Large Programs (AO5-AO7)

Number of Selected Programs 4 4 3
Total Time (Ms) 2.09 Ms 2.05 Ms 1.84 Ms

List of Large Programs:

Cen X-4

AO/Program Number: AO5/5220

Full Title: Revealing the Relation Between Hard and Soft Quiescent X-ray Spectra in in Cen X-4

PI - Institution: Michael Nowak - Massachusetts Institute of Technology

Total Exposure: 500 ks

Number of Target: 1

Primary Paper(s):

Other Information: Joint with NICER

Abstract: We propose a campaign of joint NuSTAR and NICER observations of the quiescent neutron star Cen X-4, to study the relationship between its soft X-ray flux level and its hard X-ray spectrum. The hard X-ray spectrum has been hypothesized to be due to thermal bremsstrahlung from active accretion onto the neutron star, and may transit to synchrotron emission at low flux. If the bremsstrahlung/active accretion hypothesis is correct, we should be able to measure spectral changes with our proposed campaign.

Black Hole Transient

AO/Program Number: AO5/5213

Full Title: Monitoring a Bright Outburst from a Black Hole Transient

PI - Institution: John Tomsick - University of California, Berkeley / Space Sciences Laboratory

Total Exposure: 500 ks

Number of Target: 1 (MAXI JO637-430)

Primary Paper(s): Lazar et al. (2021; ApJ, 921, 155)

Other Information:

Abstract: Much of our understanding of the properties of accretion disks, relativistic jets, and the regions of strong gravity near black holes (BHs) come from observations of BH X-ray binaries. NuSTAR has made significant contributions to these studies especially through improved measurements of reflection components that have allowed us to access the inner disk and constrain the spins of BHs. Recently, comparisons between BH spins in X-ray binaries and in binary BH mergers have further increased the level of interest in BH spins, and a main focus of this proposal is to improve assessments of the uncertainties in BH spin measurements. We propose to do this by monitoring a bright BH transient with NuSTAR to systematically quantify the effect of the changing continuum on the BH spin measurement.

CT-AGN in the NuSTAR Era

AO/Program Number: AO5/5197

Full Title: The Compton-Thick AGN Legacy Project: A Complete Sample of NuSTAR-Observed Nearby Compton-Thick AGN

PI - Institution: Stefano Marchesi - Clemson University

Total Exposure: 500 ks

Number of Target: 10

Primary Paper(s): Torres-Albà et al. (2021; ApJ, 922, 252) + Traina et al. (2021; ApJ, 922, 159)

Other Information:

Abstract: The X-ray spectral analysis of Compton thick (CT-, i.e., having intrinsic obscuration NH>1E24 cm^-2) active galactic nuclei (AGN) is key to understand the physics of the obscuring material surrounding accreting supermassive black holes. We propose to target with a combined NuSTAR/XMM-Newton observation the last 10 candidate CT-AGN the BAT 100-month survey still lacking of NuSTAR data. With this proposal, each CT-AGN candidate of this sample will have a NuSTAR observation, thus enabling the best characterization to date of CT-AGN. Thanks to the excellent statistics (both in terms of spectral counts and sample size) we will study the sample physical properties, and put tighter constraints on the true intrinsic fraction of CT-AGN in the nearby Universe and on their contribution to the CXB.


AO/Program Number: AO5/5192 + AO6+AO7/6218

Full Title: AO5 - Deep NuSTAR Observations of the JWST-NEP Time Domain Field; AO6 - Deep NuSTAR Observations of the JWST-NEP Time Domain Field - Longterm Monitoring

PI - Institution: Francesca Civano - Harvard/Smithsonian Center for Astrophysics

Total Exposure: 585 ks + 780 ks + 195 ks (re-observation of XMM data lost to proton flaring)

Number of Target: 1

Primary Paper(s): Zhao et al. (2021; MNRAS, 508, 5176)

Other Information: Joint with XMM

Abstract: AO5 - The JWST Deep Time-Domain Field in the north ecliptic pole (NEP DTDF) is a GTO target that will have continuous visibility and excellent 8-band deep (m~28) imaging and grism spectra in the NIR by JWST. In the past few years, the NEP DTDF has grown into a comprehensive survey with deep radio to X-ray data, becoming the most promising new field for extragalactic studies and time-domain investigations. We propose to perform a 585 ks NuSTAR survey in this field, reaching a sensitivity comparable to the deepest NuSTAR extragalactic surveys, detecting 20-30 sources in 3-24 keV, to focus on: X-ray variability (3-8 keV monitoring and the first 8-24 keV studies!), the true obscured AGN fraction, 0.5-24 keV spectroscopy combining NuSTAR and Chandra, and the bright NLSy1 in the field.


AO/Program Number: AO6/6044

Full Title: Building Subways: The NuSTAR Line

PI - Institution: Stefano Bianchi - Università degli Studi Roma Tre

Total Exposure: 610 ks

Number of Target: 19

Primary Paper(s):

Other Information: Coordinated with XMM and HST

Abstract: A Large Program (1.58 Ms) has been granted in XMM-Newton AO18 and 27 orbits have been awarded in HST Cycle 27 to study Supermassive Black Hole Winds in X-rays (SUBWAYS), designed to provide direct support on feedback models by deriving constraints on the energetics and duty cycle of Ultra-Fast Outflows (UFOs) in Active Galactic Nuclei. We ask now for NuSTAR observations of the 20 SUBWAYS sources (630 ks) without archival NuSTAR data. The availability of NuSTAR data above 10 keV is crucial for the objectives of SUBWAYS, and will maximise the outcome of this ambitious Large Program. The proposed observations represent a fundamental step to maintain NuSTAR science upfront during the next decade in the physically motivated investigation of multi-phase outflows.

Galaxy Clusters

AO/Program Number: AO6/6109

Full Title: Accurate Galaxy Cluster Temperatures: A Legacy Dataset with Chandra, XMM, and XRISM

PI - Institution: Daniel Wilk - University of Utah

Total Exposure: 604 ks

Number of Target: 4 (Abell 2029, Abell 478, Abell 1795, Abell 2199)

Primary Paper(s):

Other Information:

Abstract: Galaxy clusters are the most massive virialized objects in the universe, and their growth over cosmic time is sensitive to the underlying cosmology. Cluster cosmology requires accurate mass measurements, which generally depend on temperature measurements. Unfortunately, the main sources for X-ray temperatures are Chandra and XMM, which systematically disagree with each other. The hard band sensitivity of NuSTAR, however, has the potential to resolve this discrepancy and reduce the error budget on cluster-derived cosmological parameters. We propose deep observations of 4 low redshift, relaxed clusters, with extensive XMM and Chandra (and future XRISM) data, where both calibration and physical differences can be assessed in the simplest possible systems.

Pulsar Wind Nebulae

AO/Program Number: AO6/6224

Full Title: NuSTAR Hard X-ray Survey of Pulsar Wind Nebulae in Synergy with TeV Gamma-Ray Telescopes

PI - Institution: Kaya Mori - Columbia University

Total Exposure: 450 ks

Number of Target: 7

Primary Paper(s): Mori et al. (2021; PoS, submitted - arXiv:2108.00557)

Other Information:

Abstract: The proposal seeks a unique opportunity to collect legacy NuSTAR data and explore pulsar wind nebula (PWN) astrophysics at the deepest level through multi-wavelength SEDs, in synergy with the existing and near-future TeV gamma-ray telescopes. NuSTAR observations of 8 additional PWNe will complete the sampling of all 22 TeV-PWNe detectable by NuSTAR. Our targets includes PWNe detected by HAWC above 50 TeV, PWNe crushed by reverse SNR shocks, a young PWN in the Galactic Center and the archetype Vela nebula. Some of the nebulae may contain a hadronic outflow which produces TeV gamma-rays via interacting with the ISM or dense clouds. NuSTAR can probe sub-PeV electron populations through X-ray synchrotron spectra and allow us to perform spectro-imaging studies of PWNe above 10 keV.

1H 1934-063

AO/Program Number: AO7/7084

Full Title: A Deep Spectral-Timing Study of the X-ray Bright AGN 1H 1934-063

PI - Institution: Andrew Fabian - Cambridge University

Total Exposure: 500 ks

Number of Target: 1

Primary Paper(s):

Other Information:

Abstract: NuSTAR can make a transformational advance in our understanding of how luminous accreting black holes work through long observations of rapidly- variable, X-ray-bright AGN. This enables X-ray reverberation studies, already a commonplace feature of AGN, to proceed to the next level and follow the behavior of the powerful dynamic corona and map the accretion flow immediately next to the black hole, measuring both spin and mass of the black hole. We propose a 500ks NuSTAR observation of the X-ray brightest high variability NLS1 AGN 1H1934-063, with 260ks of XMM, to measure relativistic reflection and reverberation in 3 flux states.

Starburst Galaxies

AO/Program Number: AO7/7103

Full Title: The Birth of Black Holes and Neutron Stars in Starbursts: A Legacy for NuSTAR Building on an HST Treasury Program

PI - Institution: Ann Hornschemeier - NASA Goddard Space Flight Center

Total Exposure: 742 ks

Number of Target: 3 (NGC 4656, NGC 4449, NGC 4490)

Primary Paper(s):

Other Information:

Abstract: Understanding the emission from X-ray binaries in high-redshift galaxies is of utmost importance to understanding the heating of the primordial IGM. This program, to observe five starbursting, High Mass X-ray Binary (HMXB)-dominated galaxies, for a total of 1.49 Ms with NuSTAR and 207 ks with XMM- Newton, will provide a representative sample of starburst galaxies for establishing the connection between the 12-25~keV emission arising from neutron star and black hole populations and their host galaxy properties that is highly relevant to high-z galaxies. We will double the number of HMXB-dominated galaxies with measured 0.5-30~keV Spectral Energy Distributions, so we may correctly interpret high-z galaxies' X-ray emission where we only sample the rest-frame hard X-ray emission.

SNR G1.9+0.3

AO/Program Number: AO7/7117

Full Title: Monitoring the Hard X-ray Evolution of the Young Supernova Remnant G1.9+0.3 and Improving the NuSTAR Upper Limits of its 44-Ti Emission

PI - Institution: Andreas Zoglauer – University of California, Berkeley / Space Sciences Laboratory

Total Exposure: 600 ks

Number of Target: 1

Primary Paper(s):

Other Information:

Abstract: With an age of roughly 110 years, G1.9+0.3 is the youngest known supernova remnant in the Milky Way. It is also one of the few remnants in our Galaxy whose evolution we can monitor and which show evidence for emission from the 44-Ti decay chain. We propose to observe G1.9+0.3 for 600 ks. This will allow us to identify changes of spectrum, flux, and morphology between the original NuSTAR observation from 2013 and now in the hard X-ray band. In addition, this observation will significantly improve the upper limits of the 44-Ti emission, and deeply probe the uncertainty range of a potential detection of 44-Ti by Chandra, and, in the case emission is confirmed, enable its characterization. With its unique hard X-ray capabilities, only NuSTAR can carry out these observations.