The Bright Side of the X-ray Sky The XMM-Newton Bright Survey T. Maccacaro A. Caccianiga P. Severgnini V. Braito R. Della Ceca 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 (f x > ~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
Primary Selection Camera: the MOS2 detector Criteria for... Field selection Source selection Galactic latitude ( b II >20); Line of sight N H (<10 21 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..) Bright Sample (BS): Source position: R I <R<R O R I depending on target/mode R O =13' Avoid edges & gaps; No physical relation to target 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 )
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 L X - z plane for statistical and evolutionary studies and to test current AGN and XRB synthesis models. Note that unlike deep/pencil beam surveys the XMM BSS is protected against problems connected to the cosmic variance
The XMM-Newton Bright Survey Project 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 BSS in a context XMM-Newton Bright Survey Adapted from Brandt and Hasinger, ARAAA, 2005, in press
The XMM BSS in a context Chandra, XMM Deep Medium ASCA BeppoSAX HEAO 1 Photometric z + X + etc.. XMM BSS 10 meters class telescope 4 meters class telescope Broad Line AGNs X-ray spectral analysis is possible for almost all the sources in the XMM BSS!! Adapted from Akiyama et al., 2003
Optical identification & classification (217 src our own spectroscopy + literature) BS HBS Sources 389 67 Identified 311 (80%) 62 (90%) Broad Line AGN 3% Broad Line AGN 2% 2% 1% 2% 10% 16% 69% Narrow Line 2% AGN 2% Optically "Normal" Galaxy 29% Clusters of Galaxies BL Lac Objects 62% Narrow Line AGN Optically "Normal" Galaxy Clusters of Galaxies BL Lac Objects BS Stars HBS Stars
Extragalactic LogN - LogS bright sample hard bright sample AXIS (0.5-4.5 kev) From ROSAT (0.5-2.0 kev) From Lockmann Hole (5-10 kev) From HELLAS2XMM (5-10 kev) From EMSS (0.3-3.5 kev) XMM BSS From HELLAS (5-10 kev) XMM BSS
Broad Band Properties of the Sample
X-ray/optical flux ratio vs. HR2 Energy bands: 2) 0.5-2.0 kev; 3) 2.0-4.5 kev HR2 = CR3 CR3 + CR2 CR2 bright sample hard bright sample CXB CXB
Hardness ratios Energy bands: 2) 0.5-2.0 kev 3) 2.0-4.5 kev 4) 4.5-7.5 kev HR2 = HR3 = CR3 CR3 CR4 CR4 + + CR2 CR2 CR3 CR3 bright sample hard bright sample CXB CXB
X-ray/optical flux ratio vs. 2-10 kev flux bright sample hard bright sample R=21 R=21 13% with X/O>10: Type 1 + Type 2 17% with X/O>10: Type 1 + Type 2
HBS 28 Sample (18 h < RA < 5 h ) - 100% spectr. Id.) Caccianiga et al., 2004, A&A, 416, 901. HARDNESS-RATIOS CR3 CR2 HR2 = CR3 + CR2 CR4 CR3 HR3 = CR4 + CR3 Energy bands: 2) 0.5-2.0 kev 3) 2.0-4.5 kev 4) 4.5-7.5 kev OPTICAL VERSUS X-RAY ABSORPTION Type 2 QSO Sy 1 & QSO NLSy1 Sy2, QSO 2 & NELG Sy1.9 Are optical and X-ray absorption unrelated? Optically type 1: Sy1 & QSO NLSy1 Exception Optically type 2: Sy2, QSO 2 & NELG Sy1.9
A Guided Spectral Tour in the BSS and HBSS Sample
A Type 2 AGNs in the HBSS sample Optical spectrum Z=0.146 XMM X-ray spectrum (MOS+pn): Γ=2.1, n H =1.1x10 23 cm -2 Scattered Fraction = 2% L (2-10 kev, intrinsic) = 1x10 44 cgs
A High-Luminosity Type 2 AGNs Optical spectrum Z=0.562 XMM X-ray spectrum(mos+pn): Γ=1.9*, n H =2.5x10 22 cm -2 L (2-10 kev, intr.) = 3x10 44 cgs Caccianiga et al., 2004, A.A., 416,901
An Absorbed Type 1 AGNs Optical spectrum z=0.185 XMM X-ray spectrum (MOS+pn): Absorbed power-law model Γ=1.9, n H =4x10 22 cm -2 :Fe line L (2-10 kev, intrinsic) = 3x10 43 cgs
A High luminous Type 2 AGN Optical spectrum MgII? z=1.154 XMM X-ray spectrum (MOS+pn): Absorbed power-law model Γ=1.8, n H =3x10 23 cm -2 L (2-10 kev, intrinsic) = 4x10 45 cgs
A broad Line AGN with high X/0 Optical spectrum z=0.465 XMM X-ray spectrum (MOS+pn): Absorbed power-law model Γ=2.0, n H =n HGal cm -2 L (2-10 kev, intrinsic) = 5x10 44 cgs
AGN 2 UNABSORBED IN THE X-RAY ESO3.6m/EFOSC2 Sy1.9 (broad Hα) Z=0.162 XMM-Newton MOS+pn Γ=2.09 [1.95-2.20] N H <1.3x10 20 cm -2 (N h gal =2.5x10 20 cm -2 ) Caccianiga et al., 2004, A.A., 416,901
A source with a very high X/0 ratio Fx/Fo> /Fo>220 F (2-10) 10-13 cgs K 19.5 mag, R-K 5 ERO R band image (R 24.5) X-ray image (0.5-4.5 kev) Optical image (DSS) K band image
A source with a very high X/0 ratio Fx/Fo> /Fo>220 z 2.0 Fx/Fo If Fe line Z=2.27 Γ=2, Nh=6 =6x10 22 22 cm -2 (Fiore et al. 2003) L (2-10) 10)intr=5 =5x10 45 erg s -1 QSO2 CANDIDATE 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
XRB history Ueda et al., 2003 Lx = 43-44.5 Modified Unified Scheme: >50% of the 2-10 kev XRB is produced at z < 1 Redshift Distribution Type 1 AGN Type 2 AGN HBSS Sample Type 1 AGN: 39 objects Type 2 AGN: 18 objects
Lx = 43-44.5 Modified Unified Scheme: Luminosity Distribution Ueda et al., 2003 Type 1 AGN Type 2 AGN HBSS Sample Type 1 AGN: 39 objects Type 2 AGN: 18 objects Type 2 QSO 7 Type 2 QSOs
LogN - LogS of Type 1 and Type 2 AGN hard bright sample Type 1 AGN Type 2 AGN Type2AGN TotalAGN (34 ± 9)% 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
Nh-Lx plane for Type 2 AGN hard bright sample
Conclusions We have defined a complete sample of 400 Bright X-ray Sources using XMM Medium-good quality X-ray data for the majority of sources The spectroscopic ID work is almost completed Medium-good quality optical data We are accumulating multi-wavelength information from existing archives Interesting results and firm numbers are emerging from this project Unabsorbed Type 2 AGN, Type 2 QSO, high X/O, RQ vs. RL AGN
Many of the results discussed here are reported 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 Caccianiga et 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