low ionisation broad absorption line quasars (libalqsos) represent about 1% of the large bright quasar survey (lbqs) and similar optically selected samples. they have broad (> 30000 kms) low ionisation absorption lines (in particular mgii 2798 angstroms) coming from massive outflowing winds. whilst they are radio quiet, low redshift, low luminosity libalqsos seem to be bright in the far-ir, appearing as 3/7 iras selected quasars in the sample of low et al (1989 apj 340, l1). their optical-ir ratios, iras colours and optical-uv spectra all suggest the presence of a large quantity of dust. these objects are also very strong emitters in uv and (where observable) optical feii lines. the study of these lines in high redshift objects (elston et al 1994, nature, 367, 250) has recently been used to argue for early rapid star formation. if we are to study the role of strong feii emitters, libalqsos are thus the ideal objects to use. theoretically, the most common idea is that all radio quiet qsos are balqsos, but the absorption is only visible from certain directions. this cannot be the whole explaination though, because balqsos show strong nv emission and excess radio flux above what would be expected for a normal quasar (francis et al 1993, aj, 106, 417). an alternative idea is that libalqsos are an intermediate stage in the evolution of objects like ultraluminous iras galaxies (ulirgs) into quasars. this is supported by the fact that mrk 231, is a libalqso with extreme feii emission. we will obtain iso observations of libalqsos from the lbqs to test these ideas and to determine the nature of these objects. observations with iso are critical to this study as it is the only instrument currently available with the necessary sensitivity and wavelength coverage to detect objects like mrk 231 at high redshift in the rest-frame far-ir.
Instrument
PHT22
Temporal Coverage
1997-06-08T08:08:55Z/1998-01-26T02:03:48Z
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 Observations Of Low Ionisation Bal Quasars: Ultraluminous Iras Galaxies And The Nature Of Iron Quasars, 1.0, European Space Agency, https://doi.org/10.5270/esa-vuxg4uu
