1,543 research outputs found
Planck LFI flight model feed horns
this paper is part of the Prelaunch status LFI papers published on JINST:
http://www.iop.org/EJ/journal/-page=extra.proc5/jinst The Low Frequency
Instrument is optically interfaced with the ESA Planck telescope through 11
corrugated feed horns each connected to the Radiometer Chain Assembly (RCA).
This paper describes the design, the manufacturing and the testing of the
flight model feed horns. They have been designed to optimize the LFI optical
interfaces taking into account the tight mechanical requirements imposed by the
Planck focal plane layout. All the eleven units have been successfully tested
and integrated with the Ortho Mode transducers.Comment: This is an author-created, un-copyedited version of an article
accepted for publication in JINST. IOP Publishing Ltd is not responsible for
any errors or omissions in this version of the manuscript or any version
derived from it. The definitive publisher authenticated version is available
online at 10.1088/1748-0221/4/12/T1200
Full Sky Study of Diffuse Galactic Emission at Decimeter Wavelengths
A detailed knowledge of the Galactic radio continuum is of high interest for
studies of the dynamics and structure of the Galaxy as well as for the problem
of foreground removal in Cosmic Microwave Background measurements. In this work
we present a full-sky study of the diffuse Galactic emission at frequencies of
few GHz, where synchrotron radiation is by far the dominant component. We
perform a detailed combined analysis of the extended surveys at 408, 1420 and
2326 MHz (by Haslam et al. 1982, Reich 1982, Reich & Reich, 1986 and Jonas et
al. 1998, respectively). Using the technique applied by Schlegel et al. (1998)
to the IRAS data, we produce destriped versions of the three maps. This allows
us to construct a nearly-full-sky map of the spectral index and of the
normalization factor with sub-degree angular resolution. The resulting
distribution of the spectral indices has an average of beta = 2.695 and
dispersion sigma_{beta} = 0.120. This is representative for the Galactic
diffuse synchrotron emission, with only minor effects from free-free emission
and point sources.Comment: 10 pages, 16 jpeg figures, accepted to Astronomy & Astrophysics,
Comments and figure adde
Nivolumab plus Ipilimumab in Non-Small-Cell Lung Cancer
To the Editor: Although more than 10% of the patients in the CheckMate 227 trial conducted by Hellmann et al. (Nov. 21 issue)(1) had never smoked, the effect of smoking status on survival was not fully discussed. Striking differences in the clinical and molecular characteristics of lung cancers between smokers and those who have never smoked have been identified, suggesting that the cancers are separate entities.(2) In one trial,(3) patients who had never smoked had poorer responses to nivolumab (as compared with docetaxel) than current or former smokers (hazard ratio for overall survival, 1.02 vs. 0.70). In a meta-analysis involving . .
The link between calcitriol and anticancer immunotherapy: Vitamin D as the possible balance between inflammation and autoimmunity in the immune-checkpoint blockade
Anisotropies of the Cosmic Microwave Background
We review the present status of Cosmic Microwave Background (CMB) anisotropy
observations and discuss the main related astrophysical issues, instrumental
effects and data analysis techniques. We summarise the balloon-borne and
ground-based experiments that, after COBE-DMR, yielded detection or significant
upper limits to CMB fluctuations. A comparison of subsets of combined data
indicates that the acoustic features observed today in the angular power
spectrum are not dominated by undetected systematics. Pushing the accuracy of
CMB anisotropy measurements to their ultimate limits represents one of the best
opportunities for cosmology to develop into a precision science in the next
decade. We discuss the forthcoming sub-orbital and space programs, as well as
future prospects of CMB observations.Comment: 83 pages, 16 figures. Revised version, accepted by "La Rivista del
Nuovo Cimento
The Optical Emission from Gamma-ray Quasars
We present photometric observations of six radio-loud quasars that were
detected by the COMPTEL gamma-ray telescope. The data encompasses seven
wavebands in the optical and near-infrared. After correction for Galactic
extinction, we find a wide range in optical slopes. Two sources are as blue as
optically-selected quasars, and are likely to be dominated by the accretion
disc emission, while three others show colours consistent with a red
synchrotron component. We discuss the properties of the COMPTEL sample of
quasars, as well as the implications our observations have for multi-wavelength
modelling of gamma-ray quasars.Comment: 12 pages, 3 figures, accepted for publication in P.A.S.A; minor typos
correcte
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