227 research outputs found
The warm, the excited, and the molecular gas: GRB 121024A shining through its star-forming galaxy
We present the first reported case of the simultaneous metallicity
determination of a gamma-ray burst (GRB) host galaxy, from both afterglow
absorption lines as well as strong emission-line diagnostics. Using
spectroscopic and imaging observations of the afterglow and host of the
long-duration Swift GRB121024A at z = 2.30, we give one of the most complete
views of a GRB host/environment to date. We observe a strong damped Ly-alpha
absorber (DLA) with a hydrogen column density of log N(HI) = 21.88 +/- 0.10, H2
absorption in the Lyman-Werner bands (molecular fraction of log(f)~ -1.4;
fourth solid detection of molecular hydrogen in a GRB-DLA), the nebular
emission lines H-alpha, H-beta, [O II], [O III] and [N II], as well as metal
absorption lines. We find a GRB host galaxy that is highly star-forming (SFR ~
40 solar masses/yr ), with a dust-corrected metallicity along the line of sight
of [Zn/H]corr = -0.6 +/- 0.2 ([O/H] ~ -0.3 from emission lines), and a
depletion factor [Zn/Fe] = 0.85 +/- 0.04. The molecular gas is separated by 400
km/s (and 1-3 kpc) from the gas that is photoexcited by the GRB. This implies a
fairly massive host, in agreement with the derived stellar mass of
log(M/M_solar ) = 9.9+/- 0.2. We dissect the host galaxy by characterising its
molecular component, the excited gas, and the line-emitting star-forming
regions. The extinction curve for the line of sight is found to be unusually
flat (Rv ~15). We discuss the possibility of an anomalous grain size
distributions. We furthermore discuss the different metallicity determinations
from both absorption and emission lines, which gives consistent results for the
line of sight to GRB 121024A.Comment: 20 pages, 11 figures, accepted by MNRA
Sustainable smart tags with two‐step verification for anticounterfeiting triggered by the photothermal response of upconverting nanoparticles
No abstract available.This work was developed within the scope of the projects CICECO-Aveiro
Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020) and
Shape of Water (PTDC/NAN-PRO/3881/2020) financed by Portuguese
funds through the FCT/MEC and when appropriate cofinanced by
FEDER under the PT2020 Partnership Agreement. F.E.M. acknowledges
the funding received from the European Union’s Horizon 2020 research
and innovation programme under the Marie Sklodowska-Curie grant
agreement no. 823941. The support of the European Union’s Horizon
2020 FET Open program under grant agreement no. 801305
(NanoTBTech) is also acknowledged. R.R.S. acknowledges the financial
support from the Brazilian agency FAPESP (process no. 16/06612-6).publishe
Safety and Efficacy of Risuteganib in Intermediate Non-exudative Age-Related Macular Degeneration
Purpose : Risuteganib is a small synthetic peptide that regulates select integrin functions involved in the pathogenesis of dry age-related macular degeneration (AMD). This study evaluated the safety and efficay of risuteganib for the treatment of dry AMD.
Methods : Randomized, double-masked, placebo-controlled Phase 2 study in eyes with intermediate dry AMD presenting with best-corrected visual acuity (BCVA) between 20/40-20/200 was conducted across multiple centers in the United States. Patients were randomized to receive either intravitreal 1.0mg risuteganib or sham injection at baseline. At week 16, patients in the risuteganib group received a second dose and the sham group crossed over and receive a single dose of 1.0mg risuteganib. The primary endpoint was the percentage of population with ≥ 8 letters BCVA gain from baseline to week 28 in 1.0mg risuteganib vs baseline to week 12 for sham.
Results : Forty-five patients were enrolled in the study. At baseline, mean patient age was 78.8 and 75.9 years and mean baseline BCVA was 67.1 and 64.4 letters in the sham and risuteganib groups, respectively. The primary endpoint was met; 48% of patients in the risuteganib group at week 28 and 7% of patients in the sham group at week 12 gained > 8 letters from baseline (p=0.013). Of the risuteganib treated patients, 20% gained > 15 letters at week 28; no patients in the sham group at week 12 had this gain. On a post-hoc masked analysis by 2 independent reading centers, greater outer retinal and photoreceptor thickness and volume and smaller ellipsoid zone defect area in the central 1 mm zone at baseline were associated with increased BCVA response to risuteganib. Risuteganib demonstrated a good safety profile in this study.
Conclusions : Risuteganib showed significant benefit over sham in patients with dry AMD with respect to proportion of patients gaining > 8 letters of BCVA from baseline. Furthermore, post hoc analysis provides preliminary insights into baseline anatomic features that may help to determine likelihood of BCVA response to risuteganib. These findings will be confirmed in an upcoming larger trial
The miniJPAS survey: Optical detection of galaxy clusters with PZWav
Galaxy clusters are an essential tool to understand and constrain the
cosmological parameters of our Universe. Thanks to its multi-band design, J-PAS
offers a unique group and cluster detection window using precise photometric
redshifts and sufficient depths. We produce galaxy cluster catalogues from the
miniJPAS, which is a pathfinder survey for the wider J-PAS survey, using the
PZWav algorithm. Relying only on photometric information, we provide optical
mass tracers for the identified clusters, including richness, optical
luminosity, and stellar mass. By reanalysing the Chandra mosaic of the AEGIS
field, alongside the overlapping XMM-Newton observations, we produce an X-ray
catalogue. The analysis reveals the possible presence of structures with masses
of 4 M at redshift 0.75, highlighting the depth of the
survey. Comparing results with those from two other cluster catalogues,
provided by AMICO and VT, we find common clusters with cluster centre
offsets of 10060 kpc and redshift differences below 0.001. We provide a
comparison of the cluster catalogues with a catalogue of massive galaxies and
report on the significance of cluster selection. In general, we are able to
recover approximately 75 of the galaxies with 2 M. This study emphasises the potential of the J-PAS survey and
the employed techniques down to the group scales.Comment: 15 pages, 11 figures, 5 tables. Submitted to A&A in December 19, 202
Cluster Lenses
Clusters of galaxies are the most recently assembled, massive, bound
structures in the Universe. As predicted by General Relativity, given their
masses, clusters strongly deform space-time in their vicinity. Clusters act as
some of the most powerful gravitational lenses in the Universe. Light rays
traversing through clusters from distant sources are hence deflected, and the
resulting images of these distant objects therefore appear distorted and
magnified. Lensing by clusters occurs in two regimes, each with unique
observational signatures. The strong lensing regime is characterized by effects
readily seen by eye, namely, the production of giant arcs, multiple-images, and
arclets. The weak lensing regime is characterized by small deformations in the
shapes of background galaxies only detectable statistically. Cluster lenses
have been exploited successfully to address several important current questions
in cosmology: (i) the study of the lens(es) - understanding cluster mass
distributions and issues pertaining to cluster formation and evolution, as well
as constraining the nature of dark matter; (ii) the study of the lensed objects
- probing the properties of the background lensed galaxy population - which is
statistically at higher redshifts and of lower intrinsic luminosity thus
enabling the probing of galaxy formation at the earliest times right up to the
Dark Ages; and (iii) the study of the geometry of the Universe - as the
strength of lensing depends on the ratios of angular diameter distances between
the lens, source and observer, lens deflections are sensitive to the value of
cosmological parameters and offer a powerful geometric tool to probe Dark
Energy. In this review, we present the basics of cluster lensing and provide a
current status report of the field.Comment: About 120 pages - Published in Open Access at:
http://www.springerlink.com/content/j183018170485723/ . arXiv admin note:
text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author
The miniJPAS survey: clusters and galaxy groups detection with AMICO
Samples of galaxy clusters allow us to better understand the physics at play
in galaxy formation and to constrain cosmological models once their mass,
position (for clustering studies) and redshift are known. In this context,
large optical data sets play a crucial role. We investigate the capabilities of
the Javalambre-Physics of the Accelerating Universe Astrophysical Survey
(J-PAS) in detecting and characterizing galaxy groups and clusters. We analyze
the data of the miniJPAS survey, obtained with the JPAS-Pathfinder camera and
covering deg centered on the AEGIS field to the same depths and with
the same 54 narrow band plus 2 broader band near-UV and near-IR filters
anticipated for the full J-PAS survey. We use the Adaptive Matched Identifier
of Clustered Objects (AMICO) to detect and characterize groups and clusters of
galaxies down to in the redshift range . We detect 80, 30
and 11 systems with signal-to-noise ratio larger than 2.5, 3.0 and 3.5,
respectively, down to . We derive mass-proxy scaling
relations based on Chandra and XMM-Newton X-ray data for the signal amplitude
returned by AMICO, the intrinsic richness and a new proxy that incorporates the
galaxies' stellar masses. The latter proxy is made possible thanks to the J-PAS
filters and shows a smaller scatter with respect to the richness. We fully
characterize the sample and use AMICO to derive a probabilistic membership
association of galaxies to the detected groups that we test against
spectroscopy. We further show how the narrow band filters of J-PAS provide a
gain of up to 100% in signal-to-noise ratio in detection and an uncertainty on
the redshift of clusters of only placing J-PAS in
between broadband photometric and spectroscopic surveys. The performances of
AMICO and J-PAS with respect to mass sensitivity, mass-proxies qualityComment: 15 pages, 12 figures, 3 tables, submitted to A&
Bayesian Bootstrap Inference for the ROC Surface
Accurate diagnosis of disease is of great importance in clinical practice and
medical research. The receiver operating characteristic (ROC) surface is a
popular tool for evaluating the discriminatory ability of continuous diagnostic
test outcomes when there exist three ordered disease classes (e.g., no disease,
mild disease, advanced disease). We propose the Bayesian bootstrap, a fully
nonparametric method, for conducting inference about the ROC surface and its
functionals, such as the volume under the surface. The proposed method is based
on a simple, yet interesting, representation of the ROC surface in terms of
placement variables. Results from a simulation study demonstrate the ability of
our method to successfully recover the true ROC surface and to produce valid
inferences in a variety of complex scenarios. An application to data from the
Trail Making Test to assess cognitive impairment in Parkinson's disease
patients is provided
The warm, the excited, and the molecular gas: GRB 121024A shining through its star-forming galaxy★
We present the first reported case of the simultaneous metallicity determination of a gamma-ray burst (GRB) host galaxy, from both afterglow absorption lines as well as strong emission-line diagnostics. Using spectroscopic and imaging observations of the afterglow and host of the long-duratio
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