A5013819540- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Astronomical Observations and Instrumentation
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Crystal Structures and Properties
- Solidification and crystal growth phenomena
- Material Science and Thermodynamics
- Theoretical and Computational Physics
- Geophysics and Gravity Measurements
- Radiation Detection and Scintillator Technologies
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Quasicrystal Structures and Properties
- Spectroscopy and Laser Applications
- Advanced NMR Techniques and Applications
Northwestern University
2018-2024
Northwestern University
2021
Pennsylvania State University
2015-2017
Purdue University West Lafayette
2009-2013
Updated imaging and photometric results from Chandra observations of SN 1987A, covering the last 16 years, are presented. We find that 0.5-2 keV light curve has remained constant at ~8x10^-12 erg s^-1 cm^-2 since 9500 days, with 3-8 continuing to increase until least 10000 days. The expansion rate ring is found be energy dependent, such after day 6000 expands faster in 2-10 band than it does energies <2 keV. Images show a reversal east-west asymmetry between 7000 8000 days explosion. latest...
Abstract Based on our Chandra imaging-spectroscopic observations, we present the latest evolution of X-ray remnant SN 1987A. Recent changes in electron temperatures and volume emission measures suggest that blast wave 1987A is moving out dense inner ring structure, also called equatorial (ER). The 0.5–2.0 keV light curve shows a linearly declining trend (by ∼4.5% yr −1 ) between 2016 2020 as heats hitherto unknown circumstellar medium (CSM) outside ER. While peak 0.3–8.0 image still within...
We examine deep XMM-Newton Reflection Grating Spectrometer (RGS) spectra from the cores of three X-ray bright cool core galaxy clusters, Abell 262, 3581 and HCG 62. Each RGS show Fe XVII emission lines indicating presence gas around 0.5 keV. There is no evidence for O VII which would imply at still cooler temperatures. The range in detected temperature these objects a factor 3.7, 5.6 2 62, respectively. coolest only has volume filling fraction 6 3 per cent 262 3581, but likely to be Chandra...
Abstract Despite more than 30 years of searching, the compact object in Supernova (SN) 1987A has not yet been detected. We present new limits on SN using millimeter, near-infrared, optical, ultraviolet, and X-ray observations from ALMA, VLT, HST , Chandra . The are approximately 0.1 mJy ( <?CDATA $0.1\times {10}^{-26}$?> erg s −1 cm −2 Hz ) at 213 GHz, 1 L ⊙ $6\times {10}^{-29}$?> optical if our line sight is free ejecta dust, 10 36 $2\times {10}^{-30}$?> 2–10 keV X-rays. Our an order...
We measure the intracluster medium temperature distributions for 62 galaxy clusters in HI-FLUGCS, an X-ray flux-limited sample, with available data from XMM-Newton.We search correlations between width of and other cluster properties, including median temperature, luminosity, size, presence a cool core, AGN activity, dynamical state.We use Markov Chain Monte Carlo analysis which models ICM as collection emitting smoothed particles plasma.Each particle is given its own set parameters, spatial...
Spitzer observations of SN 1987A have now spanned more than a decade. Since day ~4,000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6,000 to 8,000 days after explosion, included broadband photometry at 3.6 - 24 micron, and low moderate resolution spectroscopy 5 35 micron. Here we present later observations, through 10,377, which include only measurements 4.5 These data show micron brightness clearly begun fade ~8,500, no...
We analyze three Chandra observations, with a combined exposure time of 99 ks, the Galactic supernova remnant (SNR) RCW 103, young SNR, no previous clear detections metal-rich ejecta. Based on our imaging and spectral analyses these deep data, we find evidence for ejecta emission scattered throughout remnant. X-ray from shocked is generally weak, circumstellar medium (CSM) largely dominant component across entire The CSM shows abundances ∼0.5 solar, while Ne, Mg, Si, S, Fe are up to few...
Abstract Based on observations with the Chandra X-ray Observatory, we present latest spectral evolution of remnant SN 1987A (SNR 1987A). We a high-resolution spectroscopic analysis using our new deep (∼312 ks) HETG observation taken in 2018 March as well archival grating data 2004, 2007, and 2011 similarly exposures (∼170–350 ks). perform detailed model fits to quantify changing plasma conditions over last 14 yr. Recent changes electron temperatures volume-emission measures suggest that...
We present new Hubble Space Telescope images of high-velocity Hα and Lyα emission in the outer debris SN 1987 A. The are dominated by from hydrogen atoms crossing reverse shock (RS). For first time we observe RS surface well above below equatorial ring (ER), suggesting a bipolar or conical structure perpendicular to plane. Using imaging, measure mass flux front, velocity intervals (−7500 < Vobs −2800 km s−1) (1000 7500 s−1), = 1.2 × 10−3 M yr−1. also imaging whole remnant Chandra X-ray...
The centroid energy of the Fe K$\alpha$ line has been used to identify progenitors supernova remnants (SNRs). These investigations generally considered derived from spectrum entire remnant. Here we use {\it XMM-Newton} data investigate in 6 SNRs: 3C~397, N132D, W49B, DEM L71, 1E 0102.2-7219, and Kes 73. In 73 fail detect any emission. We report a tentative first detection emission SNR with consistent its Type Ia designation. remaining remnants, spatial spectral sensitivity is sufficient...
Supernova remnants (SNRs) are complex, three-dimensional objects; properly accounting for this complexity when modeling the resulting X-ray emission presents quite a challenge and makes it difficult to accurately characterize properties of full SNR volume. We apply first time novel analysis method called smoothed particle inference, which can be used study structure, dynamics, morphology, abundances entire remnant with single analysis. SNe Ia DEM L71. present histograms maps showing global...
We analyze the X-Ray emission from supernova remnant DEM L71 using Smoothed Particle Inference (SPI) technique. The high Fe abundance found appears to confirm Type Ia origin. Our method allows us separate material ejected in explosion swept-up by shock wave. are able calculate total mass of this be about 228 $\pm$ 23 M$_{\odot}$. plot posterior distribution for number density parameter, and create a map structure within remnant. While observed shows substantial variations, we find our...
W49B is a supernova remnant (SNR) discovered over 60 years ago in early radio surveys. It has since been observed the entire wavelength range, with X-ray morphology resembling centrally-filled SNR. The nature of its progenitor star still debated. Applying Smoothed Particle Inference techniques to analyze X-Ray emission from W49B, we characterize and abundance distribution remnant. We also infer density structure derive mass individual elements present plasma. consistent an interaction...
Based on our Chandra imaging-spectroscopic observations, we present the latest evolution of X-ray remnant SN 1987A. Recent changes in electron temperatures and volume emission measures suggest that blast wave 1987A is moving out dense inner ring structure, also called equatorial (ER). The 0.5-2.0 keV light curve shows a linearly declining trend (by $\sim$4.5 % yr$^{-1}$) between 2016 2020, as heats hitherto unknown circumstellar medium (CSM) outside ER. While peak 0.3-8.0 image still within...