NASA Scientific and Technical Aerospace Reports

on small spatial scales which may correspond to structure in the underlying synchrotron nebula. Extrapolation of the
nonthermal emission component to gamma-ray energies yields a flux that is consistent with that of 2EG J0008+7307, thus
strengthening the proposition that there is a gamma-ray emitting pulsar at the center of CTA 1. Our timing studies with the
EPIC pn data revealed no evidence for pulsations, however; we set an upper limit of 61% on the pulsed fraction from this
source. The results from this study were presented.
Author
Polar Caps; Data Processing; Supernova Remnants; Neutron Stars
20040046911 Smithsonian Astrophysical Observatory, Cambridge, MA, USA
Laboratory Astrophysics using a Microcalorimeter and Bragg Crystal Spectrometer on an Electron Beam Ion Trap
Brinton, John C., Technical Monitor; Silver, Eric, et al.; March 2004; 3 pp.; In English
Contract(s)/Grant(s): NAG5-5362; No Copyright; Avail: CASI; A01, Hardcopy
During the past year we have been preparing our new microcalorimeter system for permanent delivery to the NIST EBIT.
Unfortunately, there have been delays due to technical difficulties in the fabrication of the two-stage adiabatic demagnetization
refrigerator and in the life expectancy of the thin windows used for internal thermal baffling of the infrared radiation. These
problems have been solved and we are completing tests of the entire system and it will be set up at NIST during the first week
of May. Several photos of the new system are shown in Figures 1A and 1B. This microcalorimeter spectrometer only requires
helium refills every three days (as opposed to every 24 hours) and it will hold a temperature! of 65 mK for up to 48 hours
(as opposed to 8 hours). Consequently, the efficiency of data acquisition will improve dramatically. In parallel we have
published a paper that reviews our previous work (Takacs et al. 2003), especially on Fe XVII, in the context of recent
measurements by other groups. This paper is included. We highlight a recent measurement of a broad band spectrum of Fe
in Figure 2 that simultaneously includes L and K radiation. It is compared with the simulated spectrum of the Perseus Cluster
that one could expect to obtain with a microcalorimeter in the focus of a grazing incidence telescope such as the one being
designed for Constellation X. Both the charge state distributions and the relative intensity ratios of the emission lines within
the particular charge state are very similar in the two spectra. This further demonstrates the importance and relevance of the
laboratory measurements in predicting the components of cosmic spectra.
Derived from text
Astrophysics; Bragg Angle; Calorimeters; Electron Beams; Spectrometers; Ion Beams
20040046915 Smithsonian Astrophysical Observatory, Cambridge, MA, USA
Over-Luminous Elliptical Galaxies
Mushotsky, Richard, Technical Monitor; Forman, William; March 2004; 2 pp.; In English
Contract(s)/Grant(s): NAG5-12931; No Copyright; Avail: CASI; A01, Hardcopy
We have completed a first draft of a paper on the galaxy group ESO3060170, the hottest known fossil group. We have
submitted a first draft of the paper but the final completion is delayed due to several issues mentioned by the referee that we
wish to revisit and discuss in more detail. The XMM data was combined with Chandra data which allowed a rich set of
projects. The paper discusses the north-south elongation which is similar to that of the central dominant galaxy as well as the
galaxy distribution. We detect an X-ray ‘finger’ or small tail emanating from the central galaxy to the north, suggesting motion
of the galaxy within the elongated gravitational potential. The overall agreement between XMM and Chandra data are
excellent (although the XMM data extend to larger radii). Both data sets show a cool core centered on the dominant galaxy.
Surprisingly, - the temperature maps and detailed spectra indicate that the finger of gas is NOT cool, but has the same
temperature as the ambient gas. We extracted surface brightness profiles, deprojected gas density profiles, cooling time
profiles, and entropy profiles. There is a sharp discontinuity in gas temperature where the surface brightness profile starts to
rise rapidly at 10 kpc. This produces a decrease in the cooling time and the gas entropy within 10 kpc. The central cooling
time (within 10 kpc) is less than 109 years and falls to almost half that value in the inner 5 kpc. Despite the very short cooling
time, we find no evidence (even with the excellent statistics from XMM-Newton) for multi-phased gas, i.e., a cooling flow.
We find two ‘edges’ associated with the gas distribution (common in peaked X-ray groups and galaxies). On large scales, the
temperature profile is flat and disagrees with the profile predicted by Loken et al. (2003) from detailed numerical simulations.
We studied the galaxy distribution within one virial radius. The galaxy concentration associated with the group is detectable
only within 0.3 of the virial radius (450 kpc) given the available depth of the optical galaxy catalogs at present. We have
derived total mass and gas mass distributions (from the X-ray data) and find the gas fraction approaches a constant 8% (for
H0 = 70).
Author
Elliptical Galaxies; Galactic Clusters; Luminosity; X Ray Astronomy
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