latitude.
DiscoveryDatasetID
The date of the observation in which the transient was first found.
ObsSourceID
The numerical identified of the first detection in the Public_ObsSources table.
PeakRateAtDetection
The peak count-rate in the 0.3-10 keV band in the dataset in which the transient was first detected.
PeakRateAtDetection_pos
The 1-sigma positive uncertainty on the peak count-rate in the 0.3-10 keV band in the dataset in which the transient was first detected.
PeakRateAtDetection_neg
The 1-sigma positive uncertainty on the peak count-rate in the 0.3-10 keV band in the dataset in which the transient was first detected.
PeakSoftMedBandRateAtDetection
The peak count-rate in the 0.3-2 keV band in the dataset in which the transient was first detected.
peakSoftMedBandRateAtDetection_pos
The 1-sigma positive uncertainty on the peak count-rate in the 0.3-2 keV band in the dataset in which the transient was first detected.
peakSoftMedBandRateAtDetection_neg
The 1-sigma positive uncertainty on the peak count-rate in the 0.3-2 keV band in the dataset in which the transient was first detected.
UpperLimitSource_Canned
Where the ‘best’ upper limit at the source location was taken from, where the ‘canned’ spectrum is used to convert between observatories.
UpperLimitSource_DiscoverySpectrum
Where the ‘best’ upper limit at the source location was taken from, where the discovery spectrum is used to convert between observatories.
UpperLimitSource_FullSpectrum
Where the ‘best’ upper limit at the source location was taken from, where the full spectrum is used to convert between observatories.
Significance
How far above the best upper limit the peak count rate is, in Gaussian sigmas.
InitSpecNH
The hydrogen column density found in an automated power-law fit to a spectrum built from the discovery dataset.
InitSpecGamma
The photon index found in an automated power-law fit to a spectrum built from the discovery dataset.
InitSpecCstat
The C-statistic from an automated power-law fit to a spectrum built from the discovery dataset.
InitSpecTestStat
The Churazov-weighted reduced chi^2 from an automated power-law fit to a spectrum built from the discovery dataset.
InitSpecDof
The number of degrees of freedom in the automated power-law fit to a spectrum built from the discovery dataset.
FullSpecNH
The hydrogen column density found in an automated power-law fit to a spectrum built from all observations of the transient after its discovery.
FullSpecGamma
The photon index found in an automated power-law fit to a spectrum built from all observations of the transient after its discovery.
FullSpecCstat
The C-statistic from an automated power-law fit to a spectrum built from all observations of the transient after its discovery.
FullSpecTestStat
The Churazov-weighted reduced chi^2 from an automated power-law fit to a spectrum built from all observations of the transient after its discovery.
FullSpecDof
The number of degrees of freedom in the automated power-law fit to a spectrum built from the all observations of the transient after its discovery.
DiscoveryDate
The date of the analysis in which the transient was first found.
DetectionDate
The date of the start of the observation in which the transient was first found.
DetectionMET
The MET of the start of the observation in which the transient was first found.
LSXPS_UpperLimit
An upper limit at the transient derived from the LSXPS catalogue.
LSXPS_UpperLimit_ObsID
The observation in the LSXPS catalogue from which the upper limit was derived.
XMM_UpperLimit_native
An XMM-Newton upper limit at the transient location, obtained via the HILIGT server, in native XMM count-rate units.
XMM_UpperLimit_ObsMode
The mode in which XMM was observing when the upper limit was obtained.
XMM_UpperLimit_Instrument
The XMM-Newton instrument from which the upper limit was obtained.
XMM_UpperLimit_asXRTTotal_DiscoverySpectrum
The XMM-Newton upper limit converted to a 0.3-10 keV XRT count rate, using the automated power-law fit to a spectrum built from the discovery dataset.
XMM_UpperLimit_asXRTTotal_FullSpectrum
The XMM-Newton upper limit converted to a 0.3-10 keV XRT count rate, using the automated power-law fit to a spectrum built from the all observations of the transient after its discovery.
XMM_UpperLimit_asXRTTotal_Canned
The XMM-Newton upper limit converted to a 0.3-10 keV XRT count rate, using a standard AGN spectrum.
RASS_UpperLimit_native
An ROSAT All-Sky Survey upper limit at the transient location, obtained via the HILIGT server, in native ROSAT PSPC count-rate units.
RASS_UpperLimit_asXRTSoftMed_DiscoverySpectrum
The RASS upper limit converted to a 0.3-2 keV XRT count rate, using the automated power-law fit to a spectrum built from the discovery dataset.
RASS_UpperLimit_asXRTSoftMed_FullSpectrum
The RASS upper limit converted to a 0.3-2 keV XRT count rate, using the automated power-law fit to a spectrum built from the all observations of the transient after its discovery.
RASS_UpperLimit_asXRTSoftMed_Canned
The RASS upper limit converted to a 0.3-2 keV XRT count rate, using a standard AGN spectrum.
RASS_UpperLimit_asXRTTotal_DiscoverySpectrum
The RASS upper limit converted to a 0.3-10 keV XRT count rate, using the automated power-law fit to a spectrum built from the discovery dataset.
RASS_UpperLimit_asXRTTotal_FullSpectrum
The RASS upper limit converted to a 0.3-10 keV XRT count rate, using the automated power-law fit to a spectrum built from the all observations of the transient after its discovery.
RASS_UpperLimit_asXRTTotal_Canned
The RASS upper limit converted to a 0.3-10 keV XRT count rate, using a standard AGN spectrum.
Notes
Any notes added by the XRT team.

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