265 research outputs found
Molecular Gas in the Perseus Cooling Flow Galaxy, NGC 1275
The central arcminute of the Perseus cooling flow galaxy, NGC 1275, has been
mapped with the JCMT in 12CO(2-1) at 21 arcsec resolution, with detections out
to at least 36 arcsec (12 kpc). Within the limits of the resolution and
coverage, the distribution of gas appears to be roughly E-W, consistent with
previous observations of CO, X-ray, H alpha, and dust emission. The total
detected molecular hydrogen mass is ~ 1.6 x 10^10 solar masses, using a
Galactic conversion factor. The inner central rotating disk is apparent in the
data, but the overall distribution is not one of rotation. Rather, the line
profiles are bluewards asymmetric, consistent with previous observations in HI
and [OIII]. We suggest that the blueshift may be due to an acquired mean
velocity of ~ 150 km/sec imparted by the radio jet in the advancing direction.
Within the uncertainties of the analysis, the available radio energy appears to
be sufficient, and the interpretation is consistent with that of Bohringer et
al. (1993) for displaced X-ray emission. We have also made the first
observations of 13CO(2-1) and 12CO(3-2) emission from the central 21 arcsec
region of NGC 1275 and combined these data with IRAM data supplied by Reuter et
al. (1993) to form line ratios over equivalent, well-sampled regions. An LVG
radiative transfer analysis indicates that the line ratios are not well
reproduced by a single value of kinetic temperature, molecular hydrogen
density, and abundance per unit velocity gradient. At least two temperatures
are suggested by a simple two-component LVG model, possibly reflecting a
temperature gradient in this region.Comment: 12 pages, 5 figures, uses mn.sty, accepted for publication in MNRA
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