Chandra Large and Very Large Projects

Proposal Number: 02900196

Title: THE CHANDRA DEEP SURVEY OF THE HUBBLE DEEP FIELD NORTH (HDF-N) AREA

PI Name: William Brandt

We propose to extend the Chandra X-ray survey of the HDF-N and its vicinity with a 475 ks exposure; this will give 1 Ms of total coverage on this field and will fulfill one of Chandra's central design goals. We should remain photon limited to 1 Ms and will probe the X-ray Universe more than four times deeper than any observation to date. We should resolve essentially all of the X-ray background from 0.5-8 keV and will study obscured and high-redshift active galaxies, advection dominated sources, starbursts, X-ray binaries, clusters and groups, and diffuse X-ray emission. The HDF-N field is an ideal one for multiwavelength follow-up studies due to the enormous database already in place. All data are to be placed in the public archive immediately and we will request no GO science funding.

Proposal Number: 02900378

Title: AN ULTRADEEP SURVEY IN THE CHANDRA DEEP FIELD SOUTH

PI Name: RICCARDO GIACCONI

We propose to exploit the unique combination of angular resolution, sensitivity and field-of-view of the Chandra ACIS imager to perform the deepest X-ray survey ever in the well-studied "Chandra Deep Field South" (CDFS). With a total integration time of 1.5 Msec (request for this AO: 1 Msec) we reach a 0.5-2 keV flux limit of 2E-17 cgs. We aim to detect >500 sources, i.e. AGN to z=10, clusters to z=3 and starburst galaxies to z~1. Simulations based on the existing 130 ksec observation in the CDFS and realistic source counts and correlation function models show, that Chandra exposures will not be background or confusion limited up to 3Msec. We propose to make the Chandra data public immediately.

Proposal Number: 03900164

Title: THE CHANDRA SURVEY OF THE HUBBLE DEEP FIELD NORTH AREA: A PUBLIC RESOURCE FOR THE PRESENT AND FUTURE OF X-RAY ASTRONOMY

PI Name: William Brandt

We propose to extend the Chandra deep survey of the HDF-N and its vicinity. The ultimate goal is to obtain 5 Ms of coverage over the next 5 years; currently we have 1 Ms coverage. Here we propose two public 500 ks observations. This project will fulfill one of Chandra's central design goals and will be a long-lasting legacy of Chandra, laying the groundwork for the next generation of X-ray observatories. We should remain nearly photon limited for point-sources near the aim point. We will study obscured and high-redshift AGN, starbursts, normal galaxies, clusters, groups, and diffuse X-ray emission. The HDF-N field is the ideal region for multiwavelength follow-up studies due to the enormous database already in place. Our ACIS team expertise will be extensively utilized.

Proposal Number: 04900340

Title: A CHANDRA WIDE-FIELD SURVEY TO MAP THE COSMIC WEB AND INVESTIGATE THE EVOLUTION OF NUCLEAR ACCRETION

PI Name: Christine Jones

We propose a wide-field X-ray imaging survey with deep and shallow components in order to map the structure and evolution of the Universe to redshift unity, and to probe the nature, environment and evolutionary history of AGN. The observations will cover the Bootes field of the NOAO Deep Wide-Field Survey, that is unique in its wide-field coverage and availability of deep multiwavelength imaging (including VLA and SIRTF) and optical spectroscopy. The Chandra survey is designed to sample volumes appropriate for statistical investigations of cluster environments, the space density of groups, biases in the optical and X-ray selection of groups and clusters, and AGN phenomena in relation to galaxy host properties and their evolution.

Proposal Number: 04901014

Title: A CHANDRA WIDE-FIELD SURVEY TO MAP THE COSMIC WEB AND INVESTIGATE THE EVOLUTION OF NUCLEAR ACCRETION

PI Name: Christine Jones

We propose a wide-field X-ray imaging survey with deep and shallow components in order to map the structure and evolution of the Universe to redshift unity, and to probe the nature, environment and evolutionary history of AGN. The observations will cover the Bootes field of the NOAO Deep Wide-Field Survey, that is unique in its wide-field coverage and availability of deep multi- wavelength imaging (including VLA and SIRTF) and optical spectroscopy. The Chandra survey is designed to sample volumes appropriate for statistical investigations of cluster environments, the space density of groups, biases in the optical and X-ray selection of groups and clusters, and AGN phenomena in relation to galaxy host properties and their evolution.

Proposal Number: 05900218

Title: The Extended Chandra Deep Field-South Survey: A Public Chandra Legacy

PI Name: William Brandt

We propose to extend the 1 Ms Chandra Deep Field-South (CDF-S) survey with six public 330 ks flanking observations: the Extended CDF-S (E-CDF-S). Using these, we will study the detailed cosmic history of accretion onto supermassive black holes, the role of moderate-luminosity AGN at high redshift, AGN clustering, and X-ray groups and low-luminosity clusters. The proposed observations are optimized to fill the X-ray luminosity/redshift plane at z > 1.5 where the AGN source statistics are still limited. Follow-up studies will exploit the superb E-CDF-S multiwavelength coverage including VLT/Keck spectroscopy (6000+ VLT redshifts), HST imaging (GEMS, GOODS, ACS Ultradeep Field; 734 HST orbits), intensive ground-based imaging, and scheduled SIRTF observations.

Proposal Number: 05900547

Title: The Balance of Power between Starbursts and AGN: a Chandra/SIRTF Survey.

PI Name: Belinda Wilkes

We propose a moderate-depth (70 ksec), 0.6 sq.deg. Chandra survey, the deepest/largest CONTIGUOUS area to date, in the Lockman Field of the SIRTF/SWIRE Legacy Survey coincident with a completed, ultra-deep VLA survey with deep optical and near-IR imaging in-hand. SWIRE, the largest SIRTF program, will detect >500 000 dusty galaxies to z > 2.5 in 7 fields covering 65 sq.degs. The prime science goal is to study the structure, evolution and environments of AGN, starbursts and ellipsoids over the SAME SPATIAL VOLUME out to z > 2.5. Key to this study is an X-ray survey deep enough to distinguish starbursts and AGN, including the significant, highly obscured (log Nh>22) subset. Chandra will secure X-ray identification and fluxes for ~550 (0.6 sq deg) of the field's ~7000 SWIRE sources.

Proposal Number: 05900888

Title: X-Raying the Intergalactic Medium with Blazars in Outburst

PI Name: Fabrizio Nicastro

We propose to extend our highly succesful Chandra-AO4 TOO program to the 5th Chandra cycle, to observe up to 2 blazars in exceptionally high states with the Chandra HRCS-LETG (hereinafter HLETG) for a total exposure time of 350 ks. We shall study the ``warm'', low-redshift, phase of the intergalactic medium, where most of the baryonic matter of the local (z < 1-2) Universe is believed to hide.

Proposal Number: 06900144

Title: Continuing X-Raying the Intergalactic Medium with Blazars in Outburst: Deeper in Redshift and Wider in Area.

PI Name: Fabrizio Nicastro

We propose to extend our highly succesful Chandra-AO4 and -AO5 TOO programs to the 6th Chandra cycle, to observe up to 2 blazars in exceptionally high states with the Chandra HRCS-LETG (hereinafter HLETG) for a total exposure time of {\bf 340 ks} (2 orbits). We shall dramatically reduce the uncertainty on the cosmological baryon mass density $\Omega_b$ in the local Universe studying the ``warm'', low-redshift, phase of the intergalactic medium (WHIM), where most of the baryonic matter of the $z \ls 1$ Universe is believed to hide.

Proposal Number: 06900444

Title: Deep Chandra Imaging of the Extended Groth Strip: The Co-evolution of Black Holes and Galaxies

PI Name: Kirpal Nandra

The Extended Groth Strip (EGS) is a half square degree region that has been targeted intensively for galaxy evolution studies. A remarkable array of ultra-deep data have been or will be accumulated, to include radio, near/mid/far IR, optical and UV data of depth comparable to or better than any part of the sky. It is also the subject of the massive DEEP2 redshift survey, giving high quality Keck spectra for 16-17,000 galaxies. The clear gap in the coverage of the EGS is in the X-ray, and we therefore propose to augment the single deep Chandra pointing with 7 more, to image the whole strip. Our goal is to study the co-evolution of galaxies and black holes, by examining in detail the astrophysics of AGN activity, and its relationship to the host galaxy and surrounding large scale structure.

Proposal Number: 07900865

Title: Searching for WHIM in Large-Scale Structures

PI Name: Luca Zappacosta

Simulations and observations indicate that galaxy overdensities are good tracers of the dark matter large-scale structures and therefore of the diffuse warm-hot phase (WHIM) that should be associated with them. The WHIM in these large-scale structures should have large column densities, and therefore should be much easier to detect than the low column density WHIM which has been targeted so far. However, this efficient method of investigating WHIM has yet to be exploited. We have identified 5 bright blazars just in the background of known large-scale structures. We propose to probe and study the WHIM in these structures by identifying the associated absorption lines in the spectrum of these AGNs during their outburst phases, through TOO observations for a total of 300ks with HRC-S/LETG.

Proposal Number: 08900073

Title: THE CHANDRA-COSMOS SURVEY

PI Name: Martin Elvis

We propose the Chandra-COSMOS survey which will provide an unprecedented combination of contiguous area, depth and resolution. 36 densely tiled observations will cover the central 0.7 sq.deg. COSMOS field to a uniform 200ksec depth. COSMOS explores the coupled evolution of galaxies, dark matter halos and AGNs (massive black holes) largely free of cosmic variance. COSMOS is a comprehensive survey including: HST, Spitzer, Subaru, VLT, Magellan, VLA, MAMBO, GALEX, & potentially EVLA & ALMA. Chandra resolution & sensitivity enables the study of large scale phenomena: (1) influence of the surrounding environment; (2) interaction between galaxies; (3) influence of groups and clusters: (4) BH growth and census; (5) star formation and stellar populations; (6) feedback from starbursts and AGNs.

Proposal Number: 08900745

Title: The Chandra Deep Proto-cluster Field: Black-Hole Growth and Feedback in Dense Environments

PI Name: David Alexander

Deep X-ray surveys have revolutionized our understanding of the growth of black holes (SMBH). But these surveys only sample low-density regions at high-z due to their limited solid angle. There is no comparably sensitive X-ray census of AGN in high-density regions at high-z. Such environments evolve into the most massive clusters at z=0, regions which exhibit remarkable trends in galaxy properties - which may reflect early interactions between SMBHs and their host galaxies. A survey of a proto-cluster at high-z would provide a unique view of the interplay of the growth of galaxies and their SMBHs. Here we propose a 400ks survey of the best-studied proto-cluster at high-z, to enable the first definitive study of the growth of SMBHs and their host galaxies in a dense, young, environment.

Proposal Number: 08900784

Title: The Duty Cycle of Supermassive Black Holes: X-raying Virgo

PI Name: Tommaso Treu

Nuclear accretion on to super-massive black holes (SMBHs) plays a key role in the evolution of their host galaxies, as inferred from the ubiquity of SMBHs and the correlations between BH mass, and host mass and velocity dispersion. A fundamental unadressed issue is the actual distribution of accretion rates; we propose snapshot observations of an unbiased sample of 84 early-type galaxies in the Virgo cluster. Together with joint Spitzer 24 um observations, and publicly available HST-ACS and UV data, this survey will probe low-level nuclear activity over four orders of magnitude in black hole mass, thereby delivering the first unbiased census of the duty cycle of local SMBHs.

Proposal Number: 09900660

Title: The Evolution of Faint AGN at High Redshift

PI Name: Kirpal Nandra

We propose a very deep (total 800ks/field) Chandra survey of 0.25 deg2 covering 3 contiguous fields in the Extended Groth Strip, which have exceptional multiwaveband coverage obtained by the AEGIS project. These data, in combination with the CDF North and South, will provide a definitive measurement of the evolution of faint, X-ray selected AGN from z=3-4, where the optical number counts start to drop dramatically. In combination with ultradeep Spitzer data in the same region, this survey will also provide a crucial step forward towards a more complete census of AGN activity and the importance of Compton thick AGN at high z, with associated implications for the total accretion budget of the universe.

Proposal Number: 10900836

Title: A Benchmark Observation of the Warm-Hot Intergalactic Medium

PI Name: Taotao Fang

Searching for the ``Missing baryons'', in the form of the warm-hot intergalactic medium (WHIM), is a fundamental challenge faced by the current theory of structure formation. Cosmological simulations predict that majority of the WHIM can be probed in X-ray only, yet the reported detections are often in question due to statistical and systematical issues. Based on the tentative evidence in our joint XMM-Chandra ToO observations of H 2356-309, we propose a deep, non-ToO Chandra observation to definitively detect the WHIM absorption line with a measured column density expected from theory. A null detection would place an upper limit which cannot be explained by current cosmological simulations, and put future pursuit of the WHIM with current generation of X-ray telescopes in question.

Proposal Number: 11900514

Title: COMBH: Chandra Observations of M-sigma Black Holes

PI Name: Kayhan Gultekin

Galaxies with dynamically-measured central BH masses allow us to understand BH accretion, jets, and interactions between BHs and host galaxies with a clarity not possible in random surveys. By measuring true Eddington fractions, we can calculate the energy in radiation vs mechanical jet energy and the efficacy of BHs in heating nuclear regions and affecting star formation. Remarkably, 1/3 of SMBHs making up the M-sigma relation have been poorly observed or totally unobserved with Chandra. We propose a survey of 15 M-sigma galaxies to complete the sample of reliable M-sigma SMBHs. For each galaxy we propose to obtain 30-60 ks exposures and an hour-long VLA observation. This survey will test and extend the fundamental plane of BH activity and facilitate studies of the origin of M-sigma.