The Bright Side of the X-ray SkyThe XMM-Newton Bright Survey

R. Della CecaT. Maccacaro

A. Caccianiga

P. Severgnini

V. Braito

INAF – Osservatorio Astronomico

di Brera,Milan

On behalf of the XMM-Newton Survey Science Centre

The XMM-Newton Bright Survey Project

The XMM Bright Survey is aimed at

selecting and spectroscopically identifying

a large and statistically representative

sample of bright (fx > ~7x10-14 c.g.s)

serendipitous XMM sources in the

0.5-4.5 keV energy band: Bright Sample (BS)

4.5-7.5 keV energy band: Hard Bright Sample (HBS)

Primary Selection Camera: the MOS2 detector

• Bright Sample (BS): CR (0.5-4.5 keV) > 0.01 s-1 (~7x10-14 cgs)

• Hard Bright Sample (HBS): CR (4.5-7.5 keV) > 0.002 s-1 (~7x10-14)

Criteria for ...

• Galactic latitude (|bII|>20); • Line of sight NH (<1021 cm-2);• Target confined within the

central chip;• Exposure time > 5 (-7) ks

to guarantee a flat sensitivity;

• Other (i.e. no very bright optical obj. in field, etc..)

• Source position: RI<R<RO

RI depending on

target/mode

RO =13'

• Avoid edges & gaps;

• No physical relation to

target

Primary Selection Camera: the MOS2 detector

Source selectionField selection

Among the scientific goals of the project are

• identifying X-ray “bright” sources suitable for detailed multi-wavelength follow-up studies;

• defining statistical identification procedures to select rare and interesting populations of X-ray sources (e.g. Type 2 QSO, absorbed AGNs);

• complementing medium and deep surveys to obtain a better coverage of the LX- z plane for statistical and evolutionary studies and to testcurrent AGN and XRB synthesis models.

Note that unlike deep/pencil beam surveys the XMM BSS is protected against problems connected to the cosmic variance

BS HBS

• Images used: 237 (211)

• Area Covered: 28.1 (25.17) sq.deg

• Total Source Sample 400

Sources in the Bright Sample: 389

Sources in the Hard Bright Sample: 67

(56 sources are in common)

The XMM-Newton Bright Survey Project

The XMM BSS in a context

Adapted fromBrandt and Hasinger, ARAAA, 2005, in press

XMM-Newton Bright Survey

The XMM BSS in a contextChandra , XMM

Deep Medium HEAO 1ASCABeppoSAX

XMM BSS 10 meters class telescope

4 meters class telescope

Adapted from Akiyama et al., 2003

Broad Line AGNs

Photometric z + X + etc..

X-ray spectral analysis is possible for almost all the sources in the XMM BSS!!

BS HBSSources 389 67Identified 311 (80%) 62 (90%)

Optical identification & classification(217 src our own spectroscopy + literature)

2%

1%

2%

16%

10%

69%

Broad Line AGN

Narrow LineAGN

Optically"Normal"Galaxy

Clusters ofGalaxies

BL Lac Objects

Stars

2%

2%

2%

3%

29%

62%

Broad Line AGN

Narrow LineAGN

Optically"Normal"Galaxy

Clusters ofGalaxies

BL Lac Objects

Stars

BS HBS

Extragalactic LogN - LogS

“hard” bright samplebright sample

AXIS (0.5-4.5 keV)

From ROSAT (0.5-2.0 keV)

From EMSS (0.3-3.5 keV)

XMM BSS

XMM BSS

From HELLAS(5-10 keV)

From HELLAS2XMM (5-10 keV)

From Lockmann Hole (5-10 keV)

Broad Band Properties of the

Sample

X-ray/optical flux ratio vs. HR2

“hard” bright samplebright sample

23

232

CRCR

CRCRHR

++++−−−−====Energy bands:

2) 0.5 - 2.0 keV; 3) 2.0 - 4.5 keV

CXB CXB

23

232

CRCR

CRCRHR

++++−−−−====

34

343

CRCR

CRCRHR

++++−−−−====

Energy bands:2) 0.5 - 2.0 keV3) 2.0 - 4.5 keV4) 4.5 - 7.5 keV

Hardness ratios

“hard” bright samplebright sample

CXB CXB

X-ray/optical flux ratio vs. 2-10 keV flux

“hard” bright samplebright sample

13% with X/O>10: Type 1 + Type 2 17% with X/O>10: Type 1 + Type 2

R=21 R=21

OPTICAL VERSUS X-RAY ABSORPTION

Optically type 1:Sy1 & QSO

NLSy1

Optically type 2:Sy2, QSO 2 & NELG

Sy1.9

Type 2 QSO

Exception

HBS 28 Sample (18h < RA < 5h) - 100% spectr. Id.)Caccianiga et al., 2004, A&A, 416, 901.HARDNESS-RATIOS

Sy 1 & QSONLSy1Sy2, QSO 2 & NELGSy1.9

23

232

CRCR

CRCRHR

++++−−−−====

34

343

CRCR

CRCRHR

++++−−−−====

Energy bands:2) 0.5 - 2.0 keV3) 2.0 - 4.5 keV4) 4.5 - 7.5 keV

Are optical and X-ray absorption unrelated ?

A Guided Spectral Tour in

the BSS and HBSS Sample

XMM X-ray spectrum (MOS+pn):ΓΓΓΓ=2.1, nH=1.1x1023 cm-2

Scattered Fraction = 2%

L(2-10 keV, intrinsic) = 1x1044 cgs

A Type 2 AGNs in the HBSS sample

Optical spectrum

Z=0.146

XMM X-ray spectrum(MOS+pn):ΓΓΓΓ=1.9*, nH=2.5x1022 cm-2

L(2-10 keV, intr.) = 3x1044 cgs

Optical spectrum

A High-Luminosity Type 2 AGNs

Z=0.562

Caccianiga et al., 2004, A.A., 416,901

An Absorbed Type 1 AGNs

XMM X-ray spectrum (MOS+pn):Absorbed power-law model

ΓΓΓΓ=1.9, nH=4x1022 cm-2 :Fe line

L(2-10 keV, intrinsic) = 3x1043 cgs

Optical spectrum

z=0.185

A High luminous Type 2 AGN

XMM X-ray spectrum (MOS+pn):Absorbed power-law model

ΓΓΓΓ=1.8, nH=3x1023 cm-2

L(2-10 keV, intrinsic) = 4x1045 cgs

Optical spectrum

z=1.154

MgII ?

A broad Line AGN with high X/0

XMM X-ray spectrum (MOS+pn):Absorbed power-law model

ΓΓΓΓ=2.0, nH=nHGal cm-2

L(2-10 keV, intrinsic) = 5x1044 cgs

Optical spectrum

z=0.465

AGN 2 UNABSORBED IN THE X-RAY

XMM-Newton MOS+pn

Γ=2.09 [1.95-2.20]NH<1.3x1020 cm-2

(Nhgal=2.5x1020 cm-2)

ESO3.6m/EFOSC2Sy1.9 (broad Hα)

Z=0.162

Caccianiga et al., 2004, A.A., 416,901

(R ≥≥≥≥ 24.5)

FF(2(2--10)10)≈≈≈≈≈≈≈≈1010--1313 cgscgsFxFx/Fo>/Fo>220220

K’ K’ ≈≈≈≈≈≈≈≈ 1919.5.5 magmag,, RR--K K ≥≥≥≥ 55

X-ray image

(0.5 - 4.5 keV)

Optical image (DSS)

R band image

K band image

A source with a very high X/0 ratio

ERO

FxFx/Fo>/Fo>220220 zz≈≈≈≈≈≈≈≈2.02.0

Fx

Fx /Fo

/Fo

(Fiore (Fiore etet al. 2003)al. 2003)

QSO2 CANDIDATEQSO2 CANDIDATE

ΓΓΓΓΓΓΓΓ=2, =2, NhNh=6=6x10x102222 cmcm--22

LL(2(2--10)10)intrintr=5=5x10x104545 erg serg s--11

A source with a very high X/0 ratio

If Fe lineZ=2.27

Severgnini et al., 2005, A&A, submitted

A deeper look at the HBSS

Sample

Work in progress………

HBS SAMPLE: OPTICAL BREAKDOWN

Class Spectral type Number %extra

Type 1 Sey1+QSO+NLSy1 39 65%

Type 2 Sey2+Sey1.9+QSO2 18 30%

Galaxies Optically Normal 1

Clusters Clusters of Galaxies 1

Galactic Accreting Binary 2

Unid 5

HBSS Sample

>50% of the 2-10 keV XRB

is produced at z < 1

Ueda et al., 2003

Modified Unified Scheme:XRB history

Lx = 43 - 44.5

Type 1 AGNType 2 AGN

Redshift Distribution

Type 1 AGN: 39 objectsType 2 AGN: 18 objects

Luminosity Distribution

Ueda et al., 2003

Modified Unified Scheme:

Lx = 43 - 44.5

Type 1 AGNType 2 AGN

Type 2 QSOHBSS Sample

Type 1 AGN: 39 objectsType 2 AGN: 18 objects

7 Type 2 QSOs

LogN - LogS of Type 1 and Type 2 AGN

“hard” bright sample

Type 1 AGNType 2 AGN

Expected from the XRB

synthesis models Ueda

et al., 2003

~ 41%Type 2 QSOs 0.28±±±±0.15 deg-2

Consistent with preliminary results from Caccianiga et al., 2004

)%934(2 ±≈

TotalAGN

AGNType

Nh-Lx plane for Type 2 AGN

“hard” bright sample

Conclusions• We have defined a complete sample of 400

Bright X-ray Sources using XMMMedium-good quality X-ray data for the majority of sources

• The spectroscopic ID work is almost completedMedium-good quality optical dataWe are accumulating multi-wavelength informationfrom existing archives

• Interesting results and firm numbers are emerging from this projectUnabsorbed Type 2 AGN, Type 2 QSO, high X/O, RQ vs. RL AGN

Many of the results discussed here arereported in:

♦ “XMM-Newton observations reveal AGN in apparently normal galaxies” by Severgnini et al., 2003, A&A, 406,483

♦ “The XMM-Newton HBS28 sample: Studying the obscuration in hard X-ray selected AGNs” by Caccianigaet al., 2004, A&A, 416, 901

♦ “Exploring the X-ray Sky with the XMM-Newton Bright Serendipitous Survey” by Della Ceca et al., 2004, A&A,428, 383

u “XMM-Newton spectroscopy of an X-ray selected sample of RL AGNs” by Galbiati et al., 2004, A&A, 430, 927

u “An x-ray bright ERO with an extreme x-ray to optical flux ratio” by Severgnini et al., 2005, A&A, submitted