200 research outputs found
Infrared Balloon Experiment: Improved instrumental configuration and assessment of instrument performance
No full textARGO: a balloon-borne telescope for measurements of the millimeter diffuse sky emission
No full textWe describe a millimeter Cassegrain Telescope, optimized for balloon observations of Cosmic Microwave Background (CMB) anisotropie
Foregrounds removal and CMB fluctuations in a multiband anisotropy experiment: ARGO 1993
No full textWe present the results of a diffuse radiation survey carried out at millimeter and submillimeter wavelengths in the Aries and Taurus sky regions. A balloon-borne telescope with 0 degrees.85 FWHM resolution and four millimeterwave bands scanned 147 independent sky directions. From the multiband observations we were able to separate two independent components: thermal emission from cirrus dust and cosmic microwave background (CMB) temperature fluctuations. A statistically significant detection of anisotropies is found in the data of the CMB channel: Delta T-sky = (24 +/- 7) mu K rms (95% CL plus 10% calibration error). Assuming uncorrelated Gaussian temperature fluctuations we find a band averaged estimate of the CMB anisotropy power spectrum C-l = (20 +/- 9) mu K-2 at l similar or equal to 110. The data are consistent with anisotropies in a ''standard'' Omega(b) = 0.05, n = 1 model normalized to the rms anisotropy detected by COBE Differential Microwave Radiometer
Constraints on cosmological parameters from MAXIMA-1
No full textWe set new constraints on a seven-dimensional space of cosmological parameters within the class of inflationary adiabatic models. We use the angular power spectrum of the cosmic microwave background measured over a wide range of l in the first flight of the MAXIMA balloon-borne experiment (MAXIMA-1) and the low-l results from the COBE Differential Microwave Radiometer experiment. We find constraints on the total energy density of the universe, Omega = 1.0(-0.30)(+0.15), the physical density of baryons, Omega (b)h(2) = 0.03 +/- 0.01, the physical density of cold dark matter, Omega (cdm)h(2) = 0.2(-0.1)(+0.2), and the spectral index of primordial scalar fluctuations, n(s) = 1.08 +/- 0.1, all at the 95% confidence level. By combining our results with measurements of high-redshift supernovae we constrain the value of the cosmological constant and the fractional amount of pressureless matter in the universe to 0.45 < <Omega>(Lambda) < 0.75 and 0.25 < Omega (m) < 0.50, at the 95% confidence level. Our results are consistent with a hat universe and the shape parameter deduced from large-scale structure, and in marginal agreement with the baryon density from big bang nucleosynthesis
Observations of the diffuse near-IR sky emission with a balloon-borne infrared telescope (TRIP)
No full textThe diffuse sky emission in 7 spectral bands between 2 and 4.6 microns has been observed with a cooled balloon-borne IR telescope (TRIP). The results, reported here, confirm state-of-the-art atmospheric models for the continuum emission lambda > 3 mu m and for the OH component at lambda < 2.3 mu m. On the other hand, excess flux in the 2.3 to 2.5 mu m atmospheric window is found at a level of lambda I-lambda similar or equal to 1.5 - 2 10(-10) W cm(-2) sr(-1). Given its modulation with the zenith angle, this signal can be attributed to residual atmospheric emission, possibly due to narrow saturated absorption lines. The sky brightness detected by TRIP in the atmospheric window is 1.5 magnitude fainter at balloon altitudes than the typical sky brightness at South Pole. However, in optimal atmospheric conditions, the sky brightness at South Pole can be only half a magnitude brighter
Genetically modified trees: State and perspectives
No full textNonic M., C. Vettori, F. Boscaleri, J. Milovanovic, and M. Sijacic Nikolic (2012): Genetically modified trees - state and perspectives. - Genetika, Vol 44, No. 2, 429-440. Genetically modified trees are the result of modern plant breeding. Its introduction into the environment for experimental purposes or wider cultivation is defined differently from country to country. Public opinion is divided! Conducted research are part of the activities within the COST Action FP0905 "Biosafety of forest transgenic trees", which aims to collect information and define the scientific attitude on genetically modified trees as a basis for future European Union (EU) policy in this field. The collected information refer to eight countries: four EU member states (Italy, Slovenia, Romania and Bulgaria) and four countries in the process of pre-accession (Croatia, Montenegro, Serbia and Bosnia and Herzegovina). A comparative analysis involved the state of forest resources (area of forest land and forest cover), forestry legislation, legislation relating to genetically modified organisms and the general public attitude on this issue. The collected information provide a good basis for understanding this issue in order to define a clear scientific attitude as a recommendation
OLIMPO: a few arcmin resolution survey at mm and sub-mm wavelengths
No full textOLIMPO is a 2.6 meter on-axis millimeter-wave Cassegrain telescope, mounted on an attitude controlled stratospheric balloon payload. This telescope is designed to be flown with a > 10 days Long Duration CircumPolar flight. The system contains 4 arrays of bolometers in the wavelength bands centered at 150, 220, 350, 600 GHz. The instrument will be diffraction limited at 150 GHz (3.5 arcminutes FWHM). It is currently planned to have a test flight from Trapani in 2003/4
Degree-scale observations of cosmic microwave background anisotropies
No full textWe report the first results of a millimeter search for cosmic microwave background (CMB) anisotropies, carried out by means of a balloon experiment (ARGO 1993). The experiment has observed 63 independent sky fields in Hercules, with an angular resolution of 52' FWHM, in four photometric bands at 2.0, 1.2, 0.8, and 0.5 mm. A statistically significant sky signal has been observed above detector noise at 2.0 and 1.2 mm. The signal is spectrally consistent with CMB anisotropies, while reasonable local sources of anisotropy are excluded. For temperature fluctuations with a coherence angle of theta(c) = 30' we get 1.4 x 10(-5) < DELTAT/T < 3.0 x 10(-5) (90% confidence interval, calibration error included). The data are also compared to theoretical models and are found to be in agreement with the CMB anisotropy detected by COBE
The ARGO 1993 flight: Detection of CMB anisotropies at angular scales around one degree
No full textWe report on the first analysis of the data of the ARGO 1993 experiment: a ballon-borne search for Cosmic Microwave Background (CMB) anisotropies, carried out by means of a 1.2m telescope and a four bands bolometric photometer. The experiment has scanned the Hercules region, with an angular resolution of 52 arcmin. FWHM, in four photometric bands at 2.0, 1.2, 0.8 and 0.5 mm. 63 independent temperature differences have been measured, and a statistically significant temperature fluctuation has been observed above detector noise at 2.0 and 1.2 mm. The signal is spectrally consistent with CMB anisotropies, while local sources of anisotropy are excluded by means of spectral tests using the four photometeric channels. The data are compared with theoretical models, and are found to be in agreement with the CMB anisotropy detected by COBE at larger angular scales if a 'standard' CDM model is assumed. The comparison of ARGO and COBE data allows us to exclude reheating models
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