D. McCammon
A5043868154- Superconducting and THz Device Technology
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Molecular Physics
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- Physics of Superconductivity and Magnetism
- Superconducting Materials and Applications
- Thermal Radiation and Cooling Technologies
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- Nuclear Physics and Applications
- Stellar, planetary, and galactic studies
- Dark Matter and Cosmic Phenomena
- Advanced Thermodynamic Systems and Engines
- Advanced Thermodynamics and Statistical Mechanics
- Advanced X-ray Imaging Techniques
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Particle accelerators and beam dynamics
- Advanced Thermoelectric Materials and Devices
- Pulsars and Gravitational Waves Research
University of Wisconsin–Madison
2016-2025
University of Maryland, Baltimore County
2024
Goddard Space Flight Center
1991-2024
Leibniz Association
2024
Tokyo University of Science
2024
Japan Aerospace Exploration Agency
2010-2024
Institute of Space and Astronautical Science
2024
Tokyo Metropolitan University
2007-2022
Northwestern University
2020-2022
Technical Institute of Physics and Chemistry
2020
view Abstract Citations (2212) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Interstellar photoelectric absorption cross sections, 0.03-10 keV. Morrison, R. ; McCammon, D. An effective section per hydrogen atom has been calculated as a function of energy in the keV range using most recent atomic and cosmic abundance data. Coefficients piecewise polynomial fit to numerical results are given allow convenient application automated calculations....
High-sensitivity wide-band X-ray spectroscopy is the key feature of Suzaku observatory, launched on 2005 July 10. This paper summarizes spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, high-throughput telescopes, CCD cameras, non-imaging hard detector also described.
view Abstract Citations (685) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Photoelectric Absorption Cross Sections with Variable Abundances Balucinska-Church, Monika ; McCammon, Dan Polynomial fit coefficients have been obtained for the energy dependences of photoelectric absorption cross sections 17 astrophysically important elements. These results allow calculation X-ray in range 0.03-10 keV material noncosmic abundances. Publication: The...
This paper presents new maps of the soft X-ray background from ROSAT all-sky survey. These represent a significant improvement over previous version in that (1) position resolution PSPC has been used to improve angular ~2° 12', (2) there are six energy bands divide each three into two parts, and (3) contributions point sources have removed uniform source flux level most sky. will be available electronic format later 1997.
We show that sensitive thermal detectors should be useful for measuring very small energy pulses, such as those produced by the absorption of x-ray photons. The measurement uncertainty can small, making technique promising high resolution nondispersive spectroscopy. derive limits to detectors. use these find expected a detector suitable spectroscopy in 100–10 000 eV range. If there is no noise thermalization x-ray, better than 1 full width at half maximum (FWHM) possible operating 0.1 K....
A high spectral resolution observation of the diffuse X-ray background in 60-1000 eV energy range has been made using an array 36 1 mm2 microcalorimeters flown on a sounding rocket. Detector ranged from 5 to 12 FWHM, and composite spectrum ~1 sr centered at l = 90°, b +60° was obtained with net ~9 eV. The target area includes bright keV regions but avoids Loop I North Polar Spur. Lines C VI, O VII, VIII are clearly detected intensities 5.4 ± 2.3, 4.8 0.8, 1.6 0.4 photons cm-2 s-1 sr-1,...
view Abstract Citations (376) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Analysis Procedures for ROSAT XRT/PSPC Observations of Extended Objects and the Diffuse Background Snowden, S. L. ; McCammon, D. Burrows, N. Mendenhall, J. A. Proper reduction observations extended sources or diffuse background requires techniques that are quite different from standard point-source analysis. We describe in detail an appropriate set procedures this...
We apply a wind model, driven by combined cosmic-ray and thermal-gas pressure, to the Milky Way, show that observed Galactic diffuse soft X-ray emission can be better explained than previous static gas models. find pressure is essential driving wind. Having thus defined "best-fit" model for wind, we explore variations in base parameters how wind's properties vary with changes density. demonstrate importance of cosmic rays launching winds, effect have on dynamics. In addition, this adds...
view Abstract Citations (270) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS First Maps of the Soft X-Ray Diffuse Background from ROSAT XRT/PSPC All-Sky Survey Snowden, S. L. ; Freyberg, M. J. Plucinsky, P. Schmitt, H. Truemper, Voges, W. Edgar, R. McCammon, D. Sanders, T. This paper presents an initial version diffuse background results ROSA T soft X-ray all-sky survey. These maps cover ∼98% sky in ¼ keV, ¾ and 1.5 keV bands, with ∼2°...
view Abstract Citations (311) References (73) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The soft X-ray diffuse background. McCammon, D. ; Burrows, N. Sanders, W. T. Kraushaar, L. Maps of the background intensity covering essentially entire sky with approximately 7 deg spatial resolution are presented for seven energy bands. data were obtained on a series ten sounding rocket flights conducted over seven-year period. different nature distributions in...
My life has been an interesting voyage. I became astronomer because could not imagine living on Earth and trying to understand how the Universe works. scientific career revolved around observing motions of stars within galaxies ...Read More
view Abstract Citations (250) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Structure of Galactic H i in Directions Low Total Column Density Lockman, F. J. ; Jahoda, K. McCammon, D. A detailed 21 cm study areas that have the smallest known amount HI northern sky was performed. These observations were corrected for stray radiation. region main interest, around alpha = 10(h)45(m), delta 57 deg 20 arcmin, has a minimum N(HI) 4.5 x 10 to...
Abstract We report an apparent detection of the C VI 4p to 1s transition line at 459 eV, during a long-term enhancement (LTE) in Suzaku north ecliptic pole observation 2005 September 2. The observed intensity is comparable that 2p 367 eV. This strong evidence for charge-exchange process. In addition, O VII, VIII, Ne X, and Mg XI lines showed clear enhancements. There are also features 750–900–eV range could be due some combination Fe L lines, higher order transitions VIII (3p 6p 1s), IX...
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by Institute Space and Astronautical Science (ISAS). will investigate physics high-energy universe performing high-resolution, high-throughput spectroscopy with moderate angular resolution. covers very wide energy range from 0.3 keV to 600 keV. allows combination band (5-80 keV) provided multilayer coating, focusing hard mirrors imaging detectors, high energy-resolution soft (0.3-12...
The ASTRO-H mission was designed and developed through an international collaboration of JAXA, NASA, ESA, the CSA. It successfully launched on February 17, 2016, then named Hitomi. During in-orbit verification phase, on-board observational instruments functioned as expected. intricate coolant refrigeration systems for soft X-ray spectrometer (SXS, a quantum micro-calorimeter) imager (SXI, CCD) also However, March 26, operations were prematurely terminated by series abnormal events mishaps...
Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine atmospheric gas motions within central 100~kpc of Perseus cluster using observations obtained with satellite. After correcting for point spread function telescope and optically thin emission lines, find that line-of-sight velocity dispersion hot is remarkably low mostly uniform. The reaches maxima approximately 200~km~s$^{-1}$ toward active galactic nucleus (AGN) AGN inflated...
The Hitomi SXS spectrum of the Perseus cluster, with $\sim$5 eV resolution in 2-9 keV band, offers an unprecedented benchmark atomic modeling and database for hot collisional plasmas. It reveals both successes challenges current codes. latest versions AtomDB/APEC (3.0.8), SPEX (3.03.00), CHIANTI (8.0) all provide reasonable fits to broad-band spectrum, are close agreement on best-fit temperature, emission measure, abundances a few elements such as Ni. For Fe abundance, APEC measurements...
We present the overall design and performance of Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array x-ray microcalorimeters at focus grazing-incidence mirror Telescope (SXT) for high-resolution spectroscopy celestial sources. was designed to achieve an energy resolution better than 7 eV over 0.3-12 keV range operate more 3 years in orbit. actual is 4-5 as demonstrated during extensive ground testing prior launch measured mass flow rate liquid helium cryogen...
The Line Emission Mapper (LEM) is an X-ray Probe for the 2030s that will answer outstanding questions of Universe's structure formation. It also provide transformative new observing capabilities every area astrophysics, and to heliophysics planetary physics as well. LEM's main goal a comprehensive look at galaxy formation, including stellar black-hole feedback flows baryonic matter into out galaxies. These processes are best studied in X-rays, emission-line mapping pressing need this area....
view Abstract Citations (188) References (60) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Model for the Distribution of Material Generating Soft X-Ray Background Snowden, S. L. ; Cox, D. P. McCammon, Sanders, W. T. The observational evidence relating to soft X-ray diffuse background is discussed, and a simple model its source spatial structure presented. In this with one free parameter, observed 1/4 keV intensity originates as thermal emission from...
Abstract The X-Ray Spectrometer (XRS) has been designed to provide the Suzaku Observatory with non-dispersive, high-resolution X-ray spectroscopy. As designed, instrument covers energy range 0.3 12 keV, which encompasses most diagnostically rich part of band. sensor consists a 32-channel array microcalorimeters, each an resolution about 6 eV. very low temperature required for operation (60 mK) is provided by four-stage cooling system containing single-stage adiabatic demagnetization...
Abstract The soft diffuse X-ray emission of twelve fields observed with Suzaku are presented together two additional from previous analyses. All have galactic longitudes 65$^\circ $$\lt$$\ell$$\lt$ 295$^\circ $ to avoid contributions the very bright source that extends at least 30$^\circ Galactic center. surface brightnesses nine for which apparently uncontaminated ROSAT Sky Survey (RASS) were available statistically consistent RASS values, an upper limit differences 17 $\times$...