3,255 research outputs found
Dynamics of blue compact galaxies, as revealed by their H-alpha velocity fields I. The data, velocity fields and rotation curves
Observations of six luminous blue compact galaxies (BCGs) and two star
forming companion galaxies were carried out with the CIGALE scanning
Fabry-Perot interferometer attached to the ESO 3.6m telescope on La Silla. The
observations were made in the H-alpha emission line which is prominent in BCGs.
A velocity sampling of 5 km/s and a pixel size of 0.9 arcseconds were used. In
this paper we present the observations and the data together with the velocity
fields and the derived rotation curves. In addition we provide rough estimates
of the total dynamical mass and of the ionised gas mass for each galaxy. All
galaxies display rotation, but while the companion galaxies have regular
velocity fields, those of the BCGs are complex and appear perturbed. This is
the most extensive study to date of the optical velocity fields of BCGs. The
interpretation of these results will be presented in a forthcoming paper (Paper
II).Comment: 26 pages, 14 figures. Accepted for publication in A&AS. The paper
(with figures in slightly higher resolution) and an electronic table is also
available at ftp://ftp.iap.fr/pub/from_users/ostlin/Articles/ . Replaced
version, figure captions fixe
Berpikir Kreatif dan Motivasi Belajar Pada Pembelajaran Menggunakan Problem Based Learning
Problem-based Learning (PBL) is a learning method that can change the behavior of students who passively receive information to actively seek information. However, the implementation of PBL is not in accordance to its character, causing boring learning conditions, as happened in Grade VII students of SMP Negeri 4 Palu in science subject. The purpose of this research was to improve students' creative thinking and learning motivation through the implementation of PBL in science subject in Grade VII of SMP Negeri 4 Palu. This research used a quasi-experimental method with quantitative and qualitative approaches. The research design was a pretest-posttest control group design. The sample of two classes with a total of 55 students, namely one experimental class (26 students) and one control class (29 students). Quantitative data for creative thinking variable were obtained by distributing tests and qualitative data and for learning motivation variable were obtained through questionnaires. Quantitative data were analyzed using non-parametric statistics (Mann-Whitney test) and qualitative data using the Percentage Mean Value formula. The quantitative research results show Asimp. Sig. (2-tailed)= 0.382 (>0.05). This means that H1 is rejected and H0 is accepted, which means there is no differences in the way students think creatively in the control class and the experimental class in science learning. The results of qualitative research show that students' learning motivation in the control class and the experimental class are both included in the very good criteria with the percentage in the range of 90.3% - 90.8%
UC-385 Health-E-Patient (Web Application)
Health-E-Patient is a web application that allows communication between hospitals, doctors and their patients. The product aims to provide a secure way of informing patients about appointments and medications while also allowing doctors to keep track of their patients. This application will also make it easier to communicate with your doctors and other care providers. We used Next.JS, a React-based web development framework with server-side rendering. We used MaterialUI for user interface and Firebase for Authentication and Database
The Power of Non-Determinism in Higher-Order Implicit Complexity
We investigate the power of non-determinism in purely functional programming
languages with higher-order types. Specifically, we consider cons-free programs
of varying data orders, equipped with explicit non-deterministic choice.
Cons-freeness roughly means that data constructors cannot occur in function
bodies and all manipulation of storage space thus has to happen indirectly
using the call stack.
While cons-free programs have previously been used by several authors to
characterise complexity classes, the work on non-deterministic programs has
almost exclusively considered programs of data order 0. Previous work has shown
that adding explicit non-determinism to cons-free programs taking data of order
0 does not increase expressivity; we prove that this - dramatically - is not
the case for higher data orders: adding non-determinism to programs with data
order at least 1 allows for a characterisation of the entire class of
elementary-time decidable sets.
Finally we show how, even with non-deterministic choice, the original
hierarchy of characterisations is restored by imposing different restrictions.Comment: pre-edition version of a paper accepted for publication at ESOP'1
Streamlined Calibration of the ATLAS Muon Spectrometer Precision Chambers
The ATLAS Muon Spectrometer is comprised of nearly 1200 optically Monitored Drifttube Chambers (MDTs) containing 354,000 aluminum drift tubes. The chambers are configured in barrel and endcap regions. The momentum resolution required for the LHC physics reach (dp/p = 3% and 10% at 100 GeV and 1 TeV) demands rigorous MDT drift tube calibration with frequent updates. These calibrations (RT functions) convert the measured drift times to drift radii and are a critical component to the spectrometer performance. They are sensitive to the MDT gas composition: Ar 93%, CO2 7% at 3 bar, flowing through the detector at arate of 100,000 l hr−1. We report on the generation and application of Universal RT calibrations derived from an inline gas system monitor chamber. Results from ATLAS cosmic ray commissioning data are included. These Universal RTs are intended for muon track reconstuction in LHC startup phase
Computing with and without arbitrary large numbers
In the study of random access machines (RAMs) it has been shown that the
availability of an extra input integer, having no special properties other than
being sufficiently large, is enough to reduce the computational complexity of
some problems. However, this has only been shown so far for specific problems.
We provide a characterization of the power of such extra inputs for general
problems. To do so, we first correct a classical result by Simon and Szegedy
(1992) as well as one by Simon (1981). In the former we show mistakes in the
proof and correct these by an entirely new construction, with no great change
to the results. In the latter, the original proof direction stands with only
minor modifications, but the new results are far stronger than those of Simon
(1981). In both cases, the new constructions provide the theoretical tools
required to characterize the power of arbitrary large numbers.Comment: 12 pages (main text) + 30 pages (appendices), 1 figure. Extended
abstract. The full paper was presented at TAMC 2013. (Reference given is for
the paper version, as it appears in the proceedings.
Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer
We present observations of the nearby barred starburst galaxy, M83 (NGC5236),
with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William
Herschel Telescope on La Palma. The unprecedented high resolution observations,
of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the
galaxy. The velocity field displays the dominant disk rotation with signatures
of gas inflow from kpc scales down to the nuclear regions. At the inner Inner
Lindblad Resonance radius of the main bar and centerd at the dynamical center
of the main galaxy disk, a nuclear rapidly
rotating disk with scale length of pc has formed. The nuclear
starburst is found in the vicinity as well as inside this nuclear disk, and our
observations confirm that gas spirals in from the outer parts to feed the
nuclear starburst, giving rise to several star formation events at different
epochs, within the central 100 pc radius of M83.Comment: Accepted for publication in ApJ Letters. High-resolution version can
be found at http://www.astro.su.se/~kambiz/DOC/paper-M83.pd
Reachability problems for PAMs
Piecewise affine maps (PAMs) are frequently used as a reference model to show
the openness of the reachability questions in other systems. The reachability
problem for one-dimentional PAM is still open even if we define it with only
two intervals. As the main contribution of this paper we introduce new
techniques for solving reachability problems based on p-adic norms and weights
as well as showing decidability for two classes of maps. Then we show the
connections between topological properties for PAM's orbits, reachability
problems and representation of numbers in a rational base system. Finally we
show a particular instance where the uniform distribution of the original orbit
may not remain uniform or even dense after making regular shifts and taking a
fractional part in that sequence.Comment: 16 page
Non-Nuclear Hyper/Ultraluminous X-Ray Sources in the Starbursting Cartwheel Ring Galaxy
We report the Chandra/ACIS-S detection of more than 20 ultraluminous X-ray
sources (ULXs, L_{0.5-10 keV} >~ 3 x 10^{39} ergs/sec) in the Cartwheel
collisional ring galaxy system, of which over a dozen are located in the outer
active star-forming ring. A remarkable hyperluminous X-ray source (HLX,
L_{0.5-10 keV} >~ 10^{41} ergs/sec assuming isotropic radiation), which
dominates the X-ray emission from the Cartwheel ring, is located in the same
segment of the ring as most ULXs. These powerful H/ULXs appear to be coincident
with giant HII region complexes, young star clusters, and radio and
mid-infrared hot-spots: all strong indicators of recent massive star formation.
The X-ray spectra show that H/ULXs have similar properties as those of the {\it
most luminous} ULXs found in the nearest starbursts and galaxy mergers such as
the Antennae galaxies and M82. The close association between the X-ray sources
and the starbursting ring strongly suggests that the H/ULXs are intimately
associated with the production and rapid evolution of short-lived massive
stars. The observations represent the most extreme X-ray luminosities
discovered to date associated with star-forming regions--rivaling the X-ray
luminosities usually associated with active galactic nuclei.Comment: ApJ Letters, accepted (scheduled for the Oct. 20 issue). Full
resolution paper in a single .ps.gz file available at:
http://spider.ipac.caltech.edu/staff/gao/Papers/cartw.ps.g
Rotation Curves of Spiral Galaxies
Rotation curves of spiral galaxies are the major tool for determining the
distribution of mass in spiral galaxies. They provide fundamental information
for understanding the dynamics, evolution and formation of spiral galaxies. We
describe various methods to derive rotation curves, and review the results
obtained. We discuss the basic characteristics of observed rotation curves in
relation to various galaxy properties, such as Hubble type, structure,
activity, and environment.Comment: 40 pages, 6 gif figures; Ann. Rev. Astron. Astrophys. Vol. 39, p.137,
200
- …