, converted to arcsec.
![$\max(\frac{\vert F_k-F_\vert\vert}{\sqrt{\sigma_k^2+\sigma_l^2}} \forall k,l\in[1,n])$](xmmstack_columnlist_img5.png)
The table column "Stack" comprises a short summary of how the parameter value in the summary row per stack is calculated, "Observation" of the value derived for the individual contributing observation. Values per instrument are labelled by CC, which stands for one of PN, M1, M2. The standard energy bands, defined as for 3XMM, are abbreviated by 1<= n <=5 and for the hardness ratios by 1<= i <=4. The names of columns that are also present in the other 3XMM catalogues are linked to their documentation.
| Columns 1 – 4: Detection characteristics | |||||
|---|---|---|---|---|---|
| Column name | Format | Unit | Description | Observation | Stack |
| SRCID | long | Identifier of the detection. Sources in the stacked catalogue are marked by a leading "3". | Assigned to all rows per source | ||
| OBS_ID | string | XMM-Newton observation identifier. | Per observation | null | |
| N_OBS | integer | Number of observations involved in the stack. | null | Per stack | |
| N_CONTRIB | integer | Number of observations in which the source was fitted. | null | Per stack | |
| Columns 5 – 15: Coordinates and associated identifier | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| RA | double | degrees | Right ascension (J2000). | Combined fit | |
| DEC | double | degrees | Declination (J2000). | Combined fit | |
| RADEC_ERR | float | arcsec | Square root of the sum of the squared 1σ errors in X_IMA and Y_IMA
, converted to arcsec. |
Combined fit | |
| LII | double | degrees | Galactic longitude. | Combined fit | |
| BII | double | degrees | Galactic latitude. | Combined fit | |
| X_IMA(_ERR) | float | pixel | X coordinate within the re-binned image and its 1σ error. Image pixels are binned to 4″×4″. | Combined fit | |
| Y_IMA(_ERR) | float | pixel | Y coordinate within the re-binned image and its 1σ error. Image pixels are binned to 4″×4″. | Combined fit | |
| DIST_NN | float | arcsec | Distance to the nearest neighbouring detection. | Combined fit | |
| IAUNAME | string | Registered IAU name of the source of the form "3XMMs hhmmss.s+-ddmmss" | Assigned to all rows per source | ||
| Columns 16 – 23: 3XMM counterpart: values copied from 3XMM-DR7 | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| IAUNAME_3XMMDR7 | string | IAU name assigned to the nearest unique source in 3XMM-DR7. | Assigned to all rows per source with a 3XMM-DR7 counterpart | ||
| SRCID_3XMMDR7 | long | Unique source identifier of the nearest source in 3XMM-DR7 within a correlation radius of three times the sum of the position errors. Null, if no counterpart is found. | Assigned to all rows per source with a 3XMM-DR7 counterpart | ||
| DETID_3XMMDR7 | long | Identifier of the 3XMM-DR7 per-observation detection that contributes to the unique source SRCID_3XMMDR7, if existing. | Per OBS_ID | null | |
| RA_3XMMDR7 | double | degrees | Mean right ascension of the unique 3XMM-DR7 source and its contributing detections after field rectifications. | RA per DETID_3XMMDR7 | SC_RA per SRCID_3XMMDR7 |
| DEC_3XMMDR7 | double | degrees | Mean declination of the unique 3XMM-DR7 source and its contributing detections after field rectifications. | DEC per DETID_3XMMDR7 | SC_DEC per SRCID_3XMMDR7 |
| POSERR_3XMMDR7 | float | arcsec | Position error of the unique 3XMM-DR7 source and its contributing detections, including statistical and systematic errors from the field rectification. | POSERR per DETID_3XMMDR7 | SC_POSERR per SRCID_3XMMDR7 |
| DIST_3XMMDR7 | double | arcsec | Distance between the source and the nearest unique source / its contributing detection in 3XMM-DR7. | Distance to DETID_3XMMDR7 | Distance to SRCID_3XMMDR7 |
| NDETECT_3XMMDR7 | integer | Number of DR7 detections N_DETECTIONS of the nearest unique source in 3XMM-DR7. | null | Per SRCID_3XMMDR7 | |
| Columns 24 – 71: Fluxes | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| EP_FLUX | float | erg cm–2 s–1 | All-EPIC flux: dead-time corrected count rates in the entire PSF, multiplied with the respective energy conversion factors. Null, if the exposure is zero, e.g. on chip gaps, or if the covered PSF fraction is below 15%. | Weighted mean of the instrument fluxes | |
| EP_FLUX_ERR | float | erg cm–2 s–1 | 1σ error on EP_FLUX. | Mean of the instrument fluxes weighted by the inverse squared errors | |
| EP_n_FLUX(_ERR) | float | erg cm–2 s–1 | All-EPIC flux and 1σ flux error in energy band n. Null, if the exposure is zero or if the covered PSF fraction is below 15%. Zero with non-zero errors, if no counts are detected in spite of sufficient PSF coverage. | Mean of the instrument values weighted by the inverse squared errors | |
| CC_FLUX(_ERR) | float | erg cm–2 s–1 | Total flux and 1σ flux error in instrument CC. Null / zero as before. | Sum of fluxes and flux errors per energy band | |
| CC_n_FLUX(_ERR) | float | erg cm–2 s–1 | Flux and 1σ flux error per instrument CC and energy band n. Null / zero as before. | Fit per input image | Mean of the observation-level values weighted by the exposure time |
| Columns 72 – 117: Count rates and count numbers | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| EP_RATE | float | counts s–1 | All-EPIC count rate: background-subtracted and vignetting corrected count rate in the entire PSF. Null, if the exposure is zero or if the covered PSF fraction is below 15%. Zero with non-zero errors, if no counts are detected in spite of sufficient PSF coverage. | Sum of the instrument-level count rates | Mean of the observation-level rates weighted by the exposure time |
| EP_RATE_ERR | float | counts s–1 | 1σ error on the count rate. Null, if the exposure is zero or if the covered PSF fraction is below 15%. | Square root of the quadratic sum of the errors per instrument | Combined observation-level errors weighted by the exposure time |
| CC_RATE(_ERR) | float | counts s–1 | Total count rate and count-rate error on instrument CC. Null / zero as before. | Sum of the values per energy band | Mean of the observation-level values weighted by the exposure time |
| CC_n_RATE(_ERR) | float | counts s–1 | Count rate and count-rate error per instrument CC and energy band n. Null / zero as before. | Fit per input image | Mean of the observation-level values weighted by the exposure time |
| EP_CTS | float | counts s–1 | All-EPIC count number: background-subtracted source counts in the entire PSF. Null, if the exposure is zero or if the covered PSF fraction is below 15%. | Sum of the source counts per instrument | |
| EP_CTS_ERR | float | counts s–1 | 1σ error on the count number. Null, if the exposure is zero or if the covered PSF fraction is below 15%. | Square root of the quadratic sum of the errors per instrument | |
| CC_CTS(_ERR) | float | counts s–1 | Total count number and error on instrument CC. | Sum of the values per energy band | |
| Columns 118 – 139: Detection and extent likelihoods | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| EP_DET_ML | float | Total equivalent maximum detection likelihood, normalised to two degrees of freedom. | Calculated from all valid contributing images | ||
| CC_DET_ML | float | Equivalent maximum detection likelihood for instrument CC, normalised to two degrees of freedom. | Equivalent maximum detection likelihood for instrument CC, normalised to two degrees of freedom | ||
| CC_n_DET_ML | float | Equivalent maximum detection likelihood per instrument CC and energy band n, normalised to two degrees of freedom. | Value per input image | Calculated from all valid contributing images per instrument and energy band | |
| EXTENT | float | arcsec | Source extent radius, derived from the model source PSF convolved with a beta profile. Below an extent of 6arcsec, it is considered unresolved and set to zero, the source is "point-like". | Combined fit | |
| EXTENT_ERR | float | arcsec | 1σ error on the source extent radius. Null, if the extent radius is below 6arcsec. | Combined fit | |
| EXTENT_ML | float | Likelihood that the source is extended with radius EXTENT. Null, if the source is considered point-like. | Combined fit | ||
| Columns 140 – 171: Hardness ratios | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| EP_HRi | float | Equivalent all-EPIC hardness ratios (ri+1-ri) / (ri+1+ri) between the count rates r in energy bands i and i+1. | Mean of all active instruments | ||
| EP_HRi_ERR | float | 1σ error on hardness ratio EP_HRi. | Error propagation of the contributing values | ||
| CC_HRi(_ERR) | float | Hardness ratios (ri+1-ri) / (ri+1+ri) between the count rates r in energy bands i and i+1 per instrument. | Per input images | Mean of the observations | |
| Columns 172 – 233: Fit characteristics | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| CC_EXP | float | seconds | Exposure map values per instrument CC, including vignetting effects. The effective good exposure time is given in the ONTIME columns, described below. | Sum of the contributing images | |
| CC_n_EXP | float | seconds | Exposure map values per instrument CC and energy band. | Fit per input image | Sum of the contributing images |
| CC_BG | float | counts px–1 | Background model at the central position of the source on the CCD. Null, if the exposure map is zero and if the centre of the source is located on a bad chip area. | Sum of the contributing images | |
| CC_n_BG | float | counts px–1 | Background model in energy band n at the CCD position of the source. | Sum of the contributing images in energy band n | |
| EP_ONTIME | float | seconds | Total good exposure time at the central position of the source on the CCD. Zero, if the centre of the source is located on a bad chip area. | Maximum of the good exposure time per instrument | Sum of the maximum ontimes per observation |
| CC_ONTIME | float | seconds | Total good exposure time of instrument CC at the CCD position of the source. Times are calculated by the task evselect and not vignetting corrected. | Read from the headers of the input files. | Sum of the observation-level values. |
| CC_MASKFRAC | float | Mean chip coverage in the detection mask per instrument, weighted by the point spread function of the source. | Minimum of the slightly differing values per energy band | Maximum of the observation-level values | |
| EP_OFFAX | float | arcmin | Angular distance of the source to the boresight. | Minimum of the values per instrument. | null |
| CC_OFFAX | float | arcmin | Angular distance of the source to the boresight in instrument CC. | Combined fit | null |
| CC_n_VIG | float | Vignetting fraction in instrument CC and energy band n at the central position of the source. | Read from the calibration data base | null | |
| Columns 234 – 238: Quality flags | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| STACK_FLAG | integer | Summarised quality flag of the detection. "0", if all flags are false. "1", if at least one of flags 1, 2, 3, 9 is true. "2", if at least one of flags 4–8 is true. "3", if STACK_FLAG is 2 for all contributing observations. | Numeric version of EP_FLAG | ||
| EP_FLAG | string | Quality flags of the detection, automatically set and combined into a nine-characters string. A flag "true" means a warning on a detection condition. | Worst flag of all instruments | Worst flag of all observations | |
| CC_FLAG | string | Quality flags in instrument CC. | Set per input image | Worst flag of all observations | |
| Columns 239 – 268: Inter-observation variability of sources with at least two contributing observations | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| VAR_CHI2 | float | Reduced chi square of inter-observation flux variability in all contributing observations with valid non-zero fluxes. | null |
|
|
| VAR_CHI2_n | float | Reduced chi squre of inter-observation flux variability in energy band n. | null | ||
| VAR_PROB | double | Probability that the measured flux values are consistent with constant inter-observation flux, derived from VAR_CHI2. The smaller VAR_PROB, the more likely the source shows inter-observation flux variability. | null |
|
|
| VAR_PROB_n | double | Probability that the measured flux values are consistent with constant inter-observation flux in energy band n. | null | ||
| FRATIO | float | Ratio between highest and lowest (non-zero, non-null) mean flux. | null | Fmax/Fmin | |
| FRATIO_ERR | float | 1σ error on the flux ratio. | null |
|
|
| FRATIO_n(_ERR) | float | Ratio between highest and lowest mean flux in energy band n and its 1σ error. | null | ||
| FLUXVAR | float | Largest difference between mean all-EPIC fluxes in terms of sigma. | null |
|
|
| FLUXVAR_n | float | Largest difference between mean all-EPIC fluxes in terms of sigma in energy band n. | null | ||
| Columns 269 – 273: 3XMM-DR7 intra-observation variability of sources with a DR7 light curve | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| CHI2PROB_3XMMDR7 | double | EPIC chi square probability that the time series of the nearest unique source in 3XMM-DR7 is consistent with the source having constant flux during the observation. | EP_CHI2PROB in 3XMM-DR7 | SC_CHI2PROB in 3XMM-DR7: Minimum of all contributing 3XMM-DR7 observations | |
| FVAR_3XMMDR7 | double | Fractional variance of the nearest unique source in 3XMM-DR7. | FVAR in 3XMM-DR7 of the instrument with minimum CHI2PROB | SC_FVAR in 3XMM-DR7: Observation with minimum CHI2PROB | |
| FVARERR_3XMMDR7 | double | 1σ error on FVAR_3XMMDR7. | FVAR_ERR in 3XMM-DR7 of the instrument with minimum CHI2PROB | SC_FVAR_ERR in 3XMM-DR7: Observation with minimum CHI2PROB | |
| VAR_FLAG_3XMMDR7 | boolean | Variability flag of the nearest unique source in 3XMM-DR7. True, if at least one exposure has CHI2PROB below 10–5. | VAR_FLAG in 3XMM-DR7 | SC_VAR_FLAG in 3XMM-DR7: Observation with minimum CHI2PROB | |
| SUM_FLAG_3XMMDR7 | integer | SUM_FLAG in 3XMM-DR7 | SC_SUM_FLAG in 3XMM-DR7 | ||
| Columns 274 – 284: Observation characteristics | |||||
| Column name | Format | Unit | Description | Observation | Stack |
| MJD_FIRST | double | days | Modified Julian Date of the start of the observation (JD–2400000.5). | Read from the headers of the input files | First contributing observation |
| MJD_LAST | double | days | Modified Julian Date of the end of the observation (JD–2400000.5). | Read from the headers of the input files | Last contributing observation |
| PA_PNT | float | degrees | Mean position angle of the spacecraft during the observation. | File headers | null |
| REVOLUT | short | XMM-Newton orbit of the observation. | File headers | null | |
| CC_SUBMODE | string | Observing mode of instrument CC. | File headers | null | |
| CC_FILTER | string | Filter used during the observation. | File headers | null | |
| URL_3XMMDR7 | string | Web page of the nearest unique source in 3XMM-DR7. | |||