Steven E. Boggs
A5028255329- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Advanced Semiconductor Detectors and Materials
- Solar and Space Plasma Dynamics
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Astro and Planetary Science
- High-pressure geophysics and materials
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- CCD and CMOS Imaging Sensors
- Mechanics and Biomechanics Studies
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Radiation Therapy and Dosimetry
- Geophysics and Gravity Measurements
- Advanced X-ray Imaging Techniques
- Ionosphere and magnetosphere dynamics
- Particle Accelerators and Free-Electron Lasers
University of California, San Diego
2018-2025
University of California, Berkeley
2011-2023
Berkeley College
2009-2023
Clemson University
2023
University of Maryland, College Park
2023
Kavli Institute for Particle Astrophysics and Cosmology
2023
Stanford University
2023
Goddard Space Flight Center
2023
University of Würzburg
2023
Lawrence Berkeley National Laboratory
2017
The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates band from 3 to 79 keV, extending sensitivity of far beyond ∼10 keV cutoff achieved by all previous satellites. inherently low background associated with concentrating light enables probe hard sky a more than 100-fold improvement over collimated or coded mask instruments that have operated this bandpass. Using its unprecedented...
We report the discovery of 3.76 s pulsations from a new burst source near Sgr A* observed by NuSTAR observatory. The strong signal SGR J1745−29 presents complex pulse profile modulated with pulsed fraction 27% ± 3% in 3–10 keV band. Two observations spaced nine days apart yield spin-down rate =(6.5 1.4) × 10−12. This implies magnetic field B = 1.6 1014 G, power =5 1033 erg s−1, and characteristic age P/2 =9 103 yr for rotating dipole model. However, current may be erratic, especially during...
We report the results of a multi-band observing campaign on famous blazar 3C 279 conducted during phase increased activity from 2013 December to 2014 April, including first observations it with NuSTAR. The $\gamma$-ray emission source measured by Fermi-LAT showed multiple distinct flares reaching highest flux level in this object since beginning Fermi mission, $F(E > 100\,{\rm MeV})$ $10^{-5}$ photons cm$^{-2}$ s$^{-1}$, and doubling time scale as short 2 hours. spectrum one was very hard,...
The black hole binary Cygnus X-1 was observed in late-2012 with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage over ~1-300 keV range. source soft state a multi-temperature blackbody, power-law, reflection components along absorption from highly ionized material system. high throughput of NuSTAR allows for very quality measurement complex iron line region as well rest component. is clearly broadened well-described by relativistic blurring model, an...
We present 3-50 keV NuSTAR observations of the AGN Mrk 335 in a very low flux state. The spectrum is dominated by strong features at energies iron line 5-7 and Compton hump from 10-30 keV. source variable during observation, with variability concentrated energies, which suggesting either relativistic reflection or absorption scenario. In this work we focus on interpretation, making use new models that self consistently calculate fraction, blurring angle-dependent for different coronal...
Stellar metals shine toward our eyes only Taking a different look at familiar star may still yield surprises. Boggs et al. trained the x-ray vision of NuSTAR observatory on well-studied supernova 1987A. Core-collapse explosions such as SN 1987A produce titanium isotope, 44 Ti, whose radioactive decay yields hard emission lines. All associated with 44Ti appears to be from material moving us, none away. This implies that explosion was not symmetric. These findings help explain mechanics and...
We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and Suzaku observations of the X-ray binary Cygnus X-1 in hard state. This is first time this state has been observed Cyg with NuSTAR, which enables us to study reflection broadband spectra unprecedented detail. confirm that iron line cannot be fit a combination narrow lines absorption features, instead requiring relativistically blurred profile from companion wind. use models García et al. simultaneously measure black...
We present the results of NuSTAR and XMM-Newton observations two ultraluminous X-ray sources (ULX) NGC 1313 X-1 X-2. The combined spectral bandpass satellites enables us to produce first spectrum between 0.3 30 keV, while X-2 is not significantly detected by above 10 keV. data demonstrate that has a clear cutoff whose presence was only marginally detectable with previous observations. This rules out interpretation as black hole in standard low/hard state, it deeper than predicted for...
We present coordinated multiwavelength observations of the bright, nearby BL Lac object Mrk 421 taken in 2013 January-March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations instruments, providing data from radio to very-high-energy (VHE) gamma-ray bands. NuSTAR yielded previously unattainable sensitivity 3-79 keV range, revealing that spectrum softens when source is dimmer until X-ray spectral shape saturates into a steep power law with photon index...
The distribution of elements produced in the inner-most layers a supernova explosion is key diagnostic for studying collapse massive stars. Here we present results 2.4 Ms \textit{NuSTAR} observing campaign aimed at remnant Cassiopeia A (Cas A). We perform spatially-resolved spectroscopic analyses $^{44}$Ti ejecta which use to determine Doppler shift and thus three-dimensional (3D) velocities ejecta. find an initial mass 1.54 $\pm$ 0.21 $\times 10^{-4}$ M$_{\odot}$ has day average momentum...
We report on a NuSTAR and XMM-Newton program that has observed sample of three extremely luminous, heavily obscured WISE-selected AGN at z~2 in broad X-ray band (0.1 - 79 keV). The parent sample, selected to be faint or undetected the WISE 3.4um (W1) 4.6um (W2) bands but bright 12um (W3) 22um (W4), are rare, with only ~1000 so-called W1W2-dropouts across extragalactic sky. Optical spectroscopy reveals typical redshifts for this population, implying rest-frame mid-IR luminosities L(6um)~6e46...
We present results from the coordinated broadband X-ray observations of extreme ultraluminous source Holmberg IX X-1 performed by NuSTAR, XMM-Newton and Suzaku in late 2012. These provide first high-quality spectra above 10 keV to date, extending coverage this remarkable up ~30 keV. Broadband were undertaken at two epochs, between which exhibited both flux strong spectral variability, increasing luminosity Lx = (1.90+/-0.03)e40 erg/s (3.35+/-0.03)e40 erg/s. Neither epoch exhibits a spectrum...
The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity 200 keV 10 GeV energy range with wide field of view, good spectral resolution, polarization sensitivity. Therefore, key study astrophysical objects have unique signatures gamma-ray regime, such as neutron star mergers, supernovae, flaring active galactic nuclei....
We present the results of five NuSTAR observations type 2 active galactic nucleus (AGN) in IC 751, three which were performed simultaneously with XMM-Newton or Swift/XRT. find that nuclear X-ray source underwent a clear transition from Compton-thick ($N_{\rm\,H}\simeq 2\times 10^{24}\rm\,cm^{-2}$) to Compton-thin 4\times 10^{23}\rm\,cm^{-2}$) state on timescales $\lesssim 3$ months, makes 751 first changing-look AGN discovered by NuSTAR. Changes line-of-sight column density at $\sim2\sigma$...
We present NuSTAR observations of Vela X-1, a persistent, yet highly variable, neutron star high-mass X-ray binary (HMXB). Two were taken at similar orbital phases but separated by nearly year. They show very different 3-79 keV flux levels as well strong variability during each observation, covering almost one order magnitude in flux. These allow, for the first time ever, investigations on kilo-second time-scales how centroid energies cyclotron resonant scattering features (CRSFs) depend...
MCG−6-30-15, at a distance of 37 Mpc (z = 0.008), is the archetypical Seyfert 1 galaxy showing very broad Fe Kα emission. We present results from joint NuSTAR and XMM-Newton observational campaign that, for first time, allows sensitive, time-resolved spectral analysis 0.35 keV up to 80 keV. The strong variability source best explained in terms intrinsic X-ray flux variations context light-bending model: primary, variable emission reprocessed by accretion disk, which produces secondary, less...
We present a broad band spectral analysis of the joint XMM-Newton and NuSTAR observational campaign Narrow Line Seyfert 1 SWIFT J2127.4+5654, consisting 300 ks performed during three orbits. detect relativistic broadened iron K$\alpha$ line originating from innermost regions accretion disc surrounding central black hole, which we infer an intermediate spin $a$=$0.58^{+0.11}_{-0.17}$. The intrinsic spectrum is steep ($\Gamma=2.08\pm0.01$) as commonly found in galaxies, while cutoff energy...
We present high-energy (3–30 keV) NuSTAR observations of the nearest quasar, ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5–8 data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in large apertures previous non-focusing hard X-ray telescopes. full band (0.5–30 spectrum suggests active galactic nucleus (AGN) Mrk is absorbed by a patchy Compton-thin...
Some supernovae (SNe) may be powered by the interaction of SN ejecta with a large amount circumstellar matter (CSM). However, quantitative estimates CSM mass around such SNe are missing when material is optically thick. Specifically, current estimators sensitive to uncertainties regarding density profile and velocity. Here we outline method measure thick SNe. We present new visible-light X-ray observations 2010jl (PTF 10aaxf), including first detection an in hard band using NuSTAR. The total...
We present a spectral analysis of four coordinated NuSTAR+XMM-Newton observations the Seyfert galaxy NGC 1365. These exhibit an extreme level variability, which is primarily due to variable line-of-sight absorption, revealing relatively unobscured states in this source for first time. Despite diverse range absorption states, each displays same characteristic signatures relativistic reflection from inner accretion disk. Through time-resolved spectroscopy we find that strength iron line and...
We report on the results of spectral fits made to a NuSTAR observation black hole GRS 1915+105 in "plateau" state. This state is special interest because it similar "low/hard" seen other holes, especially that compact, steady jets are launched this phase. The 3-79 keV bandpass NuSTAR, and its ability obtain moderate-resolution spectra free from distortions such as photon pile-up, extremely well suited studies disk reflection X-ray binaries. In only 15 ks net exposure, an extraordinarily...