Accepted Cycle 13 Archive Proposals

Proposal Number	Subject Category	PI Name	Title
13100089	SOLAR SYSTEM	Damian Christian	High Resolution Imaging & Spectroscopy of the Chandra Comet Survey II
13200726	STARS AND WD	David Cohen	Deriving Emission Measures and Mass-Loss Rates from Chandra Grating Spectra of OB Stars
13400191	BH AND NS BINARIES	Slavko Bogdanov	Testing the Robustness of Quiescent Low-Mass X-ray Binary Neutron Star Radius Measurements
13610189	NORMAL GALAXIES: DIFFUSE EMISSION	Xinyu Dai	An Archival Study of the Dust-to-gas Ratio of High Redshift Galaxies
13610307	NORMAL GALAXIES: DIFFUSE EMISSION	Akos Bogdan	Testing galaxy formation models: Characterizing extended hot coronae around massive spiral galaxies
13620558	NORMAL GALAXIES: X-RAY POPULATIONS	Benjamin Williams	The Archival Chandra Local Volume Survey
13700193	ACTIVE GALAXIES AND QUASARS	Tracey Turner	X-ray Spectra of Winds from AGN Accretion Disks
13700260	ACTIVE GALAXIES AND QUASARS	Robert Gibson	A LARGE-SCALE CHANDRA ARCHIVE STUDY OF THE X-RAY ACTIVITY OF OPTICALLY-VARIABLE GALAXIES
13700591	ACTIVE GALAXIES AND QUASARS	Breanna Binder	An Archival X-ray Study of Intermediate Mass Black Hole Candidates Selected By Optical Line-Width Criteria
13700844	ACTIVE GALAXIES AND QUASARS	Daniel Evans	A SERENDIPITOUS 695-KS HETG OBSERVATION OF THE CIRCINUS GALAXY: THE DEEPEST EVER STUDY OF A TYPE-2 AGN
13700851	ACTIVE GALAXIES AND QUASARS	Markos Trichas	Chandra/Herschel Survey: The Black Hole Accretion/Starburst Connection
13800104	CLUSTERS OF GALAXIES	Ka-Wah Wong	Understanding the origin of the central abundance abnormality in galaxy clusters
13800711	CLUSTERS OF GALAXIES	Pasquale Mazzotta	CHANDRA ARCHIVAL STUDY OF PLANCK CLUSTERS
13800765	CLUSTERS OF GALAXIES	John Mulchaey	A Systematic Search for X-ray Cavities in the Hot Gas in Ellipticals, Groups and Clusters
13900113	EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS	Alexander Kashlinsky	CORRELATION BETWEEN CXB AND CIB: THE NATURE OF CIB FLUCTUATIONS
13900438	EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS	Kristen McQuinn	A New Way of Looking at Starburst Dwarf Galaxies
13900886	EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS	Rik Williams	Connecting X-ray absorption lines to large-scale galaxy structures: A joint Chandra-Magellan survey
13910573	GALACTIC DIFFUSE EMISSION AND SURVEYS	David Henley	A Survey of X-ray Absorption Lines in the Galactic Halo

Subject Category: SOLAR SYSTEM

Proposal Number: 13100089

Title: High Resolution Imaging & Spectroscopy of the Chandra Comet Survey II

PI Name: Damian Christian

Our proposed study will provide remote plasma diagnostics for 11 comets observed with Chandra+ACIS that previously were only accessible via in-situ measurements. This sample contains a broad variety of comets and solar wind environments and provides us with high quality spectra and imaging to complete a uniform analysis with the latest physics-based solar wind charge exchange (SWCX) models. Our proposal goals are to: 1) Perform a detailed study of the X-ray image morphology and to search for the X-ray bow shock, 2) Investigate the temporal behavior and spectral changes as a function of changes in solar wind conditions using real time SW monitors, and 3) improve the SWCX model with discovery of new line emission, especially in the poorly explored 250 -300 eV and 1000-2000 eV regions.

Subject Category: STARS AND WD

Proposal Number: 13200726

Title: Deriving Emission Measures and Mass-Loss Rates from Chandra Grating Spectra of OB Stars

PI Name: David Cohen

We have recently developed an accurate model for the transport of X-rays through a partially ionized massive star wind with embedded shocks. We propose to apply this model, in conjunction with an APEC-based emission model, to the analysis of the grating spectra of 14 normal OB stars from the Chandra archive. This will enable a determination of the intrinsic emission contribution to the recently identified X-ray hardness vs. spectral subtype trend seen in these Chandra spectra. Any residual emission trend would pose a strong challenge to wind-shock theory. And it will also enable us to measure the mass-loss rates of OB stars using a method that is unaffected by small-scale wind clumping.

Subject Category: BH AND NS BINARIES

Proposal Number: 13400191

Title: Testing the Robustness of Quiescent Low-Mass X-ray Binary Neutron Star Radius Measurements

PI Name: Slavko Bogdanov

X-ray spectroscopic observations of thermally-emitting quiescent low-mass X-ray binaries (qLMXBs) have been used in several instances to measure the radii of these objects in an effort to constrain the neutron star (NS) equation of state (EOS). We propose to conduct a thorough investigation into the potential sources of bias in these NS radius measurements in order to establish the systematic uncertainties and ultimate limitations of this method. The voluminous Chandra archival dataset on thermally-emitting qLMXBs in globular clusters (totaling over 1.8 Ms) will be used to re-evaluate existing published radius measurements and NS EOS constraints based on our findings.

Subject Category: NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 13610189

Title: An Archival Study of the Dust-to-gas Ratio of High Redshift Galaxies

PI Name: Xinyu Dai

We propose to measure the differential X-ray absorption in a sample of ~10 gravitational lenses with significant or accurate optical extinction measurements using the archival Chandra data. By combining the X-ray and optical differential absorption measurements, we will accurately measure the dust-to-gas ratio of these cosmologically distant galaxies. Combining these new measurements with earlier measurements, we will double the sample size and test whether the dust-to-gas ratio evolves with redshift as predicted by simulations of dust formation and evolution. Such information is crucial to understand the galaxy and star formation and evolution in the presence of an absorbing ISM.

Subject Category: NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 13610307

Title: Testing galaxy formation models: Characterizing extended hot coronae around massive spiral galaxies

PI Name: Akos Bogdan

The presence of hot gaseous coronae in the dark matter halos of massive galaxies is a basic prediction of galaxy formation models. Theoretical models predict copious X-ray emission at large radii around massive spiral galaxies. We propose to stack archival Chandra data of eight massive spiral galaxies to detect and characterize extended hot coronae. The sample galaxies are optically luminous, undisturbed, have moderate star formation rates, and are sufficiently distant to be probed at large radii. Our goal is to detect hot gaseous coronae around massive spirals and to compare their observed X-ray luminosity with theoretical models. Furthermore, we will also build an X-ray surface brightness profile of the coronal emission and measure the mean gas temperature.

Subject Category: NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 13620558

Title: The Archival Chandra Local Volume Survey

PI Name: Benjamin Williams

The accretion processes that power cosmic X-ray sources have been well-studied for several decades. However, the connection between X-ray sources and their parent stellar populations is still only vaguely understood. To remedy this situation, we propose a homogeneous X-ray survey of nearby large galaxies in a volume-limited sample with extensive Hubble Space Telescope (HST) imaging. The required new Chandra observations are being analyzed, but these must be supplemented with archival data to complete our sample. Resolved stellar photometry from HST provides detailed measurements of star formation histories, which we will tie to the X-ray source populations of these galaxies, providing crucial ingredients to the understanding of the formation and evolution of X-ray sources and galaxies.

Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 13700193

Title: X-ray Spectra of Winds from AGN Accretion Disks

PI Name: Tracey Turner

Feature-rich HETG spectra of AGN reveal X-ray signatures from circumnuclear reprocessing gas spanning four orders of magnitude in column density; this gas is likely dominant in shaping X-ray spectra and variability in AGN. A recent breakthrough in understanding time lag signatures for X-ray continuum reverberation also demonstrates that the nuclear regions have a high covering fraction of absorbing, Compton-scattering gas existing on scales of light-hours and likely arising in outflowing material blown off the accretion disk. We have developed a model for X-ray radiative transfer through accretion disk winds from AGN and propose fitting this model to archived HETG spectra to better understand key wind parameters.

Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 13700260

Title: A LARGE-SCALE CHANDRA ARCHIVE STUDY OF THE X-RAY ACTIVITY OF OPTICALLY-VARIABLE GALAXIES

PI Name: Robert Gibson

We are currently using a "difference imaging" (DiffIm) analysis to identify optically variable galaxies in SDSS Stripe 82 (with 300 square degrees, 70 images per galaxy in each of the $ugriz$ filters, and high-quality SDSS spectroscopy). Variability is a tracer of AGN activity that will be widely used in upcoming surveys. We will use X-ray observations of Stripe 82 galaxies to calibrate DiffIm selection to maximize completeness and efficiency, identify new "optically dull" AGN and measure their variability, test whether variable Seyfert 2s and star-forming galaxies that we are discovering really support ("Naked"?) AGN, measure X-ray flare (or absorption "eclipse") rates in active and non-active galaxies, and compare host galaxy properties/environments for active and non-active galaxies.

Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 13700591

Title: An Archival X-ray Study of Intermediate Mass Black Hole Candidates Selected By Optical Line-Width Criteria

PI Name: Breanna Binder

We propose to follow-up on 23 intermediate-mass black hole (IMBH) candidates selected from our RASS/SDSS DR5 catalog that fall within the field of view of an archival Chandra observation. At minimum, we will be able to verify the coincidence of the X-ray source with the optical SDSS galaxy, extract a hardness ratio, and place a first constraint on the long-term variability of each IMBH candidate. We anticipate to increase the number of known, X-ray detected IMBHs by at least 5-8, without the need for new X-ray observations. We anticipate that for at least one-third our proposed IMBH candidates we will be able to perform detailed spectral fitting and timing analysis that can then be correlated with optical observations.

Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 13700844

Title: A SERENDIPITOUS 695-KS HETG OBSERVATION OF THE CIRCINUS GALAXY: THE DEEPEST EVER STUDY OF A TYPE-2 AGN

PI Name: Daniel Evans

We propose an archival program to perform a 695-ks Chandra HETG study of the Circinus Galaxy. The data, most of which were obtained serendipitously as part of an AO-10 campaign to study SN1996cr, give us an unprecedented view of one of our nearest AGN. We will use this extraordinary dataset to: (1) measure the mass and energy imparted by the AGN outflow into its kpc-scale environment; (2) create a full kinematic map of the galaxy in conjunction with SINFONI IFU observations, thereby directly constraining the extent of the outflow; and (3) examine the Compton-thick nature of the AGN.

Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 13700851

Title: Chandra/Herschel Survey: The Black Hole Accretion/Starburst Connection

PI Name: Markos Trichas

We propose to analyse all the archival Chandra data in the Herschel Multi-tiered Extragalactic Survey (HerMES) to compile the largest sample (N~1600) of powerful AGN at the main epoch of black hole growth, z=1-3, and to resolve current discrepancies on the star-formation rate of these systems. The combination of X-ray data with far-IR/submm observations provides the most robust constraints on the star-formation of AGN to test competing models for the interplay between galaxy formation and black hole growth. HerMES is ideally suited to studying star formation over the z=1-3 epoch and by adding Chandra data is the only region with the required X-ray/UV/optical/IR/submm coverage to do such a study.

Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 13800104

Title: Understanding the origin of the central abundance abnormality in galaxy clusters

PI Name: Ka-Wah Wong

It is known that the Fe abundance profiles are generally rising toward the central regions in cool core clusters. However, at least in some cool core clusters, the abundance profiles appear to be dropping closest to the center (r < 50 kpc). The abundance drops appear robust against modeling biases. We will study a large, low-redshift (z < 0.09) cluster sample (67 clusters including both cool core and non-cool core) with spatially resolved abundance maps within the central ~50 kpc. After taking into account possible modeling biases, we will quantify the central abundance drops and investigate how often and under what conditions (e.g., the presence of AGN/cool core, temperature gradient, pressure drop, etc) there is a drop. These will help us to distinguish between competing models.

Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 13800711

Title: CHANDRA ARCHIVAL STUDY OF PLANCK CLUSTERS

PI Name: Pasquale Mazzotta

This archive proposal is linked to the X-ray Visionary Project number 13800087, The Chandra-Planck Cluster Legacy, whose primary scientific goals is to characterize the massive clusters in the local (z < 0.5) Universe found through the Planck SZ analysis. To be completed, the project requires Chandra observations for all the 189 clusters in the Planck ESZ sample. With this archive proposal we request funding to perform the analysis of the 109 Cluster already available into the archive.

Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 13800765

Title: A Systematic Search for X-ray Cavities in the Hot Gas in Ellipticals, Groups and Clusters

PI Name: John Mulchaey

We propose to perform a systematic search for X-ray cavities in the hot gas in ellipticals, groups and rich clusters using the Chandra archive. Our study will provide the first comprehensive study of cavities over the full mass range from ellipticals to rich clusters. We will measure cavity properties (such as radial and tangential radii and distance from the AGN) to determine if the tight correlations found for rich clusters extend down to lower mass scales. We will also study how the incidence of cavity detection varies with the radio strength of the AGN and the presence of cool cores. Our study will provide important constraints for modeling of cavities and therefore lead to a better understanding of the role AGN feedback plays in ellipticals, groups and clusters.

Subject Category: EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 13900113

Title: CORRELATION BETWEEN CXB AND CIB: THE NATURE OF CIB FLUCTUATIONS

PI Name: Alexander Kashlinsky

We will analyze the 4Ms CDFS and 2 Ms CDFN data by cross-correlating them with the maps of source-subtracted Cosmic Infrared Background (CIB) fluctuations from Spitzer/IRAC. This will provide important information about the nature of the sources contributing to these CIB fluctuations.We will carefully subtract X-ray background, construct a common mask for the X-ray and CIB IRAC maps and compute the cross- and auto-correlations. Our pilot study demonstrates conclusively that this measurement is feasible and would lead to conclusive results. The results will enable to estimate the relative contributions of accreting sources, such as black holes, to the recently discovered CIB fluctuations (significant cross-correlations), and those emitting by stellar nucleosynthesis.

Subject Category: EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 13900438

Title: A New Way of Looking at Starburst Dwarf Galaxies

PI Name: Kristen McQuinn

Starburst dwarf galaxies are extreme environments in which the rate of star formation has a significant evolutionary effect on both the host galaxy and the interstellar medium. Yet, to date, our knowledge of X-ray emission originating from the diffuse hot gas in starburst dwarf galaxies is based on Chandra observations which were analyzed without a detailed understanding of the star formation activity that heated the gas. We propose to study archival Chandra ACIS-S observations of 6 nearby starburst dwarf galaxies for which we have already reconstructed the star formation histories (SFHs) from HST resolved stellar population data. We will connect the spatially and temporally resolved SFHs with the gas, probing the timescales of X-ray emission, and analyze the spatial structure of the gas.

Subject Category: EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 13900886

Title: Connecting X-ray absorption lines to large-scale galaxy structures: A joint Chandra-Magellan survey

PI Name: Rik Williams

As the number of deep grating observations of bright quasars in the Chandra archive grows, so does the potential to detect absorption lines from the warm-hot intergalactic medium (WHIM). However, these lines only tell part of the story: do they truly arise from the WHIM, or are they associated with outflows and coronae of individual galaxies? This question is being addressed with studies of galaxy distributions around detected UV/X-ray absorbers, but with public surveys like SDSS and 2dF that are incomplete at faint magnitudes and small separations. At Carnegie we are undertaking multi-object spectroscopic surveys to augment the public data and place better constraints on the origin of UV absorbers. Here we propose a comprehensive archival study to extend this project to X-rays.

Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 13910573

Title: A Survey of X-ray Absorption Lines in the Galactic Halo

PI Name: David Henley

We propose a Chandra survey of the O VII and O VIII absorption lines in the hot Galactic halo using archival grating observations. This survey will increase the number of sightlines for which such measurements have been made. Combining the column densities with line intensity measurements (along with estimates of the temperatures from spectral analyses) will allow us to constrain the density, path length, and pressure of the hot gas. We will compare these various quantities with the predictions of physical models, in order to determine the origin of the hot halo gas.

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