51 research outputs found
Developing Data Curation Protocols for Digital Projects at Vanderbilt: Une Micro-Histoire
This paper examines the intersection of legacy digital humanities projects and the ongoing development of research data management services at Vanderbilt University’s Jean and Alexander Heard Library. Future directions for data management and curation protocols are explored through the lens of a case study: the (re)curation of data from an early 2000s e-edition of Raymond Poggenburg’s Charles Baudelaire: Une Micro-histoire. The vagaries of applying the Library of Congress Metadata Object Description Schema (MODS) to the data and metadata of theMicro-histoirewill be addressed. In addition, the balance between curating data and metadata for preservation vs. curating it for (re)use by future researchers is considered in order to suggest future avenues for holistic research data management services at Vanderbilt
DBESM P1 (primo prototipo) Matrice di commutazione
Validazione del prototipo di scheda DBESM: na matrice di commutazione funzionale all'instradamento dei ricevitori ai back-end del sistema osservativo SR
A 20 GHz bright sample for {\delta} > +72{\deg}: I. Catalogue
During 2010-2011, the Medicina 32-m dish hosted the 7-feed 18-26.5 GHz
receiver built for the Sardinia Radio Telescope, with the goal to perform its
commissioning. This opportunity was exploited to carry out a pilot survey at 20
GHz over the area for {\delta} > + 72.3{\deg}. This paper describes all the
phases of the observations, as they were performed using new hardware and
software facilities. The map-making and source extraction procedures are
illustrated. A customised data reduction tool was used during the follow-up
phase, which produced a list of 73 confirmed sources down to a flux density of
115 mJy. The resulting catalogue, here presented, is complete above 200 mJy.
Source counts are in agreement with those provided by the AT20G survey. This
pilot activity paves the way to a larger project, the K-band Northern Wide
Survey (KNoWS), whose final aim is to survey the whole Northern Hemisphere down
to a flux limit of 50 mJy (5{\sigma}).Comment: 10 pages, 10 figures. Accepted by MNRA
Observing galaxy clusters and the cosmic web through the Sunyaev Zel'dovich effect with MISTRAL
Galaxy clusters and surrounding medium, can be studied using X-ray
bremsstrahlung emission and Sunyaev Zel'dovich (SZ) effect. Both astrophysical
probes, sample the same environment with different parameters dependance. The
SZ effect is relatively more sensitive in low density environments and thus is
useful to study the filamentary structures of the cosmic web. In addition,
observations of the matter distribution require high angular resolution in
order to be able to map the matter distribution within and around galaxy
clusters. MISTRAL is a camera working at 90GHz which, once coupled to the
Sardinia Radio Telescope, can reach angular resolution over field
of view (f.o.v.). The forecasted sensitivity is
and the mapping speed is . MISTRAL was recently
installed at the focus of the SRT and soon will take its first photons.Comment: To appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
The 2009 multiwavelength campaign on Mrk 421: Variability and correlation studies
We performed a 4.5-month multi-instrument campaign (from radio to VHE gamma
rays) on Mrk421 between January 2009 and June 2009, which included VLBA,
F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other
instruments and collaborations. Mrk421 was found in its typical (non-flaring)
activity state, with a VHE flux of about half that of the Crab Nebula, yet the
light curves show significant variability at all wavelengths, the highest
variability being in the X-rays. We determined the power spectral densities
(PSD) at most wavelengths and found that all PSDs can be described by
power-laws without a break, and with indices consistent with pink/red-noise
behavior. We observed a harder-when-brighter behavior in the X-ray spectra and
measured a positive correlation between VHE and X-ray fluxes with zero time
lag. Such characteristics have been reported many times during flaring
activity, but here they are reported for the first time in the non-flaring
state. We also observed an overall anti-correlation between optical/UV and
X-rays extending over the duration of the campaign.
The harder-when-brighter behavior in the X-ray spectra and the measured
positive X-ray/VHE correlation during the 2009 multi-wavelength campaign
suggests that the physical processes dominating the emission during non-flaring
states have similarities with those occurring during flaring activity. In
particular, this observation supports leptonic scenarios as being responsible
for the emission of Mrk421 during non-flaring activity. Such a temporally
extended X-ray/VHE correlation is not driven by any single flaring event, and
hence is difficult to explain within the standard hadronic scenarios. The
highest variability is observed in the X-ray band, which, within the one-zone
synchrotron self-Compton scenario, indicates that the electron energy
distribution is most variable at the highest energies.Comment: Accepted for publication in A&A, 18 pages, 14 figures (v2 has a small
modification in the acknowledgments, and also corrects a typo in the field
"author" in the metadata
The high brightness temperature of B0529+483 revealed by RadioAstron and implications for interstellar scattering
The high brightness temperatures, Tb 1013 K, detected in several active galactic nuclei byRadioAstron space VLBI observations challenge theoretical limits. Refractive scattering bythe interstellar medium may affect such measurements. We quantify the scattering propertiesand the sub-mas scale source parameters for the quasar B0529+483. Using RadioAstroncorrelated flux density measurements at 1.7, 4.8, and 22 GHz on projected baselines up to240 000 km we find two characteristic angular scales in the quasar core, about 100 and 10 μas.Some indications of scattering substructure are found. Very high brightness temperatures, Tb≥ 1013 K, are estimated at 4.8 and 22 GHz even taking into account the refractive scattering.Our findings suggest a clear dominance of the particle energy density over the magnetic fieldenergy density in the core of this quasar.Key words: scattering – galaxies: jets – quasars: general – quasars: individual (B0529+483) –radio continuum: galaxies.</p
MISTRAL and its KIDs
The MIllimetric Sardinia radio Telescope Receiver based on Array of Lumped elements KIDs, MISTRAL, is a cryogenic W-band (77–103 GH) LEKID camera which will be integrated at the Gregorian focus of the 64 m aperture Sardinia Radio Telescope, in Italy, in Autumn 2022. This instrument, thanks to its high angular resolution (∼13arcsec) and the wide instantaneous field of view (∼4arcmin), will allow continuum surveys of the mm-wave sky with a variety of scientific targets, spanning from extragalactic astrophysics to solar system science. In this contribution, we will describe the design of the MISTRAL camera, with a particular focus on the optimisation and test of a prototype of the focal plane
High angular resolution Sunyaev Zel’dovich observations: The case of MISTRAL
The MIllimeter Sardinia radio Telescope Receiver based on Array of Lumped elements kids, MISTRAL, is a millimetric (≃ 90GHz) multipixel camera being built for the Sardinia Radio Telescope. It is going to be a facility instrument and will sample the sky with 12 arcsec angular resolution, 4 arcmin field of view, through 408 Kinetic Inductance Detectors (KIDs). The construction and the beginning of commissioning is planned to be in 2022. MISTRAL will allow the scientific community to propose a wide variety of scientific cases including protoplanetary discs study, star forming regions, galaxies radial profiles, and high angular resolution measurements of the Sunyaev Zel'dovich (SZ) effect with the investigation of the morphology of galaxy cluster and the search for the Cosmic Web
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