Proposal code

w008

Proposal title

The Central 1~mas of the Seyfert Galaxy Mrk~231

The

Investigators and their

Affiliations

P.I. J.S.~Ulvestad NRAO, Socorro, USA
J.M.~Wrobel NRAO, Socorro, USA
C.L.~Carilli NRAO, Socorro, USA

Proposal Abstract

We propose VSOP imaging at 5 GHz of the Seyfert 1 galaxy Mrk 231 using the VLBA, Y27, and EB, quasi-simultaneously with VLBA imaging at higher frequencies. Our recent VLBA images show a north-south triple of extent 50 mas, plus a central double/triple 1 mas (0.6 h^{-1} pc) in extent with T_b > 10^9 K and aligned nearly east-west. This central source, 100--150 mJy at 5 GHz, shows a spectral turnover between 5 and 10 GHz but ground VLBI can only resolve it at 15 GHz and higher frequencies, where it is optically thin. Thus VSOP imaging of the 1-mas source at 5 GHz is essential to determine component turnover frequencies, the nature of the absorption, and the peak brightness temperatures. Mrk 231 is the best candidate among bona fide Seyfert galaxies to exhibit synchrotron self-absorption. VSOP imaging of Mrk 231 will therefore impose new and unique constraints on the physical conditions in Seyfert nuclei.

The full Cover Sheets (compressed post-script, typically 50kbytes) can be retrieved. Note that many proposals were reduced in extent by the Scientific Review Committee (e.g. by reducing the number of experiments), however the Cover Sheets contain the full proposal as submitted. Also note that AO2 proposals were submitted in May 1998, and information such as affiliations and contact details has changed for some proposers since that time. The Cover Sheets (and the details on this page, which were derived from the Cover Sheets) may therefore have changed.