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GSFC XMM-Newton GOF Status Report #065: XMM-NEWTON NEWS #29



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_/                 XMM-NEWTON NEWS #29   ---    11-Mar-2003                 _/
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                ESA, XMM-Newton Science Operations Centre at
            Villafranca del Castillo, Satellite Tracking Station
                P.O. Box - Apdo. 50727, 28080 Madrid, Spain

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SOC Home Page:           
        http://xmm.vilspa.esa.es/
Helpdesk web interface:  
        http://xmm.vilspa.esa.es/external/xmm_user_support/helpdesk.shtml
Helpdesk email address:
        xmmhelp@xmm.vilspa.esa.es
News Mailing List:
        http://xmm.vilspa.esa.es/external/xmm_user_support/xmm_news/ 

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Contents: 
          - XMM-Newton Users' Handbook update for AO-3
          - Users' Guide to the XMM-Newton Science Analysis System: update  
          - emldetect likelihoods
          - RGS Background files available
	  - OM flux conversion factors 
          

XMM-Newton Users' Handbook update for AO-3
==========================================

The XMM-Newton Users' Handbook (UHB) has been updated in preparation for 
the next Announcement of Opportunity (AO-3) reflecting latest in-flight 
experience.

The UHB contains information on the instrumentation on board XMM-Newton 
and serves as the proposal preparation document, based on which potential 
XMM-Newton users can assess the technical feasibility of their planned 
observations.

The updated XMM-Newton Users' Handbook is available now from the URL
http://xmm.vilspa.esa.es/external/xmm_user_support/documentation/


Users' Guide to the XMM-Newton Science Analysis System: update
==============================================================

XMM-Newton SOC has updated the Users' Guide to the XMM-Newton Science 
Analysis System for SAS version 5.4.1. The updated guide will be 
available from Monday, March 17, in different formats (postscript, 
pdf and html) from the XMM-Newton Proposer's Info and Manuals Web page 
(Section: Data Analysis) at URL:

http://xmm.vilspa.esa.es/external/xmm_user_support/documentation/ 
   

emldetect likelihoods
=====================

A coding error has recently been discovered in the SAS task emldetect which
performs EPIC source parameterisation. Due to this error, the detection
likelihood values reported by emldetect (i.e. in the column DET_ML in the
output files) are overestimated by a factor 2 or more, depending on the
number of input images. Other aspects of the performance of emldetect are
unaffected.

As emldetect is used in the standard XMM-Newton processing pipeline, this
problem affects EPIC source lists produced with SAS 5.4.1 or earlier. Users
are advised to treat with caution any detections in existing source lists
with low DET_ML values (especially DET_ML <~ 20) as the number of spurious
sources per EPIC image becomes significant at these values.

This error will be corrected in the next version of the SAS.

The attached table provides the conversion to correct DET_ML values with
some examples.

DET_ML conversion table
-----------------------

Table to convert emldetect (v4.11.15 and earlier) likelihood values 
(column DET_ML) to correct values. 

Examples for pipeline source lists: 
1) The old DET_ML value for a single energy band (ID_BAND=1,2,3,4 or 5) 
   is 18.0, the correct value is 8.51
2) The old DET_ML value for the summary band (5 bands, ID_BAND=0) 
   is 27.0, the correct value is 11.29
 
   old value          correct values
                1 band    2 bands   5 bands
----------------------------------------------
      5.00      2.24      2.03      1.59
      6.00      2.71      2.48      1.99
      7.00      3.18      2.93      2.39
      8.00      3.66      3.39      2.80
      9.00      4.14      3.85      3.21
     10.00      4.62      4.32      3.64
     11.00      5.10      4.78      4.06
     12.00      5.59      5.25      4.50
     13.00      6.07      5.72      4.93
     14.00      6.56      6.20      5.37
     15.00      7.04      6.67      5.82
     16.00      7.53      7.15      6.26
     17.00      8.02      7.62      6.71
     18.00      8.51      8.10      7.16
     19.00      9.00      8.58      7.61
     20.00      9.48      9.06      8.07
     21.00      9.97      9.54      8.52
     22.00     10.47     10.02      8.98
     23.00     10.96     10.50      9.44
     24.00     11.45     10.99      9.90
     25.00     11.94     11.47     10.36
     26.00     12.43     11.95     10.82
     27.00     12.92     12.44     11.29
     28.00     13.41     12.92     11.75
     29.00     13.91     13.41     12.22
     30.00     14.40     13.89     12.69
     31.00     14.89     14.38     13.16
     32.00     15.38     14.87     13.62
     33.00     15.88     15.35     14.09
     34.00     16.37     15.84     14.57
     35.00     16.86     16.33     15.04
     36.00     17.36     16.82     15.51
     37.00     17.85     17.30     15.98
     38.00     18.35     17.79     16.45
     39.00     18.84     18.28     16.93
     40.00     19.33     18.77     17.40
     41.00     19.83     19.26     17.88
     42.00     20.32     19.75     18.35
     43.00     20.82     20.24     18.83
     44.00     21.31     20.73     19.30
     45.00     21.81     21.22     19.78
     46.00     22.30     21.71     20.26
     47.00     22.80     22.20     20.74
     48.00     23.29     22.69     21.21
     49.00     23.79     23.18     21.69
     50.00     24.28     23.67     22.17
     51.00     24.78     24.16     22.65
     52.00     25.27     24.65     23.13
     53.00     25.77     25.15     23.61
     54.00     26.27     25.64     24.09


RGS Background files available
==============================

RGS Background template event files have been provided by T. Tamura,
from the RGS Team at SRON. These files have been derived from
blank-sky observations, and have total exposure times ranging from 80
to 390 ksec. They are useful when the background cannot be
accurately derived from the standard off-axis regions, e.g. in the
case of extended sources.

These files are accessible through the XMM-Newton Calibration Portal
at the following URL:

http://xmm.vilspa.esa.es/external/xmm_sw_cal/calib/index.shtml


OM Flux conversion factors
==========================

Flux conversion factors for the different filters of the Optical Monitor
(OM) have been added as keywords FCF* in the COLORMAG extension of the 
current calibration file (CCF) OM_COLORTRANS since SAS version 5.4.1. 
These conversion factors help users to get a rough estimation of flux 
densities (expressed in erg/cm^2/s/A) directly from OM count rates. The 
throughput of the OM is stable over time to within a few percent.


Yours sincerely,
XMM-Newton SOC
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