= = i propose isocam observations of the recently identified and truly unique qso 1556+3517 (z = 1.48). indeed, 1556+3517 is to date the only broad absorption line (bal) qso which is also a genuine and powerful radio source. other peculiarities of 1556+3517 are (1) it belongs to the relatively rare sub-class of low ionisation bal qsos (2) it shows absorption lines from metastable levels of iron (3) its optical spectrum is very red. all these properties suggest that 1556+3517 is a proto-qso caught in a very early stage of evolution when the source is still shrouded by a thick and hardly ionized cocoon of dust and gas. moreover, by being the only source which combines the mutually exclusive properties of radio-loudness and bal, 1556+3517 may yield clues as to the origin of both phenomena. the isocam observations are aimed at measuring the thickness of the dust cocoon and studying the environment of the nuclear source, searching in particular for signs of galactic scale burst of star formation, cooling flows or merging, which may all be related to the onset of nuclear activity.
Instrument
CAM01
Temporal Coverage
1997-03-14T06:17:10Z/1997-03-14T07:03:36Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, 1999, Iso Observation Of The Only Radio Loud Broad Absorption Line Quasar 1556+3517, 1.0, European Space Agency, https://doi.org/10.5270/esa-kttnmx5
