ROSHRI - ROSAT Results Archive Sources for the HRI

Overview

The ROSHRI data table contains a list of sources detected by the Standard Analysis Software System (SASS) in reprocessed, public HRI datasets. In addition to the parameters returned by SASS (like position, count rate, signal-to-noise, etc.) each source in the table has associated with it a set of source and sequence "flags." These flags are provided by the ROSAT data centers in the US, Germany and the UK to help the user of the ROSHRI database table quickly judge the reliability of a given source.

The ROSHRI table excludes sources that meet the following parameter criteria: false_det = 'T' or deferred = 'T' or not_checked = 'T' or un_unique ='T'. See the documentation below for descriptions of these parameters.

These data have been screened by ROSAT data centers in the US, Germany, and the UK as a step in the production of the ROSAT Results Archive. The RRA contains extracted source and associated products with an indication of reliability for the primary parameters.

Catalog Bibcode

References

More information about the ROSAT mission and the SASS can be obtained from the ROSAT USER HANDBOOK, available at

   http://heasarc.gsfc.nasa.gov/docs/rosat/rosdocs.html

Provenance

This database table was last updated in August 2001. More information about the ROSAT Results Archive for HRI sources can be obtained at the following web pages:

   http://heasarc.gsfc.nasa.gov/docs/rosat/rra/RRA.html
   http://hea-www.harvard.edu/rosat/rra.html
   http://www.aip.de/groups/xray/rosat/rra.html
   http://ledas-www.star.le.ac.uk/rra

Version

This catalog is the First ROSAT Source Catalog of Pointed Observations with the High Resolution Imager (ROSHRICAT / 1RXH). It contains arcsecond positions and count rates of 56,401 detected sources from 5393 ROSAT HRI observations covering 1.94% of the sky, including 13,452 high confidence detections and 331 obvious sources which were not detected by the SASS. It was released on August 9, 2001. (See ROSAT NEWS No. 74 at http://heasarc.gsfc.nasa.gov/mail_archive/rosnews/msg00131.html for the official announcement.)

Flag Description

The following flags are used by the datacenters in constructing the ROSHRI table. Flags are divided into "SEQUENCE FLAGS" which describe an entire data sequence, and "SOURCE FLAGS" which describe an individual source. The HRI source flags are associated with the primary SASS parameters like count rates, positions, etc., and with qualitative source characteristics.

All flags are LOGICAL, i.e. they have a value of TRUE or FALSE. A flag with a TRUE value indicates a possible problem with a source parameter. Thus, a source with no discernable problem would have all flags set to FALSE.

 Sequence flags:
 ===============

 FLAG NAME              "True" condition
 ---------               ----------------
 ASP_SUSP                obvious aspect problems (sources appear multiple or
                         have obvious ellipticity)
 EXT_EMIS                presence of extended emission over most of the field
 FIELD_FDET              one or more detected sources deemed false
 DEFERRED                data screening not done
 MISS_SRC                one or more obvious sources not detected by SASS
 BKG_SUSP                field background may be incorrect (due to inclusion
                         of high background intervals or extended emission)
 SLIS_MIS                source list is missing (no sources detected by SASS or
                         source detection stopped)

 Source Flags:
 =============

 FLAG NAME              "True" condition
 ----------              ----------------
 CONFUSED                close sources confused detection algorithm
 DET_STRUCT              source near detector structure
 EXTENDED                source is probably resolved
 FALSE_DET               detection judged to be spurious
 INTEN_SUSP              source brightness suspect
 MULT_DET                complex emission split into individual sources
 NOT_CHECKED             source not checked
 POS_SUSP                source position suspect
 ASSOCIATED              another source nearby may influence derived source
                         quantities
 VARFLG_SUSP             SASS variability flag suspect
 WITHIN_EXT              source within extended emission
 UN_UNIQUE               source matched with another source which was identified
                         in a smaller detect cell (HRI only)

Missed Sources

This version of the ROSAT Pointed HRI source catalog includes missing sources, i.e. obvious sources which were not detected by the SASS source detection software but which could be easily detected by visual inspection. Missed sources in the list are marked by negative values of their source identification numbers; i.e., the parameter 'SRCNUM' is negative for these sources. The only tabulated quantities for these visually identified missed sources are source positions; other quantities (like count rates, hardness ratios, exposure times, etc.) are not available and are set to 0 (zero) in the catalog.

Parameters

Source_Name
Name of source following IAU conventions, like: 2RXH J153127.5+312918. Note: Source names in 1st release of catalogue are blank; these names will be defined from a final source matching of detections.

Detection_Name
Name of catalogued detection following IAU conventions, like: 1RXH J153127.5+312918. Note: The detection name is NOT UNIQUE. Detections with the same position will have the same detection name; such detections may or may not represent the same astrophysical source.

Sequence_Detection_Name
Unique name for detection, based on the observation sequence id and the number of the detection in the source list for that sequence, like: 1rh200855n00.123

RA
Source Right Ascension

Dec
Source Declination

LII
Source Galactic Longitude

BII
Source Galactic Latitude

Exposure
Exposure live time (seconds)

EPI
Edge proximity indicator

X
Unblocked x source position (0.5 arcsec/pixel)

Y
Unblocked y source position (0.5 arcsec/pixel)

XY_Error
Error in position (0.5 arcsec/pixel)

Im_X
Blocked x source position (8 arcsec/pixel)

Im_Y
Blocked y source position (8 arcsec/pixel)

Lev1_X
SASS level 1 x coordinate (0.5 arcsec/pixel)

Lev1_Y
SASS level 1 y coordinate (0.5 arcsec/pixel)

Offaxis
Off axis angle averaged over observation (arcmin)

Cir_Rad
Radius of source circle for source intensity measurement (arcsec)

Gross_Cts
Total (source + background) counts within CIR_RAD

Gross_Cts_Error
Error on total (source + background) counts within CIR_RAD

Cir_Bkg
Bkg counts inside CIR_RAD

Count_Rate
Estimate of net rate in the ROSAT band (roughly 0.2-2.4 keV), in ROSAT counts/sec.

Count_Rate_Error
Error of net rate (count/sec)

_1keV_QE
1 keV Quantum efficiency which has been used to derive Count_Rate

_1keV_Vig
1 keV vignetting correction for source which has been used to derive Count_Rate

_1keV_CSC
1 keV scattering correction for source which has been used to derive Count_Rate

X_Size
X source detect cell size (arcsec)

Y_Size
Y source detect cell size (arcsec)

Box_Cts
Total counts in detection box

Threshold
Threshold for detection at this location (counts)

SNR
Signal-to-noise ratio for detection

Src_Prob
Probability that the source is unresolved: a statistic which measures how well the radial distribution matches the expected PRF. A good match produces Src_Prob=1.0

X_EC
X position of extended circle (0.5 arcsec/pixel)

Y_EC
Y position of extended circle (0.5 arcsec/pixel)

Rad_EC
Radius of the extended circle (arcsec)

EC_CSC
Extended circle scattering correction

Size_Cor
Extended circle size correction

Size_Cor_Error
Error of extended circle size correction

Begin_Date
Observation start date

End_Date
Observation finish date

ROR
ROSAT Observation Request number assigned to the observing program. Typically the target of each pointed observation will have a unique ROR number assigned to it.

Srcnum
Source Number from SASS for the given sequence

QC_Date
Date of sequence and source checking (yymmdd)

SeqID
Sequence identification (like rh400623n00)

ObsID
Observation ID (like US400623H.N1)

Site
Processing Site

SrcFlags
Summary of source flags. This is a string of abbreviations for each source flag which is set to TRUE, and indicates a possible problem with the source. The abbreviations used are c=CONFUSED, d=DET_STRUCT, e=EXTENDED f=FALSE_DET, i=INTEN_SUSP,l=LTC_SUSP, s=SPEC_SUSP, m=MULT_DET, n=NOT_CHECKED, p=POS_SUSP,a=ASSOCIATED, v=VARFLG_SUSP, w=WITHIN_EXT.

Confused
Close sources confused detect

Det_Struct
Source near detector structure

Extended
Source extended

False_Det
Detection of unreal or false source

Inten_Susp
Source brightness suspect

Spare_Ltc
Source lightcurve suspect (this flag is currently not filled since no lightcurves are available for HRI sources)

Mult_Det
Complex emission split

Not_Checked
Weak source below SNR threshold used for checking

Pos_Susp
Source position suspect

Associated
Associated source nearby

Varflg_Susp
Source variability indicator from SASS is suspect

Within_Ext
Source within extended emission

Un_Unique
Detection is matched to another detection with a smaller detect cell size

SeqFlags
Summary of sequence flags. This is a string of abbreviations for each sequence flag which is set to TRUE, and indicates a possible problem with the sequence. The abbreviations used are A=ASP_SUSP, E=EXT_EMIS, F=FIELD_FDET, D=DEFERRED, M=MISS_SRC, B=BKG_SUSP, S=SLIS_MIS, X=EXPO_MAP.

Deferred
Field not flagged by operator

Asp_Susp
Aspect solution suspect

Bkg_Susp
Background suspect

Ext_Emis
Extended emission in field

Field_Fdet
False detections in field

Src_Miss
Sources in field missed

Slis_Mis
Source list missing

Vary
Source variability flag from SASS

Comments
Source comment which may have been assigned by the checker

Qcname
Checker ID

Qcsite
Checker site

Contact Person

Questions regarding the ROSHRI database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:33:59 EDT