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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.
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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. Both operating well and can likely continue for ~ 5-10 more years.
X-ray CCD Detectors XMM-Newton EPIC Chandra ACIS
Nuclear Obscuration in Active Galaxies Obscuring “Torus” Cut-Through View
Three Important Reasons to Survey in X-rays 1. X-ray emission universal property of accreting supermassive black holes 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.
Many Complementary X-ray Surveys Ongoing About 35 ongoing surveys with Chandra and XMM-Newton. Usually performed in regions with 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 from wider X-ray surveys! Blue = Chandra Green = XMM-Newton Red = ROSAT
Supporting Multiwavelength Data: Submillimeter James Clerk Maxwell Telescope Mauna Kea, Hawaii
The Deepest X-ray Surveys to Date The 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
Optical Spectroscopic Follow-Up Observations to Get Redshifts Keck Observatory Very Large Telescope
Follow-Up Challenges and Results X-ray Number Counts for Chandra Deep Fields 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.
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.
Luminosity Dependent AGN Evolution Number-Density Changes for AGN of Different Luminosities Probe evolution of moderate luminosity AGN. More numerous! Lower luminosity AGN peaked later. Called “anti-hierarchical growth” or “cosmic downsizing.” Basic result appears robust to incompleteness, but details still uncertain. More “frugal” X-ray universe than some expected before Chandra and XMM-Newton. X-ray background not dominated by many obscured quasars. AGN make ~ 5-10% of the power in the Universe since the formation of galaxies (not ~ 50%).
Black-Hole Accretion Versus Cosmic Star Formation SFR density Scaled SMBH accretion-rate density Accretion-rate density and cosmic star-formation rate density similar to first order.
Luminosity Dependence and Evolution of AGN Spectra X-ray strong BQS BQS SDSS z > 4 snapshots E-CDF-S SDSS Seyfert 1s X-ray weak E-CDF-S BQS SDSS E-CDF-S SDSS z > 4 snapshots 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.
AGN Content of Distant Submillimeter Galaxies 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. James Clerk Maxwell Telescope Mauna Kea, Hawaii Submm sources in 2 Ms Chandra Deep Field-North Green = X-ray detected submm sources (17/20) Yellow = X-ray undetected submm sources (3/20) Can we see the black hole growing inside the forming spheroid? About 85% of submm galaxies with precise 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? 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