Letter to the Editor

VPMS J1342+2840 – an unusual quasar from the variability and proper motion survey

¹ Thüringer Landessternwarte Tautenburg, 07778 Tautenburg, Germany e-mail: meus@tls-tautenburg.de
² Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2, Ireland
³ Astronomisches Institut, Ruhr-Universität Bochum, Universitätsstr. 150/NA7, 44780 Bochum, Germany
⁴ Institute of Astronomy, Madingley Road, Cambridge CB3 1HA, UK
⁵ Laboratoire d'Astrophysique de Marseille, BP 8, 13376 Marseille Cedex 12, France
⁶ Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany

Received: 23 December 2004
Accepted: 16 February 2005

Abstract

We report the discovery of the highly peculiar, radio-loud quasar VPMS J1342+2840 () from the variability and proper motion survey. We present spectroscopic, imaging and photometric observations. The unusual spectrum shows a strong depression of the continuum over a wide wavelength range in the blue part without the typical structures of broad absorption line (BAL) troughs. The image of the quasar is unresolved and there is no evidence for a foreground object on the line of sight. The broad-band spectral energy distribution is not consistent with obvious dust reddening with the standard SMC extinction curve. The downturn of the continuum flux of VPMS J1342+2840 at short wavelengths can be caused by dust reddening only if the reddening curve is steeper then the SMC curve in the ultraviolet and is very flat at longer wavelengths. Alternatively, the dominant spectral features can be explained by low-ionization BALs forming unusually wide, overlapping absorption troughs.