download report - Sapienza
download report - Sapienza
download report - Sapienza
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Scientific Report 2007-2009<br />
Laboratories and Facilities of the Department of Physics<br />
L25. Solar Radiometry Observatory<br />
The research activities of the Meteorology group (GMET) intend to assess the influence of the decrease of ozone and its<br />
effect on UV radiation variability. The GMET equipment consists in a Brewer spectrophotometer MKIV n.067, installed<br />
in 1992 on the roof of the building of the Department of Physics in the University Campus. Direct sun measurements at 5<br />
wavelengths in the UVB and VIS regions are carried out to retrieve total O 3 and NO 2 amounts, respectively.<br />
Measurements of solar UV spectral irradiances in the<br />
spectral range from 290 to 325 nm, with a stepwidth<br />
of 0.5 nm, have been carried out since 1992. This long<br />
UV time series is necessary to assess the influence on<br />
ecosystems and on human health. In addition, erythemal<br />
dose rates have been obtained by the broadband UV<br />
radiometer (model YES UVB-1) in operation since<br />
2000. The YES radiometer has a spectral response<br />
similar to that of skin erythema and values of erythemal<br />
dose rates are obtained using a calibration matrix<br />
as a function of solar zenith angle and total ozone<br />
amounts from Brewer spectrophotometer. Ambient UV<br />
radiation is also used in the quantification of human<br />
UV exposure by means of polysulphone dosimetry,<br />
this another research activity. Ancillary meteorological<br />
measurements of air temperature, relative humidity,<br />
and wind, are also available to characterize the UV Figure 1: Solar Radiometry Observatory (University Campus).<br />
field.<br />
http://www.phys.uniroma1.it/gr/gmet/index.html<br />
Related research activities: G2.<br />
L26. The Vallinfreda astronomical Station<br />
The SCAE group has an observing facility near Vallinfreda, (a small town 50 km ENE of Rome), located at 850 m above<br />
the sea level with a rather low sky brightness (V=20.5 mag/arcsec2). Geographical coordinates are Long. 12o 58’ 52” East,<br />
Lat. +42o 06’ 01”. Routine observations at Vallinfreda started by the end of Summer 1995.<br />
The telescope is a Newtonian 50 cm f/4.5, built by GAMBATO, powered by an FS2 system, housed in a sliding-roof<br />
building (see fig. 1). A standard 12m-long container, provided by the italian Protezione Civile, gives logistical support.<br />
The focal plane instrument is an Apogee ALTA<br />
AP47 CCD camera and a TrueTech filter wheel<br />
with standard BVRI Johnson-Cousins filters, provided<br />
by Astrodon-Schuler. Electric focuser is by<br />
MicroFocuser. Guiding is made with a 15 cm f/12<br />
refractor telescope manifactured by ZEN and a<br />
StarLight Xpress MX916 camera.<br />
All telescope operations (telescope pointing, filter<br />
wheel movements, image acquisition and guiding)<br />
are controlled by a PC with Windows XP operating<br />
system. The limiting magnitude, with a<br />
S/N ratio about 0.1 is 17.5 in the R band.<br />
The telescope is mainly dedicated to monitoring<br />
of BL Lacertae objects, a subclass of Quasars with<br />
strong Radio and Gamma Rays emission, with special<br />
care for simultaneous observations with spaceborn<br />
instruments (Beppo-SAX, SWIFT, INTEGRAL, AGILE, FermiGST).<br />
Figure 2: The Vallinfreda telescope in its sliding-roof building.<br />
About 25 papers on refereed international journals have been made using (also) data obtained with the Vallinfreda<br />
telescope.<br />
http://astrowww.phys.uniroma1.it/nesci/vallin.html<br />
Related research activities: A9.<br />
<strong>Sapienza</strong> Università di Roma 194 Dipartimento di Fisica