26 June 2005
CURRENT RELEASE
Region ..................... Selected XMM Serendipitous Survey fields
Number of Fields ........... 12
Version .................... 1.0
Total Data Volume .......... 5.5 Mb
Release Date ............... June 2005
Release prepared by ........ AIP/SSC node (A. Schwope, V. Hambaryan, G.
Lamer)
PRODUCTS
Product Type ............... Stacked images of multiple and source
lists per individual XMM-Newton observation(s)
Data Volume ................ 5.5 Mb
PREVIOUS RELEASE
None
PRODUCTS IN PREVIOUS RELEASE
None
This release accompanies the paper J.P. Dietrich et al: ESO Imaging Survey: Optical follow-up of 12 selected XMM fields submitted to Astron. Astrophys. This survey was based on an idea submitted by the XMM-SSC to ESO's Survey Working Group (SWG), who turned it into a proposal submitted to the ESO-OPC. The optical part of the XMM survey (administered by the ESO Imaging Survey (EIS) and the Public Survey Group (PSG) teams) consists of follow-up optical observations of the XMM-Newton Serendipitous Sky Survey (XSSS) using the ESO Wide Field Imager (WFI) at the ESO/MPG 2.2m telescope at the La Silla Observatory. This survey seeks to obtain WFI images in B-, V-, R- and I- passbands (for minimum spectral discrimination and photometric redshift determination) of XMM fields publicly available in the XMM archive. The fields were selected and prioritized by a collaboration of interested parties from the XMM Survey Science Centre (SSC), the Bonn group (led by P. Schneider) and an appointed committee of the SWG. Four of the original 12 fields proposed for and observed in P70/71 are fields at low galactic latitude, the remaining fields, including the three fields observed as carry-over targets in P72, are at high galactic latitude.
The present release consists of an analysis 28 XMM-Newton
observations performed on 12 fields (see Table 2 of the paper by
Dietrich et al. for a distribution among the fields). The XMM-Newton
science archive (XSA) lists even more observations in the mentioned
fields. These were not considered here due to unsuitable camera
settings or non-availability of data (January 2005).
For more information about the terminology and conventions used for X-ray analysis refer to the XMM-Newton home page. The data products were created with the latest official release of the Science Analysis Software (SAS version 6.1) for XMM-Newton.
The present release consists of stacked images and source lists.
Data analysis was performed with the public SAS release v6.1 with some
AIP add-ons for the source detection. Stacked images were created for
the the XID- and a broad spectral band covering the energy ranges
0.5-4.5 keV and 0.1-12.0 keV, respectively. The contributing
observations are listed in Table 2 of Dietrich et al. Before stacking
the images were pipeline processed and filtered for good time
intervals. No background subtraction took place, since the
discrimination between source and background is particularly difficult
in X-rays in the galactic plane. Colour images were created
making use of photons in the XID-band only. Red, green and blue
channels comprise the energy ranges 0.5-1.0 keV, 1.0-2.0 keV, and
2.0-4.5 keV, respectively. Weights to the sub-images were given in a
manner that a typical extragalactic X-ray source with a power law X-ray
spectrum (photon index 1.5, absorption column density nH = 10^20
1/cm^2) would have equal photon numbers in all three bands.
Exposure times per X-ray image
T_s,pn: scheduled exposure time for pn detector (units: seconds)
T_e,pn: effective exposure for pn-detector after background filtering
T_e,m1: same for mos1 detector
T_e,m2: same for mos2 detector
| Field |
ObsID |
T_s,pn |
T_e,pn |
T_e,m1 |
T_e,m2 |
|---|---|---|---|---|---|
| XMM-01 |
0111150201 0111150101 |
123534 |
113000 |
117052 |
117052 |
| XMM-02 |
0164560501 0156960201 0156960401 |
112341 |
75100 |
82212 |
82212 |
| XMM-03 |
0112630101 |
36428 |
9500 |
12844 |
12844 |
| XMM-04 |
0094800101 |
41021 |
26400 |
31980 |
31980 |
| XMM-05 |
0125320701 0125320401 0125320501 0153950101 0133120301 0133120401 |
118409 |
55900 |
80756 |
80756 |
| XMM-06 |
0111160201 |
49616 |
34500 |
48204 |
48204 |
| XMM-07 |
0106660501 0106660401 0106660101 0106660201 0106660601 |
236013 |
202100 |
255684 |
255684 |
| XMM-08 |
0110980201 |
58237 |
54600 |
57876 |
57876 |
| XMM-09 |
0060370201 |
41273 |
38100 |
40560 |
40560 |
| XMM-10 |
0012440301 |
35366 |
29000 |
34372 |
34372 |
| XMM-11 |
0112970601 0112971601 0112972101 0111350301 0111350101 |
124816 |
43500 |
44564 |
43732 |
| XMM-12 |
0109110101 |
76625 |
71000 |
75036 |
75036 |
X-ray source lists for point-like X-ray sources were
produced
for 8 fields (10 observations) at high-galactic latitude. Source
detection was performed as a three-stage process using eboxdetect
in local and in map mode followed by a multi-PSF fit with emldetect for all sources present
in the initial source lists. The
multi-PSF fit invoked here works on 15 input images, i.e. 5 per EPIC
camera. The five energy bands used per camera cover the ranges: 1) 0.1
-- 0.5\,keV; 2) 0.5 -- 1.0\,keV; 3) 1.0 -- 2.0\,keV; 4) 2.0 --
4.5\,keV; and 5) 4.5 -- 0.5\,keV.
The source detection scheme used here is very similar to the pipeline
implemented for the production of the second XMM-Newton catalog of
X-ray sources (2XMM) to be published by the XMM-SOC later in 2005
(Watson et al., in preparation). This approach is superior to
that used for the creation of source lists which are currently stored
in the XMM-Newton Science Archive since it makes use of X-ray photons
from all cameras simultaneously. It also distinguishes between
point-like and extended X-ray sources.
We publish the source lists in two flavours, the original source
list resulting from the emldetect detection
run labeled F and a compressed
list with corrected coordinates labeled C. While the latter contains one row
per X-ray source, the former contains 19 lines per detected source, one
all_EPIC summary and each 6 lines per EPIC-camera. The six rows per
camera correspond to the five detection bands and a camera summary in
the first line. The rows in the C-lists just contain the EPIC summary
information.
Positions in the C-lists were corrected with the SAS-task eposcorr and one of the EIS optical
catalogues. With this step remaining attitude uncertainties are removed
from the source lists in statisctical manner. Corrections to the
original lists are typically small but significant. Only the list for
XMM-03 was corrected by a large amount of 13 arcsec. The eposcorr
parameters are listed in the following table.
| Field |
ObsID |
RA
offset (arcsec) |
DEC
offset (arcsec) |
ROTANG |
likelihood |
#matches |
|---|---|---|---|---|---|---|
| XMM-03 |
0112630101 |
11.9 |
-6.8 |
0.02 |
18 |
164 |
| XMM-04 |
0094800101 |
0.66 |
0.44 |
-0.08 |
61 |
584 |
| XMM-05 |
0125320401 |
-0.44 |
-2.22 |
-0.055 |
51 |
458 |
| XMM-06 |
0111160201 |
0.00 |
0.22 |
-0.068 |
54 |
602 |
| XMM-07 |
0106660101 |
-0.90 |
-1.34 |
-0.060 |
67 |
693 |
| XMM-07 |
0106660201 |
-1.34 |
-1.34 |
-0.045 |
49 |
527 |
| XMM-07 |
0106660601 |
-1.16 |
-1.78 |
-0.064 |
68 |
750 |
| XMM-08 |
0110980201 |
0.44 |
-0.66 |
-0.051 |
52 |
429 |
| XMM-09 |
0.00 |
-0.44 |
-0.019 |
54 |
418 |
|
| XMM-10 |
0012440301 |
-0.44 |
0.88 |
-0.08 |
47 |
401 |
Columns in the X-ray source lists
Col.# 1:ML_ID_SRC Unit: Format:I11 I*4 Sequence number in eml-list
Col.# 2:BOX_ID_SRC Unit: Format:I11 I*4 Sequence number in ebox-list
Col.# 3:ID_INST Unit: Format:I11 I*4 0-all EPIC, 1-pn, 2-mos1, 3-mos2
Col.# 4:ID_BAND Unit: Format:I11 I*4 0-sum, 1..5 according to band definition
Col.# 5:ID_CLUSTER Unit: Format:I11 I*4 Group number of simultaneously fitted sources
Col.# 6:SCTS Unit:counts Format:E15.5 R*4 Total summed source counts
Col.# 7:SCTS_ERR Unit:counts Format:E15.5 R*4 Error of #6
Col.# 8:X_IMA Unit:image pixels Format:E15.5 R*4 Position of source in image coordinates
Col.# 9:X_IMA_ERR Unit:image pixels Format:E15.5 R*4 Error of #8
Col.# 10:Y_IMA Unit:image pixels Format:E15.5 R*4 Position of source in image coordinates
Col.# 11:Y_IMA_ERR Unit:image pixels Format:E15.5 R*4 Error of #10
Col.# 12:EXT Unit:image pixels Format:E15.5 R*4 Extent of source
Col.# 13:EXT_ERR Unit:image pixels Format:E15.5 R*4 Error of #12
Col.# 14:DET_ML Unit: Format:E15.5 R*4 Detection likelihood
Col.# 15:EXT_ML Unit: Format:E15.5 R*4 Extent likelihood
Col.# 16:BG_MAP Unit:counts/pixel Format:E15.5 R*4 Background at source position
Col.# 17:EXP_MAP Unit:seconds Format:E15.5 R*4 Vignettinmg corrected effective exposure at source position (PSF-weighted)
Col.# 18:FLUX Unit:cgs Format:E15.5 R*4 Source flux assuming ECFs for typical extragalctic source
Col.# 19:FLUX_ERR Unit:cgs Format:E15.5 R*4 Error of #18
Col.# 20:RATE Unit:counts/s Format:E15.5 R*4 Count rate
Col.# 21:RATE_ERR Unit:counts/s Format:E15.5 R*4 Error of #20
Col.# 22:RA Unit:deg Format:E15.5 R*8 Right ascension of source
Col.# 23:DEC Unit:deg Format:E15.5 R*8 Declination of source
Col.# 24:RADEC_ERR Unit:arcsec Format:E15.5 R*4 Positional uncertainty (statistical)
Col.# 25:LII Unit:deg Format:E15.5 R*8 Galactic longitude
Col.# 26:BII Unit:deg Format:E15.5 R*8 Galactic latitude
Col.# 27:RAWX Unit:raw pixels Format:I11 I*4 Source position X in detector coordinates
Col.# 28:RAWY Unit:raw pixels Format:I11 I*4 Source position Y in detector coordinates
Col.# 29:CCDNR Unit: Format:I11 I*4 Number of CCD where source was detected
Col.# 30:HR1 Unit: Format:E15.5 R*4 Hardness ratio between band 1 and 2
Col.# 31:HR1_ERR Unit: Format:E15.5 R*4 Error of #30
Col.# 32:HR2 Unit: Format:E15.5 R*4 Hardness ratio between band 2 and 3
Col.# 33:HR2_ERR Unit: Format:E15.5 R*4 Error of #32
Col.# 34:HR3 Unit: Format:E15.5 R*4 Hardness ratio between band 3 and 4
Col.# 35:HR3_ERR Unit: Format:E15.5 R*4 Error of #34
Col.# 36:HR4 Unit: Format:E15.5 R*4 Hardness ratio between band 4 and 5
Col.# 37:HR4_ERR Unit: Format:E15.5 R*4 Error of #36
Col.# 38:CUTRAD Unit:pixels Format:E15.5 R*4 Image cut-out radius for fitting
Col.# 39:MASKFRAC Unit:pixels Format:E15.5 R*4 Fraction of PSF-coverage (subtracting dead pixels etc)
Col.# 40:EEF Unit: Format:E15.5 R*4 Energy encircled fraction (fraction of MASKFRAC within CUTRAD)
Col.# 41:VIGNETTING Unit: Format:E15.5 R*4 Vignetting
Col.# 42:ONTIME Unit: Format:E15.5 R*4 Raw integration time on ccd CCDNR
Col.# 43:DIST_NN Unit:arcsec Format:E15.5 R*4 Distance to nearest neighbour
Col.# 44:FLAG Unit: Format:A12 C*12 not used
Applies only to the eposcorr corrected source lists
Col.# 45:RA_CORR Unit:deg Format:E15.5 R*8 Corrected right ascension
Col.# 46:DEC_CORR Unit:deg Format:E15.5 R*8 Corrected declination
Col.# 47:LII_CORR Unit:deg Format:E15.5 R*8 Corrected galactic longitude
Col.# 48:BII_CORR Unit:deg Format:E15.5 R*8 Corrected galactic latitude
Image Product Calibration
Astrometry: The statistical positional uncertainty of the X-ray
sources is typically better than 2 arcsec (see Fig.9 of Dietrich et
al.). There is always a remaining systematical uncertainty due to the
attitude solution of the spacecraft of the same order. The latter can
be removed if the true source positions are known. The SAS-routine
eposcorr computes a translational shift and a rotation angle by
correlating the X-ray source list with an input catalogue. In the
pipeline processed data for the XSA correlation is performed with the
USNO-A2 catalogue. With the now available much deeper WFI-images the
number of positive correlations is much larger and the achieved
solution more reliable. After correction with
eposcorr the error budget of X-ray sources should be dominated by their
statistical uncertainties only.
Fluxes: The fluxes given in the source lists are based on ECFs
(energy conversion factors) suitable for a typical extragalactic X-ray
source with a power law photon spectrum (hardness ratio HR1=, HR2=,
HR3=). The fluxes for sources with deviating hardness ratios are
therefore somehow arbitrary.
All data products released here are based on public XMM-Newton data and publicly available software. Previous releases of the individual data happened via the XSA web-pages. Data products in the XSA are based on the then available software versions, i.e. they are in some parts outdated and they ar not the same for all contributing observations to the XMM-EIS survey. Homogeneity of the data products with the most up-to-date software is the main driver of the current release, which may be regarded as a precursor to 2XMM catalogue.
The results of the source detection process are visualised on
images in TIFF format. All detected point sources with detml=6 are
marked with white circles, the extended sources are marked with green
circles. No further screening and grading of the source lists and
detection images took place.
No source lists were produced for the galactic plane fields. For XMM09 the created source list contained many spurious sources due to remaining calibration uncertainties in the pipeline processed images and was not considered further.
Anticipated future releases include:
| Last update: June 29, 2005 | |
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