Accepted Cycle 18 Archive Proposals

Proposal Number Subject Category PI Name Title
18200029STARS AND WDEric FeigelsonMYStIX and Beyond: Empirical Insights into Clustered Star Formation
18200060STARS AND WDBrian WoodConnecting Solar and Stellar Coronal Spectroscopy
18200062STARS AND WDLeisa TownsleyMAGiX in the Chandra Archive
18400059BH AND NS BINARIESMattew BrorbyMetallicity effects on high mass X-ray binary formation
18500148SN, SNR AND ISOLATED NSSangwook ParkA Chandra Archival Study of Kepler's Supernova Remnant
18610094NORMAL GALAXIES: DIFFUSE EMISSIONXinyu DaiAn Archival Study of Dust, Gas, and Metallicity of High Redshift Galaxies
18620647NORMAL GALAXIES: X-RAY POPULATIONSFrancesca CivanoChandra stacking analysis of CANDELS galaxies at z>1.5
18700177ACTIVE GALAXIES AND QUASARSScott BarrowsBuilding the Largest HLX Catalog: The Search for Intermediate-Mass Black Holes
18700207ACTIVE GALAXIES AND QUASARSNadia ZakamskaTaking a measure of quasar winds
18700320ACTIVE GALAXIES AND QUASARSHenric KrawczynskiRevealing the Structure of the Inner Accretion Flow of the Quasar RXJ 1131-1231
18700554ACTIVE GALAXIES AND QUASARSMartin ElvisQuasars as standard candles
18800190CLUSTERS OF GALAXIESAndrea MorandiThe galaxy group outskirts via Chandra stacking
18800209CLUSTERS OF GALAXIESIrina ZhuravlevaTurbulent Heating in Radio-mode AGN Feedback
18800406CLUSTERS OF GALAXIESMing SunCooling and multi-phase medium in nearby cool cores

Subject Category: STARS AND WD

Proposal Number: 18200023


PI Name: Hans Guenther

Classical T Tauri stars (CTTS) accrete matter from a circumstellar disk. Models of an accretion shock on the stellar surface can explain the high densities seen in X-ray grating spectra of CTTS, but they consistently underpredict the accretion rates by orders of magnitude compared to optical accretion tracers. Likewise, in the proto-typical CTTS TW Hya O VII is less dense and less absorbed than Ne IX, while accretion shock models predict the opposite. We propose to derive additional empirical constraints. In an archival study of all stellar sources in the Chandra archive we will compare line ratios of CTTS and main-sequence (MS) stars to determine differences in the temperature structure of the X-ray emitting region over the sample to trace the influence of accretion.

Subject Category: STARS AND WD

Proposal Number: 18200029

Title: MYStIX and Beyond: Empirical Insights into Clustered Star Formation

PI Name: Eric Feigelson

The MYStIX project combines archival Chandra, Spitzer and UKIRT observations to establish large, relatively uncontaminated samples of recently formed stars in 20 nearby Galactic massive star forming regions. Eighteen MYStIX papers were published from 2013-16, and we request support for up to five new studies. Topics include age gradients within young stellar clusters, longevity distribution of protoplanetary disks, disk fraction maps in star forming regions, the Initial Mass Function of NGC 6530, and dynamics of the DR 21 stellar population.

Subject Category: STARS AND WD

Proposal Number: 18200060

Title: Connecting Solar and Stellar Coronal Spectroscopy

PI Name: Brian Wood

We propose to conduct a survey of main sequence stars observed by Chandra with grating spectroscopy, with the goal of interpreting these spectra in the context of solar observations. Recent observations of the solar corona from Hinode and SDO provide a much improved characterization of the spectral properties of solar quiet regions (QRs), active regions (ARs), and flaring regions (FRs). With guidance from these new solar data, we will assess whether the stellar spectra can be described as the superposition of the distinct regions observed on the Sun (QRs, ARs, and FRs); and if so, we will characterize how these components vary with stellar spectral type and coronal X-ray luminosity.

Subject Category: STARS AND WD

Proposal Number: 18200062

Title: MAGiX in the Chandra Archive

PI Name: Leisa Townsley

Massive star-forming regions (MSFRs) are engines of change across the Galaxy, providing its ionization, fueling the hot ISM, and seeding spiral arms with tens of thousands of new stars. Galactic MSFRs are springboards for understanding their extragalactic counterparts, which provide the basis for star formation rate calibrations and form the building blocks of starburst galaxies. This archive program will extend Chandra's lexicon of the Galaxy's MSFRs with in-depth analysis of 16 complexes, studying star formation and evolution on scales of tenths to tens of parsecs, distances <1 to >10 kpc, and ages <1 to >15 Myr. It fuses a "Physics of the Cosmos" mission with "Cosmic Origins" science, bringing new insight into star formation and feedback through Chandra's unique X-ray perspective.

Subject Category: BH AND NS BINARIES

Proposal Number: 18400059

Title: Metallicity effects on high mass X-ray binary formation

PI Name: Mattew Brorby

Many studies have shown that for local, low-metallicity galaxies the high mass X-ray binary population is enhanced relative to the population for near-solar metallicity star-forming galaxies. The increase in population is typically attributed to the lower metal content, though other factors may play into this correlation. We propose to study a sample of blue compact dwarf galaxies that cover a wide range in metallicity. Using a single galaxy type, we eliminate other possibly contaminating factors. We will determine whether the correlation seen in the X-ray properties of these galaxies is due mainly to metallicity effects or not. This study will result in a clearer understanding of the role metallicity plays in the X-ray properties of star-forming galaxies.

Subject Category: SN, SNR AND ISOLATED NS

Proposal Number: 18500148

Title: A Chandra Archival Study of Kepler's Supernova Remnant

PI Name: Sangwook Park

The archival Chandra data of Kepler's supernova remnant (SNR) provide an excellent opportunity for a detailed spectroscopic study of the X-ray emitting metal-rich ejecta in this historical Type Ia SNR. Particularly, studies of the spatial distributions and ionizing structures of the Fe- and Si-group ejecta elements would be an excellent opportunity to identify their specific burning sites, and thus to reveal the detailed Type Ia explosion physics and the progenitor's nature. To perform such a study, we propose a Chandra archival study program of Kepler's SNR.


Proposal Number: 18610094

Title: An Archival Study of Dust, Gas, and Metallicity of High Redshift Galaxies

PI Name: Xinyu Dai

We propose to measure the differential X-ray absorption in a sample of 13 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, gas, and metallcity properties of ISM in these cosmologically distant galaxies. Combining these new measurements with earlier measurements, we will double the sample size to constrain the evolution of ISM properties with redshift and compare with model simulations. Such information is crucial to understand the galaxy and star formation and evolution in the presence of an absorbing ISM.


Proposal Number: 18610211


PI Name: Megan Donahue

We propose to analyze the inner cooling-time and entropy profiles of 12 elliptical galaxies with strong radio AGN. X-ray studies of galaxy-cluster cores and massive ellipticals indicate that feedback from an AGN replaces energy radiated by these objects. The AGN at 10 pc seems tuned to the thermodynamic state of gas on 10 kpc scales, but how that occurs is a resilient mystery. The precipitation model posits if the AGN does not provide enough heat, then thermal instabilities rain cold clouds on it, increasing accretion from Bondi to ~100 times that rate when t_cool drops below 10 t_ff. We will test precipitation-driven feedback models by measuring t_cool and gravitational potential within the central kpc and to see how radio power is related to t_c/t_ff at small radii in these galaxies.


Proposal Number: 18620647

Title: Chandra stacking analysis of CANDELS galaxies at z>1.5

PI Name: Francesca Civano

The goal of this proposal is to study the X-ray emission of non-X-ray detected galaxies at z>1.5, beyond the peak of stellar and nuclear activity, in combination with galaxy global properties, such as stellar mass and star formation activity and their morphological classification. To achieve this goal, we will select galaxies in CANDELS. Making use of the 5 X-ray surveys with different depths (160 ks for COSMOS, 800 ks for AEGIS-XD and X-UDS, 2 Ms for GOODS-N and 4 (8) Ms GOODS-S) available in these famous fields, we will be able to reach X-ray luminosities where stellar emission dominate the nuclear one. This analysis will extend to z>1.5, the results obtained performing stacking analysis solely using the Chandra COSMOS Legacy Survey at lower redshift.


Proposal Number: 18700177

Title: Building the Largest HLX Catalog: The Search for Intermediate-Mass Black Holes

PI Name: Scott Barrows

We propose to construct the largest sample of hyperluminous X-ray sources (HLXs). This will be accomplished by combining our custom astrometric and registration pipeline with the excellent spatial resolution of Chandra, which will allow us to identify off-nuclear X-ray sources to smaller angular separations than previous catalogues. Based on our pilot study, this will increase the known number of HLXs by a factor of ~10, and analysis of their environments will constrain their nature and origin. Emission from HLXs is often posited as originating from intermediate-mass black holes (IMBHs), and from the sample we will select the most compelling IMBH candidates. These will be targets of follow-up observations to obtain mass estimates and understand the conditions under which IMBHs grow.


Proposal Number: 18700207

Title: Taking a measure of quasar winds

PI Name: Nadia Zakamska

Quasar feedback -- the strong interaction between the energy output of supermassive black holes and their surrounding environments -- is a now a key element of galaxy formation theory. We recently detected this process in action in optical and radio observations. We propose an archival and theory Chandra program to characterize and model the extended X-ray emission associated with quasar winds. Using stacking of Chandra observations of obscured quasars, we will be able to determine the average energetics and the X-ray spectrum of the X-ray emission from quasar winds extended on host galaxy scales. We will construct theoretical models of shock-heated clouds seeking to simultaneously reproduce the Chandra results and the multi-wavelength view of the quasar-driven galaxy-scale winds.


Proposal Number: 18700320

Title: Revealing the Structure of the Inner Accretion Flow of the Quasar RXJ 1131-1231

PI Name: Henric Krawczynski

We propose an Archival Research Project focusing on the 2004-2014 Chandra observations of the gravitationally lensed quasar RXJ1131-1231 (total: 461 ksec). The observations of the quadruply lensed quasar reveal the effect of energy dependent microlensing with the Fe-K-alpha line centroids shifting between 4 and 8 keV in the quasar reference frame. The results can be explained by the selective microlensing magnification of different portions of the accretion system with different Doppler and gravitational frequency shifts. The proposed work includes a refined data analysis, and the very first modeling of the data with a general relativistic ray tracing code that accounts for the 3-D geometry of the accretion disk and its corona, and with high-resolution microlensing magnification maps.


Proposal Number: 18700554

Title: Quasars as standard candles

PI Name: Martin Elvis

The non-linear relation between the X-ray and UV luminosities of quasars can in principle be used as a distance indicator, allowing to build a Hubble diagram for quasars. Here we show that new, tight constraints on the cosmological models can be obtained by merging the existing data from the literature with serendipitous Chandra observations of SDSS quasars. We propose a one-year project to analyze this new sample of more than 1,000 objects, with the main aim of increasing the precision of the estimate of the dark energy parameter $w$ by at least a factor of ~2. This survey will make use of the unique Chandra capabilities, and will open a new branch of observational cosmology, adding a unique probe of the expansion of the Universe at redshift between 2 and 6.


Proposal Number: 18800190

Title: The galaxy group outskirts via Chandra stacking

PI Name: Andrea Morandi

Galaxy groups are ideal systems to study baryonic physics, which is important for both using X-ray observations of clusters for precision cosmology and understanding galaxy formation and evolution. We know little about the hot gas properties beyond R_500 in groups, while the Planck results may imply a significant amount of gas ejected out of R_500 in groups. We propose to use stacking to study the physical properties of the hot gas in the virialization region of a sample of 71 groups (0.8 < kT < 2.8 keV, median redshift of ~ 0.07) in the Chandra archive. This project follows our previous successful project on cluster stacking and will produce important results on hot gas properties beyond R_500 in groups, with important implications on non-gravitational processes in groups.


Proposal Number: 18800209

Title: Turbulent Heating in Radio-mode AGN Feedback

PI Name: Irina Zhuravleva

Recent statistical analyses of X-ray emissivity fluctuations in the cores of the Perseus and Virgo clusters observed with Chandra revealed that most of the AGN-driven perturbations in the hot gas are due to subsonic gas motions and the dissipation of these motions provides energy sufficient to offset radiative cooling. Turbulent dissipation may therefore be the key element in resolving the gas cooling problem. We propose to extend these statistical analyses on a sample of ten galaxy clusters. These objects have deep Chandra data available in archive, the full potential of which has not been used yet. Thanks to Chandra's high resolution, we will be able to probe fluctuations on broad range of scales, addressing the problems of turbulent heating and energetics of AGN-driven perturbations.


Proposal Number: 18800406

Title: Cooling and multi-phase medium in nearby cool cores

PI Name: Ming Sun

Many early-type galaxies host strong X-ray cool cores. Yet the amount of warm and cold gas in cool cores varies significantly. What determines the conditions for multi-phase medium and star formation? What is the relationship between the gas in different phases and the radio AGN activity? We have constructed a sample of 95 nearby giant galaxies with strong X-ray cool cores. They all have sufficient Chandra data for our science goals. There are also Halpha data from our own effort and FIR data from archives for a nearly complete inventory of the hot gas, warm gas and cold gas. This archive proposal focuses on the Chandra data. The results from this large sample, backed by rich multi-wavelength data, will address some significant questions on cool cores.