2,566 research outputs found
Analysis of the SFR - M* plane at z<3: single fitting versus multi-Gaussian decomposition
The analysis of galaxies on the star formation rate - stellar mass (SFR-M*)
plane is a powerful diagnostic for galaxy evolution at different cosmic times.
We consider a sample of 24463 galaxies from the CANDELS/GOODS-S survey to
conduct a detailed analysis of the SFR-M* relation at redshifts 0.53 over more than three dex in stellar mass. To obtain SFR estimates, we
utilise mid- and far-IR photometry when available, and rest-UV fluxes for all
the other galaxies. We perform our analysis in different redshift bins, with
two different methods: 1) a linear regression fitting of all star-forming
galaxies, defined as those with specific star formation rates , similarly to what is typically done in the
literature; 2) a multi-Gaussian decomposition to identify the galaxy main
sequence (MS), the starburst sequence and the quenched galaxy cloud. We find
that the MS slope becomes flatter when higher stellar mass cuts are adopted,
and that the apparent slope change observed at high masses depends on the SFR
estimation method. In addition, the multi-Gaussian decomposition reveals the
presence of a starburst population which increases towards low stellar masses
and high redshifts. We find that starbursts make up ~5% of all galaxies at
z=0.5-1.0, while they account for ~16% of galaxies at 23 with
log8.25-11.25. We conclude that the dissection of the SFR-M* in
multiple components over a wide range of stellar masses is necessary to
understand the importance of the different modes of star formation through
cosmic time.Comment: 15 pages, 12 figures, 1 table. Accepted for publication in A&A, after
addressing referee report. Main changes with respect to v1: two new
appendixes to investigate the impact of redshift outliers and to test a
two-Gaussian component fit to the sSFR distribution. No conclusion change
Therapeutic effectiveness of epicranial nerve blocks on post-traumatic syndrome from head injury
The autor describes the case of a 53-year-old woman suffering from headache and dizziness, sometimes nausea, tinnitus in the right ear, and diffuse scalp allodynia following an occupational accident involving a head injury. Hyposensitizing treatment by anesthetic blockade at the emergence points of the epicranial nerves, which were hyperalgesic to fi nger pressure, rapidly controlled the allodynia and eventually the headache. Unexpectedly, the patient also reported reduced dizziness and resolution of the tinnitus. The unforeseen outcome highlights the unpredictable therapeutic potential of a simple and modestly invasive procedure. The neuropathophysiological interpretation is consequently very interesting
Chlorinated auxins–how does Arabidopsis thaliana deal with them?
Plant hormones have various functions in plants and play crucial roles in all developmental and differentiation stages. Auxins constitute one of the most important groups with the major representative indole-3-acetic acid (IAA). A halogenated derivate of IAA, 4-chloro-indole-3-acetic acid (4-Cl-IAA), has previously been identified in Pisum sativum and other legumes. While the enzymes responsible for the halogenation of compounds in bacteria and fungi are well studied, the metabolic pathways leading to the production of 4-Cl-IAA in plants, especially the halogenating reaction, are still unknown. Therefore, bacterial flavin-dependent tryptophan-halogenase genes were transformed into the model organism Arabidopsis thaliana. The type of chlorinated indole derivatives that could be expected was determined by incubating wild type A. thaliana with different Cl-tryptophan derivatives. We showed that, in addition to chlorinated IAA, chlorinated IAA conjugates were synthesized. Concomitantly, we found that an auxin conjugate synthetase (GH3.3 protein) from A. thaliana was able to convert chlorinated IAAs to amino acid conjugates in vitro. In addition, we showed that the production of halogenated tryptophan (Trp), indole-3-acetonitrile (IAN) and IAA is possible in transgenic A. thaliana in planta with the help of the bacterial halogenating enzymes. Furthermore, it was investigated if there is an effect (i) of exogenously applied Cl-IAA and Cl-Trp and (ii) of endogenously chlorinated substances on the growth phenotype of the plants
Indium selenide: An insight into electronic band structure and surface excitations
We have investigated the electronic response of single crystals of indium selenide by means of angle-resolved photoemission spectroscopy, electron energy loss spectroscopy and density functional theory. The loss spectrum of indium selenide shows the direct free exciton at similar to 1.3 eV and several other peaks, which do not exhibit dispersion with the momentum. The joint analysis of the experimental band structure and the density of states indicates that spectral features in the loss function are strictly related to single-particle transitions. These excitations cannot be considered as fully coherent plasmons and they are damped even in the optical limit, i.e. for small momenta. The comparison of the calculated symmetry-projected density of states with electron energy loss spectra enables the assignment of the spectral features to transitions between specific electronic states. Furthermore, the effects of ambient gases on the band structure and on the loss function have been probed
Manual do Sistema Balanço Hídrico e Calendário Agrícola.
Manual do Sistema Balanço Hídrico; Explicação e observações sobre os termos empregados nas tabelas do Balanço Hídrico; Modelo Entidade Relacionamento (MER); Objetivo operacional do sistema; Diferenciamento das duas maneiras de processamento do sistema; Funcionamento; Módulo arquivos; Módulo Balanço Hídrico; Módulo Utilitário; Módulo Sobre.bitstream/item/116808/1/834.pd
The story of supernova 'Refsdal' told by MUSE
We present MUSE observations in the core of the HFF galaxy cluster MACS
J1149.5+2223, where the first magnified and spatially-resolved multiple images
of SN 'Refsdal' at redshift 1.489 were detected. Thanks to a DDT program with
the VLT and the extraordinary efficiency of MUSE, we measure 117 secure
redshifts with just 4.8 hours of total integration time on a single target
pointing. We spectroscopically confirm 68 galaxy cluster members, with redshift
values ranging from 0.5272 to 0.5660, and 18 multiple images belonging to 7
background, lensed sources distributed in redshifts between 1.240 and 3.703.
Starting from the combination of our catalog with those obtained from extensive
spectroscopic and photometric campaigns using the HST, we select a sample of
300 (164 spectroscopic and 136 photometric) cluster members, within
approximately 500 kpc from the BCG, and a set of 88 reliable multiple images
associated to 10 different background source galaxies and 18 distinct knots in
the spiral galaxy hosting SN 'Refsdal'. We exploit this valuable information to
build 6 detailed strong lensing models, the best of which reproduces the
observed positions of the multiple images with a rms offset of only 0.26". We
use these models to quantify the statistical and systematic errors on the
predicted values of magnification and time delay of the next emerging image of
SN 'Refsdal'. We find that its peak luminosity should should occur between
March and June 2016, and should be approximately 20% fainter than the dimmest
(S4) of the previously detected images but above the detection limit of the
planned HST/WFC3 follow-up. We present our two-dimensional reconstruction of
the cluster mass density distribution and of the SN 'Refsdal' host galaxy
surface brightness distribution. We outline the roadmap towards even better
strong lensing models with a synergetic MUSE and HST effort.Comment: 21 pages, 9 figures, 6 tables; accepted for publication in the
Astrophysical Journal - extra information on data analysis added, all model
predictions and results unchange
Room-temp 2D photonic bandgap laser
Concerns the results of a research carried out on religious architectural monuments in the historical centre of Naples consiststing of an accurate census, cataloguing and mapping, in addition to the survey and representation of many churches and small chapels . The resulting data gave rise to an unprecedented documentation, made of traditional and laser scanner surveys, by providing the formal and historical architectural values of each artifact, with different degrees of analysis, from the metric and material determination up to the state of conservation, the decay of surfaces and the structural verification
A highly-ionized region surrounding SN Refsdal revealed by MUSE
Supernova (SN) Refsdal is the first multiply-imaged, highly-magnified, and
spatially-resolved SN ever observed. The SN exploded in a highly-magnified
spiral galaxy at z=1.49 behind the Frontier Fields Cluster MACS1149, and
provides a unique opportunity to study the environment of SNe at high z. We
exploit the time delay between multiple images to determine the properties of
the SN and its environment, before, during, and after the SN exploded. We use
the integral-field spectrograph MUSE on the VLT to simultaneously target all
observed and model-predicted positions of SN Refsdal. We find MgII emission at
all positions of SN Refsdal, accompanied by weak FeII* emission at two
positions. The measured ratios of [OII] to MgII emission of 10-20 indicate a
high degree of ionization with low metallicity. Because the same high degree of
ionization is found in all images, and our spatial resolution is too coarse to
resolve the region of influence of SN Refsdal, we conclude that this high
degree of ionization has been produced by previous SNe or a young and hot
stellar population. We find no variability of the [OII] line over a period of
57 days. This suggests that there is no variation in the [OII] luminosity of
the SN over this period, or that the SN has a small contribution to the
integrated [OII] emission over the scale resolved by our observations.Comment: 5 pages, 4 figures, accepted for publication in A&
Recovering the properties of high redshift galaxies with different JWST broad-band filters
Imaging with the James Webb Space Telescope (JWST) will allow for observing
the bulk of distant galaxies at the epoch of reionisation. The recovery of
their properties, such as age, color excess E(B-V), specific star formation
rate (sSFR) and stellar mass, will mostly rely on spectral energy distribution
fitting, based on the data provided by JWST's two imager cameras, namely the
Near Infrared Camera (NIRCam) and the Mid Infrared Imager (MIRI). In this work
we analyze the effect of choosing different combinations of NIRCam and MIRI
broad-band filters, from 0.6 {\mu}m to 7.7 {\mu}m, on the recovery of these
galaxy properties. We performed our tests on a sample of 1542 simulated
galaxies, with known input properties, at z=7-10. We found that, with only 8
NIRCam broad-bands, we can recover the galaxy age within 0.1 Gyr and the color
excess within 0.06 mag for 70% of the galaxies. Besides, the stellar masses and
sSFR are recovered within 0.2 and 0.3 dex, respectively, at z=7-9. Instead, at
z=10, no NIRCam band traces purely the {\lambda}> 4000 {\AA} regime and the
percentage of outliers in stellar mass (sSFR) increases by > 20% (> 90%), in
comparison to z=9. The MIRI F560W and F770W bands are crucial to improve the
stellar mass and the sSFR estimation at z=10. When nebular emission lines are
present, deriving correct galaxy properties is challenging, at any redshift and
with any band combination. In particular, the stellar mass is systematically
overestimated in up to 0.3 dex on average with NIRCam data alone and including
MIRI observations improves only marginally the estimation.Comment: 21 pages, 11 figures, 4 tables. Accepted for publication at the ApJ
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