A Protestant church

Thesis (B.S.)--University of Illinois, 1900.Typescript.Bound with 8 other B.S. theses in architecture from UIUC, 1900. IU-

Are There Any Type 2 QSOs? The Case of AXJ0341.4-4453

The X-ray source AXJ0341.4-4453 was described by Boyle et al. as a Type 2 AGN at z = 0.672 based on the absence of broad emission lines in the observed wavelength range 4000-7000 Angstroms. We obtained a new spectrum of AXJ0341.4-4453 extending to 9600 Angstroms which reveals broad Balmer lines and other characteristics of Seyfert 1 galaxies. The FWHM of broad H-beta is at least 1600 km/s, while [O III]5007 has FWHM = 730 km/s. The flux ratio [O III]5007/H-beta = 1. Thus, AXJ0341.4-4453 is by definition a narrow-line Seyfert 1 galaxy, or perhaps a moderately reddened Seyfert 1 galaxy, but it is not a Type 2 QSO. Although examples of the latter have long been sought, particularly in connection with the problem of the X-ray background, there is still virtually no evidence for the existence of any Type 2 QSO among X-ray selected samples.Comment: 4 pages, 3 figures, to appear in MNRA

Unobscured Type 2 Active Galactic Nuclei

Type 2 active galactic nuclei (AGNs) with intrinsically weak broad emission lines (BELs) would be exceptions to the unified model. After examining a number of proposed candidates critically, we find that the sample is contaminated significantly by objects with BELs of strengths indicating that they actually contain intermediate-type AGNs, plus a few Compton-thick sources as revealed by extremely low ratios of X-ray to nuclear IR luminosities. We develop quantitative metrics that show two (NGC 3147 and NGC 4594) of the remaining candidates to have BELs 2-3 orders of magnitude weaker than those of typical type 1 AGNs. Several more galaxies remain as candidates to have anomalously weak BELs, but this status cannot be confirmed with the existing information. Although the parent sample is poorly defined, the two confirmed objects are well under 1% of its total number of members, showing that the absence of a BEL is possible, but very uncommon in AGN. We evaluate these two objects in detail using multi-wavelength measurements including new IR data obtained with Spitzer and ground-based optical spectropolarimeteric observations. They have little X-ray extinction with N_H < ~10^(21) cm^(–2). Their IR spectra show strong silicate emission (NGC 4594) or weak aromatic features on a generally power-law continuum with a suggestion of silicates in emission (NGC 3147). No polarized BEL is detected in NGC 3147. These results indicate that the two unobscured type 2 objects have circumnuclear tori that are approximately face-on. Combined with their X-ray and optical/UV properties, this behavior implies that we have an unobscured view of the nuclei and thus that they have intrinsically weak BELs. We compare their properties with those of the other less-extreme candidates. We then compare the distributions of bolometric luminosities and accretion rates of these objects with theoretical models that predict weak BELs

Outline of bases to be used in predetermining costs for guidance as to sales policies

This Outline is the outgrowth of the views expressed at a series of meetings conducted by George W. Duncan, the Institute\u27s Cost Engineer, and attended by the cost representatives of the mills participating in the Narrow Sheetings, Wide Sheetings, Print Cloth, Carded Yarn, Osnaburg and Chambray Groups of the Institute. These views support, with a close approach to unanimity, the bases set forth in the Outline. Mr. Duncan has also discussed this matter with a great many individual mill executives and cost representatives, including many in branches of the industry not yet organized into Groups. In addition, this Outline has been examined and approved by Joel M. Barnes and Ralph E. Loper, Textile Cost Engineers, and by Price, Waterhouse & Company. Mr. Duncan and I believe the Outline to be sound and recommend it to the mills. This Outline is not a detailed cost manual, but is confined to developing what are regarded by the Institute and its advisers as proper basic principles. If a mill decides that its cost finding system calls for revision, the appropriate steps to that end will have to be taken by cost finding experts either in or outside of the mill\u27s organization. Our Cost Engineer, while not in position to install new or revised cost finding systems, will be glad to answer questions and render any assistance within his power

Coherent Doppler Lidar for Precision Navigation of Spacecrafts

A fiber-based coherent Doppler lidar, utilizing an FMCW technique, has been developed and its capabilities demonstrated through two successful helicopter flight test campaigns. This Doppler lidar is expected to play a critical role in future planetary exploration missions because of its ability in providing the necessary data for soft landing on the planetary bodies and for landing missions requiring precision navigation to the designated location on the ground. Compared with radars, the Doppler lidar can provide significantly higher precision velocity and altitude data at a much higher rate without concerns for measurement ambiguity or target clutter. Future work calls for testing the Doppler lidar onboard a rocket-powered free-flyer platform operating in a closed-loop with the vehicle s guidance, navigation, and control (GN&C) unit

Autonomous aircraft flight control for constrained environments

The real-time indoor autonomous vehicle test environment (RAVEN) at MIT's Aerospace Controls Laboratory is home to a diverse fleet of aircraft, from a styrofoam and cellophane dragonfly to a set of quadrotor Draganflyer helicopters. The helicopters are used primarily for swarm and health management research. Alongside these machines is a set of more conventional aircraft designed to study autonomous aircraft flight control in constrained environments. The objectives of this work are to develop and validate flight control concepts for aggressive (aerobatic) maneuvers, and, in particular, to identify the sensor suites needed, and the likely limits of achievable performance. Our work is motivated by the future goals of flying micro (or nano) air vehicles in constrained (e.g., urban or indoors) environments

Doppler Lidar Sensor for Precision Landing on the Moon and Mars

Landing mission concepts that are being developed for exploration of planetary bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe soft landing at the pre-designated sites. To address this need, a Doppler lidar is being developed by NASA under the Autonomous Landing and Hazard Avoidance (ALHAT) project. This lidar sensor is a versatile instrument capable of providing precision velocity vectors, vehicle ground relative altitude, and attitude. The capabilities of this advanced technology have been demonstrated through two helicopter flight test campaigns conducted over a vegetation-free terrain in 2008 and 2010. Presently, a prototype version of this sensor is being assembled for integration into a rocket-powered terrestrial free-flyer vehicle. Operating in a closed loop with vehicle's guidance and navigation system, the viability of this advanced sensor for future landing missions will be demonstrated through a series of flight tests in 2012

Quantum Entanglement dependence on bifurcations and scars in non autonomous systems. The case of Quantum Kicked Top

Properties related to entanglement in quantum systems, are known to be associated with distinct properties of the corresponding classical systems, as for example stability, integrability and chaos. This means that the detailed topology, both local and global, of the classical phase space may reveal, or influence, the entangling power of the quantum system. As it has been shown in the literature, the bifurcation points, in autonomous dynamical systems, play a crucial role for the onset of entanglement. Similarly, the existence of scars among the quantum states seems to be a factor in the dynamics of entanglement. Here we study these issues for a non-autonomous system, the Quantum Kicked Top, as a collective model of a multi-qubit system. Using the bifurcation diagram of the corresponding classical limit (the Classical Kicked Top), we analyzed the pair-wise and the bi-partite entanglement of the qubits and their relation to scars, as a function of the critical parameter of the system. We found that the pair-wise entanglement and pair-wise negativity show a strong maximum precisely at the bifurcation points, while the bi-partite entanglement changes slope at these points. We have also investigated the connection between entanglement and the fixed points on the branch of the bifurcation diagram between the two first bifurcation points and we found that the entanglement measures take their extreme values precisely on these points. We conjecture that our results on this behaviour of entanglement is generic for many quantum systems with a non-linear classical analogue.Comment: 14 pages, 6 figures in separate ps files, submitted for publicatio