Transcript X-rays from the First Massive Black Holes

X-rays from the First Massive Black Holes
Brandt, Vignali, Schneider, Alexander, Anderson, Bassett, Bauer, Fan,
Garmire, Gunn, Lehmer, Lopez, Kaspi, Richards, Strateva, Strauss
Are early black holes feeding
and growing in the same way
as local ones?
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
www.astro.psu.edu / users / niel / papers / highz-xray-detected.dat
X-ray Versus Optical Fluxes
X-ray and optical
fluxes correlated.
Fluxes generally low;
X-ray spectroscopy
challenging even for
XMM-Newton.
X-ray Spectroscopy at z > 4
XMM-Newton spectroscopy possible
for a few of the X-ray brightest quasars.
PSS 1326+0743
z = 4.17
XMM-Newton
Joint fitting can place respectable
average X-ray spectral constraints.
PSS 0121+0347
z = 4.13
XMM-Newton
Vignali et al. (2004)
Also see Ferrero et al. (03), Grupe et al. (04)
X-ray Spectral Comparisons at Low and High Redshifts
Significant intrinsic scatter
at all redshifts, but no
systematic trend.
Inner-disk coronae stable.
No X-ray reflection “humps”
detected.
No X-ray absorption detected.
Vignali et al. (03)
X-ray Contribution to Spectral Energy Distribution
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 effect
is primary.
No highly significant trend
with redshift.
Also see Vignali, Brandt, & Schneider (2003)
New X-ray Constraints on z > 4 Radio-Loud Quasars
Bassett et al. (04)
Blazars
12 high-redshift RLQs with flat radio
spectra and moderate-to-high R.
Lopez et al. (04)
Fill X-ray observation gap
between RQQs and blazars.
Representative of majority of RLQs.
New RLQ targets
100% detection rate with
some bright objects great
for XMM-Newton.
Small-scale, jet-linked X-ray
component (SSC) consistent
at z > 4 and z ~ 0.
Radio quiet
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 > 4
One “favored” model for X-ray jet emission
is IC/CMB. Need bulk relativistic velocities
on kpc scales.
If true, X-ray jets can outshine cores at z > 4.
Use Chandra’s imaging to search for such
X-ray luminous jets.
We do not detect X-ray jets in any of our
12 RLQs (including objects similar to
3C 273 and PKS 0637-752).
Physical sizes < 10-15 kpc.
Such X-ray luminous jets are rare.
Following Rees & Setti (1968) etc.
Perhaps synchrotron with multiple electron
populations?
X-ray Survey Constraints on z > 4 AGN
Probe moderate-luminosity, typical AGN at z > 4
Minimize absorption bias (rest-frame 2-40 keV)
High-redshift sources
and candidates in central
Chandra Deep Field-N
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.
Vignali et al. (02)
Ongoing Chandra and XMM-Newton Surveys
21 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
X-ray Stacking of Large Lyman Break Galaxy Samples from GOODS
z ~ 3.0
z ~ 3.8
Lehmer et al. (04)
468 U-dropouts from GOODS-N
338 B-dropouts from GOODS-N, S
Effective exposure = 0.8 Gs ~ 25 yr
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 supernova
remnants – no need to invoke numerous lower luminosity AGN.
Also see Moustakas & Immler (04), Wang et al. (04)
General Conclusions
AGN at z ~ 4-6 and z ~ 0-2 have
reasonably similar X-ray and
broad-band spectra. No hints of
different accretion/growth mechanisms.
(After controlling for luminosity effects)
Small-scale X-ray emission regions
insensitive to strong large-scale
environmental 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 Prospects
Improve 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 with
best positions for ~ 20 years.
Both Chandra and XMM-Newton can go
wider.
Long-Term Prospects – Proto-Quasars and
Black Holes from the First Stars
1 Chandra count per 35 yr