1,608 research outputs found
An extended XMM-Newton observation of the Seyfert galaxy NGC 4051. II. Soft X-ray emission from a limb-brightened shell of post-shock gas
An extended XMM-Newton observation of the Seyfert I galaxy NGC 4051 in 2009
revealed a complex absorption spectrum, with a wide range of outflow velocities
and ionisation states.The main velocity and ionisation structure was
interpreted in Paper I in terms of a decelerating, recombining flow resulting
from the shocking of a still higher velocity wind colliding with the ISM or
slower moving ejecta. The high sensitivity of the XMM-Newton observation also
revealed a number of broad emission lines, all showing evidence of
self-absorption near the line cores. The line profiles are found here to be
consistent with emission from a limb-brightened shell of post-shock gas
building up ahead of the contact discontinuity. While the broad emission lines
remain quasi-constant as the continuum flux changes by an order of magnitude,
recombination continua of several H- and He-like ions are found to vary in
response to the continuum, providing an important key to scaling the ionised
flow.Comment: Accepted for publication in MNRA
Embodiment of the interpersonal nexus: revealing qualitative research findings on shoulder surgery patients
The Implementation of an Introductory Medical Terminology and Abbreviations Session into the GW SMHS Pre-Matriculation Program
Space Station Freedom environmental control and life support system phase 3 simplified integrated test detailed report
A description of the phase 3 simplified integrated test (SIT) conducted at the Marshall Space Flight Center (MSFC) Core Module Integration Facility (CMIF) in 1989 is presented. This was the first test in the phase 3 series integrated environmental control and life support systems (ECLSS) tests. The basic goal of the SIT was to achieve full integration of the baseline air revitalization (AR) subsystems for Space Station Freedom. Included is a description of the SIT configuration, a performance analysis of each subsystem, results from air and water sampling, and a discussion of lessons learned from the test. Also included is a full description of the preprototype ECLSS hardware used in the test
Waste management in Cange, Haiti
Our goal is to create a self-sustained waste management system in order to improve the sanitation and environmental health in Cange, Haiti. Cange currently has no waste management system; garbage is either piled in ravines or burned. We have divided Cange\u27s waste into three waste streams for treatment: organics, plastics, and other. The organics will be primarily treated with municipal scale composting windrows and the finished compost will be sold to surrounding farms. The plan for the plastic materials is to work with merchants to minimize the need and use of disposable plastic, repurpose used plastic waste into other marketable items (e.g., woven bags, construction blocks, etc.), and to recycle them at a newly formed micro-recycling facility. Other materials are expected to be mainly construction debris, which is already widely repurposed by the community, so it will be collected in a central refuse pile. In conclusion, we believe this system will effectively process the waste in a beneficial manner to the community
Fast Split-Radix and Radix-4 Discrete Cosine Transform Algorithms
The Discrete Fourier Transform (DFT) has a plethora of applications in applied mathematics and electrical engineering. Discrete Cosine Transform (DCT) is a real-arithmetic analogue of DFT. DCTs with orthogonal trigonometric transforms have been especially popular in recent decades due to their applications in digital video technology and high efficiency video coding. One can say that DCT is the key transform in image processing, signal processing, finger print enhancement, quick response code (QR code), multi-mode interface, etc.
In this talk, we first introduce sparse and scaled orthogonal factorization for the DCT and inverse DCT. Afterwards, we present fast split-radix and radix-4 DCT and inverse DCT algorithms. We show that the proposed algorithms attain the lowest theoretical multiplication complexity and arithmetic complexity for 8-point DCT II/III matrices. We perform execution time of the proposed algorithms while verifying the connection to the order of the arithmetic complexity. Finally, the language of signal flow graph representation of digital structures is used to describe potential for real-world circuit implementation
Transit System Evaluation Process: From Planning to Realization
Many frameworks exist to help transit agencies plan, operate, and monitor the performance of transit in rural and urban communities. No framework integrates these three critical business practices into one coherent and flexible framework useful to rural and small-sized cities. The primary objective of this research was to integrate planning, operations, and performance measurement activities into a framework designed to evaluate transit in the context of overall mobility. By combining planning, evaluation, and performance monitoring processes, a succinct framework useful to transit agencies and planners was created. In addition to city entities, colleges and universities operating or contracting transit systems also benefit from such a framework by creating a process that can be tailored to their needs as well. The framework outlines the activities necessary to complete a fixed route transit evaluation through an examination of the entire transportation system. Specific methodologies for each activity were not included in the framework because they must be customized to fit the needs and resources available to the evaluating entity but several example methods are presented in a case-study application of the proposed framework itself. The framework was tailored for use by rural and small cities and small- and medium-sized universities; however, it can be customized to meet the needs of any agencies or department regardless of the location. A case study of Clemson Universityâs on-campus transit route, operated by Clemson Area Transit, in Clemson, South Carolina revealed that the proposed framework worked well in bringing stakeholders together and achieving the intended objectives
High-ionization mid-infrared lines as black hole mass and bolometric luminosity indicators in active galactic nuclei
We present relations of the black hole mass and the optical luminosity with
the velocity dispersion and the luminosity of the [Ne V] and the [O IV]
high-ionization lines in the mid-infrared (MIR) for 28 reverberation-mapped
active galactic nuclei. We used high-resolution Spitzer Infrared Spectrograph
and Infrared Space Observatory Short Wavelength Spectrometer data to fit the
profiles of these MIR emission lines that originate from the narrow-line region
of the nucleus. We find that the lines are often resolved and that the velocity
dispersion of [Ne V] and [O IV] follows a relation similar to that between the
black hole mass and the bulge stellar velocity dispersion found for local
galaxies. The luminosity of the [Ne V] and the [O IV] lines in these sources is
correlated with that of the optical 5100A continuum and with the black hole
mass. Our results provide a means to derive black hole properties in various
types of active galactic nuclei, including highly obscured systems.Comment: accepted for publication in ApJ
Accretion-Inhibited Star Formation in the Warm Molecular Disk of the Green-valley Elliptical Galaxy NGC 3226
We present archival Spitzer photometry and spectroscopy, and Herschel
photometry, of the peculiar "Green Valley" elliptical galaxy NGC~3226. The
galaxy, which contains a low-luminosity AGN, forms a pair with NGC~3227, and is
shown to lie in a complex web of stellar and HI filaments. Imaging at 8 and
16m reveals a curved plume structure 3 kpc in extent, embedded within the
core of the galaxy, and coincident with the termination of a 30 kpc-long HI
tail. In-situ star formation associated with the IR plume is identified from
narrow-band HST imaging. The end of the IR-plume coincides with a warm
molecular hydrogen disk and dusty ring, containing 0.7-1.1 10
M detected within the central kpc. Sensitive upper limits to the
detection of cold molecular gas may indicate that a large fraction of the H
is in a warm state. Photometry, derived from the UV to the far-IR, shows
evidence for a low star formation rate of 0.04 M yr
averaged over the last 100 Myrs. A mid-IR component to the Spectral Energy
Distribution (SED) contributes 20 of the IR luminosity of the galaxy,
and is consistent with emission associated with the AGN. The current measured
star formation rate is insufficient to explain NGC3226's global UV-optical
"green" colors via the resurgence of star formation in a "red and dead" galaxy.
This form of "cold accretion" from a tidal stream would appear to be an
inefficient way to rejuvenate early-type galaxies, and may actually inhibit
star formation.Comment: Accepted for Publication ApJ Oct 201
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