Chandra X-Ray Observatory
	(CXC)

Please note that the abstracts refer to the PROPOSED project - which is not necessarily identical to the approved project.
For accurate target information, please check the Observation Catalog.


Cycle 7 Accepted Archive Proposals

Proposal NumberSubject CategoryPI NameTitle
07200793STARS AND WD Susan Hojnacki X-ray Spectral Classification of Young Stars: Beyond Orion
07300359WD BINARIES AND CV Thierry Lanz Characterizing Type Ia Supernova Progenitor Candidates
07500323SN, SNR AND ISOLATED NS Roger Romani PWN Tori and Jets: Pulsar Spin and Plasma Flow
07610308NORMAL GALAXIES: DIFFUSE EMISSION Ming Sun X-ray coronae of early-type galaxies in rich clusters
07610567NORMAL GALAXIES: DIFFUSE EMISSION K. Kuntz The Spectrum of the Diffuse Emission in Spiral Disks
07610745NORMAL GALAXIES: DIFFUSE EMISSION Andrew Baker The CO-to-H2 Conversion Factor from X-ray Shadowing
07620522NORMAL GALAXIES: X-RAY POPULATIONS Jonathan McDowell Standard Photometry for Chandra and XMM
07620604NORMAL GALAXIES: X-RAY POPULATIONS Dong-Woo Kim Luminosity Function of LMXB in Early Type Galaxies
07620779NORMAL GALAXIES: X-RAY POPULATIONS Walter Lewin A comprehensive variability study of the rare class of very luminous (>1e38 erg/s) X-ray sources in nearby galaxies
07620919NORMAL GALAXIES: X-RAY POPULATIONS Jonathan Grindlay Serving ChaMPlane Results, Data and Tools
07700438ACTIVE GALAXIES AND QUASARS George Chartas AN ARCHIVAL STUDY OF THE X-RAY SPECTRAL EVOLUTION OF QUASARS
07700713ACTIVE GALAXIES AND QUASARS Aaron Steffen Revealing the Unresolved Hard Cosmic X-ray Background
07701051ACTIVE GALAXIES AND QUASARS Daniel Harris Imaging Extragalactic Jets
07800105CLUSTERS OF GALAXIES Tesla Jeltema Cluster Structure Throughout the Ages: An Observational Benchmark for Cosmology, Simulations, and Surveys
07800467CLUSTERS OF GALAXIES Pasquale Mazzotta An Archival Study of the Metal Distribution and X-ray Scaling Relations in Galaxy Clusters at 0.1< z <0.7
07800629CLUSTERS OF GALAXIES Paul Nulsen Model-independent X-ray Mass Determinations for Clusters of Galaxies
07800633CLUSTERS OF GALAXIES Massimiliano Bonamente Direct measurement of the Hubble flow at z=0.15-0.9 with X-ray and Sunyaev Zel'dovich Effect data of galaxy clusters
07800937CLUSTERS OF GALAXIES Yen-Ting Lin Evolution of Baryons in Galaxy Clusters
07900156EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS Ilana HARRUS A X-ray complement to an existing optical/UV catalogue. The Chandra view of the XMM-Newton OM catalogue.
07900591EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS Paul Green The History of Supermassive Black Hole Accretion from the ChaMP
07900905EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS William Brandt Hunting for X-ray Outbursts from Galactic Nuclei
07910188GALACTIC DIFFUSE EMISSION AND SURVEYS FREDERIK PAERELS Studies of Astrophysical Dust with Chandra
07910227GALACTIC DIFFUSE EMISSION AND SURVEYS Yangsen Yao X-ray Absorption Line Spectroscopy of Galactic Hot Diffuse Gas

Subject Category:STARS AND WD

Proposal Number: 07200793

Title:X-ray Spectral Classification of Young Stars: Beyond Orion

PI Name: Susan Hojnacki

A large fraction of Chandra observing time has been devoted to the study of young star clusters. However, physical processes responsible for X-ray emission from pre-main-sequence stars are not fully understood and are hotly debated within the X-ray astronomy community. Our work involves running our existing X-ray spectral classification algorithm on Chandra observations of Orion. The results indicate relationships between X-ray spectral classes and fundamental stellar parameters. Are these relationships unique to Orion? Will they generalize to other star forming regions? We propose to extend our algorithm, to classify X-ray sources in additional star formation regions based on our current Orion source groupings to determine if there are correlations similar to those we've found in Orion.


Subject Category:WD BINARIES AND CV

Proposal Number: 07300359

Title:Characterizing Type Ia Supernova Progenitor Candidates

PI Name: Thierry Lanz

The identification of SN Ia progenitors still remains elusive. The most promising channel to form SN Ia involves accreting white dwarfs that sustain steady nuclear burning. They are observed as ultrasoft X-ray sources. Our NLTE analysis of the LETGS spectrum of the supersoft source CAL 83 gives the first direct spectroscopic evidence of a massive WD. We need now to show that massive WDs are common in supersoft sources. We propose to perform a similar NLTE model atmosphere analysis of the 5 other supersoft sources that have been observed with Chandra. We will derive the properties of the WDs and of the binary systems, thus constraining the evolution of Close Binary Supersoft X-ray Sources. We will explore the role of nova-like winds in CBSS for understanding the WD evolution.


Subject Category:SN, SNR AND ISOLATED NS

Proposal Number: 07500323

Title:PWN Tori and Jets: Pulsar Spin and Plasma Flow

PI Name: Roger Romani

We propose a comprehensive re-analysis of the Chandra archive of pulsar wind nebulae whose termination shocks show cylindrical symmetry, tracing the pulsar spin axis. We will use software we have developed to fit these images and extract pulsar and PWN position angles, inclinations and shock scales. We will also fit for Doppler boosting in the jets and tori and will use spectral fits to infer nebula magnetic fields and energetics. We will publish an atlas of PWN structures and geometrical parameters (with errors) and use the fit values to probe the origin of pulsar birth kicks and the nature of the pulsar beaming.


Subject Category:NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 07610308

Title:X-ray coronae of early-type galaxies in rich clusters

PI Name:Ming Sun

Chandra has detected several small (~3 kpc) coronae in the cores of early-type galaxies in rich clusters. These embedded galaxy coronae are perfect targets to study gas stripping, heat conduction, viscosity and various environmental effects. Moreover, they can provide fuel to the central SMBH and trigger AGN activity, as signaled by their associated strong radio sources. We propose to analyze archival ACIS data for 29 nearby rich clusters (63 pointings with a total exposure time of 2 Msec) to identify and examine the properties of surviving gas coronae. Our results will greatly improve our understanding of the SMBH feedback in massive galaxies in rich clusters, the environmental effects on coronae, ICM/corona gas physics and transport processes.


Subject Category:NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 07610567

Title:The Spectrum of the Diffuse Emission in Spiral Disks

PI Name: K. Kuntz

The spectra of the diffuse disk emission from late-type spirals show a wide variety that appears to correlate with Hubble type; the later the galaxy, the softer the spectrum. The bulk of the diffuse X-ray emission is due to star-formation. Comparison with local star-formation suggests that this trend reflects an increased contribution by super-bubbles in later-type spirals. We propose to correlate the spectral fit parameters with other multi-wavelength measures of the quantity and quality of star formation. Of the eighteen face-on galaxies in the Chandra archive with good data, only six have been published. In this study we will analyse the entire set to verify the observed trend and elucidate its physical cause.


Subject Category:NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 07610745

Title:The CO-to-H2 Conversion Factor from X-ray Shadowing

PI Name: Andrew Baker

We propose to make direct measurements of the CO-to-H2 conversion factor in three nearby active galaxies. Our technique relies on comparison of high-resolution CO and X-ray data in regions where background (extraplanar) X-ray emission is shadowed by foreground (disk) molecular clouds. By combining the intensity of the CO emission with the H2 column implied by the X-ray absorption, we will obtain measurements of the conversion factor that are independent of assumptions about virialization or isotopomer abundance ratios. Translation of absorbed X-ray flux to H2 column will require a detailed custom analysis of existing data from ACIS and other instruments, motivating this as an archive proposal.


Subject Category:NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 07620522

Title:Standard Photometry for Chandra and XMM

PI Name: Jonathan McDowell

This archival proposal will develop and calibrate a consistent broad-band photometric system for ACIS observations, allowing model-independent flux and color comparisons for faint sources taking into account the changing sensitivity of the instrument which compromises the usual approach of unfluxed hardness-ratio diagrams to separate source types. We will also calibrate the system for XMM data, permitting ACIS-I, ACIS-S and XMM measurements all to be placed on the same hardness ratio and color-color scales. The science product will be a {\bf spectral standards catalog}, delivered as a set of reference PHA files and corresponding models; and a paper {\bf defining the energy bands}, {\bf tabulating} on-axis corrections and giving color-color tracks for different source types.


Subject Category:NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 07620604

Title:Luminosity Function of LMXB in Early Type Galaxies

PI Name: Dong-Woo Kim

We propose to build the most reliable high luminosity (Lx > a few x 10^37 erg s^-1) X-ray luminosity function of LMXBs in early type galaxies, using Chandra archival data. We will correct for the incompleteness in the faint Lx end (Lx < 10^38 erg s^-1) and for the contamination by background sources in the bright Lx end (Lx > 10^39 erg s^-1). A large sample (~3500 LMXBs) will allow us to unambiguously determine the XLF in various sub-samples and to systematically investigate the XLF dependency on different galactic environments (metal-rich/poor GC vs. field LMXBs; galactic center vs. outskirts), different galaxy properties (stellar age and metallicity, GC contents, gas contents, morphology) and different cluster environments (in the field, group or cluster).


Subject Category:NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 07620779

Title:A comprehensive variability study of the rare class of very luminous (>1e38 erg/s) X-ray sources in nearby galaxies

PI Name: Walter Lewin

We propose to perform a comprehensive study of the long-term (months-years) variability of about 200 very luminous (>10^38 erg/sec) X-ray sources in 23 nearby galaxies. This class of objects consists of neutron-star and black-hole X-ray binaries, and the enigmatic ultra-luminous X-ray sources (ULX). Our knowledge of long-term variability of this rare, very luminous, class is extremely limited. The existing multiple Chandra exposures of galaxies have made it possible for the first time to enter new discovery space. This study (using 2.2 Msec of archival data) will also be able to classify many of the sources and has the potential of discovering new types.


Subject Category:NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 07620919

Title:Serving ChaMPlane Results, Data and Tools

PI Name: Jonathan Grindlay

We propose to complete in cycle 7 our ChaMPlane survey of low luminosity X-ray sources near the galactic plane (b<12deg). Final database creation and archiving and analysis of the large dataset will be conducted. Analysis of galactic bulge fields for the distribution of logN-logS will be completed, and remaining fields between the bulge and anti-center will be systematically analyzed. Tools for serving the data will be further developed. X-ray vs. optical databases, images and catalogs will be posted on line and published for widescale use by the community. Support from the archive program is required to complete this major effort.


Subject Category:ACTIVE GALAXIES AND QUASARS

Proposal Number: 07700438

Title:AN ARCHIVAL STUDY OF THE X-RAY SPECTRAL EVOLUTION OF QUASARS

PI Name: George Chartas

We recently found evidence of a possible correlation of the X-ray spectral slope of radio-quiet quasars (RQQs) at z > 1.5 with X-ray luminosity. We propose to use archival data to analyze moderate-to-high signal-to-noise (S/N) spectra of a modest number of RQQs at z>1.5. We have also submitted a complimentary proposal to observe several high-z lensed RQQs with Chandra. The main scientific goals of this archival proposal are to: (a) Test the previously observed correlation between X-ray luminosity and photon index of z>1.5 RQQs. (b) The significant increase in the present sample size will allow us to test the correlation in narrower redshift bands and thus better constrain the epoch at which possible changes in the average emission properties of AGN occurred.


Subject Category:ACTIVE GALAXIES AND QUASARS

Proposal Number: 07700713

Title:Revealing the Unresolved Hard Cosmic X-ray Background

PI Name: Aaron Steffen

We propose to use archival data from the Chandra Deep Fields, combined with archival Spitzer and HST GOODS Legacy data, to find the sources that comprise the unresolved hard (2-8 keV) Cosmic X-ray Background (CXB). By combining the X-ray flux from the infrared-selected AGN population using X-ray stacking techniques, it is possible to determine if this obscured AGN population is the source of the unresolved hard CXB. In addition, we propose to test luminosity-dependent AGN obscuration theories not addressed in the simple "unified" AGN model by calculating the bolometric luminosities of the infrared selected AGNs. We also propose to compile a comprehensive GOODS AGN catalog, which will contain and grade AGN candidates selected via many different empirical techniques.


Subject Category:ACTIVE GALAXIES AND QUASARS

Proposal Number: 07701051

Title:Imaging Extragalactic Jets

PI Name: Daniel Harris

We propose a systematic reanalysis of all 73 Chandra observations of AGNs that revealed evidence for X-ray emission from the kilo-parsec scale radio or optical jets. The reanalysis will allow us to perform a systematic comparison of the X-ray and radio jet morphologies. Our study will make an important contribution to determining the emission mechanism, and to constraining the nature of the jet fluid and the structure of the jet. All our important data products will be made available to the community.


Subject Category:CLUSTERS OF GALAXIES

Proposal Number: 07800105

Title:Cluster Structure Throughout the Ages: An Observational Benchmark for Cosmology, Simulations, and Surveys

PI Name: Tesla Jeltema

Using archival data, we will quantify the evolution of cluster structure with redshift. This study will greatly expand on the work of Jeltema et al. (2005), which showed for the first time that cluster structure evolves with redshift. This study was limited to 40 clusters allowing a firm detection of structure evolution, but not strong constraints on the rate of evolution. We will more than double this sample. The proposed study will greatly improve constraints on the rate of structure evolution as well as whether this evolution is constant or occurs at a preferred redshift. These results will provide a benchmark which can be compared to cosmological models, numerical simulations, and cluster surveys, and they will also be used to assess the effects of merging on other cluster properties.


Subject Category:CLUSTERS OF GALAXIES

Proposal Number: 07800467

Title:An Archival Study of the Metal Distribution and X-ray Scaling Relations in Galaxy Clusters at 0.1< z <0.7

PI Name: Pasquale Mazzotta

This proposal aims at exploiting the archived observations of galaxy clusters in the redshift range 0.1


Subject Category:CLUSTERS OF GALAXIES

Proposal Number: 07800629

Title:Model-independent X-ray Mass Determinations for Clusters of Galaxies

PI Name: Paul Nulsen

We propose to use high quality X-ray data from the Chandra archive to determine the mass distributions of about 60 clusters of galaxies over the largest possible range of radii. By avoiding unwarranted assumptions, model-independent methods make best use of high quality data. We will employ two model-independent methods. That used by Nulsen & Boehringer (1995) to determine the mass of the Virgo Cluster and a new method, that will be developed as part of the project. The new method will fit a general mass model directly to the X-ray spectra, making best possible use of the fitting errors to constrain mass profiles.


Subject Category:CLUSTERS OF GALAXIES

Proposal Number: 07800633

Title:Direct measurement of the Hubble flow at z=0.15-0.9 with X-ray and Sunyaev Zel'dovich Effect data of galaxy clusters

PI Name: Massimiliano Bonamente

We propose to use X-ray and SZE observations of galaxy clusters to measure the cosmic distance scale out to z~1. This approach, based on the physics of ionized plasmas in clusters, is independent of the HST Key Project results, and probes the Hubble flow to higher redshift. Our sample comprises 37 clusters at z=0.14-0.89, all of which with archived Chandra observations and deep SZE images from our 30 GHz interferometric receivers on the OVRO and BIMA arrays. Previous attempts to calculate cluster distances using X-ray and SZE data relied upon a simple isothermal beta model. We have implemented more accurate models that account for temperature, abundance and density structure. The analysis will include a detailed treatment of the systematic uncertainties associated with our method.


Subject Category:CLUSTERS OF GALAXIES

Proposal Number: 07800937

Title:Evolution of Baryons in Galaxy Clusters

PI Name: Yen-Ting Lin

We propose to conduct a detailed census of cluster baryons with a large sample of clusters drawn from the Chandra archive. While the exquisite Chandra data measure both the total binding mass and that in the ICM, the deep near-IR data we already obtained allow an accurate account of stellar mass in cluster galaxies. The sample spans a large range in both redshift and mass, making it ideal for studying the interplay between the ICM and galaxies and characterizing the galaxy population transformation in clusters. Using these clusters as calibrators at intermediate redshifts for the tight correlation between the total galaxy light and cluster mass, we will be able to develop an efficient cluster mass estimator for large cluster surveys involving near-IR bands.


Subject Category:EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 07900156

Title:A X-ray complement to an existing optical/UV catalogue. The Chandra view of the XMM-Newton OM catalogue.

PI Name: Ilana HARRUS

We propose the compilation of the Chandra ACIS images associated with the XMM-Newton Optical Monitor (OM) catalogue that we have just completed. The resulting catalogue will be published as a reference guide containing X-ray, optical and UV images of X-ray selected objects at the comparable spatial resolution (the OM has a spatial resolution similar to that of Chandra ACIS). This catalogue will offer an unique opportunity for scientists to discover quickly existing equivalences between wavelengths, impossible to detect with the EPIC X-ray files associated with the OM images. We will scan the complete Chandra archive to extract ACIS images for all the fields that have an associated optical or UV images.


Subject Category:EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 07900591

Title:The History of Supermassive Black Hole Accretion from the ChaMP

PI Name: Paul Green

The Chandra Multiwavelength Project (ChaMP) is the widest area sensitive (logfx > -15) serendipitous X-ray survey to date, providing an invaluable probe of supermassive black hole (SMBH) accretion in 3 critical regimes; above z~3 to test the turnover of luminous optical quasars, below z~1 to track the population boom of lower luminosity AGN, and below z~0.5 to determine the fraction of galaxies hosting active accretion. We request funding to leverage our investments both deep and wide. To go deep, we propose for deep (i=24) NOAO Gemini-North multi-object spectroscopy in 4 key fields. To go wide, we extend from 2 to 6 years of Chandra data, and cross-correlate with the SDSS DR4 across some 170 fields to pave the L-z plane and expand our large, uniform, multi-wavelength public database.


Subject Category:EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 07900905

Title:Hunting for X-ray Outbursts from Galactic Nuclei

PI Name: William Brandt

Transient X-ray outbursts from galactic nuclei are likely caused by inevitable fueling events of nuclear supermassive black holes when a star, planet, or gas cloud is tidally disrupted and partially accreted. We propose to extend current studies of such events by searching for new X-ray outbursts with harder X-ray spectra, lower X-ray luminosities, and higher redshifts. We will pursue a two-pronged strategy utilizing a combination of (1) about 380 fields with moderate-depth coverage by both Chandra and XMM-Newton and (2) deep Chandra surveys, primarily the Chandra Deep Fields. Aside from their innate interest, our results will be useful for planning future missions such as the Black Hole Finder Probe, Lobster, ROSITA, and LISA.


Subject Category:GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 07910188

Title:Studies of Astrophysical Dust with Chandra

PI Name: FREDERIK PAERELS

We propose to perform a series of interrelated X-ray studies of the physical properties of astrophysical dust. The archive contains a series of very rich datasets for spectroscopic and imaging studies of dust, which have not yet been analyzed for this purpose. Specifically, we propose to analyze very bright HETGS datasets on Cygnus X-3 and GRS1915+105. We will extend the analysis to fainter sources, with the ultimate goal of initiating X-ray studies of extragalactic dust.


Subject Category:GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 07910227

Title:X-ray Absorption Line Spectroscopy of Galactic Hot Diffuse Gas

PI Name: Yangsen Yao

In a preliminary study along the sight-lines toward 7 Galactic LMXBs, we have detected Ne IX, O VII, and/or O VIII absorption lines, which all appear to be interstellar in origin. The absorbing gas is surprisingly concentrated at Galactic disk and/or toward Galactic central region. The results could be strongly biased, however, because of the limited sample of the sight-lines. We propose a systematic study to utilize the full archival data sets and to carefully re-examine the gas spatial distribution with a total of 16 sight-lines. We will measure the thermal and kinematic properties of the hot gas along many of these sight-lines. Such a hot gas characterization will also help us to estimate the Galactic contribution to the similar cz~0 absorptions observed in AGN spectra.


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Smithsonian Institute Smithsonian Institute

The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA.   Email:   cxchelp@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2017. All rights reserved.