Accepted Cycle 20 Archive Proposals

Proposal Number Subject Category PI Name Title
20200070STARS AND WDDamian ChristianA new coronal diagnostic using a photopumped X-ray line
20200135STARS AND WDEric FeigelsonSuperflares from Pre-Main Sequence Stars
20400452BH AND NS BINARIESNatalie HellMapping the clumpy stellar wind in a sample of high-mass X-ray binaries
20500446SN, SNR AND ISOLATED NSVinay KashyapThe X-ray Hot Spots of SN 1987A
20500688SN, SNR AND ISOLATED NSOleg KargaltsevDiscovering compact objects in intermediate age clusters
20610246NORMAL GALAXIES: DIFFUSE EMISSIONJiang-Tao LiHot circum-galactic medium as a legacy of Chandra archive
20620227NORMAL GALAXIES: X-RAY POPULATIONSScott BarrowsBuilding the Largest Catalogue of Intermediate Redshift ULXs: Evolution out to z=0.3
20620295NORMAL GALAXIES: X-RAY POPULATIONSBret LehmerA PHYSICAL PARAMETERIZATION OF THE EVOLVING X-RAY EMISSION FROM NORMAL GALAXIES OBSERVED IN THE CHANDRA DEEP FIELDS
20620472NORMAL GALAXIES: X-RAY POPULATIONSShuo ZhangA Systematic Analysis on M31* X-ray Variability with 3 Ms of Chandra Data from 1999 to 2016
20620582NORMAL GALAXIES: X-RAY POPULATIONSMatthew MalkanCalibrating the Lx-SFR relation in starbursts at ``Cosmic Noon'
20700644ACTIVE GALAXIES AND QUASARSKeigo FukumuraUnderstanding AGN Warm Absorbers: A systematic Correlation Analysis of Physical Properties
20800092CLUSTERS OF GALAXIESAdam MantzLooking for (cluster) relaxation? Try the SPA.
20800178CLUSTERS OF GALAXIESGerrit SchellenbergerThe eHIFLUGCS galaxy cluster sample
20800429CLUSTERS OF GALAXIESAndrea MorandiCluster scaling relations from Chandra, Planck and SDSS
20900338EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYSMichael KossRedshifting z<0.3 AGN into the Chandra Deep Fields To Understand Black Hole Growth
Subject Category: STARS AND WD

Proposal Number: 20200070

Title: A new coronal diagnostic using a photopumped X-ray line

PI Name: Damian Christian

There are many examples of line coincidence photopumping in astrophysics at optical and UV wavelengths, such as Bowen fluorescence, but none to our knowledge at X-rays. We have identified a scheme where He-like Ne IX is photopumped by H-like Na X, which predicts intensity enhancement in the Ne IX 82.76 A line. A comparison of our models with a solar flare spectrum reveals line enhancement, with good agreement between theory and observation. We now propose to extend the work to measure 82.76 A line enhancements in a selected sample of stellar coronae. The degree of line enhancement provides a powerful new diagnostic for accurately measuring flare loop pathlengths, which combined with flare models will also allow the determination of other flare parameters, such as magnetic field strength.

 Subject Category: STARS AND WD

Proposal Number: 20200135

Title: Superflares from Pre-Main Sequence Stars

PI Name: Eric Feigelson

Solar-type stars exhibit their highest levels of magnetic activity during their early convective pre-main sequence (PMS) phase of evolution. The most powerful individual X-ray flares, superflares, have peak luminosities of log(Lx)=31-33 erg/s and total energies log(Ex)=35-36 erg. The Chandra archive MYStIX and SFiNCs surveys have identified 32,500 PMS stars in nearby star forming regions from this X-ray emission. We propose here the identification and analysis of a *complete* sample of X-ray superflares from an underlying population of 150,000 PMS stars in these surveys. Science goals include: comparing giant single loop vs. loop arcade models; comparing to optical band superflares; comparing to flares on the contemporary Sun; and implications for early planetary atmospheres.

 Subject Category: BH AND NS BINARIES

Proposal Number: 20400452

Title: Mapping the clumpy stellar wind in a sample of high-mass X-ray binaries

PI Name: Natalie Hell

We recently demonstrated that orbital-phase and hardness-resolved high-resolution spectroscopy allows us to identify and characterize individual components of the multi-phase stellar wind, consisting of cold dense material embedded in hot tenuous gas, in high-mass X-ray binaries (HMXBs) and map the wind structure (Grinberg, Hell, et al., 2017). We propose to conduct this analysis consistently on a sample of wind-fed HMXBs, using archival Chandra-HETGS observations. By comparing the results between the systems, we will for the first time systematically study the effect of binary geometry and donor type onto differences in wind structure.

 Subject Category: SN, SNR AND ISOLATED NS

Proposal Number: 20500446

Title: The X-ray Hot Spots of SN 1987A

PI Name: Vinay Kashyap

We propose to carry out a reanalysis of archival Chandra observations of SN1987A to track the spatial and spectral evolution of X-ray hotspots. We have developed a powerful image reconstruction algorithm that makes it feasible to compare Chandra images with Hubble features at the 0.1" scale. The analysis will enable the study of the physics of the interaction of the interstellar medium with the supernova blast wave in unprecedented detail. We will derive density and thermal characteristics of the clumps in the equatorial ring around SN1987A, and set strong constraints on theoretical models of the evolution of the remnant. We will improve the reconstruction algorithm to compute the extents of the hotspots, and determine their spectral characteristics at high spatial resolution.

 Subject Category: SN, SNR AND ISOLATED NS

Proposal Number: 20500688

Title: Discovering compact objects in intermediate age clusters

PI Name: Oleg Kargaltsev

We propose a systematic search for compact objects (COs) in the fields of 11 nearby open clusters with ages between 5 and 400 Myrs observed with ACIS-I. This range of ages represents a sweet spot for finding and studying COs either isolated or in binaries. We expect to be able to reach limiting luminosities of 10^{29}-10^{30} erg/s for selected clusters. Our search will be aided by the existing automated classification tool which relies on supervised learning from a training sample of ~9,000 sources of known types and by sensitive optical/NIR survey data (and dedicated archival deep observations) which only recently became available for the selected clusters. We will learn more about the X-ray faint end of the CO population which is typically undetectable in other environments.

 Subject Category: NORMAL GALAXIES: DIFFUSE EMISSION

Proposal Number: 20610246

Title: Hot circum-galactic medium as a legacy of Chandra archive

PI Name: Jiang-Tao Li

In the past two decades, Chandra has formed a rich X-ray archive of nearby galaxy halos before ACIS has degraded significantly. Most of these observations are not deep enough for the study of the extended CGM, which plays a key role in the co-evolution of galaxies and their environment. We propose stacking analysis of a large galaxy sample selected from the Chandra archive to detect the hot CGM beyond the inner halo highly disturbed by feedback. We will examine if the radial distribution of hot gas can be characterized with any universal relations. We will estimate the mass of the hot CGM and compare the baryon budget of galaxies in different subsamples. We will also measure the cooling rate of the CGM and examine if it can be an important source of gas supply to continuue star formation.

 Subject Category: NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 20620227

Title: Building the Largest Catalogue of Intermediate Redshift ULXs: Evolution out to z=0.3

PI Name: Scott Barrows

We propose a Chandra archival research project to build the largest catalog of intermediate redshift (z<0.3) ultra-luminous X-ray sources (ULXs). We will accomplish this by using our astrometric procedure that is optimized for registering Chandra/ACIS datasets with optical imaging, allowing us to resolve offset X-ray sources down to sub-arcsecond angular separations. Based on our pilot study, this project will increase the known number of intermediate redshift ULXs by a factor of over 30, and we will publish it for broad use by the community. As demonstrated by our preliminary results, analysis of this uniformly selected sample will permit an understanding of how the ULX population evolves out to z=0.3 and thus a deeper knowledge of their formation mechanisms and physical nature.

 Subject Category: NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 20620295

Title: A PHYSICAL PARAMETERIZATION OF THE EVOLVING X-RAY EMISSION FROM NORMAL GALAXIES OBSERVED IN THE CHANDRA DEEP FIELDS

PI Name: Bret Lehmer

In the Chandra Deep Field-South, we recently found that the LMXB luminosity per stellar mass (LX/M*) and HMXB luminosity per SFR (LX/SFR) evolve with redshift as LX/M* ~ (1+z)^2-3 and LX/SFR ~ (1+z). However, when extrapolated to higher redshifts, these relations overpredict LX and do not convey how global changes stellar age and metallicity likely drive the evolution of the scaling relations. In this archival proposal, we will use ultradeep Chandra and multiwavelength data in the GOODS North and South regions, and a new decomposition technique, to derive how X-ray emission evolves as a function of age for a range of metallicities, and will provide a new physically-motivated empirical parameterization for how the X-ray emission of various galaxy populations evolve with redshift.

 Subject Category: NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 20620472

Title: A Systematic Analysis on M31* X-ray Variability with 3 Ms of Chandra Data from 1999 to 2016

PI Name: Shuo Zhang

Supermassive black holes (SMBHs) in galactic nuclei in the local universe are remarkably underluminous. M31*, located in the nucleus of Andromeda, is only the second underluminous SMBH (after Sgr A*) to show recurrent X-ray faring activity. After a major outburst in early 2006, M31* entered an active stage with frequent X-ray flares. There have been a total of 3 Ms of Chandra data accumulated for M31*. However, this rich dataset has not been adequately explored to search for and characterize M31* flares. Due to the lack of a systematic study, little is known about M31*'s flare characteristics. We thus propose a first systematic analysis of M31* X-ray variability using all Chandra data obtained from 1999 to 2016, enabling a first comparison to the variability characteristics of Sgr A*.

 Subject Category: NORMAL GALAXIES: X-RAY POPULATIONS

Proposal Number: 20620582

Title: Calibrating the Lx-SFR relation in starbursts at ``Cosmic Noon'

PI Name: Matthew Malkan

We will measure Lx/SFR for 1500 HST emission-line galaxies,at z=0.5-2-the epoch of Cosmic Noon. Some are extreme primitive dwarf starbursts,of the type which reionized the IGM. In 5 deep Chandra fields, they have measured gas metallicities,stellar masses,star formation rates and sizes (SFR density). Careful stacking (in soft and hard-X bands) will show how Lx/SFR depends on metallicity, extending this empirical relation to low metals and low mass/high SFR at early cosmic epochs.We will check for influence on the X-ray emission from the intensity of star formation, measured as a ratio of SFR to stellar mass,or by SFR surface density.We will separate out the possible X-ray emission from AGN components, to measure Lx from pure star formation.CSTACK tests on 9% of our sample prove feasibility.

 Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 20700644

Title: Understanding AGN Warm Absorbers: A systematic Correlation Analysis of Physical Properties

PI Name: Keigo Fukumura

We propose to investigate variable nature of the observed X-ray warm absorbers (WAs) from an archival sample of 6 radio-quiet Seyfert AGNs by analyzing potential correlations among X-ray property, absorber's velocity (v_out) and equivalent width (EW), as recently suggested in some ultra-fast outflows (UFOs). Distinct from the past phenomenological studies, our approach is physically motivated in the context of the MHD-driven disk-wind model involving the wind density profile and geometry, which can probe the underlying physical mechanisms responsible for such putative WA correlations by utilizing strong lines (e.g. Al xiii, Mg xii, Si xiv and S xvi). Our sources have been observed over many Chandra cycles as appropriate for identifying and studying WA variability over multi-epochs.

 Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 20800092

Title: Looking for (cluster) relaxation? Try the SPA.

PI Name: Adam Mantz

We propose a morphological study of some 650 galaxy clusters, updating and expanding a study of 361 clusters previously published by our team. Our methods are tailored to provide a fair basis for comparing clusters across all redshifts, despite e.g. variations in data quality and image coverage. We will identify highly dynamically relaxed clusters suitable for cosmological tests based on the universal gas mass fraction for massive clusters, and will make the associated cosmological measurements for these clusters. We will explore how cool cores and merger rates vary with redshift, halo mass, and sample selection (e.g. X-ray vs Sunyaev-Zel'dovich); and relationships among X-ray morphologies, scatter from average cluster scaling relations, and AGN triggering in cluster galaxies.

 Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 20800178

Title: The eHIFLUGCS galaxy cluster sample

PI Name: Gerrit Schellenberger

Statistically complete, representative X-ray selected samples of galaxy clusters are essential for many applications, such as, cosmological studies, quantitative analyses of the cool-core fractions, central AGN activity, and even instrumental cross calibration. We will analyze the data of eHIFLUGCS, currently the largest complete X-ray selected cluster sample. We have already analyzed several subsamples, such as the HIFLUGCS and most of the clusters with only XMM observations. We now propose to analyze the archival Chandra data of 85 clusters. Our first priority will be a cosmological study using the individually determined total masses of all clusters. Furthermore, we will investigate the cool-core properties, radio emission of the central AGNs and cross calibration issues.

 Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 20800429

Title: Cluster scaling relations from Chandra, Planck and SDSS

PI Name: Andrea Morandi

We propose to combine Planck-SZ and SDSS-redMaPPer data with the Chandra archival data of 180 clusters to investigate X-ray/SZ/optical scaling relations. We compare directly the pressure content from X-ray with the SZ flux to infer the Y_X-Y_SZ relation. We then transfer the Y_X-M mass calibration from Chandra and optical richness - mass relation from redMaPPer to the Y_SZ-M relation (covariance corrected), obtaining Chandra and SDSS based mass calibrations. The latter relations can be thus compared with the Y_SZ-M Planck relation. This allows us to investigate the impact of systematics on the mass calibration for the Planck SZ data, and their ramifications on the cosmological parameters. We will also examine other important scaling relations on the ICM.

 Subject Category: EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 20900338

Title: Redshifting z<0.3 AGN into the Chandra Deep Fields To Understand Black Hole Growth

PI Name: Michael Koss

Over its lifetime Chandra has observed >30 extragalactic survey fields at depths between 100 ks to 7 Ms that cumulatively add up to several several years of observations to resolve most of the cosmic X-ray background. These surveys however, remain highly biased against heavily obscured AGN. We will use a sample of 639 unbeamed Swift BAT detected with high quality X-ray spectra from 0.5-200 keV from the BASS Survey, to create a set of X-ray spectral templates over the range of interesting redshifts (z=1-2), to predict what the Chandra AGN spectra should be, to correct for known or suspected biases and search for evolutionary effects. These measurements will contribute to the enduring legacy of these deep fields and their ability to understand black hole growth across cosmic time.