48 research outputs found
The Rest-frame Optical Colors of 99,000 SDSS Galaxies
We synthesize the rest-frame Stroemgren colors using SDSS spectra for 99,088
galaxies selected from Data Release 1. This narrow-band ~200 AA photometric
system (uz, vz, bz, yz), first designed for the determination of effective
temperature, metallicity and gravity of stars, measures the continuum spectral
slope of galaxies in the rest-frame 3200-5800 AA wavelength range. Galaxies
form a remarkably narrow locus (~0.03 mag) in the resulting color-color
diagram. The Bruzual & Charlot population synthesis models suggest that the
position of a galaxy along this locus is controlled by a degenerate combination
of metallicity and age of the dominant stellar population. Galaxy distribution
along the locus is bimodal, with the local minimum corresponding to an ~1 Gyr
old single stellar population. The position perpendicular to the locus is
independent of metallicity and age, and reflects the galaxy's dust content, as
implied by both the models and the statistics of IRAS detections. A comparison
of this locus with the galaxy locus in the H_delta-D_n(4000) diagram, utilized
by Kauffmann et al. (2003) to estimate stellar masses, reveals a tight
correlation, although the two analyzed spectral ranges barely overlap. Overall,
the galaxy spectral energy distribution in the entire UV to near-IR range can
be described as a single-parameter family with an accuracy of 0.1 mag, or
better. This nearly one-dimensional distribution of galaxies in the
multi-dimensional space of measured parameters strongly supports the conclusion
of Yip et al. (2004), based on a principal component analysis, that SDSS galaxy
spectra can be described by a small number of eigenspectra. Apparently, the
contributions of stellar populations that dominate the optical emission from
galaxies are combined in a simple and well-defined way.Comment: Accepted for publication in MNRAS; 19 pages, 28 color figure
Abc method – guarantor of real costs in the mining extractive industry entities
The article aims to emphasize the importance of the ABC method in the provision of real production costs within mining extractive industry entities in Romania. Starting from the progress of investigations undertaken in the specialty literature regarding the adaptation and implementation of the ABC method to the specifics of the entities in the mining and quarrying industry to the achievements made so far by various specialists, the authors of this article demonstrate the successful implementation of the ABC method in mining entities in Romania and the determination of the real costs. The documentation which was the basis of the study and comparison between applicative traditional method used and the ABC method applied is likely to prove the viability of the organization of the managerial accounting of mining extractive industry entities in Romania in order to increase their performances. The article ends with the conclusions of the authors concerning the enlargement of the successful implementation of the ABC method in mining extractive industry entities in Romania
Abc method – guarantor of real costs in the mining extractive industry entities
The article aims to emphasize the importance of the ABC method in the provision of real production costs within mining extractive industry entities in Romania. Starting from the progress of investigations undertaken in the specialty literature regarding the adaptation and implementation of the ABC method to the specifics of the entities in the mining and quarrying industry to the achievements made so far by various specialists, the authors of this article demonstrate the successful implementation of the ABC method in mining entities in Romania and the determination of the real costs. The documentation which was the basis of the study and comparison between applicative traditional method used and the ABC method applied is likely to prove the viability of the organization of the managerial accounting of mining extractive industry entities in Romania in order to increase their performances. The article ends with the conclusions of the authors concerning the enlargement of the successful implementation of the ABC method in mining extractive industry entities in Romania
Dashboard, Tool for Monitoring and Measuring the Performances of Entities within Mining Extractive
This article aims to emphasis the importance of dashboard in monitoring and measuring the performances of entities within mining extractive industry of Romania. Having regard to the stage of the researches carried out in the specialty literature regarding the implementation of ABC method to the peculiarity of entities within mining extractive industry and up to the achievements made at present by various professionals, the authors of this article demonstrate the utility of dashboard in monitoring and measuring the performances of mining entities of Romania and of making decisions based on information provided by it. The main tool underlying the elaboration of dashboard was presented, namely the results account as accounting synthesis document of managerial accounting. The article ends with the conclusions of authors with a view to advantages and importance of using the dashboard of ABC method within the entities of mining extractive industry of Romania
Dashboard, Tool for Monitoring and Measuring the Performances of Entities within Mining Extractive
This article aims to emphasis the importance of dashboard in monitoring and measuring the performances of entities within mining extractive industry of Romania. Having regard to the stage of the researches carried out in the specialty literature regarding the implementation of ABC method to the peculiarity of entities within mining extractive industry and up to the achievements made at present by various professionals, the authors of this article demonstrate the utility of dashboard in monitoring and measuring the performances of mining entities of Romania and of making decisions based on information provided by it. The main tool underlying the elaboration of dashboard was presented, namely the results account as accounting synthesis document of managerial accounting. The article ends with the conclusions of authors with a view to advantages and importance of using the dashboard of ABC method within the entities of mining extractive industry of Romania
Hubble Space Telescope Spectroscopy of the Balmer lines in Sirius B
Sirius B is the nearest and brightest of all white dwarfs, but it is very
difficult to observe at visible wavelengths due to the overwhelming scattered
light contribution from Sirius A. However, from space we can take advantage of
the superb spatial resolution of the Hubble Space Telescope to resolve the A
and B components. Since the closest approach in 1993, the separation between
the two stars has become increasingly favourable and we have recently been able
to obtain a spectrum of the complete Balmer line series for Sirius B using
HST?s Space Telescope Imaging Spectrograph (STIS). The quality of the STIS
spectra greatly exceed that of previous ground-based spectra, and can be used
to provide an important determination of the stellar temperature (Teff =
25193K) and gravity (log g = 8.556). In addition we have obtained a new, more
accurate, gravitational red-shift of 80.42 +/- 4.83 km s-1 for Sirius B.
Combining these results with the photometric data and the Hipparcos parallax we
obtain new determinations of the stellar mass for comparison with the
theoretical mass-radius relation. However, there are some disparities between
the results obtained independently from log g and the gravitational redshift
which may arise from flux losses in the narrow 50x0.2arcsec slit. Combining our
measurements of Teff and log g with the Wood (1995) evolutionary mass-radius
relation we get a best estimate for the white dwarf mass of 0.978 M. Within the
overall uncertainties, this is in agreement with a mass of 1.02 M obtained by
matching our new gravitational red-shift to the theoretical M/R relation.Comment: 11 pages, 6 figures, accepted for publication in the Monthly Notices
of the Royal Astronomical Societ
The early-type dwarf galaxy population of the Hydra I cluster
We analyse the properties of the early-type dwarf galaxy population in the
Hydra I cluster. We investigate the galaxy luminosity function (LF), the
colour-magnitude relation (CMR), and the magnitude-surface brightness relation
down to M_V~-10 mag. Another goal of this study is to find candidates for
ultra-compact dwarf galaxies (UCDs). Two spectroscopic surveys performed with
Magellan I/LDSS2 and VLT/VIMOS, as well as deep VLT/FORS1 images in V and I
bands were examined. We identify cluster members by radial velocity
measurements and select other cluster galaxy candidates by their morphology.
One possible UCD candidate with M_V=-13.26 mag is found. Our sample of 100
morphologically selected dwarf galaxies defines a CMR that extends the CMR of
the giant cluster galaxies to the magnitude limit of our survey (M_V~-10 mag).
It matches the relations found for the Local Group and the Fornax cluster
dwarfs almost perfectly. The Hydra I dwarfs also follow a magnitude-surface
brightness relation similar to that of the LG dwarfs. Moreover, we observe a
continuous relation for dwarf galaxies and giant early-type galaxies when
plotting the central surface brightness \mu_0 of a S\'ersic model vs. the
galaxy magnitude. The effective radius is found to be largely independent of
the luminosity for M_V>-18 mag, being R_e~0.8 kpc. We derive a very flat
faint-end slope of the LF (\alpha = -1.13 \pm 0.04) from fitting a Schechter
function, whereas fitting a power law for M_V>-14 mag gives \alpha = -1.40 \pm
0.18. Our findings suggest that early-type dwarf and giant galaxies are the
same class of objects. The similarity of the dwarf galaxy scaling relations to
other environments implies that internal processes could be more important for
their global photometric properties than external influences. (abridged)Comment: 17 pages, 16 figures, accepted for publication in A&A, 4 references
added to the replaced versio
Relating basic properties of bright early-type dwarf galaxies to their location in Abell 901/902
We present a study of the population of bright early-type dwarf galaxies in
the multiple-cluster system Abell 901/902. We use data from the STAGES survey
and COMBO-17 to investigate the relation between the color and structural
properties of the dwarfs and their location in the cluster. The definition of
the dwarf sample is based on the central surface brightness and includes
galaxies in the luminosity range -16 >= M_B >~-19 mag. Using a fit to the color
magnitude relation of the dwarfs, our sample is divided into a red and blue
subsample. We find a color-density relation in the projected radial
distribution of the dwarf sample: at the same luminosity dwarfs with redder
colors are located closer to the cluster centers than their bluer counterparts.
Furthermore, the redder dwarfs are on average more compact and rounder than the
bluer dwarfs. These findings are consistent with theoretical expectations
assuming that bright early-type dwarfs are the remnants of transformed
late-type disk galaxies involving processes such as ram pressure stripping and
galaxy harassment. This indicates that a considerable fraction of dwarf
elliptical galaxies in clusters are the results of transformation processes
related to interactions with their host cluster.Comment: 12 pages, 8 figures, accepted for publication in A&A, typo corrected
in abstrac
The Ks-band Tully-Fisher Relation - A Determination of the Hubble Parameter from 218 ScI Galaxies and 16 Galaxy Clusters
The value of the Hubble Parameter (H0) is determined using the
morphologically type dependent Ks-band Tully-Fisher Relation (K-TFR). The slope
and zero point are determined using 36 calibrator galaxies with ScI morphology.
Calibration distances are adopted from direct Cepheid distances, and group or
companion distances derived with the Surface Brightness Fluctuation Method or
Type Ia Supernova. Distances are determined to 16 galaxy clusters and 218 ScI
galaxies with minimum distances of 40.0 Mpc. From the 16 galaxy clusters a
weighted mean Hubble Parameter of H0=84.2 +/-6 km s-1 Mpc-1 is found. From the
218 ScI galaxies a Hubble Parameter of H0=83.4 +/-8 km s-1 Mpc-1 is found. When
the zero point of the K-TFR is corrected to account for recent results that
find a Large Magellanic Cloud distance modulus of 18.39 +/-0.05 a Hubble
Parameter of 88.0 +/-6 km s-1 Mpc-1 is found. A comparison with the results of
the Hubble Key Project (Freedman et al 2001) is made and discrepancies between
the K-TFR distances and the HKP I-TFR distances are discussed. Implications for
Lamda-CDM cosmology are considered with H0=84 km s-1 Mpc-1. (Abridged)Comment: 37 pages including 12 tables and 7 figures. Final version accepted
for publication in the Journal of Astrophysics & Astronom
To which countries do European psychiatric trainees want to move to and why?
publisher: Elsevier articletitle: To which countries do European psychiatric trainees want to move to and why? journaltitle: European Psychiatry articlelink: http://dx.doi.org/10.1016/j.eurpsy.2017.06.010 content_type: article copyright: © 2017 Elsevier Masson SAS. All rights reserved.publisher: Elsevier articletitle: To which countries do European psychiatric trainees want to move to and why? journaltitle: European Psychiatry articlelink: http://dx.doi.org/10.1016/j.eurpsy.2017.06.010 content_type: article copyright: © 2017 Elsevier Masson SAS. All rights reserved.BACKGROUND: There is a shortage of psychiatrists worldwide. Within Europe, psychiatric trainees can move between countries, which increases the problem in some countries and alleviates it in others. However, little is known about the reasons psychiatric trainees move to another country. METHODS: Survey of psychiatric trainees in 33 European countries, exploring how frequently psychiatric trainees have migrated or want to migrate, their reasons to stay and leave the country, and the countries where they come from and where they move to. A 61-item self-report questionnaire was developed, covering questions about their demographics, experiences of short-term mobility (from 3 months up to 1 year), experiences of long-term migration (of more than 1 year) and their attitudes towards migration. RESULTS: A total of 2281 psychiatric trainees in Europe participated in the survey, of which 72.0% have 'ever' considered to move to a different country in their future, 53.5% were considering it 'now', at the time of the survey, and 13.3% had already moved country. For these immigrant trainees, academic was the main reason they gave to move from their country of origin. For all trainees, the overall main reason for which they would leave was financial (34.4%), especially in those with lower (2500€) incomes, personal reasons were paramount (44.5%). CONCLUSIONS: A high number of psychiatric trainees considered moving to another country, and their motivation largely reflects the substantial salary differences. These findings suggest tackling financial conditions and academic opportunities