Chandra Large and Very Large Projects

Proposal Number: 02700294

Title: DETERMINING THE NATURE OF THE VARIABLE ABSORPTION IN NGC 3783 WITH CHANDRA/HST

PI Name: Ian George

We propose 5 Chandra/HETG observations of NGC 3783, each simultaneous with HST/STIS observations already approved. The observations will allow the accurate determination of the variable continuum, absorption & emission line properties known to exist in this Seyfert, and constitute the most comprehensive study possible of the nature, origin and evolution of the X-ray & UV absorbers in an AGN. Such absorbers constitute a major component of the circumnuclear gas in AGN, and only the HETG has the resolution to make these measurements. It is vital to perform such a detailed study early in the mission to facilitate the correct interpretation of the Chandra & XMM observations of this and other AGN. We also ask the TAC to approve a restructuring of Chandra time already awarded to this study.

Proposal Number: 02700728

Title: FINDING THE BARYONS IN THE LOW REDSHIFT UNIVERSE.

PI Name: Smita Mathur

Recent estimates of the primordial deuterium abundance, combined with the theory of big bang nucleosynthesis (BBN), imply a baryon density parameter $\Omega_b \approx 0.04 h_{70}^{-2}$. The main reservoir of low redshift baryons is still ``missing''. All the observed stellar and gaseous components add up to only $\Omega_b \approx 0.004h_{70}^{-1}$, a factor of ten below the BBN abundance. Hydrodynamic cosmological simulations predict that a large fraction of the low redshift baryons should reside in a hot diffuse intergalactic medium (IGM). We propose to exploit the excellent spectral resolution of Chandra gratings to probe the low redshift IGM with sensitive X-ray spectroscopy. We expect to detect the main reservoir of low redshift baryons with observations of OVII absorption lines.

Proposal Number: 03700413

Title: AN IN-DEPTH STUDY OF THE X-RAY SOURCE POPULATION AND HOT ISM OF THE ANTENNAE GALAXIES

PI Name: Giuseppina Fabbiano

We propose a deep 375~ks observation of the prototypical merger galaxies NGC~4038/39 (``The Antennae''), divided into 5 time segments. Together with the archival data, we will obtain a deep 450ks ACIS-S exposure and time monitoring over 3 yrs. The unique significance of the Antennae for our understanding of mergers and the extraordinary characteristics of the X-ray emission of this system, make this study essential for probing a wide range of fundamental questions on the properties and evolution of XRBs, the range of black hole masses implied by the rich ULX population, the properties of the multiphase ISM, and the evolution of galaxy mergers, that cannot be addressed by looking at more normal galaxies.

Proposal Number: 03700438

Title: RESOLVING THE WARM ABSORBER IN NGC 5548

PI Name: Jelle Kaastra

We propose to map the ionization and velocity structure of the X-ray and UV absorbers in NGC 5548 with the LETGS and HETGS of Chandra and STIS/HST. NGC 5548 is an important target for this kind of study because 1) it shows multiple kinematic components in the UV characterized by a range in ionization parameter and effective column, 2) it shows evidence for multiple kinematic and ionization components in previous Chandra X-ray spectra, and 3) it has a low Galactic column, which permits coverage of spectral lines out to 80 Angstrom with the LETGS. These data yield the ionization parameter and column density of the absorption-line regions as a function of radial velocity, and constrain the elemental abundances and shape of the unobserved EUV continuum.

Proposal Number: 04700532

Title: CONNECTING THE X-RAY AND UV IONIZED ABSORBERS IN MRK 279

PI Name: Jelle Kaastra

We propose a deep X-ray/UV spectroscopy campaign on the bright Seyfert 1 galaxy Mrk 279, using Chandra LETGS, HST/STIS, and FUSE. Our main scientific goal is to study the AGN outflow seen as an ionized absorber in this galaxy, focusing on the crucial connection between the X-ray and UV manifestations of the outflows. We will map the ionization and velocity structure, measure the elemental abundances and then determine the mass and kinetic luminosity flux of the outflow - all stepping stones for studying the importance of outflows in the evolution of AGN and their host galaxies. In addition we will use the LETGS data to determine the existence of relativistic CNO emission lines in the spectrum.

Proposal Number: 05700535

Title: A Chandra HETGS & HST view of the Warm and Lukewarm absorbers in IRAS 13349+2438

PI Name: Julia Lee

We propose 300~ks Chandra HETGS simultaneous with 4 HST orbits primarily to study the warm absorber environment (chemical compositions, velocities, absorbing column) of the archetypal infrared quasar IRAS 13349+2438. We will look for associations between the X-ray and UV absorbers, and study the properties of dust extinction in this source. Inner shell excitation lines from low ionization ions (previously only probed in the UV) will be compared with HST measurements. We will resolve many of the individual lines of the UTA to put ionization limits on a possible `lukewarm' absorber. The HST spectrum will give us a first view of Ly-alpha and Si IV in this source at shorter wavelengths.

Proposal Number: 07701072

Title: High-resolution spectroscopy of 'binary' AGN in the colliding galaxies of NGC 6240

PI Name: Claude Canizares

We propose to measure the kinematics of the AGNs inside the two colliding spiral galaxies in NGC 6240, by conducting an emission line analysis with the High Energy Transmission Grating Spectrometer (HETGS). Measuring the black hole kinematics will provide new constraints for models of galactic mergers with AGNs, which in turn are important to understand the link between the growth of supermassive black holes and their host galaxies. We can also extract HETGS spectra of the interface between the AGNs and the starburst region, in order to determine whether or not the predicted quenching of the starburst has started occurring near the AGNs.

Proposal Number: 08700512

Title: Jets, Bubbles, Binaries, and Hot Gas: A Deep Observation of Centaurus A

PI Name: Ralph Kraft

We propose to observe Centaurus A, the nearest radio galaxy and the nearest massive early-type galaxy, for 1.2 Ms. We will probe the particle acceleration processes of the jet to an unprecedented sensitivity, by measuring its spectrum and morphology on the scale of radiative energy losses. We also will measure the proper motions and velocity shear of X-ray knots. We will measure the temperature and density structure of the shock around the SW radio lobe to study the hydrodynamics of the lobe/ISM interaction to a level previously seen only in Galactic SNRs. We will detect hundreds of X-ray binaries, probe the GC/LMXB link, and investigate their temporal properties. Finally, we will measure the thermodynamic paramters of the gas and the elemental abundance throughout the ISM.

Proposal Number: 08700551

Title: The Chandra-RBGS Survey of a Complete Sample of Luminous Infrared Galaxies

PI Name: David Sanders

We propose a Chandra-ACIS survey of a complete sample of Luminous Infrared Galaxies (LIRGs) with Lir >10^11.5, from the IRAS Revised Bright Galaxy Sample (RBGS). All of these objects are interacting/merging gas-rich spirals. Our new observations will provide a uniform and complete census of AGN and X-ray luminous starbursts in the nearest and brightest LIRGs, and will complement approved Spitzer-IRAC+MIPS, and HST-ACS imaging of the same sample. The results will be used to address the following key questions: are binary AGN a common feature of these LIRGs, and if so, when and at what level is the AGN activity triggered in each nucleus ? and can the fueling and growth of massive black holes be correlated in time with the merger phase ?

Proposal Number: 08700916

Title: The Definitive Chandra Observations of NGC 4258

PI Name: Michael Nowak

We propose a 320 ksec HETG observation of NGC 4258. This will yield a high S/N nuclear spectra that is uncontaminated by extended emission or pileup. We will measure the fluorescent Kalpha line strength and width, search for low energy emission lines as expected in some ADAF models, and accurately measure the absorbing column. The latter may be probing the warped disk structure. We will search for nuclear flaring, as observed in Sgr A*. The S/N for observations of the `anomalous arms' will be increased over previous observations. The binary population will be surveyed down to an implied isotropic luminosity of 10^36 erg/s. Our observation will be coordinated with the VLA, to further test the "fundamental plane" of black hole radio/X-ray activity.

Proposal Number: 10700504

Title: The multi-faceted X-ray activity of low-redshift active galaxies

PI Name: Mark Birkinshaw

We propose ACIS-I observations of Chandra-unobserved low-redshift 3CRR active galaxies and their environments. The data will complete Chandra observations of 3CRR at z < 0.1, making the sample useful for statistical studies. Only Chandra can resolve the multiple components of these sources, as is needed for an improved understanding of source physics and gas heating. The imaging and spectroscopy of cores, jets, hot spots, and atmospheres will be of permanent legacy value. We will use the data to investigate particle acceleration, interactions between radio plasma and the ISM and IGM, the emission mechanisms of hot spots, and AGN fueling. Comparison with our complete Spitzer coverage and HST images will aid interpretation. The dataset will be made public immediately.

Proposal Number: 10700584

Title: Deconstructing AGN X-ray Spectra - Time for a Paradigm Shift?

PI Name: Tracey Turner

We aim to detect and measure the ionization state and outflow velocities in the well-studied low-BH-mass AGN NGC 4051. We have been granted a 340 ks Suzaku observation to study continuum and low-resolution line spectral variability; HETG spectroscopy complements this by isolating narrow absorption lines arising from key zones of gas, allowing us to measure ionization, column and outflow velocities of the multiple ionized zones. A moderately ionized zone in particular can mimic the appearance of a broad Fe emission line but can be revealed by 6.5 keV Fe Kalpha absorption, for which there is already tentative evidence. A 320 ks HETG exposure will provide powerful diagnostic signatures across a wide range of ionisation. We also request HST time for tie-in UV spectroscopy.

Proposal Number: 11700019

Title: A Deep Chandra HETG View of Outflowing Warm Absorbers and Relativistically Blurred Emission in ESO 323-G077

PI Name: Claude Canizares

We propose a 300-ks Chandra HETG observation of ESO 323-G077, a remarkable Seyfert galaxy that shows evidence of two highly ionized warm absorbers and a relativistically broadened Fe Ka emission line (Jimenez-Bailon et al. 2008). We will use the high energy resolution of the HETG to provide the first strong constraints on the nature of the absorbers, and test the hypothesis that they form part of a two-phase outflow from the AGN. We will also this detailed parametrization of the underlying X-ray continuum and circumnuclear absorption to determine if the Fe Ka line is relativistically blurred. Finally, we will use the zero-order HETG image to explore the relationship between any spatially extended X-ray emission and the known [OIII] emission that forms the narrow-line region.

Proposal Number: 11700501

Title: The Size of Quasar Non-Thermal/X-ray Emission Regions

PI Name: Christopher Kochanek

We will use microlensing, where the stars in a lens galaxy magnify the accretion disk of a gravitationally lensed quasar, to measure the sizes of the X-ray emission regions of 7 gravitationally lensed quasars with well-sampled optical light curves and accretion disk size measurements. We will use these to determine the scaling of the non-thermal emission regions with black hole mass. For two ``active'' systems, RXJ1131-1231 and Q2237+0305, we will use longer observations in order to measure the X-ray energy dependence of the size. We have HST time to monitor the 6 with UV flux to probe thermal emission from near the inner edge of the disk. These observations can only be done with Chandra because future X-ray observatories will lack the necessary angular resolution.

Proposal Number: 11700510

Title: The environmental and epoch dependence of radio-loud AGN feedback

PI Name: Judith Croston

Feedback from radio-loud AGN outbursts is now thought to be an important ingredient in galaxy formation models, potentially solving the `cooling flow' problem in cluster centres and helping to resolve long-standing problems in reconciling CDM models with observed properties of groups and clusters. Now that the role of radio-loud AGN feedback is established, the next step is to understand the relationship between radio-loud AGN energy input, environment and epoch, which appears complex and is currently poorly understood. This Chandra Large Project aims to address this question by characterizing the environments of a unique sample of radio galaxies spanning three orders of magnitude in radio luminosity at a single, cosmologically interesting redshift.

Proposal Number: 11700858

Title: Jet-ISM Interactions in a Restarting Radio Galaxy 4C 29.30

PI Name: Aneta Siemiginowska

We propose to study interactions between radio plasma and ISM with a deep 300ksec Chandra ACIS-S observation of a low redshift radio galaxy, 4C 29.30 where the complexity of such interactions is uniquely displayed allowing a direct mapping of the initial stage of the radio source growth. The high resolution Chandra image will match the resolution of optical and radio structures observed in this source. The X-ray morphology will provide the critical information needed for studying physical conditions and understanding the impact of the evolving radio source onto the host galaxy environment. Our target presents a great laboratory to study the physical mechanisms of AGN feedback, and so provide strong constraints on models of galaxy evolution.