NOAO > Observing Info > Approved Programs > 2009A-0086
|
NOAO > Observing Info > Approved Programs > 2009A-0086 |
|
PI: Roger Lynds, NOAO, rlynds@noao.edu
Address: P.O. Box 26732, 950 N. Cherry Ave, Tucson, Arizona 85726, United States
CoI: Earl O'Neil, Raytheon
Title: Precursors to Galaxy Merging
Abstract:
NGC 6745 and two minor satellite galaxies comprise a physical system
in which the companions have penetrated the material volume of the
larger galaxy. When the non-stellar material in two galaxies meet at
differential velocities much greater than the speed of sound, shock
waves in the combined medium are produced which, in turn, tend to foster
new star formation. Because the stars and clusters that are produced
will kinematically reflect on average the momentum balance of the
material from which they are made, the whole assemblage of new stars
will be kinematically distinct from either of the galaxies involved in
the encounter and will in fact become a new galaxy in its own distinct
orbit.
In the case of NGC 6745, one of these star-forming encounters is
currently in progress, and we will not have the opportunity to observe
the gravitation integrity of the resulting system of new stars.
However, there is evidence in the case of a second companion galaxy that
such a star-forming encounter occurred long ago. We think we have
detected the stars that were produced in that encounter, but that
detection is at the limit of existing observational material. We
therefore ask for telescope time to obtain especially deep imaging so as
to assess the dispersal of the stars along the common orbit.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
|
NOAO > Observing Info > Approved Programs > 2009A-0086 |
|