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PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. Conditions at Dome C are known to be exceptional for astronomy. The seeing (above ∼30 m height), coherence time, and isoplanatic angle are all twice as good as at typical mid-latitude sites, while the water-vapour column, and the atmosphere and telescope thermal emission are all an order of magnitude better. These conditions enable a unique scientific capability for PILOT, which is addressed in this series of papers. The current paper presents an overview of the optical and instrumentation suite for PILOT and its expected performance, a summary of the key science goals and observational approach for the facility, a discussion of the synergies between the science goals for PILOT and other telescopes, and a discussion of the future of Antarctic astronomy. Paper II and Paper III present details of the science projects divided, respectively, between the distant Universe (i.e. studies of first light, and the assembly and evolution of structure) and the nearby Universe (i.e. studies of Local Group galaxies, the Milky Way, and the Solar System).
A total of 200 (Large White × Landrace) sows were used in a 39-day study to evaluate the effects of feeding a non-starch polysaccharide (NSP)-hydrolysing enzyme multicomplex (Rovabio® Excel) in conjunction with a high- or reduced nutrient-density diet during lactation on sow body condition, feed intake and progeny performance. Eight sows were selected each week for 25 weeks, blocked by parity and BW into groups of four, and within the block randomly assigned to one of the four treatments (n = 50/treatment). Treatments were: (1) LND: low energy (13.14 MJ of DE/kg), low CP (15%) diet; (2) LND + RE: LND with 50 mg/kg NSP-hydrolysing enzyme; (3) HND: high energy (14.5 MJ of DE/kg), high CP (16.5%) diet; and (4) HND + RE: HND with 50 mg/kg NSP-hydrolysing enzyme. Sows were fed treatment diets from day 109 of gestation until the day of subsequent service. Between weaning and re-service, Rovabio® Excel addition to LND diets resulted in an increase in energy intake; however, a reduction was observed when supplemented to the HND diet (P < 0.05). The inclusion of Rovabio® Excel increased feed and energy intake during week 3 (days 15 to 21) of lactation (P < 0.05). Sows fed diets supplemented with Rovabio® Excel had greater back-fat depth at weaning and service (P < 0.05); however, the magnitude of change in back-fat depth during lactation and from farrowing to service was not different between treatments. Feeding the HND diet increased energy intake before farrowing, throughout lactation and during the weaning to service interval (P < 0.01); however, overall, average daily feed intake tended to be reduced (P < 0.10). At service, sows fed the HND diet were heavier than sows fed the LND diet (P < 0.05); however, the magnitude of change in BW between treatments was not different. Feeding the HND diet to sows resulted in a tendency for heavier piglets at birth (P = 0.10) that tended to grow at a faster rate and be heavier at weaning than piglets from sows fed the LND diet (P = 0.06). These results indicate that NSP-degrading enzymes offer minimal benefit to sows and their progeny when fed before and during lactation; however, increasing energy intake of sows during lactation may beneficially affect progeny.
This report provides the recommendations of ARENA Working Group 1 concerning the development of and objectives for a wide-field, optical/infrared, 2.5 m class telescope for Antarctica. It discusses the key science drivers for such a telescope, the performance and capabilities it should have, and the logistics and infrastructure issues relevant to its construction and operation.
We examined the efficacy of 2 commercially available wipes to effectively remove, kill, and prevent the transfer of both methicillin-resistant and methicillin-susceptible Staphylococcus aureus from contaminated surfaces. Although wipes play a role in decreasing the number of pathogenic bacteria from contaminated surfaces, they can potentially transfer bacteria to other surfaces if they are reused.
In a first part the paper reviews some of the major Spitzer legacy imaging
surveys to show the quantity of data available, and the subsequent need for
spectroscopic follow-up surveys on equivalent wide fields. They are
required for many science cases, as giant star forming regions, young
planetary nebulea, the Galactic Centre, nearby galaxies, distant galaxy
clusters. This capability of wide, integral field spectroscopy, missing in
all the existing and planned astronomical facilities, thus, appears among
the most pertinent choice for the future of astronomy at Dome C. For the
instrumental solution, a
flexibility in the choice of spectral resolution and spectral domain on a
broad infrared range is desirable to be able to undertake a large variety of study, on
extragalactic and galactic fields as well. This capability can be only offered by
an Imaging FTS. It fully benefits from the low thermal background
emission of Dome C, particularly in the 1.8 to 5.5 μm range, and reach
an optimum sensitivity by imaging emission lines. In a difficult site as
Dome C, a dedicated, medium-size telescope would be the most effective way
of exploiting such an instrument.
The paper starts from the rationale, already presented in 2004 at the first
Toulouse meeting on astronomy at Dome C, to propose an infrared, wide-field
Imaging FTS (IFTS) as a first generation instrument behind a 2 to 3 m
optical telescope. Such an instrument could fully take advantage of all the
properties of the site for imagery and spectroscopy and offer an instrument
presently needed after the numerous imaging surveys. Simulations have been
conducted to define the range of field size and of resolution which could
be reachable. Then, derived from the study of H2 Explorer (H2EX) an IFTS
for a space project, an optical design for a 2 to 25 μm instrument,
imaging a 10'×10' field, has been developed, based on a dual ouput
interferometer, using cat's eyes retroreflectors in its arms. With a
maximum optical path difference (OPD) of 30 cm a spectral resolution of
105 at 2 μm (20 000 at 25 μm) is possible with this field
size, behind a PILOT-type telescope (2.4 m) and a minimum beam size of
80 mm within the interferometer. With the same optics and the same
mechanism of control of the OPD, two interchangeable beamsplitters (2 to
5.5 μm and 6 to 25 μm) and the corresponding detector arrays (InSb
and Si:As) cover the entire spectral range. The
instrument must be cryogenic (temperature around 50 K) to make the thermal
background from the optics negligible. The best sensitivity is obtained
through narrow-band filters (2%) isolating lines in emission-line
regions. Such a survey instrument has never been built before. It calls for
a dedicated telescope for the best use of this type of instrument on the
Dome C site.
The hot strip mill of Arcelor in Fos has been revamped between February 2001 and July 2002.
Positive/negative (±200 tons per side) bending actuators were installed on the four first
stands of the finisher. This investment made it possible to further improve the geometry
of the products (crown and thickness control), as well as the reliability and productivity
of the HSM.
In the study of extended sources such as star forming regions, galactic
planetary nebulae or comets wide field integral-field spectroscopy at high
spectral resolution in the infrared, would be the ideal tool. It is shown
that an imaging FTS (IFTS) is the only instrument which can combine a wide
field, up to ~10', with a spectral resolution ≥105. At
Dome C, in the 2 to 25 μm region, as instrument of a 3-m class
telescope, a wide-field IFTS would have no equivalent in space and on
ground. It can take full advantage of all the astronomical properties of
this site, in particular the lowest thermal background emission conditions
on Earth. A program to simulate the expected performances has been
developed. At the highest resolution the best sensitivity implies the
use of narrow-band filters on the emission lines of interest.
The photometric instruments in space (most, corot)
are going to open new insights on the knowledge of stellar interiors. However,
ground-based asteroseismic observations remain justified as they can bring complementary velocity measurements, and allow the study of much more targets.
A competitive instrument must make it possible the observation of
a representative set of solar-like stars
with magnitude down to 5, and a velocity precision as low as a few
cm s-1 after 5 nights behind a 2-m class telescope.
The siamois project based on a Fourier interferometer has emerged as a
suitable solution to fulfil the specifications for a ground-based
asteroseismic network. The photon noise limited
performances have been examined and compared to those of a grating
spectrometer (Mosser et al. 2003) showing
that this type of instrument can reach the required specifications. With a
design based on a monolithic interferometer, with a compact
instrument easy to set up, to operate remotely with a limited data-flow,
it can fit well the harsh conditions of Dome C.
Main advantage, a single unit is needed due to the
circumpolar position of the targets for the Doppler detection of stellar
oscillations on solar-type stars.
As a test bed, siamois could be put on 0.8-m class telescope like irait
(Busso et al. these proceedings).
D. Field, Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark and Observatoire de Paris-Meudon,
J. L. Lemaire, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France; Université de Cergy-Pontoise, F-95806 Cergy Cedex, France,
J. P. Maillard, Institut d'Astrophysique, 98bis, Boulevard Arago, F-75014 Paris, France,
S. Leach, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France,
G. Pineau des Forêts, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France,
E. Falgarone, Ecole Normale Supérieure, 24 Rue Lhomond, 75231 Paris Cedex 05, France,
F. P. Pijpers, Theoretical Astrophysics Centre, University of Aarhus, DK-8000 Aarhus C, Denmark,
M. Gerin, Ecole Normale Supérieure, 24 Rue Lhomond, 75231 Paris Cedex 05, France,
F. Rostas, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France,
D. Rouan, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France,
L. Vannier, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France
High spatial and spectral resolution observations are reported of H2 infrared emission from the reflection nebulæ NGC2023 and NGC7023. The local molecular gas is strongly perturbed by the presence of the massive stars which power these nebulae. Data yield information on the small-scale structure, the temperature and density and the dynamics of the excited gas. Excited material is found to be hot (400-500K), dense (105-106 cm−3) and clumped containing substantial flows and velocity fields.
The two reflection nebulæ NGC2023 and NGC7023 are prototypes of regions in which recently formed massive stars are interacting strongly with their parent gas. The outcome of these interactions is important in understanding the cycle of star formation in which massive stars are created and, by perturbing their surroundings, influence the nature of the gas in which future stars may form. The goal of our work is to examine in detail the perturbed gas around massive young stars. Some of the observations of infrared (IR) emission of molecular hydrogen in NGC2023 and NGC7023, performed in recent years in our group, are described below.
Nebulosity in NGC2023 and NGC7023 is excited by B-stars of temperatures respectively 22,000K and 20,400K. The distance between the star and the illuminated surrounding gas is ∼ 0.1 pc in both nebulæ. NGC2023 shows a strong IR excess with emission from small dust particles plus extended red emission, and has an associated molecular cloud with OH, HCHO, HCN, CO, CH, CH+ and other detections (see Field et al. 1994).
C. Joblin, CESR-CNRS, 9 Av. du Colonel Roche, 31028 Toulouse, France,
J. P. Maillard, IAP-CNRS, 98 bis Bd. Arago, 75014 Paris, France,
I. Vauglin, Observatoire de Lyon, 69561 Saint Genis Laval Cdx, France,
C. Pech, CESR-CNRS, 9 Av. du Colonel Roche, 31028 Toulouse, France,
P. Boissel, LPCR-CNRS, Bât 350, Université Paris Sud, 91405 Orsay Cdx, France
Polycyclic aromatic hydrocarbons (PAHs) could play an important role in interstellar chemistry. In particular, it is important to evaluate their possible contribution to the formation of H2. To address this question, recent laboratory results and new observations are presented. Although still preliminary, these first results are very encouraging. First, the photodissociation of PAHs isolated in ion traps and exposed to UV light involves the loss of pairs of hydrogen atoms which are likely to form H2 molecules. Second, the PAH and H2 emission observed in the photodissociation region associated with the young stellar object S106-IR was found to coincide at some positions. This suggests a coupling between the interstellar PAH and H2 populations. More results are expected in the near future.
The Infrared Space Observatory (ISO) has recently showed the ubiquity of the emission features at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 µm in the interstellar medium (First ISO Results 1996, Boulanger 1999). Amongst the carriers for these features, polycyclic aromatic hydrocarbons (PAHs) are the best candidates as far as an excitation mechanism and a reasonable spectral agreement are concerned. A lot of infrared spectroscopy has been performed in the laboratory since the initial proposal by Léger & Puget (1984) and Allamandola et al. (1985) to find the laboratory species whose spectrum match the interstellar spectrum (Szczepanski & Vala 1993, Joblin et al. 1995, Cook et al. 1998, Allamandola & Hudgins 1999, Hudgins & Allamandola 1999, etc…).
Reducing the protein content of commercial diets in Europe would reduce environmental nitrogen pollution. It has been demonstrated that this could be achieved by employing crystalline amino acid supplementation (e.g. Chavel and Granier, 1994; Fuller et al, 1979a, b). Accurate information on the true ileal digestible amino acid requirements of the modern lean genotype pig is necessary in order to ensure optimal production at low protein intakes. The objective of this study was to identify the optimum ileal digestible methionine:lysine (met:lys) ratio to achieve maximal growth and food conversion efficiency of the lean genotype pig given low protein diets.
The source IRS16 has been observed with the FTS at the Canada-France -Hawaii Telescope, in July 1987 and May 1988, in an attempt of spectral resolution associated with spatial resolution. Three positions were observed with a 2.5 arcsec aperture, centered on the sub-structures SW, NE and NW. Brα and Brγ spectra were obtained at respective velocity resolutions of 210 and 140 km s−1, allowing resolution of the line profiles. The detection of hydrogen emission was marginal on NW, and strong on SW and NE, showing a net velocity difference of the gas of 160 km s−1. The Brα line on SW has very extended wings suggesting two components of different origin. These observations imply a difference of physical nature of the objects located in the vicinity of Sgr A∗.
The multiplex properties of the Fourier Transform Spectrometer (FTS) can be considered as disadvantageous with modern detectors and large telescopes, the dominant noise source being no longer in most applications the detector noise. Nevertheless, a FTS offers a gain in information and other instrumental features remain: flexibility in choosing resolving power up to very high values, large throughput, essential in high–resolution spectroscopy with large telescopes, metrologic accuracy, automatic substraction of parasitic background. The signal–to–noise ratio in spectra can also be improved: by limiting the bandwidth with cold filters or even cold dispersers, by matching the instrument to low background foreoptics and high–image quality telescopes. The association with array detectors provides the solution for the FTS to regain its full multiplex advantage.
Profiles of the hydrogen Paß, Paγ and Brγ lines of an A0IV star γ Gem were obtained at a high resolution to investigate at what degree the hydrogen IR lines can be useful for fine tests of the NLTE model atmospheres. All three lines show a deep and narrow absorption core in a good qualitative agreement with the predictions of the available NLTE models for B stars, thus proving that the NLTE effects are important for A stars as well. New NLTE models were computed to extend the grid down to 9500 °K and to include 8 discrete levels of H atom into the energy balance. However, further theoretical work is necessary to compare the observed profiles and the theory.
High resolution spectrograms of the two well known Be binary systems ζ Tau and KX And were obtained , in the IR ( 2-2.5µ ), with the Fourier Transform Spectrometer of the CFHT. They do not reveal evidence of a cool giant companion.
We have used the Cassegrain-focus Fourier Transform Spectrometer of the Canada-France-Hawaii Telescope to record high-resolution (0.03 cm−1), high signal-to-noise ratio spectra of the extreme carbon stars IRC+10°216 and CIT6 in the 2850–3100 cm−1 region. Upper limits were obtained for the column densities of silicon nitride (2-0 band of the A-X system), ethylene (ν11 fundamental band at ν0 = 2988.7 cm−1), and ethane (ν7 fundamental band at ν0 = 2985.4 cm−1).
A Michelson interferometer was put into operation during the year 1972 at the Coudé focus of the Haute-Provence Observatory’s 76-in. telescope. We built this instrument at Aimé Cotton Laboratory (Orsay-France) where the method of Fourier Transform Spectroscopy has been largely developed in the direction of very high resolution work. A complete description of this device has been given elsewhere (Guelachvili and Maillard, 1970) and further details on the present study are reported by Maillard (1973).
High resolution spectra of Jupiter and Saturn were obtained with a Fourier Transform Michelson interferometer. A comparison of the observed spectra, after elimination of the solar and terrestrial contributions to absorption, with synthetic profiles for the reflecting layer model has permitted new determinations of the Lorentz half-width, the methane abundance, the rotational temperature and the pressure at the level of formation of the methane lines for both Jupiter and Saturn.
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