118 research outputs found
3C 345: the historical light curve (1967-1990) from the digitized plates of the Asiago Observatory
In the frame of a large project to digitize the plate archives of the Italian
and Vatican Astronomical Observatories, we have already performed the
digitization of all available plates of the field of the quasar 3C345. The
plates, approximately 100, were taken with the three telescopes of the Asiago
Observatory (122 cm, 182 cm, 67/90 cm Schmidt Telescope) in the period from
1967 to 1990. We present here essentially new data, mostly in the B band, about
the variability of 3C 345 and also of other four objects (3 quasars and the
active galaxy NGC 6212) in the same field, in that period. Beyond the well
known 3C 345 itself, also the other three quasars show variability, with a
range of 2.0 mag for Q1 and Q2, 1 mag for Q3. The low level variability
detected for the nucleus of NGC 6212 is more suspicious, and should be
confirmed by linear detector data.Comment: 8 pages, 9 figures, 7 tables, submitted to MNRA
3C 345: The Historical Light Curve (1966-1991) from the digitized plates of the Asiago Observatory
In the frame of a large project to digitize the plate archives of the Italian
and Vatican Astronomical Observatory, we have already performed the
digitization of all available plates of the field of 3C345. The plates,
approximately 100, were taken with the three telescopes of the Asiago
Observatory (122 cm, 180 cm, 67/90 Schmidt Telescope) in the period from 1966
to 1991. Many of them were not analyzed till now, so we present here
essentially new data about the variability of 3C 345 and also of other six
quasars in the same field, in that period
Mining the local Universe: the QSO space density
We present progress results of a new survey for bright QSOs (V<14.5, R<15.4,
B_J30. The
surface density of QSOs brighter than B_J=14.8 turns out to be 2.9 +- 0.8
10^{-3} deg^{-2}. The optical Luminosity Function at 0.04 < z < 0.3 shows
significant departures from the standard pure luminosity evolution, providing
new insights in the modelling of the QSO phenomenon.Comment: 6 pages Latex, with 3 PostScript figures. To appear in the
Proceedings of the MPA/ESO/MPE Joint Astronomy Conference "Mining The Sky",
July 31 - August 4, 2000, Garching, German
LE REGIONI D'EUROPA TRA IDENTITĂ€ LOCALI, NUOVE COMUNITĂ€ E DISPARITĂ€ TERRITORIALI
L’Europa è oggi attraversata da una forte domanda di autonomia da parte dei territori: da un lato, a tutela dell’identità delle comunità locali e, dall’altro, per la crescente rivendicazione di una più ampia rappresentanza delle cittadinanze. Queste istanze possono, però, mettere a rischio gli obiettivi di equilibrio e di coesione economica, sociale e territoriale, da sempre al centro della riflessione e delle proposte sviluppate dagli studiosi delle scienze regionali. La recente crisi ha acuito l’instabilità e allargato i complessivi divari tra le regioni, anche nella loro dinamica interna di evoluzione. Alla resilienza economica non sempre è corrisposto, nell’attuale transizione verso un nuovo paradigma, il mantenimento di solidi livelli di coesione sociale e di integrazione tra aree e comunità .
Il volume raccoglie una selezione di contributi presentati alla XXXIX Conferenza Italiana di Scienze Regionali, svoltasi a Bolzano il 17, 18 e 19 settembre 2018. Nella sua articolazione, esso si sviluppa in tre parti. La prima analizza il tema della domanda di autonomia da parte dei territori all’interno dello sviluppo economico e sociale di regioni e paesi, e dell’attuale dibattito sul federalismo differenziato. Nella seconda le riflessioni si estendono alla crescente disparità tra aree centrali e aree periferiche, tra aree interne e aree esposte, tra Nord e Sud dei Paesi e dell’Europa, mentre nella terza parte, l’analisi guarda ai mutevoli equilibri tra territori e sistemi locali urbani e rurali, tra pianura e montagna e, all’interno delle aree montane, tra i fondivalle maggiormente urbanizzati e i territori di alta quota, zone spesso di confine tra province, regioni e stati.
La novità editoriale di quest’anno è rappresentata da uno spazio dedicato a brevi contributi a cura di giovani autori vincitori dei premi AISRe.Europe is today crossed by a strong demand for autonomy from the territories: to protect the identity of local communities and, also analyze the growing demand for a broader representation of citizens. However, these issues can jeopardize the objectives of balance and economic, social and territorial cohesion, which have always been at the center of the reflection and proposals developed by scholars of regional sciences. The recent crisis has worsened instability and widened the overall gaps between the regions, including in their internal dynamics of evolution. Economic resilience is not always matched, in the current transition towards a new paradigm, by maintaining solid levels of social cohesion and integration between areas and communities.
The volume collects a selection of contributions presented at the XXXIX Italian Conference of Regional Science, held in Bolzano on 17, 18 and 19 September 2018. The volume is divided into three parts. The first analyzes the issue of the demand for autonomy by the territories within the economic and social development of regions and countries, and the current debate on differentiated federalism. In the second, the reflections extend to the growing disparity between central and peripheral areas, between internal and exposed areas, between North and South of countries and Europe, while in the third part, the analysis looks at the changing balance between territories and systems. urban and rural areas, between plains and mountains and, within mountain areas, between the most urbanized valleys and high altitude territories, areas often bordering provinces, regions and states.
This year ia space is dedicated to short contributions by young authors who have won the AISRe Awards
Emission Line Galaxies and Active Galactic Nuclei in WINGS clusters
We present the analysis of the emission line galaxies members of 46 low
redshift (0.04 < z < 0.07) clusters observed by WINGS (WIde-field Nearby Galaxy
cluster Survey, Fasano et al. 2006). Emission line galaxies were identified
following criteria that are meant to minimize biases against non-star forming
galaxies and classified employing diagnostic diagrams. We have examined the
emission line properties and frequencies of star forming galaxies, transition
objects and active galactic nuclei (AGNs: LINERs and Seyferts), unclassified
galaxies with emission lines, and quiescent galaxies with no detectable line
emission. A deficit of emission line galaxies in the cluster environment is
indicated by both a lower frequency with respect to control samples, and by a
systematically lower Balmer emission line equivalent width and luminosity (up
to one order of magnitude in equivalent width with respect to control samples
for transition objects) that implies a lower amount of ionised gas per unit
mass and a lower star formation rate if the source is classified as Hii region.
A sizable population of transition objects and of low-luminosity LINERs
(approx. 10 - 20% of all emission line galaxies) is detected among WINGS
cluster galaxies. With respect to Hii sources they are a factor of approx. 1.5
more frequent than (or at least as frequent as) in control samples. Transition
objects and LINERs in cluster are most affected in terms of line equivalent
width by the environment and appear predominantly consistent with "retired"
galaxies. Shock heating can be a possible gas excitation mechanism able to
account for observed line ratios. Specific to the cluster environment, we
suggest interaction between atomic and molecular gas and the intracluster
medium as a possible physical cause of line-emitting shocks.Comment: Astronomy and Astrophysics, accepte
LE REGIONI D’EUROPA TRA IDENTITÀ LOCALI, NUOVE COMUNITÀ E DISPARITÀ TERRITORIAL
Europe today is crossed by a strong demand for autonomy from the territories: on the one hand, to protect the identities of local communities and, on the other, for the growing demand for a wider representation of resident citizens. However, these requests can jeopardize the objectives of balance and integration between parts of the territory and between those who live in them, objectives that have always been at the center of reflection and proposals developed in the context of regional sciences. The recent crisis has heightened instability and widened economic and social gaps not only between regions, but also within the regions themselves. The North-South gaps in Italy have further increased and, in a post-crisis phase, this unstoppable process requires ever greater scientific and policy insights in terms of commitment and intervention capacity. If the economic growth of the past decade had found impetus in expanding the spaces of relationships and exchanges, the responses to the threats brought about by the crisis materialized in the closure of borders and in the defense of local levels of well-being. A particular specification of this theme also concerns the relationships between urban and rural territories and local systems, between plains and mountains as well as mountain areas, .
The preface is therefore an acute reflection on issues of urgent relevance for Italy and of great interest for the regional sciences, accepting important scientific and policy challenges
The Asiago-ESO/RASS QSO Survey II. The Southern Sample
This is the second paper of a series describing the Asiago-ESO/RASS QSO
survey, a project aimed at the construction of an all-sky statistically
well-defined sample of very bright QSOs (B_J < 15). Such a survey is required
to remove the present uncertainties about the properties of the local QSO
population and constitutes an homogeneous database for detailed evolutionary
studies of AGN. We present here the complete Southern Sample, which comprises
243 bright (12.60 < B_J < 15.13) QSO candidates at high galactic latitudes
(|b_{gal}| > 30^{\circ}). The area covered by the survey is 5660 sq. deg.
Spectroscopy for the 137 still unidentified objects has been obtained. The
total number of AGN turns out to be 111, 63 of which are new identifications.
The properties of the selection are discussed. The completeness and the success
rate for this survey at the final stage are 63% and 46%, respectively.Comment: 36 pages Latex, with 15 PostScript figures. Accepted for publication
in Astronomical Journa
OmegaWINGS: OmegaCAM@VST observations of WINGS galaxy clusters
The Wide-field Nearby Galaxy-cluster Survey (WINGS) is a wide-field
multi-wavelength survey of X-ray selected clusters at z =0.04-0.07. The
original 34'x34' WINGS field-of- view has now been extended to cover a 1 sq.deg
field with both photometry and spectroscopy. In this paper we present the
Johnson B and V-band OmegaCAM/VST observations of 46 WINGS clusters, together
with the data reduction, data quality and Sextractor photometric catalogs.
With a median seeing of 1arcs in both bands, our 25-minutes exposures in each
band typically reach the 50% completeness level at V=23.1 mag. The quality of
the astrometric and photometric accuracy has been verified by comparison with
the 2MASS as well as with SDSS astrometry, and SDSS and previous WINGS imaging.
Star/galaxy separation and sky-subtraction procedure have been tested comparing
with previous WINGS data.
The Sextractor photometric catalogues are publicly available at the CDS, and
will be included in the next release of the WINGS database on the VO together
with the OmegaCAM reduced images. These data form the basis for a large ongoing
spectroscopic campaign with AAOmega/AAT and is being employed for a variety of
studies. [abridged]Comment: submitted to A&
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