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Proposal Number: 10200195

Title: NGC 3603: X-rays from Massive Stars in a Galactic Starburst Cluster

PI Name: Leisa Townsley

NGC 3603 is one of the youngest truly massive stellar clusters in the Milky Way and has long served as a springboard for understanding super star clusters such as R136 at the heart of 30 Doradus in the Large Magellanic Cloud. Recent advances in ground-based infrared imaging and visual spectroscopy applied to NGC 3603 are yielding new catalogs of pre-main sequence stars and new spectral types for massive stars; advances in ACIS data analysis techniques now give robust X-ray source properties in crowded fields that facilitate comparison with these new datasets. We will apply these new methods to the ACIS-I observation of NGC 3603 to study its massive stars (including over half of the Galaxy's O3 stars), hundreds of pre-main sequence stars, and diffuse emission that pervades the cluster.

Proposal Number: 10200345

Title: Novel Coronal Temperature Determinations using HETGS

PI Name: Peter Beiersdorfer

We propose to determine the temperature of the coronal regions that are the source of the Fe XVII emission using dielectronic recombination satellite lines. These satellites are generally weak, but they can be observed in the HEG and MEG spectra of Capella formed by adding all available observations (596 ksec). The temperature derived by this method will be compared to the temperature derived from the differential emission measure (DEM), providing a much needed test of the accuracy of the udernlying charge fraction calculations. Our propsed analysis will open up a new way of determining the Fe XVII coronal temperature, which can be applied in the future to the analysis of the spectra from other stellar coronae.

Proposal Number: 10200545

Title: The ChaSte Survey

PI Name: Jeremy Drake

Existing X-ray field star surveys have revealed problems in our understanding of magnetic activity evolution with time and in the star formation history of the solar neighbourhood. Comparison of predictions from a state-of-the-art model of Galactic stellar X-ray emission with X-ray detection fractions of stars in Chandra deep fields and star counts from wider {\it Chandra} L3 and ChESS catalogs will: (1) build the first detailed picture of the evolution of magnetic dynamos and coronal heating for stars with ages 1-10 Gyr; (2) Probe the Galactic disk star formation history and test conclusions of earlier stellar X-ray population surveys that find evidence for an excess of young yellow stars.

Proposal Number: 10200734

Title: Understanding accretional astrophysics and the development of young stars

PI Name: Sonali Shukla

We propose the first globally-consistent analysis of Chandra/HETGS observations of young stars in order to characterize their X-ray emission. The objects we propose to study include three cTTS, four wTTS, two post-T Tauri stars, and one young star, spanning several evolutionary stages of stellar development. By exploring both the flaring and quiescent states of these stars and comparing the line-ratios sensitive to temperature, density, and abundances, we can note similarities and differences among those thought to be actively accreting material from circumstellar material and those no longer accreting. Our analysis will provide insight into the unique X-ray spectral characteristics produced by different X-ray generation mechanisms (i.e., coronal activity, accretion) in young stars.

Proposal Number: 10300134

Title: Extracting the Maximum Information from the Grating Observations of Cataclysmic Variables

PI Name: Eric Schlegel

We propose to carry out the first global analysis of the grating observations of cataclysmic variables using the recent uniformly-reprocessed data. We intend to fit each detected line for centroid, equivalent width, and line flux and assign an upper limit for expected but undetected lines. While the density ratio {\it R} is affected by UV radiation, we will explore the properties of that UV radiation, particularly for the generally-unstudied EUV band. The temperature diagnostic ratio, {\it G}, will be compared for all CVs.

Proposal Number: 10500608

Title: Searching for XRO 080109-like X-ray transients from the Chandra public archive

PI Name: Bing Zhang

Motivated by the serendipitous discovery of an X-ray ourburst associated with a Type Ib/c supernova (XRO 080109/SN 2008D), we propose to systematically search for XRO 080109-like sources in the Chandra public archive, aiming at more accurately constraining the event rate as well as exploring the physical origin of these events. We demonstrate that an algorithm that has been applied to the Swift XRT data can be readily applied to the Chandra data. We will at least search through all the NGC galaxies that have been observed by Chandra, and will continue search through the whole Chandra public archive. Both positive and negative discoveries of new sources would greatly improve our understanding of the nature of these events and supernova explosions in general.

Proposal Number: 10500712

Title: X-ray transients in the Chandra archive

PI Name: Eran Ofek

X-ray flares probe a large variety of astrophysical objects. This includes Galactic flare stars; GRBs; SNe; and potentially yet unknown phenomena. We propose to carry out a detailed search for X-ray flares and variable sources, with time scales of ~1-10^4 s, in the entire Chandra archive. Moreover, we will followup, in optical/NIR, the transients and variable sources that we will find, in order to study their nature. This will be possible thanks to the unparalleled spatial resolution of Chandra. We will use this search to: measure the unobscured rate of core-collapse SNe; study the physics of shock breakouts; uncover the nature of X-ray transients detected by other missions; characterize the variability of flaring stars; and finally to look for new kinds of astrophysical explosions.

Proposal Number: 10500848

Title: UNDERSTANDING THE SYNCHROTRON AND NON-THERMAL BREMSSTRAHLUNG RADIATION FROM THE CASSIOPEIA A SNR

PI Name: Michael Stage

Analysis of RXTE data of shell-type SNRs shows that the high energy (10-100 keV) spectra are hard power-laws (Allen 1997), but controversy whether they are synchrotron emission concentrated at the forward shock, or non-thermal bremsstrahlung from reverse-shocked ejecta. Previously, we identified and fit the characteristics of thousands of regions dominated by synchrotron emission using the Cas A megasecond (Stage 2006). Using these results and RXTE and Suzaku spectra, we will determine the shape and flux of the composite synchrotron and non-thermal bremsstrahlung spectra. Comparing the non-thermal and thermal bremsstrahlung emission, we will estimate the fraction of electrons which are non-thermal, a measure of particle acceleration efficiency.

Proposal Number: 10610823

Title: Linking the Stellar Content to the X-ray View of Spiral Galaxies: An X-ray/Optical Study of M33 and M101

PI Name: Larry Maddox

The formation and evolution of massive stars injects material and energy into interstellar medium (ISM) of galaxies. Gas that is heated to one million degrees is observed as diffuse X-ray emission. We propose an archival study of the nearby galaxies M101 and M33 to study the relationship between star formation and diffuse gas properties using Ms Chandra observations. These deep surveys provide an excellent opportunity to study the diffuse properties of nearby spirals. Existing optical surveys will be employed to relate the stellar population distribution to the physical conditions of the hot ISM. Additionally, the Ms observation of M101 will allow us to study long term variability of luminous X-ray point sources on timescales of hours to years.

Proposal Number: 10620182

Title: ChAInGeS: The Chandra Arp Interacting Galaxies Survey

PI Name: Beverly Smith

Dozens of ultra-luminous X-ray point sources (ULXs) have been seen in nearby galaxies, particularly interacting galaxies. Previous studies suggest that ULXs are more likely to be found in tidal features, but this is uncertain. We seek to determine whether there is a statistically-significant correlation between ULXs and tidal features, which would imply that the extreme environments of these features are particularly conducive to the formation of ULXs. We propose to use archival Chandra images of a well-studied sample of interacting galaxies for which we have obtained GALEX UV, SARA optical, and Spitzer infrared images and have calculated spatially-resolved stellar population ages. Comparison with the Chandra results will help to distinguish between two competing models for ULXs.

Proposal Number: 10620633

Title: The Dependence of LMXBs on the Encounter Rate in Globular Clusters from an Archival Analysis of Very Deep Data for M87

PI Name: Stephen Zepf

We propose to analyze archival Chandra observations of M87 including 500 ks ACIS-I and 160 ks ACIS-S observations to identify low-mass X-ray binaries (LMXBs) in this massive elliptical galaxy. We will then match these to extremely deep 50-orbit HST-ACS images of M87 in which we have identified and characterized its globular clusters. This will allow us to determine how the probability a globular cluster hosts a LMXB depends on its structural parameters. The extraordinary depth of these data and the very rich M87 system allows a unique opportunity to address this question. The result will provide key observational constraints on the dynamical evolution of globular clusters, the fate of compact objects in these clusters, and the dynamical formation of LMXBs in cluster cores.

Proposal Number: 10620658

Title: The evolution of elliptcal galaxies with different fine-structure indices

PI Name: Andreas Zezas

We propose to analyze archival Chandra data for a sample of 14 early type galaxies over a wide range of fine-structure index (an indicator of their dynamical state). Our analysis will focus on the 2-dimensional distribution of the discrete X-ray sources and comparison with the distribution of the globular clusters (GC) and the optical morphology of these galaxies. A strong correlation between the X-ray sources and GCs will indicate preferential Low Mass X-ray Binary (LMXB) formation in dense stellar environments. In addition the evolution of the XLF as a function of the dynamical state of the galaxies will provide constraints on the evolution of LMXBs. Finally, we will address models for the formation of the hot haloes in elliptical galaxies by studying the diffuse emission of our objects

Proposal Number: 10620794

Title: ChaMPlane-III: maximizing Chandra's legacy in the Galactic Plane

PI Name: Maureen van den Berg

The Chandra Multi-wavelength Plane survey (ChaMPlane) represents a vast X-ray/optical/IR database that we have built around archival ACIS pointings of the Galactic Plane. This proposal requests support to continue our analyis of this archive and to achieve our main science goal: constrain the Galactic population of faint X-ray binaries with compact objects - for the first time - on Galactic scales. We also ask support to bring our project to a next phase: ChaMPlane-III will integrate public optical/IR Galactic surveys into our analysis and open up our own archive. ChaMPlane-III will contribute to maximize Chandra's legacy in the Galactic Plane.

Proposal Number: 10620831

Title: The X-ray point source populations in nearby galaxies

PI Name: Jifeng Liu

Here we propose to study the X-ray point source populations of 419 nearby galaxies with Chandra ACIS archival data, the most comprehensive of such. The goals for the proposed study are three-fold. (1) we present to the X-ray community a catalog for X-ray sources within the D25 (and 2 X D25) isophotes of the 419 nearby galaxies. (2) we present a library of XLFs for each galaxy, compare the XLFs for different groups of galaxies with similar properties, and study how the important XLF details change from group to group and from galaxy to galaxy. (3) we classify the sources and study how the different populations change with host galaxies.

Proposal Number: 10700266

Title: A Large-Scale Variability Study of Quasars with Optical/UV Spectroscopy

PI Name: Robert Gibson

We will conduct a large-scale variability study of spectroscopically-identified quasars (QSOs) in the Chandra archive using automated data reduction/analysis procedures we have developed for previous archive studies. Using the large archived sample of sources at a wide range of redshifts, we will constrain the amplitude of QSO luminosity variation as a function of time scale, luminosity, redshift, Eddington ratio, black hole mass, and UV emission/absorption properties. We will also address contemporary topics such as testing for increases in variability at redshifts $z > 2$ and whether trends in variability properties of Seyfert AGN extend to QSO luminosities.

Proposal Number: 10700674

Title: Jet Diagnostics with Long Chandra Observations of Mkn 421

PI Name: Giovanni Fossati

We propose to analyze a selected set of archived Chandra observations of the blazar Mkn 421 to address outstanding questions concerning the existence, entity and nature of intra-band X-ray lags and of the relationship between the synchrotron peak energy and the source luminosity. Chandra datasets are uniquely suited for this investigation because of their uninterrupted extension in time, and good energy bandpass. In particular, the chosen datasets constitute the longest truly uninterrupted observations of Mkn 421 ever performed by any satellite.

Proposal Number: 10800103

Title: Probing the Evolution of Groups with AEGIS

PI Name: Tesla Jeltema

We propose an archival study of groups of galaxies in the Extended Groth Strip. We will probe the evolution of groups to high redshifts, including models of non-gravitational heating, and compare optical and X-ray group selection. With the AEGIS Chandra data, we can detect typical groups out z=1 and low mass groups at intermediate redshifts, allowing the first constraints on the evolution of group scaling relations and greatly increasing the number of known high-redshift groups. The DEEP2 survey also provides a large, spectroscopically-selected group sample at high redshift; combined with the deep Chandra data this allows the first comparison of group selection at z~1.

Proposal Number: 10800330

Title: The Detectability of AGN Cavities in Cooling-Flow Clusters

PI Name: Laura Birzan

Chandra images have revealed giant cavities in the hot atmospheres of clusters that where created by the central AGN. However, cavities are missed in some systems due to underexposed images or low surface brightness contrast. Using Chandra archival data of ~60 cavity systems, we propose to quantitatively understand the incompleteness due to detectability and sample selection. As some of the biases in current samples are due to the fact that the cavities are detected by eye, we will develop an automated method for detecting cavities to allow precise determination of selection biases. An understanding of the biases is important to models of cavity formation and evolution and to the energy budget and duty cycle of the outbursts.

Proposal Number: 10800548

Title: Galaxy Cluster Scaling Relation Evolution using Simultaneous XMM and Chandra Constraints

PI Name: Karl Andersson

We propose the simultaneous analysis of Chandra ACIS and XMM-Newton EPIC data of up to 85 clusters of galaxies using our full instrument Monte Carlos of EPIC and ACIS instruments. The MC is used to constrain a non-symmetrical kilo-parametric, spatial and spectral, cluster model using datasets from both instruments. In a recent study of 101 XMM-Newton observed clusters of galaxies we find a weak evolution of the L-T relation and an indication that this evolution depends on the amount of substructure in the clusters. The addition of the Chandra data would enable the study of how the scatter in the scaling relations depends on the cluster luminosity and temperature morphology. The dataset will also be used to investigate the emergence and evolution of clusters with cool cores.

Proposal Number: 10900558

Title: How the ChaMP Stacks Up: 17 Years of Chandra Time on SDSS Galaxies

PI Name: Paul Green

Models linking cosmological structure formation, galaxy evolution, and accretion processes are flourishing, but crucial X-ray tests in the local Universe are truant. Both wide sky area and sensitive X-ray flux limits (below E-15 cgs) are needed to secure the low-z boundary conditions for these models. By leveraging the vast SDSS galaxy samples with groundwork laid by the Chandra Multiwavelength Project (ChaMP), we propose X-ray stacking encompassing ~554 Msec of Chandra exposure to characterize (1) the relationship between accretion and small-scale environment (2) the star-formation/accretion transition and (3) the X-ray properties of normal galaxies over the last few Gyr.

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