1,967 research outputs found
Observations of cold dust in nearby elliptical galaxies
Spectral energy distribution (SED) analyses that include new millimeter to far-infrared (FIR) observations obtained with continuum instruments on the Nobeyama and James Clerk Maxwell Telescopes and the Infrared Space Observatory are presented for seven nearby (<45 Mpc) FIR-bright elliptical galaxies. These are analyzed together with archival FIR and shortwave radio data obtained from the NASA/IPAC Extragalactic Database (NED). The radio to infrared SEDs are best-fitted by power law plus graybody models of dust residing in the central galactic regions within a 2.4 kpc diameter and with temperatures between ~21 and 28 K, emissivity index simeq2, and masses from ~1.6 to 19 Ă 105 Mâ. The emissivity index is consistent with dust constituting amorphous silicate and carbonaceous grains previously modeled for stellar-heated dust observed in the Galaxy and other nearby extragalactic sources. Using updated dust absorption coefficients for this type of dust, dust masses are estimated that are similar to those determined from earlier FIR data alone, even though the latter results implied hotter dust temperatures. Fluxes and masses that are consistent with the new FIR and submillimeter data are estimated for dust cooler than 20 K within the central galactic regions. Tighter physical constraints for such cold, diffuse dust (if it exists) with low surface brightness will need sensitive FIR to submillimeter observations with the Spitzer Space Telescope, SCUBA2, or ALMA
Procedures for a competency/performance based education program according to Bandura\u27s social cognitive theory
Dieser Beitrag berichtet ĂŒber ein Trainingsverfahren zur Kompetenzanbahnung in GroĂgruppen. Im Sommersemester 1991 wurden 54 Studierende der PĂ€dagogischen Hochschule SchwĂ€bisch GmĂŒnd in einer zweistĂŒndigen Semesterveranstaltung im Zuhören, Eingehen auf BeitrĂ€ge, Fragenstellen, FĂŒhren bestimmter GesprĂ€che und in der Moderation von Diskussionen geschult. In Anlehnung an Banduras sozial kognitive Theorie liefen die einzelnen Veranstaltungen stets in drei Phasen ab: Die Aufmerksamkeit der Teilnehmerinnen wurde auf die zu erwerbende Kompetenz gelenkt; sodann erging die Aufforderung, sich gegenseitig die Wahrnehmungen mitzuteilen, und gegen Ende wurden die Handlungsspektren oder -strukturen gemeinsam erarbeitet. Die Teilnehmerinnen wurden schlieĂlich mit der Aufforderung entlassen, die Bewusstseinsinhalte verfĂŒgbar zu halten, um im Berufsfeld der Einsicht entsprechend handeln zu können. Die Unterschiede hinsichtlich der kognitiven ReprĂ€sentanzen waren sowohl auf der Vor- und Nachtest-Basis als auch zwischen mĂ€nnlichen und weiblichen Teilnehmerinnen signifikant. (DIPF/Orig.)This article refers to a special procedure for a Competency/Performance Based Teacher Education Program. 54 students of the Teacher Training College in SchwĂ€bisch GmĂŒnd have been trained in specific competencies and Performances in classroom interaction such as listening, encouraging, questioning, and leading discussions. Following the mastery learning concept the participants were involved into attentional processes, retention processes, and production processes according to Bandura\u27s social cognitive theory. The students had to undergo a pretest and a posttest to check up the cognitive representations. The results show significant differences in two directions as far as the results between the tests and the male and female students are concerned. (DIPF/Orig.
Lepton Flavour Violation in charged leptons within SUSY-seesaw
In this paper we review our main results for Lepton Flavour Violating (LFV)
semileptonic tau decays and muon-electron conversion in nuclei within the
context of two Constrained SUSY-Seesaw Models, the CMSSM and the NUHM. The
relevant spectrum is that of the Minimal Supersymmetric Standard Model extended
by three right handed neutrinos, and their corresponding SUSY
partners, , (). We use the seesaw mechanism for
neutrino mass generation and choose a parameterisation of this mechanism that
allows us to incorporate the neutrino data in our analysis of LFV processes. In
addition to the full one-loop results for the rates of these processes, we will
also review the set of simple formulas, valid at large , which are
very useful to compare with present experimental bounds. The sensitivity to
SUSY and Higgs sectors in these processes will also be discussed. This is a
very short summary of the works in Refs. \cite{Arganda:2008jj} and
\cite{Arganda:2007jw} to which we refer the reader for more details.Comment: 6 pages, 6 figures. To be published in the proceedings of the Tau08
Conference, Novosibirsk, Russia, 22-25 September 200
High Resolution Molecular Gas Maps of M33
New observations of CO (J=1->0) line emission from M33, using the 25 element
BEARS focal plane array at the Nobeyama Radio Observatory 45-m telescope, in
conjunction with existing maps from the BIMA interferometer and the FCRAO 14-m
telescope, give the highest resolution (13'') and most sensitive (RMS ~ 60 mK)
maps to date of the distribution of molecular gas in the central 5.5 kpc of the
galaxy. A new catalog of giant molecular clouds (GMCs) has a completeness limit
of 1.3 X 10^5 M_sun. The fraction of molecular gas found in GMCs is a strong
function of radius in the galaxy, declining from 60% in the center to 20% at
galactocentric radius R_gal ~ 4 kpc. Beyond that radius, GMCs are nearly
absent, although molecular gas exists. Most (90%) of the emission from low mass
clouds is found within 100 pc projected separation of a GMC. In an annulus 2.1<
R_gal <4.1 kpc, GMC masses follow a power law distribution with index -2.1.
Inside that radius, the mass distribution is truncated, and clouds more massive
than 8 X 10^5 M_sun are absent. The cloud mass distribution shows no
significant difference in the grand design spiral arms versus the interarm
region. The CO surface brightness ratio for the arm to interarm regions is 1.5,
typical of other flocculent galaxies.Comment: 14 pages, 14 figures, accepted in ApJ. Some tables poorly typeset in
emulateapj; see source files for raw dat
SZ and X-ray combined analysis of a distant galaxy cluster, RX J2228+2037.
We have performed a combined analysis of X-ray and Sunyaev-Zel'dovich data in
the direction of the distant galaxy cluster, RX J2228+2037. Fitting a
-model to the high-resolution HRI data gives kpc and . The dependency of the
Sunyaev-Zel'dovich effect with respect to the gas temperature allows us,
through the additional use of the 21 GHz data of the cluster, to determine keV. Extrapolating the gas density profile out
to the virial radius ( Mpc), we derived a gas mass of
. Within
the hypothesis of hydrostatic equilibrium, the corresponding extrapolated total
mass for this source is: , which corresponds to a gas fraction of . Our results on the temperature and on the cluster mass classify
RX J2228+2037 among the distant, hot and very massive galaxy clusters. Our work
highlights the power of the association of galaxy cluster mapping observations
in X-ray and the SZ effect to derive the cluster's physical properties, even
without X-ray spectroscopy.Comment: 7 pages, 4 figures, accepted for publication in A&
Probabilistic Search for Object Segmentation and Recognition
The problem of searching for a model-based scene interpretation is analyzed
within a probabilistic framework. Object models are formulated as generative
models for range data of the scene. A new statistical criterion, the truncated
object probability, is introduced to infer an optimal sequence of object
hypotheses to be evaluated for their match to the data. The truncated
probability is partly determined by prior knowledge of the objects and partly
learned from data. Some experiments on sequence quality and object segmentation
and recognition from stereo data are presented. The article recovers classic
concepts from object recognition (grouping, geometric hashing, alignment) from
the probabilistic perspective and adds insight into the optimal ordering of
object hypotheses for evaluation. Moreover, it introduces point-relation
densities, a key component of the truncated probability, as statistical models
of local surface shape.Comment: 18 pages, 5 figure
Recommended from our members
Coargumenthood and the processing of pronouns
We report three eye-movement experiments and an offline task investigating structural constraints on pronoun resolution in different contexts. This included âcoargumentâ contexts in which a pronoun was the direct object of a verb (âThe surgeon remembered that Jonathan had noticed himâ), so-called picture noun phrases (âThe surgeon remembered that Jonathan had a picture of himâ) and picture noun phrases with a possessor (âThe surgeon remembered about Jonathanâs picture of himâ). In each eye-movement experiment, we observed longer reading times when the nonlocal antecedent (âthe surgeonâ) mismatched in stereotypical gender with the pronoun, but little evidence of the gender of the local antecedent (âJonathanâ) influencing reading times. The offline task suggested readers occasionally interpret pronouns as referring to local antecedents, especially in non-coargument contexts. These results suggest that structural constraints constitute more highly weighted cues to antecedent retrieval than gender congruency during the initial stages of memory retrieval during pronoun resolution
Arc-like distribution of high CO(J=3-2)/CO(J=1-0) ratio gas surrounding the central star cluster of the supergiant HII region NGC 604
We report the discovery of a high CO(J=3-2)/CO(J=1-0) ratio gas with an
arc-like distribution (``high-ratio gas arc'') surrounding the central star
cluster of the supergiant HII region NGC 604 in the nearby spiral galaxy M 33,
based on multi-J CO observations of a 5' 5' region of NGC 604
conducted using the ASTE 10-m and NRO 45-m telescopes. The discovered
``high-ratio gas arc'' extends to the south-east to north-west direction with a
size of 200 pc. The western part of the high-ratio gas arc closely
coincides well with the shells of the HII regions traced by H and radio
continuum peaks. The CO(J=3-2)/CO(J=1-0) ratio, R_{3-2/1-0}, ranges between 0.3
and 1.2 in the observed region, and the R_{3-2/1-0} values of the high-ratio
gas arc are around or higher than unity, indicating very warm (T_kin > 60 K)
and dense (n(H_2) > 10^{3-4} cm^{-3}) conditions of the high-ratio gas arc. We
suggest that the dense gas formation and second-generation star formation occur
in the surrounding gas compressed by the stellar wind and/or supernova of the
first-generation stars of NGC 604, i.e., the central star cluster of NGC 604.Comment: 4 pages, 4 figures. The Astrophysical Journal Letters, in pres
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