Search results for "observatory"
showing 10 items of 329 documents
The energy spectrum of cosmic rays beyond the turn-down around 1017 eV as measured with the surface detector of the Pierre Auger Observatory
2021
The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargüe. We are very grateful to the following agencies and organizations for financial support: Argentina – Comisión Nacional de Energía Atómica; Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Gobierno de la Provincia de Mendoza; Municipalidad de Malargüe; NDM Holdings and Valle Las Leñas; in gratitude for their continuing cooperation over land access; Australia – the Australian Research Council; Be…
JUNO sensitivity to low energy atmospheric neutrino spectra
2021
Atmospheric neutrinos are one of the most relevant natural neutrino sources that can be exploited to infer properties about cosmic rays and neutrino oscillations. The Jiangmen Underground Neutrino Observatory (JUNO) experiment, a 20 kton liquid scintillator detector with excellent energy resolution is currently under construction in China. JUNO will be able to detect several atmospheric neutrinos per day given the large volume. A study on the JUNO detection and reconstruction capabilities of atmospheric $\nu_e$ and $\nu_\mu$ fluxes is presented in this paper. In this study, a sample of atmospheric neutrino Monte Carlo events has been generated, starting from theoretical models, and then pro…
ARGO-YBJ constraints on very high energy emission from GRBs
2009
The ARGO-YBJ (Astrophysical Radiation Ground-based Observatory at YangBaJing) experiment is designed for very high energy $\gamma$-astronomy and cosmic ray researches. Due to the full coverage of a large area ($5600 m^2$) with resistive plate chambers at a very high altitude (4300 m a.s.l.), the ARGO-YBJ detector is used to search for transient phenomena, such as Gamma-ray bursts (GRBs). Because the ARGO-YBJ detector has a large field of view ($\sim$2 sr) and is operated with a high duty cycle ($>$90%), it is well suited for GRB surveying and can be operated in searches for high energy GRBs following alarms set by satellite-borne observations at lower energies. In this paper, the sensitivit…
APOGEE Data Releases 13 and 14: Stellar Parameter and Abundance Comparisons with Independent Analyses
2018
Data from the SDSS-IV / Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) have been released as part of SDSS Data Releases 13 (DR13) and 14 (DR14). These include high resolution H-band spectra, radial velocities, and derived stellar parameters and abundances. DR13, released in August 2016, contained APOGEE data for roughly 150,000 stars, and DR14, released in August 2017, added about 110,000 more. Stellar parameters and abundances have been derived with an automated pipeline, the APOGEE Stellar Parameter and Chemical Abundance Pipeline (ASPCAP). We evaluate the performance of this pipeline by comparing the derived stellar parameters and abundances to those inferred from opti…
SPI/INTEGRAL observation of the Cygnus region
2003
We present the analysis of the first observations of the Cygnus region by the SPI spectrometer onboard the Integral Gamma Ray Observatory, encompassing ${\sim}$ 600 ks of data. Three sources namely Cyg X-1, Cyg X-3 and EXO 2030+375 were clearly detected. Our data illustrate the temporal variability of Cyg X-1 in the energy range from 20 keV to 300 keV. The spectral analysis shows a remarkable stability of the Cyg X-1 spectra when averaged over one day timescale. The other goal of these observations is SPI inflight calibration and performance verification. The latest objective has been achieved as demonstrated by the results presented in this paper.
The Multi-frequency Robotic facility REM: first results
2004
The REM Observatory, recently installed and commissioned at la Silla Observatory Chile, is the first moderate aperture robotic telescope able to cover simultaneously the visible-NIR (0.45-2.3 microns) wavelength range. Due to its very fast pointing and its full robotization REM is conceived for fast transients observation. The high throughput Infrared Camera (REMIR) and the Visible imaging spectrograph (ROSS), simultaneously fed by a dichroic, allow to collect high S/N data in an unprecedented large spectral range on a telescope of this size. The REMobservatory is an example of a versatile and agile facility necessary complement to large telescopes in fields in which rapid response and/or t…
Gravitational lensing on the Cosmic Microwave Background by gravity waves
1997
We study the effect of a stochastic background of gravitational waves on the gravitational lensing of the Cosmic Microwave Background (CMB) radiation. It has been shown that matter density inhomogeneities produce a smoothing of the acoustic peaks in the angular power spectrum of the CMB anisotropies. A gravitational wave background gives rise to an additional smoothing of the spectrum. For the most simple case of a gravitational wave background arising during a period of inflation, the effect results to be three to four orders of magnitude smaller than its scalar counterpart, and is thus undetectable. It could play a more relevant role in models where a larger background of gravitational wa…
Caii H and K spectroscopic observations in active binary systems
1990
We have performed high resolution spectroscopic observations of five active binary systems in the Caii H and K lines at La Palma Observatory. We present the absolute fluxes calculated at the surface of the stars and we discuss the spectral characteristics observed, presence of double emissions and phase variations.
XMM‐NewtonObservations of the Supernova Remnant IC 443. I. Soft X‐Ray Emission from Shocked Interstellar Medium
2006
The shocked interstellar medium around IC443 produces strong X-ray emission in the soft energy band (E<1.5 keV). We present an analysis of such emission as observed with the EPIC MOS cameras on board the XMM-Newotn observatory, with the purpose to find clear signatures of the interactions with the interstellar medium (ISM) in the X-ray band, which may complement results obtained in other wavelenghts. We found that the giant molecular cloud mapped in CO emission is located in the foreground and gives an evident signature in the absorption of X-rays. This cloud may have a torus shape and the part of torus interacting with the IC443 shock gives rise to 2MASS-K emission in the southeast. The…
The wide field imager for the International X-ray Observatory
2009
The large collecting area of the X-ray optics on the International X-ray Observatory (IXO), their good angular resolution, the wide bandwidth of X-ray energies and the high radiation tolerance required for the X-ray detectors in the focal plane have stimulated a new development of devices which unify all those science driven specifications in one single detector. The concept of a monolithic, back-illuminated silicon active pixel sensor (APS) based on the DEPFET structure is proposed for the IXO mission, being a fully depleted, back-illuminated 450 μm thick detector with a physical size of about 10 × 10 cm 2 corresponding to the 18 arcmin field of view. The backside will be covered with an i…