Open AccessUsing slitless spectroscopy to study the kinematics of the planetary nebula population in M94
Author(s) -
Douglas N. G.,
Gerssen J.,
Kuijken K.,
Merrifield M. R.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03574.x
Subject(s) - physics , planetary nebula , astronomy , spectroscopy , astrophysics , nebula , protoplanetary nebula , kinematics , astrobiology , population , stars , medicine , classical mechanics , environmental health
The planetary nebula populations of relatively nearby galaxies can be easily observed and provide both a distance estimate and a tool with which dynamical information can be obtained. Usually the requisite radial velocities are obtained by multi‐object spectroscopy once the planetary nebulae have been located by direct imaging. Here we report on a technique for measuring planetary nebula kinematics using the double‐beam ISIS spectrograph at the William Herschel Telescope in a novel slitless mode, which enables the detection and radial velocity measurements to be combined into a single step. The results on our first target, the Sab galaxy NGC 4736, allow the velocity dispersion of the stellar population in a disc galaxy to be traced out to four scalelengths for the first time and are consistent with a simple isothermal sheet model.