Search results for "Instrumentation"
showing 10 items of 4914 documents
Observation of the rare B(s)(0) + decay from the combined analysis of CMS and LHCb data.
2015
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported licence.-- et al.
Solar neutrino physics with Borexino
2018
We present the most recent solar neutrino results from the Borexino experiment at the Gran Sasso underground laboratory. In particular, refined measurements of all neutrinos produced in the {\it pp} fusion chain have been made. It is the first time that the same detector measures the entire range of solar neutrinos at once. These new data weakly favor a high-metallicity Sun. Prospects for measuring CNO solar neutrinos are also discussed.
Pinpointing the SMBH in NGC1052
2016
Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical models based on Blandford & Znajek (1977MNRAS.179..433B) extract the rotational energy from a Kerr black hole, which could be the case for NGC1052, to launch these jets. This requires magnetic fields on the order of 1000G to 10000G. We imaged the vicinity of the SMBH of the AGN NGC1052 with the Global Millimetre VLBI Array and found a bright and compact central feature that is smaller than 1.9 light days (100 Schwarzschild radii) in radius. Interpreting this as a blend of the unresolved jet bases, we derive the magnetic field at 1 Schwarzschild radius to lie betwe…
Sub-milliarcsecond imaging of 3C111
2020
Flares in radio-loud active galactic nuclei (AGNs) are thought to be associated with the injection of fresh plasma into the compact jet base. Such flares are usually strongest and appear earlier at shorter radio wavelengths. Hence, very long baseline interferometry (VLBI) at millimeter (mm)-wavelengths is the best-suited technique for studying the earliest structural changes of compact jets associated with emission flares. Aims. We study the morphological changes of the parsec-scale jet in the nearby (z=0.049) gamma-ray bright radio galaxy 3C 111 following a flare that developed into a major radio outburst in 2007. We analyse three successive observations of 3C 111 at 86 GHz with the Global…
22GHz image of 3C 273
2017
RadioAstron is a 10m orbiting radio telescope mounted on the Spektr-R satellite, launched in 2011, performing Space Very Long Baseline Interferometry (SVLBI) observations supported by a global ground array of radio telescopes. With an apogee of ~350000km, it is offering for the first time the possibility to perform as-resolution imaging in the cm-band. The RadioAstron Active Galactic Nuclei (AGN) polarization Key Science Project (KSP) aims at exploiting the unprecedented angular resolution provided by RadioAstron to study jet launching/collimation and magnetic-field configuration in AGN jets. The targets of our KSP are some of the most powerful blazars in the sky. We present observations at…
New sample of large angular size radio galaxies. I.
2001
We present a new sample of 84 large angular size radio galaxies selected from the NRAO VLA Sky Survey. Radio sources with declination above +60{deg}, total flux density greater than 100mJy at 1.4GHz and angular size larger than 4' have been selected and observed with the VLA at 1.4 and 4.9GHz. The radio observations attempt to confirm the large angular size sources and to isolate the core emission for optical identification. In this paper, the first of a series of three, we present radio maps of 79 sources from the sample and discuss the effects of the selection criteria in the final sample. 37 radio galaxies belong to the class of giants, of which 22 are reported in this paper for the firs…
GES: pre-main-sequence clusters [Fe/H]
2017
The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open clusters allow us to derive both the radial metallicity distribution and its evolution over time. In this paper we perform the first investigation of the present-day radial metallicity distribution based on [Fe/H] determinations in late type members of pre-main-sequence clusters. Because of their youth, these clusters are therefore essential for tracing the current inter-stellar medium metallicity. We used the products of the Gaia-ESO Survey analysis of 12 young regions (age<100Myr), covering Galactocentric distances from 6.67 to 8.70kpc. For the fir…
VRi light curves of the lensed QSO HE 0435-1223
2011
We present VRi photometric observations of the quadruply imaged quasar HE0435-1223, carried out with the Danish 1.54m telescope at the La Silla Observatory. Our aim was to monitor and study the magnitudes and colors of each lensed component as a function of time.
ALMA third image of lensed quasar PKS 1830-211
2020
Strong gravitational lensing distorts our view of sources at cosmological distances but brings invaluable constraints on the mass content of foreground objects and on the geometry and properties of the Universe. We report the detection of a third continuum source toward the strongly lensed quasar PKS 1830-211 in ALMA multi-frequency observations of high dynamic range and high angular resolution. This third source is point-like and located slightly to the north of the diagonal joining the two main lensed images, A and B, 0.3" away from image B. It has a flux density that is 140 times weaker than images A and B and a similar spectral index, compatible with synchrotron emission. We conclude th…
Quantum-state-selective decay spectroscopy of 213Ra
2017
An experimental scheme combining the mass resolving power of a Penning trap with contemporary decay spectroscopy has been established at GSI Darmstadt. The Universal Linear Accelerator (UNILAC) at GSI Darmstadt provided a 48Ca beam impinging on a thin 170Er target foil. Subsequent to velocity filtering of reaction products in the Separator for Heavy Ion reaction Products (SHIP), the nuclear ground state of the 5n evaporation channel 213Ra was mass-selected in SHIPTRAP, and the 213Ra ions were finally transferred into an array of silicon strip detectors surrounded by large composite germanium detectors. Based on comprehensive geant4 simulations and supported by theoretical calculations, the …