X-ray sky survey of bright, serendipitous sources with 2XMMi at the AIP Speaker: Alexander Kolodzig...

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X-ray sky surveyof bright, serendipitous sources

with 2XMMi at the AIP

Speaker: Alexander Kolodzig

Origin: Humboldt-Uni Berlin, Germany

Institute: AIP (Astronomical Institute Potsdam),

Potsdam, Germany

Tutor: Axel Schwope

ESAC Summer Alumni Trainee Meeting 2009

The 2XMMi-Catalog

2XMMi = The incremental second XMM-Newton serendipitous source catalogue

– largest X-ray source catalogue (2009)

4117 XMM-Newton observations (2000 – 2008)

– each field is visually screened

~1.0% sky area covered independently

289083 rows of X-ray detections

221012 unique X-ray sources

300 columns of information per detection21.07.2009 2XMMi-Survey of bright sources at AIP - Alexander Kolodzig 2

• selection conditions (among others):– inspired by Della Ceca et al. (2004)– bright sources:

• SOFT-Band [0.5 - 4.5 keV]– Rate > 0.01 counts/sec Likelihood > 18

• HARD-Band [4.5 -12.0 keV]– Rate > 0.002 counts/sec Likelihood > 12

– serendipitous sources• just point sources• off axis angle ≥ 3 arcmin no center of the observation

• just certain Observation Field Classifications21.07.2009 2XMMi-Survey of bright sources at AIP - Alexander Kolodzig 3

source selection

• matching with the catalogs:1. SDSS (Sloan Digital Sky Survey) Data Release 6

2. BSS (XMM-Newton Bright Source Sample, Della Ceca et al. (2004))

– similar survey but of the BSS with 400 sources identified

3. NED (NASA/IPAC Extragalactic Database)

4. SIMBAD

– identify possible optical counterparts• add information of:

– optical magnitude– red shift– source type

21.07.2009 2XMMi-Survey of bright sources at AIP - Alexander Kolodzig 4

source matching

SOFT-Band selection

HARD-Band selection

• 2XMMi-Catalog (in ecliptic coordinates)

X-ray sky map

• SOFT-Band (in ecliptic coordinates)

sky map ofidentified sources

• HARD-Band (in ecliptic coordinates)

sky map ofidentified sources

distribution ofknown source types

• SOFT-Band (in ecliptic coordinates)

sky map ofknown source types

• HARD-Band (in ecliptic coordinates)

sky map ofknown source types

• ratio: X-ray flux / optical flux

SOFT-Band

HARD-Band

comparison ofstars, galaxies & QSO’s

• optical flux [mag] vs. galactic latitude [deg]

• optical flux [mag] vs. red shift [log(z)]

– compare optical type and X-ray source• identify of additional or wrong optical counterparts

– development of automatic type-identifying method for X-ray bright sources

– new list of unknown, maybe interesting X-ray sources

characterisation of the X-ray sky

further applications

Thank You For Your Attention!

Contributions or Questions?

e-mail: alex_kolo@gmx.de

Backup - Slides

The 2XMMi-Catalog

• 2XMMi-Catalog:– constructed by SSC (XMM-Newton Survey Science Centre)

– serendipitous: found by coincidence

XMM-Newton Observatory

• factsheet :– ESA Satellite, launched 1999– most sensitive X-ray telescope (so far)– 3 independent X-ray cameras (PN, MOS1, MOS2)

• energy range: 0.15 - 15 keV• field of view: 0.5 degree

– 2 X-ray reflection grating spectrometers (RGS) – 1 independent optical/UV monitor (OM)

• simultaneous longtime observations in x-ray and optical

• my tasks:

1. selecting the “bright, serendipitous sources”

2. matching with other catalogs

3. statistics

Task - Overview

• selection-conditions (among others):– serendipitous sources:

• just point sources• Offaxis Angel ≥ 3 arcmin

– no detection from the center of the observation field

• Observation Field Classification:– f = all detections are potential target– n = the target was not detected or in the field

1. Selecting

• Selection-Conditions:– OBS_CLASS < 4

• Quality classification of the whole observation, <10% has been flagged– EP_EXTENT < 6 arsec

• extent radius of a source detected, < 6" = point-source– M1,M2,PN_SubMode= “FullWindow/ExtentedWindow”– TSERIES = True (has Light-Curve)– SPECTRA = True (has Spectra)– SUM_FLAG = 0

• summary flag of the source is derived from the EPIC flag, 0 = “none of the flags was set”

– M2_OFFAX ≥ 3 arcmin, ≤ 13 arcmin just serendipitous sources

– RATE and Likelihood for each BAND of the M2-Camera• SOFT: >0.01 counts/sec , Likelihood >18• HARD: >0.002 counts/sec , Likelihood >12

– FIELD_CLASS: n,f just serendipitous sources• f - 'field', that is, all detections are potential target• n - the target was not detected or in the field , whole field is serendipitous

1. Selecting

• Data mainly from EPIC MOS2-Camera:– explained by the paper:

http://xmmssc-www.star.le.ac.uk/XID/XMMBSDellaCeca04.pdf

– detector pattern simplifies the analysis of the field• e.g. object source target is fully contained in the central

– it has the best PSF– gaps between the EPIC MOS chips are narrower– sensitivity with the bright sources isn’t important

• Matching:– matching with coordinates (RA & DEC)– error-radius: 3 arcsec

• possible identification of wrong optical counterparts

– Matching-Tool: “STILTS” (script-version of TOPCAT)

– purpose:• identify possible optical counterparts• add Information of:

– optical magnitude– red shift– source type

2. Matching

• matched with the following catalogs:1. SDSS (Sloan Digital Sky Survey) Data Release 6

– 62.435 sources (with known & unknown source types)– pre-matched catalog with 2XMMi

2. BSS (XMM-Newton Bright Source Sample, from SSC)

– 400 sources– similar but smaller survey of 2XMMi

3. NED (NASA/IPAC Extragalactic Database)

– 163 million sources (with known & unknown source types)– Data-Extraction difficult

4. SIMBAD– 4.6 million sources

2. Matching

• Plot: normalized with the circle area

3. Statistics offaxis angel distribution

3. Statistics

• Results:Number of Sources

SOFT HARD* Description

933 (0,4%) 217 (0,1%) serendipitous bright sources

468 (50%) 121 (56%) identify sources and known type

128 (14%) 23 (11%) identify sources but unknown type

337 (36%) 73 (34%) unknown sources (so far)

*Hard-Band without “detections” which appear as well in the Soft-Band

3. Statistics

• Results: Number of Det./Src.SOFT HARD Stage3171 1132 Det.: without Field-Class1104 543/234* Det.: total Selection933 473/217* Src.: total Selection0.42% 0.21%/0.10*% from now just source-numbers

? ?* identify with SDSS?(?) ?*(?*) identify with BSS (additional)?(?) ?*(?*) identify with NED (additional)? (?%) ?* (?%) identify sources (known & unknown type)

? (?%) ?* (?%) unknown sources (so far)*Hard-Band without “detections” which appear as well in the Soft-Band

• 2XMMi-Catalog (in ecliptic coordinates)

X-ray sky map

• X-ray flux [log(erg/(cm²s))] vs. red shift [log(z)]

• red shift [log(z)] vs. galactic latitude [deg]

Overview

X-ray sky survey of bright, serendipitous sources with 2XMMi at the AIP Speaker: Alexander Kolodzig...

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