2,228 research outputs found
X-ray and optical variability of Seyfert 1 galaxies as observed with XMM-Newton
We have examined simultaneous X-ray and optical light curves of a sample of
eight nearby Seyfert 1 galaxies observed using the EPIC X-ray cameras and
Optical Monitor on board XMM. The observations span ~1 day and revealed optical
variability in four of the eight objects studied. In all cases, the X-ray
variability amplitude exceeded that of the optical both in fractional and
absolute luminosity terms. No clearly significant correlations were detected
between wavebands using cross correlation analysis. We conclude that, in three
of the four objects in which optical variability was detected, reprocessing
mechanisms between wavebands do not dominate either the optical or X-ray
variability on the time-scales probed.Comment: 9 pages, 2 figures, accepted for publication in MNRA
Evidence for an intermediate line region in AGN's inner torus region and its evolution from narrow to broad line Seyfert I galaxies
A two-components model for Broad Line Region (BLR) of Active Galactic Nuclei
(AGN) has been suggested for many years but not widely accepted (e.g., Hu et
al. 2008; Sulentic et al. 2000; Brotherton et al. 1996; Mason et al. 1996).
This model indicates that the broad line can be described with superposition of
two Gaussian components (Very Broad Gaussian Component (VBGC) and InterMediate
Gaussian Component (IMGC)) which are from two physically distinct regions;
i.e., Very Broad Line Region (VBLR) and InterMediate Line Region (IMLR). We
select a SDSS sample to further confirm this model and give detailed analysis
to the geometry, density and evolution of these two regions. Micro-lensing
result of BLR in J1131-1231 and some unexplained phenomena in Reverberation
Mapping (RM) experiment provide supportive evidence for this model. Our results
indicate that the radius obtained from the emission line RM normally
corresponds to the radius of the VBLR, and the existence of the IMGC may affect
the measurement of the black hole masses in AGNs. The deviation of NLS1s from
the M-sigma relation and the Type II AGN fraction as a function of luminosity
can be explained in this model in a coherent way. The evolution of the two
emission regions may be related to the evolutionary stages of the broad line
regions of AGNs from NLS1s to BLS1s. Based on the results presented here, a
unified picture of hierarchical evolution of black hole, dust torus and galaxy
is proposed.Comment: 58 pages, 19 figures, 1 table. Matches the published versio
Chiasma
Newspaper reporting on events at the Boston University School of Medicine in the 1960s
Fandom and activism: Experimenting with memetic communication appeals about human rights issues during the 2022 winter Olympic games
In the sports context, activism is a popular focus of inquiry. In fact, scholars have posited that sports present an ideal platform for human rights and political activism and protest (Agyemang, Singer, & DeLorme, 2010; Coombs & Cassilo, 2017; Kaufman & Wolff, 2010). This study aims to analyze the persuasiveness of memetic communication in the global sports context by investigating the influence of exposure to social advocacy memes on issue importance and general attitudes toward global human rights. This experiment relied on MTurk participants in an online experiment using Qualtrics software hosted by the Communication Research Lab at a Midwest University. We measure the persuasive influence of a variety of persuasive strategies (e.g., assertive, comparative, calls to action, and appeals to self-efficacy) as well as explicit affiliations within a real-time global sports context (e.g., 2022 Winter Olympics). These findings add to existing scholarship by focusing on post-exposure behavioral intentions (e.g., diffusion intentions, advocacy intentions, consumption intentions, and information-seeking intentions) likely to spur activism and advocacy. These findings support the position that memetic communications help to serve as a motivational catalyst for information-seeking behaviors about global human rights issues in real-time global sports contexts. Discussion and limitations are provided
Analyzing the Prophylactic and Therapeutic Role of Inoculation to Facilitate Resistance to Conspiracy Theory Beliefs
Conspiracy theories pose a variety of social and psychological consequences for individuals and society, and research suggests that around half of the U.S. population believes at least one. A two-phase inoculation experiment was conducted. Inoculated participants reported more negative general attitudes toward conspiracy theories and lower Phase II generic conspiracist beliefs, which are both indicators of harm-reduction and the beneficial healing impacts of therapeutic inoculation. The addition of therapeutic inoculation as a harm-reduction or healing technique in practitioners’ stakeholder response toolkit is a valuable contribution to both theory and practice
REAL: Resilience and Adaptation using Large Language Models on Autonomous Aerial Robots
Large Language Models (LLMs) pre-trained on internet-scale datasets have
shown impressive capabilities in code understanding, synthesis, and general
purpose question-and-answering. Key to their performance is the substantial
prior knowledge acquired during training and their ability to reason over
extended sequences of symbols, often presented in natural language. In this
work, we aim to harness the extensive long-term reasoning, natural language
comprehension, and the available prior knowledge of LLMs for increased
resilience and adaptation in autonomous mobile robots. We introduce REAL, an
approach for REsilience and Adaptation using LLMs. REAL provides a strategy to
employ LLMs as a part of the mission planning and control framework of an
autonomous robot. The LLM employed by REAL provides (i) a source of prior
knowledge to increase resilience for challenging scenarios that the system had
not been explicitly designed for; (ii) a way to interpret natural-language and
other log/diagnostic information available in the autonomy stack, for mission
planning; (iii) a way to adapt the control inputs using minimal user-provided
prior knowledge about the dynamics/kinematics of the robot. We integrate REAL
in the autonomy stack of a real multirotor, querying onboard an offboard LLM at
0.1-1.0 Hz as part the robot's mission planning and control feedback loops. We
demonstrate in real-world experiments the ability of the LLM to reduce the
position tracking errors of a multirotor under the presence of (i) errors in
the parameters of the controller and (ii) unmodeled dynamics. We also show
(iii) decision making to avoid potentially dangerous scenarios (e.g., robot
oscillates) that had not been explicitly accounted for in the initial prompt
design.Comment: 13 pages, 5 figures, conference worksho
Report on the health of Colorado's forests
The reports describes "an annual investigation of critical forest health issues, including the identification of priority areas across the state where current forest conditions demand timely action." They are intended to "expand Coloradans' knowledge of and interest in our state's forest resources.".Reports produced by the Colorado State Forest Service in conjunction with Colorado Department of Natural Resources, Division of Forestry.Includes bibliographical references.January 2017Fire and water. The words themselves evoke contrasting forces of nature - fire, often viewed as an all-consuming inferno of destruction; water, a quenching and life-sustaining means of rejuvenation. But such generalizations are not always accurate, especially in Colorado. Fire is necessary to the ecology of healthy forests, and can be a useful wildland firefighting tool for containment and fuels reduction, while life-giving streams and rivers may turn into raging torrents that cause heavy erosion and loss of property and life. So important are these two natural elements that we've chosen them for the focus of this year's forest health report, to give you a better understanding of their impacts on Colorado's forested lands. Fire and water are integrally linked as necessary components in shaping a healthy, natural forest environment; in return, both are heavily influenced by forests themselves. Fire has significant impacts on people and forests; less obvious are the effects it has on the quality and quantity of water available for human and agricultural consumption. The demand for water, of particular concern in rapidly developing sections of our state, underscores the need to work across organizational boundaries to develop effective solutions. Interagency efforts highlight the importance of forest management to safeguard water supplies from post-fire erosion so water providers can maintain their ability to provide safe, clean water to Colorado residents in a cost-effective, consistent manner. In this report, we take the opportunity to highlight collaborative partnerships and projects with Denver Water, Northern Water, the City of Ouray and professionals implementing Colorado's Water Plan
Multiwavelength XMM-Newton observations of the Laor et al. sample of PG quasars
We present XMM-Newton/EPIC spectra for the Laor et al. sample of Palomar
Green quasars. We find that a power-law provides a reasonable fit to the 2-5
keV region of the spectra. Excess soft X-ray emission below 2 keV is present
for all objects, with the exception of those known to contain a warm absorber.
A single power-law is, however, a poor fit to the 0.3-10.0 keV spectrum and
instead we find that a simple model, consisting of a broken power-law (plus an
iron line), provides a reasonable fit in most cases. The equivalent width of
the emission line is constrained in just twelve objects but with low (<2 sigma)
significance in most cases. For the sources whose spectra are well-fit by the
broken power-law model, we find that various optical and X-ray line and
continuum parameters are well-correlated; in particular, the power-law photon
index is well-correlated with the FWHM of the Hbeta line and the photon indices
of the low and high energy components of the broken power-law are
well-correlated with each other. These results suggest that the 0.3-10 keV
X-ray emission shares a common (presumably non-thermal) origin, as opposed to
suggestions that the soft excess is directly produced by thermal disc emission
or via an additional spectral component. We present XMM-Newton/OM data which we
combine with the X-ray spectra so as to produce broad-band spectral energy
distributions, free from uncertainties due to long-term variability in
non-simultaneous data. Fitting these optical-UV spectra with a Comptonized disc
model indicates that the soft X-ray excess is independent of the accretion
disc, confirming our interpretation of the tight correlation between the hard
and soft X-ray spectra.Comment: Accepted for publication in MNRA
- …