Accepted Cycle 23 Archive Proposals

Proposal Number Subject Category PI Name Title
23200443STARS AND WDDavid PrincipeInvestigating the Role of X-ray Photoevaporation and Absorption in Spatially-resolved Circumstellar Disks
23200595STARS AND WDAdam FosterDefinitive Velocity Measurements for Stellar Accretion Shocks and Coronae
23400195BH AND NS BINARIESThomas MaccaroneTESTING THE AGE HYPOTHESIS FOR Be X-RAY BINARIES
23400461BH AND NS BINARIESMarko MicicA QUEST FOR INTERMEDIATE-MASS BLACK HOLES
23400462BH AND NS BINARIESCharles HaileyA Deep Census of Quiescent X-ray Binaries in the central parsec region around Sgr A*
23500427SN, SNR AND ISOLATED NSDaniel PatnaudeAn Archival Study of G292.0+1.8
23610212NORMAL GALAXIES: DIFFUSE EMISSIONDavid BuoteThe Radial Mass Profiles of Massive Relic Galaxies
23610396NORMAL GALAXIES: DIFFUSE EMISSIONAkos BogdanA comprehensive survey of the missing baryons
23620241NORMAL GALAXIES: X-RAY POPULATIONSBret LehmerEMERGENT SPECTRA OF YOUNG X-RAY EMITTING POPULATIONS ACROSS ENVIRONMENTS
23700328ACTIVE GALAXIES AND QUASARSAlessandro PecaTHE LARGE STRIPE-82 X-RAY (S82XL) SURVEY
23700412ACTIVE GALAXIES AND QUASARSAndy GouldingCalibrating the Lx-SFR relation in the dwarf galaxy regime
23800100CLUSTERS OF GALAXIESSteven EhlertProbabilistic Non X-ray Background Subtraction for CIAO
23800186CLUSTERS OF GALAXIESMing SunX-ray coronae in galaxy clusters --- deep and deeper !
23910056GALACTIC DIFFUSE EMISSION AND SURVEYSSmita MathurWhere is the super-virial hot gas? Disentangling the location of the hot circumgalactic medium of the Milky Way
23910599GALACTIC DIFFUSE EMISSION AND SURVEYSLia CorralesA Holistic Study of Sgr~A* Accretion
Subject Category: STARS AND WD

Proposal Number: 23200443

Title: Investigating the Role of X-ray Photoevaporation and Absorption in Spatially-resolved Circumstellar Disks

PI Name: David Principe

Planets are ubiquitous in the Universe and they form in the chemically and physically complex environments of circumstellar disks. Several recent ALMA surveys have observed nearby star-forming regions at unprecedented spatial resolutions to resolve their planet-forming disks. These surveys provide stringent constraints on circumstellar disk properties such as dust/gas mass, radius, inclination, substructures, and chemistry leading to the most comprehensive list of physical disk characteristics known. We propose an archival Chandra/XMM program that leverages the X-ray detection of 95 star-disk systems imaged by ALMA so as to establish new probes of the structure and chemistry of these disks.

 Subject Category: STARS AND WD

Proposal Number: 23200595

Title: Definitive Velocity Measurements for Stellar Accretion Shocks and Coronae

PI Name: Adam Foster

As the Chandra High Energy Transmission Grating (HETG) Spectrometer accumulates stellar spectra with longer and longer exposure times, we now have the opportunity to measure the intrinsic stellar line profiles, in particular thermal and turbulent broadening. Such measurements can provide new insights into plasma proceses, e.g. in coronae and accretion shocks, to complement the more familiar plasma parameters using line flux ratio diagnostics; however, broadening in cool stars is often less than the HETG instrumental width and thus must be disentangled from it. We propose to improve the instrumental line spread function and then apply it to stellar spectra, in particular that of the Classical T Tauri system TW Hya.

 Subject Category: BH AND NS BINARIES

Proposal Number: 23400195

Title: TESTING THE AGE HYPOTHESIS FOR Be X-RAY BINARIES

PI Name: Thomas Maccarone

We propose an archival data analysis project to test whether Be X-ray binary formation is a strong function of age, as has been proposed over the years. It is well known that the Small Magellanic Cloud has a dramatically larger ratio of Be X-ray binary transients to total star formation than the Milky Way does. It has been debated whether this arises from low metallicity or from a finely tuned star formation age distribution. Recently, theoretical work has provided a much firmer foundation for the age hypothesis, and this motivates a test of the idea with a substantial-sized sample of galaxies. We propose analyzing the archival data for the star-forming galaxies with $>1 M_\odot$ per year of star formation and looking for a correlation with age indicators.

 Subject Category: BH AND NS BINARIES

Proposal Number: 23400461

Title: A QUEST FOR INTERMEDIATE-MASS BLACK HOLES

PI Name: Marko Micic

Intermediate-mass black holes (IMBHs) represent the missing link between stellar mass and supermassive black holes (BHs). IMBHs in their high state should produce a specific signature: thermal peaks in supersoft X-ray regime and X-ray luminosities between 10^40-10^42 erg/s. Also, from scaling relations it follows that IMBHs are associated with dwarf galaxies. We will combine Chandra X-ray database and catalogs of members of galaxy clusters to obtain deep X-ray observations of 60000 dwarf galaxies in order to search for IMBHs signatures. Upon completion of our work we expect to provide the evidence for the existence of a large population of IMBHs. Our project has the potential to shed new light on BH and galaxy evolution, BH/galaxy symbiosis problem and many other astrophysical topics.

 Subject Category: BH AND NS BINARIES

Proposal Number: 23400462

Title: A Deep Census of Quiescent X-ray Binaries in the central parsec region around Sgr A*

PI Name: Charles Hailey

Based on 1.4 Ms Chandra ACIS-I observations of the Galactic Center, a remarkable concentration of a dozen non-thermal X-ray sources was discovered within a parsec of the nearest supermassive black hole at Sgr A*. Their spectral and timing properties point to a population of quiescent X-ray binaries, although a small fraction of rotation-powered milli-second pulsars are still viable. We propose to analyze 5 Ms of archival ACIS-S data of Sgr A* to increase the number of quiescent X-ray binaries by a factor of ~3 in the central few parsecs and greatly extend variability constraints. Our expected results will identify the nature of more X-ray sources and provide the most stringent test to date on the fundamental theory of X-ray binary formation around Sgr A*.

 Subject Category: SN, SNR AND ISOLATED NS

Proposal Number: 23500427

Title: An Archival Study of G292.0+1.8

PI Name: Daniel Patnaude

Supernova remnant blastwave dynamics and ejecta chemistry provide insight into the evolution and ultimate fates of massive stars. G292.0+1.8 is a ~ 3000 year old supernova remnant which is bright in X-ray emission from shocked ejecta and circumstellar material. G292 has been observed with Chandra for nearly 1 Ms, primarily as two long ACIS-I observations in 2006 and 2017. Here we propose an archival study of G292. We will measure the proper motion of the blastwave and ejecta, and, for the first time, make a direct measurement of the proper motion of the central pulsar. We will combine these data with ground based optical spectroscopic data and construct a three dimensional view of this young supernova remnant.

 Subject Category: NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 23610212

Title: The Radial Mass Profiles of Massive Relic Galaxies

PI Name: David Buote

Spatially compact stellar profiles and very old stellar populations have established compact elliptical galaxies (CEGs) as massive relic galaxies (MRGs); i.e., local analogs of the high-redshift ``red nuggets'' thought to represent the progenitors of today's early-type galaxies (ETGs). We propose an archival study of a sample of MRGs to map their stellar, gas, and DM profiles to establish if high halo concentrations are typical for MRGs and if their inner mass profiles differ from those of local ETGs.

 Subject Category: NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 23610396

Title: A comprehensive survey of the missing baryons

PI Name: Akos Bogdan

A significant fraction of the baryons remain unaccounted for on the largest scales, which defines the missing baryon problem. It is hypothesized that the majority of the missing baryons reside in the hot phases of the warm-hot intergalactic medium (WHIM). A promising approach to resolve this problem is to probe X-ray absorption lines imprinted on the spectrum of background quasars by the WHIM. We propose to utilize archival Chandra LETG observations of 9 quasars along with a novel stacking approach to probe X-ray absorption lines to unprecedented limits and establish a comprehensive picture of the WHIM. We will identify multiple ions, characterize the average properties and map the density distribution of WHIM filaments, as well as precisely constrain the baryon census of the universe.

 Subject Category: NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 23620241

Title: EMERGENT SPECTRA OF YOUNG X-RAY EMITTING POPULATIONS ACROSS ENVIRONMENTS

PI Name: Bret Lehmer

Recent studies have revealed that high-mass X-ray binary (HMXB) populations become more luminous per unit star-formation rate (SFR) with declining metallicity. These populations are expected to contribute an important source of ionizing photons that could impact local environments and heat the high-redshift intergalactic medium. We propose an archival program using ~5 Ms of Chandra data for 55 nearby (D < 30 Mpc) star-forming galaxies to construct a first quantitative framework for how the average X-ray spectra from HMXBs varies with point-source luminosity in a diversity of environments (i.e., varying SFR and metallicity). Our framework will allow us to construct informed young-population X-ray SEDs that can be used to simulate SEDs of galaxies throughout the Universe.

 Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 23700328

Title: THE LARGE STRIPE-82 X-RAY (S82XL) SURVEY

PI Name: Alessandro Peca

High-luminosity AGN may have a powerful impact on their host galaxies influencing the star formation activity, and may represent the evolutionary key phase when the majority of the mass is accreted onto the central SMBH. These rare objects require large-area surveys to be discovered in representative numbers. We propose to analyze Chandra observations not yet included in the SDSS Stripe 82 region X-ray survey, with the goal of investigating the uncharted high-z, high-Nh and high-luminosity regimes of X-ray selected AGN, increasing by 50% the X-ray data analyzed so far (S82X). With a total new area of 45 deg2, the proposed survey (S82XL) would create the largest sample of luminous (logLx>45), obscured (logNh>23) and/or high-redshift (z>3) X-ray selected AGN with unsurpassed multiband data.

 Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 23700412

Title: Calibrating the Lx-SFR relation in the dwarf galaxy regime

PI Name: Andy Goulding

Using the Chandra archive combined with a well-selected set of nearby (D<12 Mpc) dwarf galaxies all with exquisite multiwavelength data from Hubble, Galex and Spitzer, we propose to calibrate the L_X--SFR relation in the low galaxy mass regime, and search for an already hinted at dependence on metallicity. Such a calibration is essential to understand the AGN content of low mass galaxies identified in current and future X-ray survey fields.

 Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 23800100

Title: Probabilistic Non X-ray Background Subtraction for CIAO

PI Name: Steven Ehlert

Non X-ray background (NXB) events are one of the key limitations to interpreting Chandra observations of faint, diffuse X-ray sources. We have developed a new algorithm for accounting for the NXB events that performs better than a simple subtraction calculation in this regime. As compared to a simple subtraction, our calculation better accounts for the Poisson nature of both the sky and NXB counts and cannot result in negative count rates. Because of its potential application across a wide range of Chandra source classes, we propose to develop and deliver this algorithm to the CXC for community use. Proposed funds will be used to support a software developer who will assist in integrating this algorithm into the CIAO analysis framework.

 Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 23800186

Title: X-ray coronae in galaxy clusters --- deep and deeper !

PI Name: Ming Sun

X-ray coronae of cluster galaxies present important constraints to our models of galaxy evolution. Chandra has played a key role in this field. However, previous studies were limited by the typical depth of the data so mainly massive galaxies, typically with luminous X-ray coronae, were studied. As Chandra has invested a large amount of time on nearby clusters in the last 15 years, we propose an archival study of X-ray coronae in nearby clusters with 21 Ms of data, focusing on some outstanding questions, e.g. the X-ray faint coronae from 0.1 - 1.0 L* galaxies, the dependency of the corona population with galaxy luminosity, color and its location in the phase diagram. Besides individual studies, we will also apply stacking to go even deeper from the already deep Chandra data.

 Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 23910056

Title: Where is the super-virial hot gas? Disentangling the location of the hot circumgalactic medium of the Milky Way

PI Name: Smita Mathur

The discovery of ten million degree hot gas in the circumgalactic medium (CGM) of the Milky Way has been a surprise. While the million degree warm-hot gas is expected from shock heating in the galaxy formation process, the source of the super-virial temperature could be related to galaxy evolution, associated with feedback. But is the hot gas truly from the extended CGM, or from the extra-planar region? We propose an archival program to disentangle the location of the hot gas. We will probe sightlines to Galactic X-ray binaries with high signal-to-noise grating spectra and model the hot gas distribution in radial and vertical directions around the stellar disk. Our program will yield guaranteed science results, providing inputs to models of galaxy formation, evolution and feedback.

 Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 23910599

Title: A Holistic Study of Sgr~A* Accretion

PI Name: Lia Corrales

In this proposal, we seek to align the interpretation of the archival high resolution spectrum of Sgr A* with simulations of its accretion flow and surrounding Galactic Center (GC) environment. Sgr A* is fed from the winds of Wolf Rayet (WR) stars orbiting it within the central parsec of our galaxy. Using the RIAF model for the Sgr A* accretion flow, in which the quiescent X-ray emission arises from a plasma in collisional ionization equilibrium, we will test the pressure-temperature profiles from simulations of the GC WR population against the HETG spectrum. We will then map the 3D simulations to a 2D image with high resolution spectral information, using MARX to simulate the HETG spectrum as a function of radius. This will enable a search for velocity structure in the accretion flow.