Browsing by Author "Parisi, P."

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Accurate classification of 17 AGNs detected with Swift/BAT
    (2009) Parisi, P.; Galaz, Gaspar; Minniti, D.; Parisi, P.; Galaz, Gaspar; Minniti, D.; Parisi, P.; Galaz, Gaspar; Minniti, D.; Parisi, P.; Galaz, Gaspar; Minniti, D.
  • Thumbnail Image
    Item
    Accurate classification of 29 objects detected in the 39 month Palermo Swift/BAT hard X-ray catalogue
    (2012) Parisi, P.; Galaz, Gaspar; Minniti, D.; Parisi, P.; Galaz, Gaspar; Minniti, D.; Parisi, P.; Galaz, Gaspar; Minniti, D.; Parisi, P.; Galaz, Gaspar; Minniti, D.
  • Thumbnail Image
    Item
    Accurate classification of 75 counterparts of objects detected in the 54-month Palermo Swift/BAT hard X-ray catalogue
    (2014) Parisi, P.; Masetti, N.; Rojas, A. F.; Jiménez Bailón, E.; Chavushyan, V.; Palazzi, E.; Bassani, L.; Bazzano, A.; Bird, A. J.; Galaz, Gaspar; Minniti, D.; Morelli, L.; Ubertini, P.; Parisi, P.; Masetti, N.; Rojas, A. F.; Jiménez Bailón, E.; Chavushyan, V.; Palazzi, E.; Bassani, L.; Bazzano, A.; Bird, A. J.; Galaz, Gaspar; Minniti, D.; Morelli, L.; Ubertini, P.
  • No Thumbnail Available
    Item
    BL Lacertae identifications in a ROSAT-selected sample of Fermi unidentified objects
    (2013) Masetti, N.; Sbarufatti, B.; Parisi, P.; Jimenez-Bailon, E.; Chavushyan, V.; Vogt, F. P. A.; Sguera, V.; Stephen, J. B.; Palazzi, E.; Bassani, L.; Bazzano, A.; Fiocchi, M.; Galaz, G.; Landi, R.; Malizia, A.; Minniti, D.; Morelli, L.; Ubertini, P.
    The optical spectroscopic followup of 27 sources belonging to a sample of 30 high-energy objects selected by positionally cross correlating the first Fermi/LAT Catalog and the ROSAT All-Sky Survey Bright Source Catalog is presented here. It has been found or confirmed that 25 of them are BL Lacertae objects (BL Lacs), while the remaining two are Galactic cataclysmic variables (CVs). This strongly suggests that the sources in the first group are responsible for the GeV emission detected with Fermi, while the two CVs most likely represent spurious associations. We thus find an 80% a posteriori probability that the sources selected by matching GeV and X-ray catalogs belong to the BL Lac class. We also show suggestions that the BL Lacs selected with this approach are probably high-synchrotron-peaked sources and in turn good candidates for the detection of ultra-high-energy (TeV) photons from them.
  • No Thumbnail Available
    Item
    Searching for active galactic nuclei among unidentified INTEGRAL sources
    (2011) Maiorano, E.; Landi, R.; Stephen, J. B.; Bassani, L.; Masetti, N.; Parisi, P.; Palazzi, E.; Parma, P.; Bird, A. J.; Bazzano, A.; Ubertini, P.; Jimenez-Bailon, E.; Chavushyan, V.; Galaz, G.; Minniti, D.; Morelli, L.
    We report on a new method to identify active galactic nuclei (AGNs) among unidentified INTEGRAL sources. This method consists of cross-correlating unidentified sources listed in the fourth Imager on Board the INTEGRAL Satellite (IBIS) Survey Catalogue first with infrared and then with radio catalogues and a posteriori verifying, by means of X-ray and optical follow-up observations, the likelihood of these associations. In order to test this method, a sample of eight sources has been extracted from the fourth IBIS catalogue. For seven sources of the sample, we obtained an identification, whereas the last one (IGR J03103+5706) has insufficient information for a clear classification and deserves more in-depth study. We identified three objects (IGR J08190-3835, IGR J17520-6018 and IGR J21441+4640) as AGNs and suggest that three more (IGR J00556+7708, IGRJ17219-1509 and IGR J21268+6203) are likely active galaxies on the basis of their radio spectra, near-infrared photometry and location above the Galaxy plane. One source (IGR J05583-1257) has been classified as a starburst galaxy, but it might have been spuriously associated with the INTEGRAL detection.
  • Thumbnail Image
    Item
    Symbiotic stars in OGLE data - I. Large magellanic cloud systems
    (2014) Angeloni, Rodolfo; Ferreira Lopes, C.E.; Masetti, N.; Di Mille, F.; Pietrukowicz, Pawel; Udalski, A.; Navarrete Silva, Camila Andrea; Puzia, Thomas H.; Catelan, Márcio; Guzmán Carmine, Christian Dani; Schaefer, B. E.; Parisi, P.; Landi, R.