We present the historic light curve of 1WGA J0447.9-0322, spanning the time interval from 1962 to 1991, built using the Asiago archive plates. The source shows small fluctuations of about 0.3 mag around B 16 until 1986 and a fast dimming of its average level by about 0.5 mag after that date, again with small short-term variations. The variability pattern is within the values shown by other QSOs with long-term monitoring, notwithstanding its high X-ray/optical ratio. We also present its overall spectral energy distribution using literature data and recent UV-optical Swift observations.
Optical variability of the strong-lined and X-ray-bright source 1WGA J0447.9-0322 / Nesci, Roberto; M., Mandalari; Gaudenzi, Silvia. - In: THE ASTRONOMICAL JOURNAL. - ISSN 0004-6256. - STAMPA. - 133:3(2007), pp. 965-970. [10.1086/510514]
Optical variability of the strong-lined and X-ray-bright source 1WGA J0447.9-0322
NESCI, Roberto;GAUDENZI, Silvia
2007
Abstract
We present the historic light curve of 1WGA J0447.9-0322, spanning the time interval from 1962 to 1991, built using the Asiago archive plates. The source shows small fluctuations of about 0.3 mag around B 16 until 1986 and a fast dimming of its average level by about 0.5 mag after that date, again with small short-term variations. The variability pattern is within the values shown by other QSOs with long-term monitoring, notwithstanding its high X-ray/optical ratio. We also present its overall spectral energy distribution using literature data and recent UV-optical Swift observations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
