X-rays from the First Massive Black HolesBrandt, Vignali, Schneider, Alexander, Anderson, Bassett, Bauer, Fan,

Garmire, Gunn, Lehmer, Lopez, Kaspi, Richards, Strateva, Strauss

www.astro.psu.edu / users / niel / papers / highz-xray-detected.dat

Chandra 4-10 ks snapshots (>100)

z > 4.8 SDSS, Opt. bright, RLQs, Exotic

High detection fraction

ROSAT, Chandra, XMM-Newton archives

Additional z > 4 detections

Supporting samples at z = 0-4

Deep X-ray surveys

Are early black holes feeding and growing in the same way as local ones?

X-ray Versus Optical Fluxes

X-ray and optical fluxes correlated.

Fluxes generally low;X-ray spectroscopy challenging even forXMM-Newton.

X-ray Spectroscopy at z > 4

Also see Ferrero et al. (03), Grupe et al. (04)Vignali et al. (2004)

PSS 1326+0743z = 4.17XMM-Newton

PSS 0121+0347z = 4.13XMM-Newton

XMM-Newton spectroscopy possiblefor a few of the X-ray brightest quasars.

Joint fitting can place respectableaverage X-ray spectral constraints.

X-ray Spectral Comparisons at Low and High Redshifts

Vignali et al. (03)

Significant intrinsic scatterat all redshifts, but nosystematic trend.

Inner-disk coronae stable.

No X-ray reflection “humps”detected.

No X-ray absorption detected.

X-ray Contribution to Spectral Energy Distribution

Also see Vignali, Brandt, & Schneider (2003)

Combine high-redshift sample with well-defined, lower-redshift samples to constrain X-ray evolution.

Want broad lum. and z coverage to break degeneracies

High-detection fraction (pattern censoring issues)

Reliable separation of RQQ and RLQ

Good BAL removal / control

New sample of ~ 152 SDSS and PSS quasars spanning z = 0.02-6.28

Partial correlation analyses indicate luminosity effectis primary.

No highly significant trendwith redshift.

New X-ray Constraints on z > 4 Radio-Loud Quasars

Bassett et al. (04)

Radio quiet

New RLQ targets

BlazarsLopez et al. (04)

12 high-redshift RLQs with flat radiospectra and moderate-to-high R.

Fill X-ray observation gapbetween RQQs and blazars.

Representative of majority of RLQs.

100% detection rate with some bright objects great for XMM-Newton.

Small-scale, jet-linked X-raycomponent (SSC) consistentat z > 4 and z ~ 0. Degree of X-ray enhancement vs. RQQs

X-ray spectral shape

Suggestive evidence for X-ray absorption.

Rarity of X-ray Luminous Jets at z > 4One “favored” model for X-ray jet emissionis IC/CMB. Need bulk relativistic velocitieson kpc scales.

If true, X-ray jets can outshine cores at z > 4.

Use Chandra’s imaging to search for suchX-ray luminous jets.

We do not detect X-ray jets in any of our12 RLQs (including objects similar to 3C 273 and PKS 0637-752).

Physical sizes < 10-15 kpc.

Such X-ray luminous jets are rare.

Perhaps synchrotron with multiple electronpopulations?

Following Rees & Setti (1968) etc.

X-ray Survey Constraints on z > 4 AGN Probe moderate-luminosity, typical AGN at z > 4

Minimize absorption bias (rest-frame 2-40 keV)

Find or constrain sky density exploiting Lyman break. Alexander et al. (01), Barger et al. (03), Cristiani et al. (04), Koekemoer et al. (04)

Constraints on reionization.

High-redshift sourcesand candidates in centralChandra Deep Field-N

Vignali et al. (02)

Ongoing Chandra and XMM-Newton Surveys21 Ongoing Deep Surveys 18 Ongoing Wide Surveys

~ 3.5 sq. degrees in total

Lists above available from astro-ph/0403646

Constraining Lower Luminosity AGN at High Redshift

z ~ 3.0z ~ 3.8

Lehmer et al. (04)

X-ray Stacking of Large Lyman Break Galaxy Samples from GOODS

468 U-dropouts from GOODS-N

Effective exposure = 0.8 Gs ~ 25 yr

338 B-dropouts from GOODS-N, S

Effective exposure = 0.4 Gs ~ 13 yr

Also tight constraints on V, i dropouts at z ~ 5, 6

Observed X-ray emission plausibly from X-ray binaries and supernovaremnants – no need to invoke numerous lower luminosity AGN.

Also see Moustakas & Immler (04), Wang et al. (04)

General ConclusionsAGN at z ~ 4-6 and z ~ 0-2 havereasonably similar X-ray andbroad-band spectra. No hints ofdifferent accretion/growth mechanisms.

(After controlling for luminosity effects)

Small-scale X-ray emission regionsinsensitive to strong large-scaleenvironmental differences from z ~ 0-6. X-ray emission universal.

X-ray surveys giving significant demographic constraints on mod.-lum.AGN at highest redshifts.

Some Future ProspectsImprove coverage at z = 5 - 6.5 +

Other selection methods – minimize bias IR, submm, mm

Minority populations Weak-line quasars, BALQSOs, RLQs

Better X-ray spectral and variability studies

Chandra can go significantly deeper withbest positions for ~ 20 years.

Both Chandra and XMM-Newton can gowider.

Long-Term Prospects – Proto-Quasars and Black Holes from the First Stars

1 Chandra count per 35 yr