Bibcode
DOI
O'Dowd, Matthew; Urry, C. Megan; Scarpa, Riccardo; Wayth, Randall B.; Webster, Rachel L.
Bibliographical reference
The Astrophysical Journal, Volume 627, Issue 1, pp. 125-133.
Advertised on:
7
2005
Journal
Citations
1
Refereed citations
1
Description
H1517+656 is an unusual source, even for a BL Lac object. It is one of
the most luminous BL Lac objects known, with extreme emission properties
at radio, optical, and X-ray frequencies. Furthermore, in our WFPC2
snapshot survey we discovered a series of peculiar arcs describing a
2.4" radius ring surrounding the source. This paper describes follow-up
observations with additional WFPC2 bands and the STIS long-pass filter,
which have revealed this structure to be the remnants of a very recent
galaxy merger. Population synthesis modeling has shown that regions of
the arcs have stellar populations with age<20 Myr. In addition, the
circularity of the arcs indicates that the plane of the collision and
hence accretion is very close to the plane of the sky. Given that BL Lac
jets are thought to be aligned with the line of sight, this observation
may provide a direct link between the transfer of angular momentum in an
interaction and the generation of a radio source.