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1SXPS Catalogue: On-line Documentation
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This catalogue has now been superseded by 2SXPS.
Summary / Quick-start information
Data included | 2004 Dec 12 — 2012 October 12 |
Sky coverage | 1905 square degrees |
Typical Sensitivity (0.3—10 keV) | 3×10-13 erg cm-2 s-1 (single observation) 9×10-14 erg cm-2 s-1 (stacked images) |
Typical position error | 5.5′′ (90% confidence radius, including systematics) |
Detections | 585,443 |
Unique sources | 151,524 |
Variable sources | 28,906 |
Uncatalogued sources | 82,282 |
False positive rate | Flag=Good | 0.3% |
Flag=Good/Reasonable | 1% |
Flag=Good/Reasonable/Poor | 10% |
Table 1. Summary details of the 1SXPS catalogue.
The 1SXPS catalogue covers 1905 square degrees on the sky and contains position, fluxes, spectral
details and variability information for 151,524 X-ray point sources
detected by the Swift X-ray Telescope between 2004 Dec 12 and 2012
October 12. Each source has a detection flag which indicates how likely
it is to be a real astrophysical object. Table 1 shows the false positive rate as a function of
flag and other summary information.
The catalogue, which is described in full in Evans et
al (2014) employs an
iterative sliding-cell detection procedure, which is significantly more sensitive than previous XRT catalogues.
This process is described in detail in the paper and summarised here.
Extensive verification has also been carried out to ascertain the reliability and completeness
of the catalogue and the various products. We also cross correlated this catalogue with a number
of existing catalogues and databases.
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Data Access and Usage
The catalogue can be downloaded as a FITS file, CSV file or SQL dump
or queried through this page. 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, please cite Evans et al. (2014) 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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Catalogue Contents
There are four tables available for download:
- Sources
- This is the main catalogue table, the only one which is available in Vizier. This contains the details of the 151,524 unique sources
in the catalogue.
- Detections
- This contains details of the individual detections in each dataset and energy band, of the sources.
- Datasets
- This contains details of the individual datasets (observations and stacked images) of which the catalogue is composed.
- Cross correlations
- This contains details of sources from external catalogues which are positionally coincident with 1SXPS sources.
[Back to top | 1SXPS index]
Sources Table
The Sources table is the main catalogue table, and gives details of each unique source identified in the catalogue.
There are 1/2 columns in this table in total, so for ease of consideration we have grouped them into the following categories:
Identifiers
There is 1 column in this group. Show.
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Position information
There are 7 columns in this group. Show.
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- RA
- The Right Ascension (J2000) of the source, taken from the individual detection with the smallest error.
- Decl
- The declination (J2000) of the source, taken from the individual detection with the smallest error.
- Err90
- The 90% confidence radial position error on the source position, taken from the individual detection with the smallest error. This includes the astrometric systematic error.
- AstromType
- This relates the provenance of the astrometry used to derive the source position.
- 0: Astrometry from the Swift star trackers.
- 1: Astrometry from rectification with 2MASS.
- l
- The Galactic longitude in degrees of the best position of the source.
- b
- The Galactic latitude in degrees of the best position of the source.
- OffAxis
- The mean distance angle (in arc minutes) of the source from the centre of the XRT detector averaged over all observations in which the source was
detected and inside the XRT field of view. There is a handful of sources for which this value is -1. This indicates that the source centre was never in
the field of view, that is, the detection and centroid was based on the wings of the PSF that extended into the field of view.
[Hide position columns | Back to Sources table | Back to top | 1SXPS index]
Exposure information
There are 5 columns in this group. Show.
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- Exposure
- The total exposure at the location of the source in seconds, including datasets in which the source was not detected.
- StartDate
- The UT date and time of the start of the first observation of the source location (regardless of whether the source was detected).
- StopDate
- The UT date and time of the end of the last observation of the source location (regardless of whether the source was detected).
- NumObs
- The total number of datasets (observations+stacked images) which cover the location of the source, including those in which the source was not detected.
- NumDetObs
- The number of datasets (observations+stacked images) in which the source was detected.
[Hide exposure columns | Back to Sources table | Back to top | 1SXPS index]
Flag information
There are 6 columns in this group. Show.
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- DetFlag
- The best detection flag from all detections of the source. This is a numerical value, normally 0 (=Good), 1 (=Reasonable) or 2 (=Poor)
For sources which lie inside a region which was identified in the manual screening stage as containing artefacts the flag values are 8, 9 and 10 for the three categories.
Those in a region manually marked as containing diffuse emission have flag values of 16,17 and 18.
In the case where the flag has a value >2 the Good, Reasonable or Poor definitions indicate the strength of the detection,
however the source is highly likely nonetheless to be spurious.
- Fieldflag
- The best field flag from all detections of the source. This can be either Good (=0) or Flagged (=1 or 2). The latter indicates that there are artefacts (flag=1) and/or extended emission (flag=2) in the field which may affect the flux levels of the point sources detected.
- DetFlag_band0
- The best total-band (0.3—10 keV) detection flag from all detections of the source.
- DetFlag_band1
- The best soft-band (0.3—1 keV) detection flag from all detections of the source.
- DetFlag_band2
- The best medium-band (1—2 keV) detection flag from all detections of the source.
- DetFlag_band3
- The best hard-band (2—10 keV) detection flag from all detections of the source.
[Hide flag columns | Back to Sources table | Back to top | 1SXPS index]
Count-rate information
There are 30 columns in this group. Show.
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- Rate_band0
- The time-averaged total-band (0.3—10 keV) count-rate of the source, in counts per second.
- Rate_band0_pos
- The 1-σ positive error on the time-averaged total-band (0.3—10 keV) count-rate of the source. If more than 30 events were detected in this band (after background subtraction) this is the Poisson error, otherwise it is calculated from the Bayesian method of Kraft, Burrows & Nousek (1991).
- Rate_band0_neg
- The 1-σ negative error on the time-averaged total-band (0.3—10 keV) count-rate of the source. If more than 30 events were detected in this band (after background subtraction) this is the Poisson error, otherwise it is calculated from the Bayesian method of Kraft, Burrows & Nousek (1991).
- Rate_band1
- The time-averaged soft-band (0.3—1 keV) count-rate of the source, in counts per second.
- Rate_band1_pos
- The 1-σ positive error on the time-averaged soft-band (0.3—1 keV) count-rate of the source.
- Rate_band1_neg
- The 1-σ negative error on the time-averaged soft-band (0.3—1 keV) count-rate of the source.
- Rate_band2
- The time-averaged medium-band (1—2 keV) count-rate of the source, in counts per second.
- Rate_band2_pos
- The 1-σ positive error on the time-averaged medium-band (1—2 keV) count-rate of the source.
- Rate_band2_neg
- The 1-σ negative error on the time-averaged medium-band (1—2 keV) count-rate of the source.
- Rate_band3
- The time-averaged hard-band (2—10 keV) count-rate of the source, in counts per second.
- Rate_band3_pos
- The 1-σ positive error on the time-averaged hard-band (2—10 keV) count-rate of the source.
- Rate_band3_neg
- The 1-σ negative error on the time-averaged hard-band (2—10 keV) count-rate of the source.
- Counts_band0
- The total number of events (not background subtracted or exposure corrected) in the total-band (0.3—10 keV) image, in the source extraction region for this source. This is found by summing the counts in the individual observations of the location, not from the stacked image.
- Counts_band1
- The total number of events (not background subtracted or exposure corrected) in the soft-band (0.3—1 keV) image, in the source extraction region for this source.
- Counts_band2
- The total number of events (not background subtracted or exposure corrected) in the medium-band (1—2 keV) image, in the source extraction region for this source.
- Counts_band3
- The total number of events (not background subtracted or exposure corrected) in the hard-band (2—10 keV) image, in the source extraction region for this source.
- BGCounts_band0
- The sum of the background map in the in the total-band (0.3—10 keV) source extraction region for this source. This is found by summing the maps in the individual observations of the location, not from the stacked image.
- BGCounts_band1
- The sum of the background map in the in the soft-band (0.3—1 keV) image, in the source extraction region for this source.
- BGCounts_band2
- The sum of the background map in the in the medium-band (1—2 keV) image, in the source extraction region for this source.
- BGCounts_band3
- The sum of the background map in the in the hard-band (2—10 keV) image, in the source extraction region for this source.
- CF_band0
- The count-rate correction factor in the total band (0.3—10 keV). The count-rate correction factor. This corrects for vignetting, bad columns pile-up and the finite radius over which counts were extracted.
- CF_band1
- The count-rate correction factor in the soft band (0.3—1 keV). The count-rate correction factor.
- CF_band2
- The count-rate correction factor in the medium band (1—2 keV). The count-rate correction factor.
- CF_band3
- The count-rate correction factor in the hard band (2—10 keV). The count-rate correction factor.
- HR1
- The HR1 hardness ratio = (M-S)/(M+S) where M and S are the medium (1—2 keV) and soft (0.3—1 keV) band count-rates. If both bands had more than 100 photons and an SNR of at least 2 this was calculted simply from this equation, otherwise the Bayesian approach of Park et al. (2006) was employed.
- HR1_pos
- The 1-σ positive error on HR1. In a small number of cases where the Bayesian approach of Park et al. (2006) was used to derive HR1, the mean HR value lay outside the 1-σ confidence interval. In these cases the HR1_pos error may be negative.
- HR1_neg
- The 1-σ negative error on HR1. In a small number of cases where the Bayesian approach of Park et al. (2006) was used to derive HR1, the mean HR value lay outside the 1-σ confidence interval. In these cases the HR1_neg error may be positive.
- HR2
- The HR2 hardness ratio = (H-M)/(H+M) where H and M are the hard (2—10 keV) and medium (1—2 keV) band count-rates. If both bands had more than 100 photons and an SNR of at least 2 this was calculted simply from this equation, otherwise the Bayesian approach of Park et al. (2006) was employed.
- HR2_pos
- The 1-σ positive error on HR2. In a small number of cases where the Bayesian approach of Park et al. (2006) was used to derive HR2, the mean HR value lay outside the 1-σ confidence interval. In these cases the HR2_pos error may be negative.
- HR2_neg
- The 1-σ negative error on HR2. In a small number of cases where the Bayesian approach of Park et al. (2006) was used to derive HR2, the mean HR value lay outside the 1-σ confidence interval. In these cases the HR2_neg error may be positive.
[Hide count-rate columns | Back to Sources table | Back to top | 1SXPS index]
Variability information
There are 8 columns in this group. Show.
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- PvarPchiSnapshot_band0
- The probability that the source is constant within a single snapshot in the total band (0.3—10 keV), as derived from the Pearson's χ2 test. The minimum recordable value for this is 1.1×10-16 so values of 0 mean <1.1×10-16.
- PvarPchiSnapshot_band1
- The probability that the source is constant within a single snapshot in the soft band (0.3—1 keV), as derived from the Pearson's χ2 test.
- PvarPchiSnapshot_band2
- The probability that the source is constant within a single snapshot in the medium band (1—2 keV), as derived from the Pearson's χ2 test.
- PvarPchiSnapshot_band3
- The probability that the source is constant within a single snapshot in the hard band (2—10 keV), as derived from the Pearson's χ2 test.
- PvarPchiObsID_band0
- The probability that the source is constant between observations in the total band (0.3—10 keV), as derived from the Pearson's χ2 test.
- PvarPchiObsID_band1
- The probability that the source is constant between observations in the soft band (0.3—1 keV), as derived from the Pearson's χ2 test.
- PvarPchiObsID_band2
- The probability that the source is constant between observations in the medium band (1—2 keV), as derived from the Pearson's χ2 test.
- PvarPchiObsID_band3
- The probability that the source is constant between observations in the hard band (2—10 keV), as derived from the Pearson's χ2 test.
[Hide variability columns | Back to Sources table | Back to top | 1SXPS index]
Spectral/Flux information
There are 111 columns in this group. Show.
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- GalNH
- 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:
- 0: Fixed spectrum
- 1: HR-interpolated
- 2: Fitted spectrum
- whichAPEC
- Which of the available estimates of the APEC spectral ECF and fluxes is given in the summary fields:
- 0: Fixed spectrum
- 1: HR-interpolated
- 2: Fitted spectrum
- PowECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming the power-law spectrum indicated by the
whichPow
field.
- PowECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming the power-law spectrum indicated by the
whichPow
field.
- PowFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), assuming the power-law spectrum indicated by the
whichPow
field.
- PowFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the band0Rate_pos
field multiplied by the PowECFO
field, so does not include uncertainties in the spectral modelling.
- PowFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the band0Rate_neg
field multiplied by the PowECFO
field, so does not include uncertainties in the spectral modelling.
- PowPeakFlux
- The maximum observed 0.3—10 keV flux (in erg cm-2 s-1) for the power-law spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the PowECFO
field.
- PowPeakFlux_pos
- The 1-σ positive error on the maximum observed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the PowECFO
field, so does not include uncertainties in the spectral modelling.
- PowPeakFlux_neg
- The 1-σ negative error on the maximum observed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the PowECFO
field, so does not include uncertainties in the spectral modelling.
- PowUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), assuming the power-law spectrum indicated by the
whichPow
field.
- PowUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the band0Rate_pos
field multiplied by the PowECFU
field, so does not include uncertainties in the spectral modelling.
- PowUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the band0Rate_neg
field multiplied by the PowECFU
field, so does not include uncertainties in the spectral modelling.
- PowPeakUnabsFlux
- The maximum unabsorbed 0.3—10 keV flux (in erg cm-2 s-1) for the power-law spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the PowECFU
field.
- PowPeakUnabsFlux_pos
- The 1-σ positive error on the maximum unabsorbed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the PowECFU
field, so does not include uncertainties in the spectral modelling.
- PowPeakUnabsFlux_neg
- The 1-σ negative error on the maximum unabsorbed 0.3—10 keV flux for the power-law spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the PowECFU
field, so does not include uncertainties in the spectral modelling.
- APECECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming the APEC spectrum indicated by the
whichPow
field.
- APECECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming the APEC spectrum indicated by the
whichPow
field.
- APECFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), assuming the APEC spectrum indicated by the
whichPow
field.
- APECFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the band0Rate_pos
field multiplied by the APECECFO
field, so does not include uncertainties in the spectral modelling.
- APECFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the band0Rate_neg
field multiplied by the APECECFO
field, so does not include uncertainties in the spectral modelling.
- APECPeakFlux
- The maximum observed 0.3—10 keV flux (in erg cm-2 s-1) for the APEC spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the APECECFO
field.
- APECPeakFlux_pos
- The 1-σ positive error on the maximum observed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the APECECFO
field, so does not include uncertainties in the spectral modelling.
- APECPeakFlux_neg
- The 1-σ negative error on the maximum observed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the APECECFO
field, so does not include uncertainties in the spectral modelling.
- APECUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), assuming the APEC spectrum indicated by the
whichPow
field.
- APECUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the band0Rate_pos
field multiplied by the APECECFU
field, so does not include uncertainties in the spectral modelling.
- APECUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the band0Rate_neg
field multiplied by the APECECFU
field, so does not include uncertainties in the spectral modelling.
- APECPeakUnabsFlux
- The maximum unabsorbed 0.3—10 keV flux (in erg cm-2 s-1) for the APEC spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the APECECFU
field.
- APECPeakUnabsFlux_pos
- The 1-σ positive error on the maximum unabsorbed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the APECECFU
field, so does not include uncertainties in the spectral modelling.
- APECPeakUnabsFlux_neg
- The 1-σ negative error on the maximum unabsorbed 0.3—10 keV flux for the APEC spectrum indicated by the
whichPow
field. This is taken from the bin in the total-band per-snapshot light curve with the highest value, multiplied by the APECECFU
field, so does not include uncertainties in the spectral modelling.
- FixedPowECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field).
- FixedPowECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field).
- FixedPowFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), assuming a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field).
- FixedPowFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux for a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_pos
field multiplied by the FixedPowECFO
field, so does not include uncertainties in the spectral modelling.
- FixedPowFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux for a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_neg
field multiplied by the FixedPowECFO
field, so does not include uncertainties in the spectral modelling.
- FixedPowUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), assuming a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field).
- FixedPowUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux for a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_pos
field multiplied by the FixedPowECFU
field, so does not include uncertainties in the spectral modelling.
- FixedPowUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux for a power-law spectrum with a photon index of 1.7 absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_neg
field multiplied by the FixedPowECFU
field, so does not include uncertainties in the spectral modelling.
- FixedAPECECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field).
- FixedAPECECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), assuming an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field).
- FixedAPECFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), assuming an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field).
- FixedAPECFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux for an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_pos
field multiplied by the FixedAPECECFO
field, so does not include uncertainties in the spectral modelling.
- FixedAPECFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux for an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_neg
field multiplied by the FixedAPECECFO
field, so does not include uncertainties in the spectral modelling.
- FixedAPECUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), assuming an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field).
- FixedAPECUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux for an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_pos
field multiplied by the FixedAPECECFU
field, so does not include uncertainties in the spectral modelling.
- FixedAPECUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux for an APEC spectrum with a temperature of 1 keV absorbed by the Galactic column (from the
GalNH
field). This is taken from the band0Rate_neg
field multiplied by the FixedAPECECFU
field, so does not include uncertainties in the spectral modelling.
- InterpPowECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra.
- InterpPowECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra.
- InterpPowFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra.
- InterpPowFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. This is taken from the
band0Rate_pos
field multiplied by the InterpPowECFO
field, so does not include uncertainties in the spectral modelling.
- InterpPowFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. This is taken from the
band0Rate_neg
field multiplied by the InterpPowECFO
field, so does not include uncertainties in the spectral modelling.
- InterpPowUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra.
- InterpPowUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. This is taken from the
band0Rate_pos
field multiplied by the InterpPowECFU
field, so does not include uncertainties in the spectral modelling.
- InterpPowUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. This is taken from the
band0Rate_neg
field multiplied by the InterpPowECFU
field, so does not include uncertainties in the spectral modelling.
- InterpPowNH
- The absorption column (in cm-2) of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra.
- InterpPowNH_pos
- The 1-σ positive error absorption column of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. A value of -1 indicates that this error could not be constrained.
- InterpPowNH_neg
- The 1-σ negative error absorption column of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. A value of +1 indicates that this error could not be constrained.
- InterpPowGamma
- The power-law photon index of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra.
- InterpPowGamma_pos
- The 1-σ positive error on the power-law photon index of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. A value of -1 indicates that this error could not be constrained.
- InterpPowGamma_neg
- The 1-σ negative error on the power-law photon index of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of power-law spectra. A value of +1 indicates that this error could not be constrained.
- InterpAPECECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra.
- InterpAPECECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra.
- InterpAPECFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra.
- InterpAPECFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. This is taken from the
band0Rate_pos
field multiplied by the InterpAPECECFO
field, so does not include uncertainties in the spectral modelling.
- InterpAPECFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. This is taken from the
band0Rate_neg
field multiplied by the InterpAPECECFO
field, so does not include uncertainties in the spectral modelling.
- InterpAPECUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra.
- InterpAPECUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. This is taken from the
band0Rate_pos
field multiplied by the InterpAPECECFU
field, so does not include uncertainties in the spectral modelling.
- InterpAPECUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. This is taken from the
band0Rate_neg
field multiplied by the InterpAPECECFU
field, so does not include uncertainties in the spectral modelling.
- InterpAPECNH
- The absorption column (in cm-2) of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra.
- InterpAPECNH_pos
- The 1-σ positive error absorption column of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. A value of -1 indicates that this error could not be constrained.
- InterpAPECNH_neg
- The 1-σ negative error absorption column of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. A value of +1 indicates that this error could not be constrained.
- InterpAPECkT
- The APEC plasma temperature (in keV) of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra.
- InterpAPECkT_pos
- The 1-σ positive error on the APEC plasma temperature of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. A value of -1 indicates that this error could not be constrained.
- InterpAPECkT_neg
- The 1-σ negative error on the APEC plasma temperature of the spectrum of the source derived from the hardness ratios of the source, interpolated on a look-up table of APEC spectra. A value of +1 indicates that this error could not be constrained.
- P_pow
- If the (HR1,HR2) values of the source lie inside the range allowed by the simple power-law spectrum, this field is 1. Otherwise it is the probability of obtaining the measured hardness ratios and errors if the true spectrum is that which gives (HR1,HR2) closest to the source's values.
- P_APEC
- If the (HR1,HR2) values of the source lie inside the range allowed by the simple APEC spectrum, this field is 1. Otherwise it is the probability of obtaining the measured hardness ratios and errors if the true spectrum is that which gives (HR1,HR2) closest to the source's values.
- FittedPowECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux from an automated power-law spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_pos
field multiplied by the FittedPowECFO
field, so does not include uncertainties in the spectral modelling.
- FittedPowFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux from an automated power-law spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_neg
field multiplied by the FittedPowECFO
field, so does not include uncertainties in the spectral modelling.
- FittedPowUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux from an automated power-law spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_pos
field multiplied by the FittedPowECFU
field, so does not include uncertainties in the spectral modelling.
- FittedPowUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux from an automated power-law spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_neg
field multiplied by the FittedPowECFU
field, so does not include uncertainties in the spectral modelling.
- FittedPowNH
- The absorption column (in cm-2) of the spectrum of the source from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowNH_pos
- The 1-σ positive error absorption column of the spectrum of the source from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowNH_neg
- The 1-σ negative error absorption column of the spectrum of the source from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowGamma
- The power-law photon index of the spectrum of the source from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowGamma_pos
- The 1-σ positive error on the power-law photon index of the spectrum of the source from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowGamma_neg
- The 1-σ negative error on the power-law photon index of the spectrum of the source from an automated power-law spectral fit to an automatically-extracted spectrum of the source.
- FittedPowChi
- The Churazov-weighted χ2 value of the best fitting power-law spectral model.
- FittedPowDOF
- The number of degrees of freedom in the power-law spectral fit.
- FittedPowRedChi
- The Churazov-weighted χν2 value of the best fitting power-law spectral model.
- FittedAPECECFO
- The counts-to-observed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECECFU
- The counts-to-unabsorbed-flux (0.3—10 keV) conversion factor (in erg cm-2 ct-1), derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECFlux
- The observed 0.3—10 keV flux (in erg cm-2 s-1), derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECFlux_pos
- The 1-σ positive error on the observed 0.3—10 keV flux derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_pos
field multiplied by the FittedAPECECFO
field, so does not include uncertainties in the spectral modelling.
- FittedAPECFlux_neg
- The 1-σ negative error on the observed 0.3—10 keV flux derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_neg
field multiplied by the FittedAPECECFO
field, so does not include uncertainties in the spectral modelling.
- FittedAPECUnabsFlux
- The unabsorbed 0.3—10 keV flux (in erg cm-2 s-1), derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECUnabsFlux_pos
- The 1-σ positive error on the unabsorbed 0.3—10 keV flux derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_pos
field multiplied by the FittedAPECECFU
field, so does not include uncertainties in the spectral modelling.
- FittedAPECUnabsFlux_neg
- The 1-σ negative error on the unabsorbed 0.3—10 keV flux derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source. This is taken from the
band0Rate_neg
field multiplied by the FittedAPECECFU
field, so does not include uncertainties in the spectral modelling.
- FittedAPECNH
- The absorption column (in cm-2) of the spectrum of the source derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECNH_pos
- The 1-σ positive error absorption column of the spectrum of the source derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECNH_neg
- The 1-σ negative error absorption column of the spectrum of the source derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECkT
- The APEC plasma temperature (in keV) of the spectrum of the source derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECkT_pos
- The 1-σ positive error on the APEC plasma temperature of the spectrum of the source derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECkT_neg
- The 1-σ negative error on the APEC plasma temperature of the spectrum of the source derived from the hardness ratios of the source, from an automated APEC spectral fit to an automatically-extracted spectrum of the source.
- FittedAPECChi
- The Churazov-weighted χ2 value of the best fitting APEC spectral model.
- FittedAPECDOF
- The number of degrees of freedom in the APEC spectral fit.
- FittedAPECRedChi
- The Churazov-weighted χν2 value of the best fitting APEC spectral model.
[Hide spectral/flux columns | Back to Sources table | Back to top | 1SXPS index]
Cross-correlation information
There are 7 columns in this group. Show.
Hide column list.
- Numxcorr
- The number of sources in the external catalogues against which we performed cross-correlation, which are within 3-σ of the location of this source. Where available, the uncertainty in the external catalogue source position was added in quadrature with the 1SXPS uncertainty to perform this match.
- Numxcorr_slim
- The number of sources in the external catalogues against which we performed cross-correlation excluding 2MASS and USNO-B1, which are within 3-σ of the location of this source. Where available, the uncertainty in the external catalogue source position was added in quadrature with the 1SXPS uncertainty to perform this match.
- isROSHRI
- Whether the object does (1) or does not (0) match an object in the Rosat HRI catalogue.
- isROSPSPC
- Whether the object does (1) or does not (0) match an object in the Rosat PSPC catalogue.
- is3XMM
- Whether the object does (1) or does not (0) match an object in the 3XMM DR4 catalogue.
- isXMMSL1
- Whether the object does (1) or does not (0) match an object in the XMMSL1 XMM-Newton slew survey catalogue.
- isSwiftFT
- Whether the object does (1) or does not (0) match an object in the Swift-FT catalogue.
- is1SWXRT
- Whether the object does (1) or does not (0) match an object in the 1SWXRT catalogue.
- isXRTGRB
- Whether the object does (1) or does not (0) match a catalogued XRT position of a Gamma Ray Burst.
- isSDSSQSO
- Whether the object does (1) or does not (0) match an object in the SDSS QSO DR5 catalogue.
- is2MASS
- Whether the object does (1) or does not (0) match a 2MASS source.
- isUSNOB1
- Whether the object does (1) or does not (0) match a USNO-B1 source.
- isSIMBAD
- Whether the object does (1) or does not (0) match a SIMBAD object.
- xcorrIDs
- The identifiers of the external catalogue sources which are within 3-σ of the 1SXPS source, as a semi-colon delimited list of
object (catalogue)
strings.
[Hide cross-correlation columns | Back to Sources table | Back to top | 1SXPS index]
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.
- DetID
- The unique identifier of this detection.
- obsID
- The unique identifier of the dataset in which the detection occurred. If this number is less than 8000 it is the number of the stacked image,
otherwise it is a Swift obsid.
- Band
- The band in which this detection occurred, as an integer:
- 0: Total band = 0.3—10 keV
- 1: Soft band = 0.3—1 keV
- 2: Medium band = 1—2 keV
- 3: Hard band = 2—10 keV
- DetFlag
- The detection flag assigned for this specific detection. This is a numerical value, normally 0 (=Good), 1 (=Reasonable) or 2 (=Poor)
For sources which lie inside a region which was identified in the manual screening stage as containing artefacts the flag values are 8, 9 and 10 for the three categories.
Those in a region manually marked as containing diffuse emission have flag values of 16,17 and 18.
In the case where the flag has a value >2 the Good, Reasonable or Poor definitions indicate the strength of the detection,
however the source is highly likely nonetheless to be spurious.
- img_x
- The
sky
x position of the source in the specific dataset and energy band shown. For single observations, the nominal pointing
direction corresponds to sky
coordinates (500.5,500.5). For stacked images, (500.5,500.5) corresponds to the position of the field given in the Datasets table,
but due to the nature of stacked image, this gives no information about where on the detector the source location was.
- img_y
- The
sky
y position of the source in the specific dataset and energy band shown. For single observations, the nominal pointing
direction corresponds to sky
coordinates (500.5,500.5). For stacked images, (500.5,500.5) corresponds to the position of the field given in the Datasets table,
but due to the nature of stacked image, this gives no information about where on the detector the source location was.
- OffAxis
- The mean off-axis angle (in arc minutes) of the source in this specific dataset and energy band. This is calculated only from the snapshot
during which source is inside the field of view. A value of -1 indicates that the source centre is never in the field of view (i.e. it was detected
and localised via the PSF wings).
- RA
- The Right Ascension (J2000) of the source as determined from this specific dataset and energy band, using the astrometry from the on-board star trackers.
- RA_pos/RA_neg
- These 2 columns give the 1-σ statistical error on the source RA, determined from the PSF fit. For a small number
of sources, the fit code was unable to determine an error in which case this field is empty.
- Decl
- The declination (J2000) of the source as determined from this specific dataset and energy band, using the astrometry from the on-board star trackers.
- Dec_pos/Dec_neg
- These 2 columns give the 1-σ statistical error on the source declination, determined from the PSF fit. For a small number
of sources, the fit code was unable to determine an error in which case this field is empty.
- Err90
- The 90% confidence radial position error, including systematic error, using the astrometry from the on-board star trackers.
This is derived from the RA and Decl errors above and has been converted to 90% confidence using Rayleigh statistics, with the the 3.5′′
astrometric systematic error from the star trackers added in quadrature. For the sources where one of the individual RA/Dec pos/neg
errors was unavailable, the statistical radial 90% confidence error was set to be 14.6′′/√C (where C is the number
of events used in the PSF fit) and the systematic error was combined with this.
- RA_corr
- The Right Ascension (J2000) of the source, as determined from this specific dataset and energy band, with the astrometry derived by correlating the X-ray sources detected in this image with the 2MASS catalogue.
- Decl_corr
- The declination (J2000) of the source, as determined from this specific dataset and energy band, with the astrometry derived by correlating the X-ray sources detected in this image with the 2MASS catalogue.
- Err90_corr
- The 90% confidence radial position error, derived as for The
Err90
field above, but where the systematic error
is taken from the X-ray/2MASS rectification process and not the on-board star trackers.
- l,b
- The Galactic co-ordinates of the source, in decimal degrees.
- Counts
- The total number of events (not background subtracted or exposure corrected) at the location of the source.
The size and shape of the extraction region is a function of the source brightness and may vary between datasets and energy bands.
- BGCts
- The total number of counts in the background map at the location of the source. The size and shape of the extraction region is the same as for the
Counts detected
field.
- FieldExposure
- The on-axis exposure time, in seconds, of the dataset in which this detection occurred.
- CF
- The count-rate correction factor (κ in equation 9 of Evans et al. 2013) which corrects the count rate for vignetting, bad columns, pile up and the finite radius over which counts were extracted.
- Rate
- The on-axis equivalent mean count-rate for the source in this specific observation and energy band.
- Rate_pos/neg
- The 1-σ uncertainty in the count-rate. For sources with fewer than 30 detected events after background subtraction, this is
calculated using the Bayesian approach of Kraft, Burrows & Nousek (1991),
other Poisson statistics are employed.
- ExposureFraction
- The mean exposure time in the source extraction region as a fraction of the on-axis exposure time in the image.
- Cstat
- The C statistic value from the PSF fit to the source.
- Cstat_nosrc
- The C-statistic value calculated for a model with no source present.
- LogLikelihood
- The log likelihood of the difference between
Cstat
and Cstat_nosrc
for 2 degrees of freedom being coincidence.
- SNR
- The signal-to-noise ratio of the source during the sliding cell detection phase, when this source was detected.
- Celldet_width
- The full width (in pixels, 1 pixel=2.357′′) of the cell in which the source was detected.
- PSF_radius
- The radius (in pixels) of the region used to perform the source PSF fit and likelihood test.
- PSF
- The PSF profile used to determine the source position, likelihood and count rate.
- ol_warn
- If a catalogued optical source bright enough to cause optical loading at the level of ≥10-3 ct s-1 pix-1
lies within 30′′ of the position of this detection, this field records how many magnitudes brighter than the level at
which this optical loading occurs that source is catalogued as being.
- FieldFlag
- The flag assigned to the dataset of this detection. This can be either Good (=0) or Flagged (=1 or 2). The latter indicates that there are artefacts (flag=1) and/or extended emission (flag=2) in the field which may affect the flux levels of the point sources detected.
- NNDist
- The distance in arc seconds to the nearest source also detected in this dataset and energy band. If no other sources are detected this is empty.
- OKNNDist
- The distance in arc seconds to the nearest source flagged as Good or Reasonable also detected in this dataset and energy band. If no such sources are detected this is empty.
- Num_snapshots
- The number of snapshots in this dataset in which the source lies within the field of view.
- ImageBG
- The mean background (in ct s-1 pix-1) of the image in which this detection occurred.
- MergeRadius
- The radius (in pixels, 1 pix=2.357′′) around this detection of the source within which detections are assumed to be aliases of the source, and are thus discarded.
- SourceID
- The 1SXPS source of which this is a detection.
[Back to top | 1SXPS index]
Datasets Table
The Datasets table contains information about individual datasets — observations and stacked images — which make up
the 1SXPS catalogue.
- ID
- The unique identifier of the dataset. If this number is less than 8000 it is the number of the stacked image,
otherwise it is a Swift obsid.
- RA
- The Right Ascension (J2000.0) of the image centre in degrees.
- Decl
- The Right Ascension (J2000.0) of the image centre in degrees.
- l,b
- The Galactic coordinates of the image centre in degrees.
- IsStacked
- Whether this dataset is (1) or is not (0) a stacked image.
- Exposure
- The on-axis exposure time of the dataset, in seconds.
- FieldBG_band0
- The mean background value in the total (0.3—10 keV) band in ct s-1 pix-1. This is measured from the background map before the detected sources have been added to it.
- Field BG_band1
- The mean background value in the soft (0.3—1 keV) band in ct s-1 pix-1. This is measured from the background map before the detected sources have been added to it.
- Field BG_band2
- The mean background value in the medium (1—2 keV) band in ct s-1 pix-1. This is measured from the background map before the detected sources have been added to it.
- Field BG_band3
- The mean background value in the hard (2—10 keV) band in ct s-1 pix-1. This is measured from the background map before the detected sources have been added to it.
- Numsrc_band0
- The number of sources detected in the total (0.3—10 keV) band image of this dataset.
- Numsrc_band1
- The number of sources detected in the soft (0.3—1 keV) band image of this dataset.
- Numsrc_band2
- The number of sources detected in the medium (1—2 keV) band image of this dataset.
- Numsrc_band3
- The number of sources detected in the hard (1—10 keV) band image of this dataset.
- NumOK_band0
- The number of Good and Reasonable sources detected in the total (0.3—10 keV) band image of this dataset.
- NumOK_band1
- The number of Good and Reasonable sources detected in the soft (0.3—1 keV) band image of this dataset.
- NumOK_band2
- The number of Good and Reasonable sources detected in the medium (1—2 keV) band image of this dataset.
- NumOK_band3
- The number of Good and Reasonable sources detected in the hard (1—10 keV) band image of this dataset.
- MedianNNDist_band0
- The median distance between sources detected in the total (0.3—10 keV) band image of this dataset, in arc seconds.
- MedianNNDist_band1
- The median distance between sources detected in the soft (0.3—1 keV) band image of this dataset, in arc seconds.
- MedianNNDist_band2
- The median distance between sources detected in the medium (1—2 keV) band image of this dataset, in arc seconds.
- MedianNNDist_band3
- The median distance between sources detected in the hard (2—10 keV) band image of this dataset, in arc seconds.
- Date_start
- The UT date at time at which the observation began. For stacked images this is the time of the first observation within the stacked image.
- Date_stop
- The UT date at time at which the observation began. For stacked images this is the time of the first observation within the stacked image.
- FieldFlag
- The flag assigned to the field by manual inspection. This can be either Good (=0) or Flagged (=1 or 2).
The latter indicates that there are artefacts (flag=1) and/or extended emission (flag=2) in the field which may affect the flux levels of the
point sources detected.
- NumSnapshots
- The number of snapshots in the dataset.
- AstromErr
- If the astrometry of this image could be determined by matching the XRT sources with the 2MASS catalogue,
this gives the 90% confidence radial error associated with that astrometry.
- Stacked image
- For observations this gives the ID of the stacked image to which the observation contributes (if any). For stacked images, this
gives the ID of any other stacked images which overlap this dataset.
[Back to top | 1SXPS index]
Cross Correlations Table
The Cross correlations table contains details of the cross correlation between the 1SXPS sources and other catalogues.
- 1SXPS_ID
- The name of the source in the 1SXPS catalogue.
- ExtCat_ID
- The name of the matched source in the external catalogue.
- Catalogue
- The name of the catalogue in which the match occurs.
- Distance
- The distance, in arc seconds, between the 1SXPS source and the external catalogue source.
- RA
- The Right Ascension (J2000), in decimal degrees, of the source in the external catalogue.
- Decl
- The declination (J2000), in decimal degrees, of the source in the external catalogue.
- Err90
- The 90% confidence radial error in the external catalogue position (if available). Where necessary, this has been converted from
a 1-σ error using Rayleigh statistics, and has had any relevant systematic error added.
[Back to top | 1SXPS index]