37 research outputs found
L3CCD results in pure photon counting mode
Theoretically, L3CCDs are perfect photon counting devices promising high
quantum efficiency (90%) and sub-electron readout noise (<0.1
e-). We discuss how a back-thinned 512x512 frame-transfer L3CCD (CCD97) camera
operating in pure photon counting mode would behave based on experimental data.
The chip is operated at high electromultiplication gain, high analogic gain and
high frame rate. Its performance is compared with a modern photon counting
camera (GaAs photocathode, QE 28%) to see if L3CCD technology, in its
current state, could supersede photocathode-based devices.Comment: 9 pages, 9 figures, to appear in SPIE conference proceedings vol
5499, "Optical & IR Detectors for Astronomy" Glasgow UK, 21-24 June 200
Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer
We present observations of the nearby barred starburst galaxy, M83 (NGC5236),
with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William
Herschel Telescope on La Palma. The unprecedented high resolution observations,
of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the
galaxy. The velocity field displays the dominant disk rotation with signatures
of gas inflow from kpc scales down to the nuclear regions. At the inner Inner
Lindblad Resonance radius of the main bar and centerd at the dynamical center
of the main galaxy disk, a nuclear rapidly
rotating disk with scale length of pc has formed. The nuclear
starburst is found in the vicinity as well as inside this nuclear disk, and our
observations confirm that gas spirals in from the outer parts to feed the
nuclear starburst, giving rise to several star formation events at different
epochs, within the central 100 pc radius of M83.Comment: Accepted for publication in ApJ Letters. High-resolution version can
be found at http://www.astro.su.se/~kambiz/DOC/paper-M83.pd
The Brazilian Tunable Filter Imager for the SOAR telescope
This paper presents a new Tunable Filter Instrument for the SOAR telescope.
The Brazilian Tunable Filter Imager (BTFI) is a versatile, new technology,
tunable optical imager to be used in seeing-limited mode and at higher spatial
fidelity using the SAM Ground-Layer Adaptive Optics facility at the SOAR
telescope. The instrument opens important new science capabilities for the SOAR
community, from studies of the centers of nearby galaxies and the insterstellar
medium to statistical cosmological investigations. The BTFI takes advantage of
three new technologies. The imaging Bragg Tunable Filter concept utilizes
Volume Phase Holographic Gratings in a double-pass configuration, as a tunable
filter, while a new Fabry-Perot (FP) concept involves technologies which allow
a single FP etalon to act over a large range of interference orders and
spectral resolutions. Both technologies will be in the same instrument.
Spectral resolutions spanning the range between 25 and 30,000 can be achieved
through the use of iBTF at low resolution and scanning FPs beyond R ~2,000. The
third new technologies in BTFI is the use of EMCCDs for rapid and cyclically
wavelength scanning thus mitigating the damaging effect of atmospheric
variability through data acquisition. An additional important feature of the
instrument is that it has two optical channels which allow for the simultaneous
recording of the narrow-band, filtered image with the remaining (complementary)
broad-band light. This avoids the uncertainties inherent in tunable filter
imaging using a single detector. The system was designed to supply tunable
filter imaging with a field-of-view of 3 arcmin on a side, sampled at 0.12" for
direct Nasmyth seeing-limited area spectroscopy and for SAM's visitor
instrument port for GLAO-fed area spectroscopy. The instrument has seen first
light, as a SOAR visitor instrument. It is now in comissioning phase.Comment: accepted in PAS
FIREBall-2: advancing TRL while doing proof-of-concept astrophysics on a suborbital platform
Here we discuss advances in UV technology over the last decade, with an
emphasis on photon counting, low noise, high efficiency detectors in
sub-orbital programs. We focus on the use of innovative UV detectors in a NASA
astrophysics balloon telescope, FIREBall-2, which successfully flew in the Fall
of 2018. The FIREBall-2 telescope is designed to make observations of distant
galaxies to understand more about how they evolve by looking for diffuse
hydrogen in the galactic halo. The payload utilizes a 1.0-meter class telescope
with an ultraviolet multi-object spectrograph and is a joint collaboration
between Caltech, JPL, LAM, CNES, Columbia, the University of Arizona, and NASA.
The improved detector technology that was tested on FIREBall-2 can be applied
to any UV mission. We discuss the results of the flight and detector
performance. We will also discuss the utility of sub-orbital platforms (both
balloon payloads and rockets) for testing new technologies and proof-of-concept
scientific ideasComment: Submitted to the Proceedings of SPIE, Defense + Commercial Sensing
(SI19
FIREBall-2: The Faint Intergalactic Medium Redshifted Emission Balloon Telescope
The Faint Intergalactic Medium Redshifted Emission Balloon (FIREBall) is a
mission designed to observe faint emission from the circumgalactic medium of
moderate redshift (z~0.7) galaxies for the first time. FIREBall observes a
component of galaxies that plays a key role in how galaxies form and evolve,
likely contains a significant amount of baryons, and has only recently been
observed at higher redshifts in the visible. Here we report on the 2018 flight
of the FIREBall-2 Balloon telescope, which occurred on September 22nd, 2018
from Fort Sumner, New Mexico. The flight was the culmination of a complete
redesign of the spectrograph from the original FIREBall fiber-fed IFU to a
wide-field multi-object spectrograph. The flight was terminated early due to a
hole in the balloon, and our original science objectives were not achieved. The
overall sensitivity of the instrument and telescope was 90,000 LU, due
primarily to increased noise from stray light. We discuss the design of the
FIREBall-2 spectrograph, modifications from the original FIREBall payload, and
provide an overview of the performance of all systems. We were able to
successfully flight test a new pointing control system, a UV-optimized,
delta-doped and coated EMCCD, and an aspheric grating. The FIREBall-2 team is
rebuilding the payload for another flight attempt in the Fall of 2021, delayed
from 2020 due to COVID-19.Comment: 23 Pages, 14 Figures, Accepted for Publication in Ap
L'organisation du travail en élevage : Enseigner la méthode bilan travail
La méthode Bilan Travail vise à produire des connaissances sur l'organisation du travail et les temps de travaux en exploitation d'élevage. En situation pédagogique auprès d'élèves de l'enseignement technique, la méthode permet à un groupe de travailler en démarche de projet dans un cadre pluridisciplinaire avec des alternances nécessaires entre apports théoriques, travaux dirigés ou pratiques, et travail personnel. Elle place les apprenants en situation réelle dans le cadre de l'exploitation agricole et mobilise leurs qualités d'observation, d'écoute, de réflexion et d'analyse. Cette méthode est utilisée par des enseignants et formateurs de l'enseignement agricole technique qui l'intègrent dans des modules de formations allant du niveau V au niveau III
"What are you interested in?"-A survey on 601 nursing homes residents activities interests
ABSTRACT Lack of engagement in activities is a common feature of nursing homes residents. As apathy is the most frequent behavioural disturbance, understanding residents' interests is a milestone for tailored challenging interventions targeting engagement enhancement. Objective: To depict the activities interests of nursing homes residents. Method: An electronic version of the Test of Interest "TILT" which regroups 40 images of activities has been developed and adapted for the Ipad. Residents were asked to answer by yes or no to the question "are you interested by this activity", for each activity found interesting, the patient had then to categorize it in either Work/ occupation-Personal-Leisure-Family. Population: A total of 601 residents from 19 nursing homes have completed the survey from March to May 2011. The surveyed nursing homes from the South East of France were comparable of nursing homes figures in France. Results: We interviewed 601 individuals (female, n = 484) aged 85.9 years, out of those, 56% had stayed more than one year in an institution. Nearly half of the population (45.3%) was from 80 -89 year of age, followed by 36.1% from 90 -99. The educational background was principally from primary school (36%) and high school (30.8%). Most of the residents were classified has having dementia (35.3%). From the 40 activities presented to each participant, "enjoying a good meal" has been found to be the most interesting activity by 83% of the population followed by "dressing up", 75.9% and "watching TV", 75.5%. Female participants reported more interest in place of worship, family pictures and being with grand children then males (p < 0.01). We found that the presence of "dementia" diagnosis" triggered the lack of interest compared to none demented or none cognitively impaired residents (p < 0.01). It was found that participants aged 55 -69 were more the most interested to do video games (p < 0.05), though this may be interpreted as a positive step toward functional and cognitive rehabilitation program using virtual reality as a mean for intervention