1,592 research outputs found
Robust limit on a varying proton-to-electron mass ratio from a single H2 system
The variation of the dimensionless fundamental physical constant mu=m_p/m_e
can be checked through observation of Lyman and Werner lines of molecular
hydrogen in the spectra of distant QSOs. Our intention is to asses the accuracy
of the investigation concerning a possible variation of mu and to provide more
robust results for QSO 0347-383. The goal in mind is to resolve the current
controversy on variation of mu and devise explanations for the different
findings. We achieve this not by another single result but by providing
alternative approaches to the problem. An analysis based on independent data
sets of QSO 0347-383 is put forward and new approaches for some of the steps
involved in the data analysis are introduced. We analyse two independent sets
of observations of the same absorption system and for the first time we apply
corrections for the observed offsets between discrete spectra Drawing on two
independent observations of a single absorption system in QSO 0347-383 our
detailed analysis yields dmu/mu = 15 +/- (9_stat + 6_sys) x 10^{-6} at
z_abs=3.025. Based on the overall goodness-of-fit we estimate the limit of
accuracy to about 300 m/s, consisting of roughly 180 m/s due to the uncertainty
of the fit and about 120 m/s allocated to systematics This work presents
alternative approaches to handle systematics and introduces methods required
for precision analysis of QSO spectra available in the near future.Comment: 9 pages, 10 figures, submitted to A&
Multiple origins for the DLA at toward PKS 1127145 indicated by a complex dust depletion pattern of Ca, Ti, and Mn
We investigate the dust depletion properties of optically thick gas in and
around galaxies and its origin we study in detail the dust depletion patterns
of Ti, Mn, and Ca in the multi-component damped Lyman- (DLA) absorber
at toward the quasar PKS 1127145.} We performed a
detailed spectral analysis of the absorption profiles of CaII, MnII, TiII, and
NaI associated with the DLA toward PKS 1127145, based on optical
high-resolution data obtained with the UVES instrument at the Very Large
Telescope (VLT). We obtained column densities and Doppler-parameters for the
ions listed above and determine their gas-phase abundances, from which we
conclude on their dust depletion properties. We compared the Ca and Ti
depletion properties of this DLA with that of other DLAs. One of the six
analyzed absorption components shows a striking underabundance of Ti and Mn in
the gas-phase, indicating the effect of dust depletion for these elements and a
locally enhanced dust-to-gas ratio. In this DLA and in other similar absorbers,
the MnII abundance follows that of TiII very closely, implying that both ions
are equally sensitive to the dust depletion effects. Our analysis indicates
that the DLA toward PKS 1127145 has multiple origins. With its narrow line
width and its strong dust depletion, component 3 points toward the presence of
a neutral gas disk from a faint LSB galaxy in front of PKS 1127145, while
the other, more diffuse and dust-poor, absorption components possibly are
related to tidal gas features from the interaction between the various,
optically confirmed galaxy-group members. In general, the Mn/CaII ratio in
sub-DLAs and DLAs possibly serves as an important indicator to discriminate
between dust-rich and dust-poor in neutral gas in and around galaxies.Comment: 10 pages, 8 figures, accepted for A&
Diffuse interstellar bands {\lambda}5780 and {\lambda}5797 in the Antennae Galaxy as seen by MUSE
ABRIDGED: Diffuse interstellar bands (DIBs) are faint spectral absorption
features of unknown origin. Research on DIBs beyond the Local Group (LG) will
surely blossom in the era of the ELTs. A possibility that needs to be explored
is the use of integral field spectrographs. We do so by using MUSE data for the
Antennae Galaxy, the closest major galaxy merger. High S-to-N spectra were
created by co-adding the signal of many spatial elements. The emission of the
underlying stellar population was modeled using STARLIGHT. To our knowledge, we
have derived the first maps for the DIBs at l5780 and l5797 in galaxies outside
the LG. The l5780 DIB was detected in an area of ~0.6 arcmin2, corresponding to
a linear scale of ~25 kpc2. This region was sampled using >200 independent
lines of sight. The DIB l5797 was detected in >100 independent lines of sight.
Both DIBs are associated with a region with high emission in the HI 21 cm line,
implying a connection between atomic gas and DIBs, as the correlations for the
Milky Way also suggest. Conversely, there is mild spatial association between
the two DIBs and the molecular gas, in agreement with results for our Galaxy
that indicate a lack of correlation between DIBs and molecular gas. The overall
structure for the DIB strength distribution and extinction are comparable.
Within the system, the l5780 DIB clearly correlates with the extinction. Both
DIBs follow the relationship between equivalent width and reddening when data
for several galaxies are considered. Unidentified Infrared emission Bands
(UIBs, likely caused by PAHs) and the l5780 and l5797 DIBs show similar but not
identical spatial distributions. We attribute the differences to extinction
effects without necessarily implying a radically different nature of the
respective carriers. The results illustrate the enormous potential of integral
field spectrographs for extragalactic DIB research.Comment: 12 pages, 13 figures, accepted by Astronomy & Astrophysics; version
corrected by English edito
Variability of the proton-to-electron mass ratio on cosmological scales
So far the only seemingly significant indication of a cosmological variation
exists for the proton-to-electron mass ratio as stated by Reinhold et al.
(2006). The measured indication of variation is based on the combined analysis
of H2 absorption systems in the spectra of Q0405-443 and Q0347-383 at z=2.595
and z=3.025, respectively. The high resolution data of the latter is reanalyzed
in this work to examine the influence of different fitting procedures and
further potential nonconformities. This analysis cannot reproduce the
significance achieved by the previous detection.Comment: 10 pages, 8 figures, as to appear in EPJ special - ACFC 2007
conference proceeding
Public Support of the Processing and Marketing of Agricultural Products: A Driver of Innovation in the Food Industry?
At issue in this paper is the role of innovation within the public support of food-industries under EU rural development policy. It is focused on the questions: Are there fundamental economic characteristics of highly innovative in comparison to less innovative enterprises? And, what are successful strategies to promote innovations by intervention of the state. Baseline information is given through the data ascertainment of investment grant applications and collaboration with local state departments.Innovation, industrial policy, investment assistance, food-industry, state-intervention, Agribusiness, Agricultural and Food Policy, Marketing,
Towards DIB mapping in galaxies beyond 100 Mpc. A radial profile of the 5780.5 diffuse interstellar band in AM 1353-272 B
Diffuse Interstellar Bands (DIBs) are non-stellar weak absorption features of
unknown origin found in the spectra of stars viewed through one or several
clouds of Interstellar Medium (ISM). Research of DIBs outside the Milky Way is
currently very limited. Specifically spatially resolved investigations of DIBs
outside of the Local Group is, to our knowledge, inexistent. Here, we explore
the capability of the high sensitivity Integral Field Spectrograph, MUSE, as a
tool to map diffuse interstellar bands at distances larger than 100 Mpc. We use
MUSE commissioning data for AM 1353-272 B, the member with highest extinction
of the "The Dentist's Chair", an interacting system of two spiral galaxies.
High signal-to-noise spectra were created by co-adding the signal of many
spatial elements distributed in a geometry of concentric elliptical half-rings.
We derived decreasing radial profiles for the equivalent width of the
5780.5 DIB both in the receding and approaching side of the companion
galaxy up to distances of 4.6 kpc from the center of the galaxy.
Likewise, interstellar extinction, as derived from the Halpha/Hbeta line ratio
displays a similar trend, with decreasing values towards the external parts.
This translates into an intrinsic correlation between the strength of the DIB
and the extinction within AM 1353-272 B consistent with the current existing
global trend between these quantities when using measurements for both Galactic
and extragalactic sight lines. Mapping of DIB strength in the Local Universe as
up to now only done for the Milky Way seems feasible. This offers a new
approach to study the relationship between DIBs and other characteristics and
species of the ISM in different conditions as those found in our Galaxy to the
use of galaxies in the Local Group and/or single sightlines towards supernovae,
quasars and galaxies outside the Local Group.Comment: 4 pages, 4 figures, accepted for publication as a Letter in Astronomy
and Astrophysics; Received 10 February 2015 / Accepted 20 February 2015 ;
English corrections include
Type-D Personality in Unemployed Subjects: Prevalence, Self-Efficacy and Heart Rate Variability/Autonomic Response
Background: Unemployment may impair mental and physical health. The influencing factors causing such negative effects are relevant from an individual and public health perspective. The personality as one possible influencing factor was discussed. This study investigated the prevalence of the type-D personality in an unemployed population and its connections to socio-demographic, psychological and heart rate variability (HRV) parameters.
Methods: A questionnaire set including socio-demographics, type-D scale (DS14), Complaint list (BL), Beck-Depression-Inventory II (BDI-II) and the General Self-Efficacy Scale (GSE) was handed out to 203 unemployed individuals [126 females, mean age ± SD: 42.36 ± 11.08]. For HRV assessment (RMSSD), a subsample of 83 participants [50 females, median age ± IQR: 47.00 ± 17.00] passed the âstress-testsâ (timed breathing, d2-attention-stress-test, math test) while heart frequency (HF) was acquired via the Stressball software (BioSign GmbH, Ottenhofen, Germany).
Results: 53% of the unemployed had a type-D personality. Compared to non-type-D individuals, type-D individuals had rarely children and by trend a lower educational level; they showed significantly higher scores in the BDI-II and lower scores in the GSE and BL. No differences were observed in mean HF or RMSSD during all the stress-tests.
Conclusion: The HRV of individuals with a type-D personality is no worse than that of individuals without a type-D personality. Type-D personality was significantly associated with negative health effects regarding depressiveness, self-efficacy and physical complaints. Our main findings implicate that the DS14 could serve as a short and reliable screening instrument to select concerned unemployed individuals who might be at risk for negative health effects for adequate intervention
Real-time crowding information can help contain Covid-19
A study shows that when people have crowding information about medical practices, they tend to select less crowded ones - by Martin Adam, Dominick Werner, Charlotte Wendt and Alexander Benlia
Neuropsychological assessment methodology revisited: metatheoretical reflections
Theory building in neuropsychology, similar to other disciplines, rests on metatheoretical assumptions of philosophical origin. Such assumptions regarding the relation of psychological and physiological variables influence research methodologies as well as assessment strategies in fields of application. Here, we revisit the classic procedure of Double Dissociation (DD) to illustrate the connection of metatheory and methodology. In a seemingly unbridgeable opposition, the classical neuropsychological procedure of DD can be understood as either presupposing localizationism and a modular view of the brain, or as a special case of the generalized neuro-lens model for neuropsychological assessment. In the latter case, it is more easily compatible with a perspective that emphasizes the systemic-network, rather than the modular, nature of the brain, which as part of the organism, proportionately mediates the situatedness of the human being in the world. This perspective not only makes it possible to structure ecological validation processes and give them a metatheoretical foundation, but also to interlace it with the phenomenological insight that the laboratory as one context of empirical research may be analyzed in terms of situated experience. We conclude with showing that both the localizationist and the system science approach can agree on a view of the brain as a dynamical network, and that metatheory may thus offer important new perspectives of reconciliation.Peer Reviewe
- âŠ