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NASA NTRS1990

Soft X-ray properties of Seyfert galaxies. I - Spectra

Results are presented from a study of soft X-ray spectra of 75 Seyfert galaxies observed by the Einstein Observatory IPC. The spectra in this sample (mostly high-luminosity Seyfert type 1s) are found to be consistent with a single power-law index alpha = 81. The AGN spectra observed with the IPC are compared with those from higher energy experiments, where AGN spectra have power law indices alpha = 0.7. It is found that the IPC spectra are systematically steeper than the HEAO 1 A-2 spectra of the same Seyfert galaxies, indicating a flattening toward higher energies.

Kruper, J. S.↗

NASA NTRS1992

QSO's to B less than 22 and the cosmic x ray background radiation: A fluctuations correlation approach

The contribution of faint Quasi Stellar Objects (QSO's) and other discrete sources to the cosmic X-Ray Background (XRB) is estimated using an optically selected QSO sample in SA 68.2 in conjunction with archived x-ray images from the Einstein Image Proportional Counter (IPC). A new generalization of the 'x-ray image stacking' technique is employed; this new approach tests for a positional 'correlation' between positive x-ray fluctuations in the IPC images, and the locations of the optically selected QSO's. Correlation with thirty SA 68.2 QSO's permits a highly sensitive measurement of the ensemble mean x-ray flux for QSO's with 19 less than B(sub J) less than 22. Although the IPC images are of modest depth, a limiting sensitivity 1.2 times 10 to the minus 14th power erg/sec/sq cm (0.3 to 3.5 keV) is effectively archieved comparable to that of the Rosat medium deep surveys.

Anderson, S. F.↗

NASA NTRS1993

An X-ray method for detecting substructure in galaxy clusters - Application to Perseus, A2256, Centaurus, Coma, and Sersic 40/6

We use the moments of the X-ray surface brightness distribution to constrain the dynamical state of a galaxy cluster. Using X-ray observations from the Einstein Observatory IPC, we measure the first moment FM, the ellipsoidal orientation angle, and the axial ratio at a sequence of radii in the cluster. We argue that a significant variation in the image centroid FM as a function of radius is evidence for a nonequilibrium feature in the intracluster medium (ICM) density distribution. In simple terms, centroid shifts indicate that the center of mass of the ICM varies with radius. This variation is a tracer of continuing dynamical evolution. For each cluster, we evaluate the significance of variations in the centroid of the IPC image by computing the same statistics on an ensemble of simulated cluster images. In producing these simulated images we include X-ray point source emission, telescope vignetting, Poisson noise, and characteristics of the IPC. Application of this new method to five Abell clusters reveals that the core of each one has significant substructure. In addition, we find significant variations in the orientation angle and the axial ratio for several of the clusters.

Mohr, Joseph J.↗

NASA NTRS1993

Model-based reasoning for power system management using KATE and the SSM/PMAD

The overall goal of this research effort has been the development of a software system which automates tasks related to monitoring and controlling electrical power distribution in spacecraft electrical power systems. The resulting software system is called the Intelligent Power Controller (IPC). The specific tasks performed by the IPC include continuous monitoring of the flow of power from a source to a set of loads, fast detection of anomalous behavior indicating a fault to one of the components of the distribution systems, generation of diagnosis (explanation) of anomalous behavior, isolation of faulty object from remainder of system, and maintenance of flow of power to critical loads and systems (e.g. life-support) despite fault conditions being present (recovery). The IPC system has evolved out of KATE (Knowledge-based Autonomous Test Engineer), developed at NASA-KSC. KATE consists of a set of software tools for developing and applying structure and behavior models to monitoring, diagnostic, and control applications.

Morris, Robert A.↗

NASA NTRS1994

Einstein x ray observations of the core of the Shapley Supercluster in northern Centaurus

We present Einstein x ray observations of the core of the Shapley Supercluster, one of the richest and densest known mass concentrations in the local (z less than 0.1) universe. We used Imaging Proportional Counter (IPC) observations supplemented with data from the Einstein Slew Survey to determine the locations and structure of mass concentrations in the region. An x ray map composed of IPC observations of the central (10 deg x 10 deg) region of the Shapley Supercluster is presented. We present evidence that the X-ray clusters observed within 5 deg of the core of the supercluster are on average brighter than those of corresponding richness class distributed throughout the sky. However, we measure no significant difference in the galaxy formation efficiency of these cluster of galaxies compared to other, more isolated clusters. We also find one previously uncataloged cluster-sized mass concentration in the core of the Shapley Supercluster. This new cluster, 'SC 1327-312', is relatively x ray bright (F(sub x) = 1.1 + or - 0.2 x 10(exp -11) erg sec(exp -1) cm(exp -2)) and L(sub x) = 1.1 + or - 0.2 x 10(exp 44) erg sec(exp -1) within 10 minutes, assuming z = 0.0477, H(sub 0) = 50, q(sub 0) = 0). As SC 1327-312 lies well within an Abell radius of the richness R = 4 cluster Shapley 8 (A3558), we suggest it may contribute to an artificially high galaxy count and richness classification for shapley 8. From slew data, we estimate an x ray luminosity for Shapley 8 which is just half the mean luminosity of the four other R = 4 clusters observed by the IPC, further suggesting the richness classification to be an overestimate.

Breen, Jeffrey↗

NASA NTRS1995

The faint X-ray sources in and out of omega Centauri: X-ray observations and optical identifications

We present the results of an observation of the globular cluster omega Cen (NGC 5139) with the Einstein high-resolution imager (HRI). Of the five low-luminosity X-ray sources toward omega Cen which were first identified with the Einstein imaging proportional counter (IPC) (Hertz and Grindlay 1983a, b), two are detected in the Einstein HRI observation: IPC sources A and D. These detections provide source positions accurate to 3 sec-4 sec; the positions are confirmed in a ROSAT HRI observation reported here. Using CCD photometry and spectroscopy, we have identified both sources as foreground dwarf M stars with emission lines (dMe). The chance projection of two Mde stars within approximately 13 min of the center of omega Cen is not extraordinary, given the space density of these stellar coronal X-ray sources. We discuss the possible nature of the three as yet unidentified IPC sources toward omega Cen, and consider the constraints that the Einstein observations place on the total population of X-ray sources in this cluster. The integrated luminosity from faint X-ray sources in omega Cen appears to be low relative to both the old open cluster M67 and the post-core-collapse globular, NGC 6397.

Cool, Adrienne M.↗

NASA NTRS2006

Thermal Cycle Reliability of PBGA/CCGA 717 I/Os

Status of thermal cycle test results for a nonfunctional daisy-chained peripheral ceramic column grid array (CCGA) and its plastic ball grid array (PBGA) version. both having 560 I/Os. were presented in last year's conference. Test results included environmental data for three different thermal cycle regimes (-55 C/125 C, -55 C/100 C, and -50 C /75 C). Update information on these - especially failure type for assemblies with high and low solder volumes-were presented. The thermal cycle test procedure followed those recommended IPC-9701 for tin-lead solder joint assemblies. Revision A of this specification covers guideline thermal cycle requirements for Pb-free solder joints. Some background information discussed during release of this specification with its current guideline recommendations were also presented. In a recent reliability investigation a fully populated CCGA with 717 I/Os was also considered for assembly reliability. evaluation. The functional package is a field-programmable gate array that has much higher processing power than its previous version. This new package is smaller in dimension, has no interposer, and has a thinner column wrapped with copper for reliability improvement. This paper will also present thermal cycle test results for this package assembly and its plastic version with 728 I/Os. both of which were exposed to three different cycle regimes. Two cycle profiles were those specified by IPC- 9701A for tin-lead, i.e. -55 to 100 C and -55 to 125 C and one was a cycle profile specified by Mil-Std-883, i.e.. -65 C/150 C which is generally used for ceramic hybrid packages. Per IPC-9701 A, test vehicles were built using daisy chain packages and were continuously monitored. The effects of many process and assembly variables-including corner staking commonly used for improving resistance to mechanical loading such as drop and vibration loads--were also considered as part of the test matrix. Optical photomicrographs were taken at various thermal cycle intervals to document damage progress and behavior. Representative samples of these along with cross-sectional photomicrographs at higher magnification taken by scanning electron microscopy (SEM) to determine crack propagation and failure analyses for packages are also presented.

staking↗

DOE OSTI2026

D$e^+e^-$ffusion: Capturing the Beam-Beam Physics of $e^+e^-$ Collisions with Diffusion Models

Beam-induced backgrounds at high-luminosity $e^+e^-$ colliders, such as the FCC-ee, are dominated by incoherent pair creation (IPC), and require computationally expensive simulations with dedicated Monte Carlo (MC) event generators. Reliable detector and machine-detector interface studies necessitate event samples that are several orders of magnitude larger than what is practically attainable with existing MC. To alleviate this bottleneck, we present D$e^+e^-$ffusion, a denoising diffusion probabilistic model that operates as a permutation-equivariant, set-valued surrogate for fast IPC simulation. Trained on a small GuineaPig++ sample, D$e^+e^-$ffusion faithfully reproduces the marginal and joint kinematic, angular, and positional distributions of all three IPC production processes. In addition, we assess the fidelity at the detector level by propagating both Geant4 and D$e^+e^-$ffusion events through a Geant4 simulation of the CLD vertex detector and by training a transformer-based two-sample classifier; the classifier achieves an area under the ROC curve of $0.553 \pm 0.016$. The trained model generates events nearly four orders of magnitude faster than Geant4, paving the way for a fast-simulation surrogate for FCC-ee design studies.

Chahine, Antonio [Imperial Coll., London]↗

DOE OSTI2026

Lightfall v0.0.1

Lightfall is a desktop application for synchrotron beamline instrument control, data acquisition, and live analysis at the Advanced Light Source (ALS). Built on Python and Qt, it provides a native graphical interface for operating beamline hardware, configuring and executing experimental scans, and visualizing results in real time. Key features include direct integration with EPICS control systems, a built-in electronic logbook, remote beamline access over secure tunnels, and an interprocess communication (IPC) architecture that coordinates with external analysis applications via ZMQ and EPICS process variables. This IPC approach allows Lightfall to orchestrate specialized analysis tools—including GPU-accelerated streaming correlators—without embedding them, avoiding the dependency conflicts common in monolithic scientific software platforms. Compared to prior approaches such as Xi-CAM's plugin-based architecture, Lightfall's design cleanly separates instrument control from domain-specific analysis, enabling feedback-driven acquisition where live analysis results can adjust scan parameters during an experiment. Its native Qt interface provides responsive performance for real-time data visualization that web-based alternatives struggle to match. Lightfall is designed for use by beamline scientists and staff operating synchrotron instruments at national user facilities.

Pandolfi, Ronald [Lawrence Berkeley National Labor↗

NASA NTRS1973

Integrated Propulsion Control System program.

Description of a three-year exploratory research program for the design, development, and flight evaluation of an Integrated Propulsion Control System (IPCS). The primary objectives of this program are to establish through flight test the potential improvements in steady-state and transient propulsion system performance that can be achieved as a direct result of new modes of control, more direct sensing of engine and inlet parameters, and the use of more sophisticated, high-speed digital computation. A F-111 E aircraft with the left inlet and engine modified to the IPCS configuration will be used to conduct the flight evaluation.

Bentz, C. E.↗

NASA NTRS1978

Propulsion/flight control integration technology (PROFIT) design analysis status

The propulsion flight control integration technology (PROFIT) program was designed to develop a flying testbed dedicated to controls research. The preliminary design, analysis, and feasibility studies conducted in support of the PROFIT program are reported. The PROFIT system was built around existing IPCS hardware. In order to achieve the desired system flexibility and capability, additional interfaces between the IPCS hardware and F-15 systems were required. The requirements for additions and modifications to the existing hardware were defined. Those interfaces involving the more significant changes were studied. The DCU memory expansion to 32K with flight qualified hardware was completed on a brassboard basis. The uplink interface breadboard and a brassboard of the central computer interface were also tested. Two preliminary designs and corresponding program plans are presented.

Carlin, C. M.↗

NASA NTRS1980

A soft X-ray halo around SU UMa

The dwarf nova SU UMa was observed with the imaging proportional counter (IPC) detector on the Einstein X-ray Observatory on 4 October 1979 at 4 h UT for about 3,000 s. An X-ray source was detected at the position of the star. It had a flux of 1.3 x 10 to -11th erg/sq cm s (0.6 counts per s) in the 0.1-4.5 keV energy range of the IPC, assuming a spectral temperature of about 10 keV. In addition, several areas of weaker emission were observed which form a ring that is symmetrically disposed about the position of the dwarf nova. This latter emission is detected only at energies below 0.7 keV; the possibility that it arises in material that has been ejected from the star in a nova-like event is discussed.

Cordova, F. A.↗

NASA NTRS1981

An X-ray study of the galactic center

The results from two long observations with the Einstein Observatory Imaging Proportional Counter (IPC) of an approximately 1 x 1 deg field centered near the galactic nucleus are presented. The X-ray images reveal a complex of weak sources within 20 arcmin of the galactic nucleus (Sgr A West) together with a region of apparently diffuse emission about 25 x 15 arcmin in extent. Three of the sources are tentatively identified: two with nearby galactic objects, and a third positionally coincident with Sgr A West itself (within the arcmin-accuracy available with the IPC). The nature of this source and the implications of both the high source density and presence of diffuse emission in the galactic center region are discussed.

Watson, M. G.↗

NASA NTRS1982

Einstein observations of the 1978 November 19 gamma ray burst source field

It is pointed out that several years after the discovery of cosmic gamma ray bursts (GRB) their sources have not yet been identified, although searches have been conducted in optical, X-ray, and radio wavelengths. The three smallest error boxes are now related to the events of Mar. 5, 1979, Apr. 6, 1979, and Nov. 19, 1978. X-ray observations, with the Imaging Proportional Counter (IPC) of the Einstein Observatory, were made for all three locations. A description is presented of the results of the 8200 second IPC observation of the Nov. 19, 1978 GRB, made on July 1 and 2, 1980. Three sources were detected. However, two of them were outside the GRB error box. The third source is located well inside the burst error box.

Pizzichini, G.↗

NASA NTRS1982

Compact X-ray sources in the Large Magellanic Cloud

Sixteen Einstein X-ray sources in the field of the Large Magellanic Cloud (LMC) that appear non-extended in the IPC detector have recently been accurately positioned with the HRI to make optical follow-up studies feasible. At least twelve of these are not associated with the LMC, including one Seyfert galaxy at a redshift of 0.076 and eleven late type galactic foreground stars, some showing photometric behavior typical for RS CVn and BY Dra variables. Two sources are identified with faint blue variable objects, one of them has been observed to exhibit He II 4686 and variable Balmer emission lines being reminiscent of the low mass X-ray binary LMC X-2. The IPC source 1E0501438-7037.6 is probably associated with the LMC OB star Sk-70 36 which has been found to show ellipsoidal light variations with a period of 6.94 d. The results strongly suggest that a gap in the X-ray binary luminosity function of the LMC exists between 10 to the 36th and 10 to the 38th ergls.

Pakull, M. W.↗

NASA NTRS1982

X-ray observations to detect hot coronae around galaxies

X-ray observations were made of two nearby edge-on spiral galaxies with the Imaging Proportional Counter (IPC) on the Einstein Observatory in an effort to detect hot (1,000,000 K), gaseous galactic coronae. No diffuse emission from galactic coronae was detected. Upper limits to diffuse emission (0.3-2.9 keV) are 10 to the 39th ergs/sec (NGC 3628) and 2 x 10 to the 38th ergs/sec (NGC 4244). The measurements indicate that less than 1/1000 of the energy supplied by supernovae in these galaxies appears as soft X-rays. The energy from supernovae may be radiated away by cool gas (less than 600,000 K) whose emission is undetectable by the Einstein Observatory, or the energy may be carried away by a hot wind (10,000,000 K) which radiates inefficiently. Serendipitous X-ray sources from the two IPC fields are listed.

Bregman, J. N.↗

NASA NTRS1983

The X-ray morphology of Abell 1367

X-ray observations of the nearby cluster Abell 1367 were made with the Imaging Proportional Counter (IPC) and High Resolution Imager (HRI) aboard the Einstein Observatory. The IPC is used to study the diffuse cluster emission. With the HRI, eight point sources are detected above the diffuse cluster emission, three of which are apparently associated with cluster galaxies. In addition, the HRI observations have resolved 13 extended features with characteristic radii of order arcmin, eight of which are associated with cluster galaxies. These extended sources have luminosities of 1.5-6.5 x 10 to the 41st per (H0)50)-squared ergs per sec in the 0.5-4.5 keV band and constitute about 60% of the total cluster emission. The ways in which these hot galactic coronae can be maintained are discussed.

Bechtold, J.↗

NASA NTRS1984

Einstein Observations of the Cygnus Loop

The imaging instruments on the Einstein Observatory were used to study the detailed X-ray structure of the Cygnus Loop. An arc minute resolution map of the 0.1-4.0 keV emission from the entire remnant was obtained with the imaging proportional counter (IPC). The bright northeastern and western limbs were mapped with the high resolution imager (HRI). The large-scale structure of the Loop is well modeled as a limb-brightened shell of hot gas at 2 x 10 to the 6th K created by the expansion of a blast wave into an inhomogeneous interstellar medium. The pulse-height data from the IPC indicate that the center of the remnant is generally hotter than the limb with temperatures as high as 4 x 10 to the 6th K. The X-ray maps show good general correlation with large-scale radio and optical structure, and in some cases good detailed correlation with faint optical filaments dominated by hydrogen line emission.

Ku, W. H.-M.↗