black holes in the deepest extragalactic x-ray surveys
DESCRIPTION
X-ray Multi-Mirror Mission-Newton. Chandra X-ray Observatory. Black Holes in the Deepest Extragalactic X-ray Surveys. Angular res. and positions improved by factor ~ 10. 50-250 times sensitivity of previous missions. Photon collection improved by factor ~ 10. - PowerPoint PPT PresentationTRANSCRIPT
Black Holes in the Deepest Extragalactic X-ray Surveys
Chandra X-ray Observatory X-ray Multi-Mirror Mission-Newton
Angular res. and positions improved by factor ~ 10.
50-250 times sensitivity of previous missions.
Photon collection improved by factor ~ 10.
Both operating well and can likely continue for ~ 5-10 more years.
X-ray Imaging Optics
X-ray CCD Detectors
Chandra ACIS
XMM-Newton EPIC
The Cosmic X-ray Background
X-rays from Active Galaxies
Nuclear Obscuration in Active Galaxies
Obscuring “Torus” Cut-Through View
Three Important Reasons to Survey in X-rays
2. Penetrating; reduced absorption bias 3. Low dilution by host-galaxy light
X-ray emission can penetrate and measure large amounts of absorbing material.
Majority of active galaxies are absorbed.
Absorption bias drops going to high redshift.
1. X-ray emission universal property of accreting supermassive black holes
Penetrating Power of X-rays
Many Complementary X-ray Surveys Ongoing
About 35 ongoing surveys with Chandra and XMM-Newton.
Usually performed in regionswith strong multiwavelength data and / or notable objects.
Together the surveys cover a broad part of the sensitivity vs. solid-angle “discovery space”.
I will focus on results from the deepest X-ray surveys.
Equally important results fromwider X-ray surveys!
Blue = ChandraGreen = XMM-NewtonRed = ROSAT
Supporting Multiwavelength Data: HST
Supporting Multiwavelength Data: Spitzer
Supporting Multiwavelength Data: Submillimeter
James Clerk Maxwell TelescopeMauna Kea, Hawaii
The Deepest X-ray Surveys to DateThe Chandra Deep Field-North (CDF-N) The CDF-S and Extended CDF-S
250 ks to 2 Ms coverage
1125 arcmin2 (~ 150% Moon)
~ 990 point sources
Matching of X-ray and Optical Sources
Optical Spectroscopic Follow-Up Observations to Get Redshifts
Keck Observatory
Very Large Telescope
Follow-Up Challenges and Results
50-70% spectroscopic completeness overall. Good completeness to I ~ 23-24.
Hundreds of very faint sources, often with weak-to-moderate line emission. Further deep spectroscopy needed to identify these. Likely are obscured AGN at z ~ 1.5-6.
More than 70% of sources are z ~ 0.1-5 AGN. AGN source density ~ 7200 deg -2.
Also many starburst and normal galaxies. Rapidly rising population to faintest X-ray fluxes.
X-ray Number Counts for Chandra Deep Fields
Highlights on Some Key Topics
Number-density and spectral evolution of AGN.
AGN content of distant submillimeter galaxies.
Other great topics: Host galaxies, AGN clustering, variability, absorption, starburst & normal galaxies,clusters & groups.
Evolution of Luminous Quasars
Luminosity Dependent AGN EvolutionProbe evolution of moderateluminosity AGN. More numerous!
Lower luminosity AGN peakedlater. Called “anti-hierarchical growth” or “cosmic downsizing.”
Basic result appears robust to incompleteness, but detailsstill uncertain.
More “frugal” X-ray universethan some expected beforeChandra and XMM-Newton.
X-ray background not dominated by many obscured quasars.
AGN make ~ 5-10% of the powerin the Universe since the formationof galaxies (not ~ 50%).
Number-Density Changes for AGN of Different Luminosities
Black-Hole Accretion Versus Cosmic Star Formation
SFR density
Scaled SMBHaccretion-rate density
Accretion-rate density and cosmic star-formation rate density similar to first order.
Luminosity dependence of X-ray vs. total power. X-ray fraction declines with luminosity. Not understood.
No detectable redshift dependence. X-ray-to-optical flux ratios of AGN change by < 30% from z = 0-6.
Despite large number-density changes, individual AGN “unit” is remarkably stable over ~ all of cosmic history.
X-ray strong
X-ray weak
SDSSz > 4 snapshots
BQS E-CDF-SSDSS
E-CDF-SSDSS
BQS
Luminosity Dependence and Evolution of AGN Spectra
z > 4 snapshots
SDSS
E-CDF-S
BQS
Seyfert 1s
AGN Content of Distant Submillimeter Galaxies
James Clerk Maxwell TelescopeMauna Kea, Hawaii
Submm from dust-shrouded starbursts forming stars at ~ 1000 solar masses / year.
About 1000 times more common at z ~ 2 as today.
Likely seeing the epoch of spheroid formation in massive galaxies at z ~ 1.5-4.0.
Can we see the black hole growing inside the forming spheroid?
About 85% of submm galaxies withprecise positions have detections in Chandra Deep Field-North.
Detection fraction much higher than for any other coeval galaxy population.
Most appear to contain obscured AGN.
Seeing simultaneous growth of black hole and spheroid in “pre-quasar” phase?
Submm sources in 2 Ms Chandra Deep Field-NorthGreen = X-ray detected submm sources (17/20)
Yellow = X-ray undetected submm sources (3/20)
0.5-8 keV image
Pushing Back the “Edge” of the X-ray Universe
Chandra has not yet reached its natural limits.
Can go much deeper while remaining confusion free and largely photon limited.
• Heavily obscured AGN that are currently missed
• Better photon statistics for better X-ray spectra and variability
• Normal and starburst galaxies
Prospects for the Long Term
NuSTAR
eROSITA
International X-ray Observatory