European X-ray CalorimeterUtrecht, October 2004 (Some) astrophysical drivers for a high-resolution imaging X-ray spectrometer Xavier Barcons Instituto de Física de Cantabria (CSIC-UC)

European X-ray CalorimeterUtrecht, October 2004 Science context The missing baryons: studies of the Warm and Hot Intergalactic Medium (WHIM) Black hole growth rate and spin evolution: measurement of the Fe line profile at different redshifts Accretion disk precession: binary black holes?

European X-ray CalorimeterUtrecht, October 2004 The Warm and Hot Intergalactic Medium

European X-ray CalorimeterUtrecht, October 2004 Main goals of WHIM studies Measure baryon density as a function of z (missing baryons), comparing with cold (Lyman-  cloud) component. Chemical evolution of the Universe (groups/clusters and strong systems). Heating mechanisms (photoionisation, gravitational heating etc.) Determine cosmological distribution (filaments)

European X-ray CalorimeterUtrecht, October 2004 The Warm & Hot IGM Large fraction of baryons at T~ K IGM hotter towards low redshift (baryons falling onto potential wells) Extra heating might be present due to star formation & AGNs Davé et al 2002

European X-ray CalorimeterUtrecht, October 2004 Thermal history of WHIM Davé et al (2001)

European X-ray CalorimeterUtrecht, October 2004 T and ion column density (Fang, Bryan & Canizares 2002)

European X-ray CalorimeterUtrecht, October 2004 The expected column density distribution Fang & Canizares (2000) Expect tens of O-VIII absorbers per unit z with N>10 15 cm -2

European X-ray CalorimeterUtrecht, October 2004 Doppler parameters: thermal width and turbulence Typical Doppler param b~ km s -1 Larger values for stronger systems (groups and clusters) Fang, Byan & Canizares 2002

European X-ray CalorimeterUtrecht, October 2004 Sensitivity: equivalent width detection limit Rule of thumb: For a S/N>10 spectrum, sampled to  2-3 channels per resolution element, narrow absorption lines can be detected with an equivalent width as small as a fraction of a channel width. EW  0.1 eV (5 0.5 keV) is a realistic limit for XEUS, if equipped with a 1eV-resolution spectrograph

European X-ray CalorimeterUtrecht, October 2004 Sensitivity:expected S/N ratio S( )= cgs: 10 sources/deg 2 ~ XEUS+STJ  =2, N HI = cm -2 Resolution ~1 eV Exposure time ~ 100 ks No background

European X-ray CalorimeterUtrecht, October 2004 Sensitivity Curve of growth for OVIII 2 eV 1 eV ½ eV

European X-ray CalorimeterUtrecht, October 2004 Fe line diagnostics in distant AGN

European X-ray CalorimeterUtrecht, October 2004 Lockman Hole 800 ks XMM-Newton observation XEUS should be able to determine redshifts and study Fe lines individually Average rest-frame spectra show relativistic Fe-lines type-1 AGN EW~700eV Streblyanskaya et al., 2004 type-2 AGN EW~500eV

European X-ray CalorimeterUtrecht, October 2004 Fe line profile in distant AGN A relativistic Fe line profile provides information on the innermost parts of the accretion disk and, eventually, on the SMBH itself (spin) Assume: –Concurrence cosmology –L(0.5-2)=10 44 erg s -1,  =1.9 –Laor profile, incl=30º, Rmin=10, Rmax=400,  =2. –EW=300 eV –1 Ms exposure

European X-ray CalorimeterUtrecht, October 2004 z=1 z=2 z=3 z=5 Spectral resolution

European X-ray CalorimeterUtrecht, October 2004 Evolution of SMBH spin Fe line profile potentially testable out to z~3-5 for typical type 1 AGNs, but requires long exposures NFI’s can do better than WFI, but only one object at a time. Study of samples to that level of detail very unlikely

European X-ray CalorimeterUtrecht, October 2004 Binary SMBHs and disk precession

European X-ray CalorimeterUtrecht, October 2004 XEUS tests of binary SMBHs Super-massive Black Holes in galaxy centres + mergers implies binary SMBHs. Evidence from long-term variability in the BL Lac OJ 287 (Sillanpää et al 1988) and others. Binary SMBHs might be stable over very long periods (Valtaoja et al 1989) Mergers might play an important role in SMBH growth along cosmic history

European X-ray CalorimeterUtrecht, October 2004 Jet precession in 3C273 Jet precession from VLBI long-term monioring (Abraham & Romero 1999) Model fits to 16 year Jet precession

European X-ray CalorimeterUtrecht, October 2004 A binary SMBH in 3C273? Romero et al (1999) find that the jet precession does likely arise from precession in the accretion disk. Effects on the Fe line profile: –Azhimutally averaged –Orbital period ~10 5 s Incl=8º-14º Incl=56º-62º

European X-ray CalorimeterUtrecht, October 2004 Accretion disk precession Causes: –Binary SMBH, one dominating X-ray emission. –Non-aligned SMBH spin and accretion disk axis not aligned Accretion disk precession due to the close SMBH The relativistic Fe emission line will change as a result of a change in inclination angle: –Shape (especially blue edge) –Intensity

European X-ray CalorimeterUtrecht, October 2004 Simulations L(2-10)= 6.25 x erg s -1,  =1.6, z=0.158 Fe line with EW=200 eV (Yaqoob & Serlemitsos 2000) Simulations with various inclination angles and BH angular momenta (Schwarzschild and maximally rotating Kerr Disk emissivity profile  r -2.5

European X-ray CalorimeterUtrecht, October 2004 XEUS/TES vs CONX/Calorimeter 100 ks, inclination angles separated 4º Sharp blue edge of Fe line Strongly dependent on inclination

European X-ray CalorimeterUtrecht, October 2004 Results XEUS/TES delivers inclination angle with precission 0.3º (90% confidence) in 100 ks. CONSTELLATION-X/2eV delivers inclination angle with precission 1º (90% confidence) in 100 ks. Spectral resolution essential Effective area necessary to test fainter sources See Torres, Romero, Barcons & Yun (2004, ApJL, astro-ph/ )

European X-ray CalorimeterUtrecht, October 2004 Do we need a CIS for this science? Imaging spectrometers –Point and extended sources –Degraded redshift sensitivity –High efficiency Gratings –Point sources only –Flat redshift sensitivity (  / ~constant) –Moderate efficiency High spectral resolution certainly needed in the full keV bandpass: 2 different instruments