ISO observations of the radio-loud BALQSO 1556+3517 *
Received 12 September 1997 / Accepted 25 November 1997
To date, the quasar 1556+3517 is the only radio loud Broad Absorption Line QSO (BALQSO; Becker et al. 1997). This prompted narrow band filter imaging observations in the range 4-15 µ with the ISO satellite. The source is clearly detected in all filters and appears point-like and isolated at the resolution of ISO. The overall Spectral Energy Distribution (SED) in peaks at a rest wavelength and is reddened by 1.6 visual magnitudes. Correction for reddening brings 1556+3517 within 1.3 sigma from the dividing line between radio-loud and radio-quiet sources. The mid-IR luminosity integrated over the 1.8-6 µ rest wavelength range is (), which requires at least of dust and of associated gas. It is unlikely that such a large mass stems from the BAL wind itself.
Key words: quasars: absorption lines quasars: individual: 1556+3517 infrared: galaxies
* Based on observations with ISO, an ESA project with Instruments funded by ESA member states (especially the PI countries: France, Germany, The Netherlands and the United Kingdom) with the participation of ISAS and NASA
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© European Southern Observatory (ESO) 1998
Online publication: March 3, 1998