The Planetary Nebula System of M33

Details The Planetary Nebula System of M33 The Planetary Nebula System of M33

2004-06-21

arxiv.org/abs/astro-ph/0406462v1

Astrophys.J. 614 (2004) 167-185

Astronomy and Astrophysics

Astrophysics

45 pages, including 12 figures (some with reduced resolution); accepted for publication in the Astrophysical Journal

Scientific paper

10.1086/423414

We report the results of a photometric and spectroscopic survey for planetary nebulae (PNe) in the Local Group spiral galaxy M33. We use our sample of 152 PNe to derive an [O III] planetary nebula luminosity function (PNLF) distance of (m-M)_0 = 24.86^+0.07-0.11 (0.94^+0.03-0.05 Mpc). Although this value is ~ 15% larger than the galaxy's Cepheid distance, the discrepancy likely arises from differing assumptions about the system's internal extinction. Our photometry (which extends >3 mag down the PNLF), also reveals that the faint-end of M33's PN luminosity function is non-monotonic, with an inflection point ~2 mag below the PNLF cutoff. We argue that this feature is due to the galaxy's large population of high core-mass planetaries, and that its amplitude may eventually be useful as a diagnostic for studies of stellar populations. Fiber-coupled spectroscopy of 140 of the PN candidates confirms that M33's PN population rotates along with the old disk, with a small asymmetric drift of \~ 10km/s. Remarkably, the population's line-of-sight velocity dispersion varies little over ~4 optical disk scale lengths, with sigma_{rad}~20km/s. We show that this is due to a combination of factors, including a decline in the radial component of the velocity ellipsoid at small galactocentric radii, and a gradient in the ratio of the vertical to radial velocity dispersion. We use our data to show that the mass scale length of M33's disk is ~2.3 times larger than that of the system's IR luminosity and that the disk's V-band mass-to-light ratio changes from M/L_V ~0.3 in the galaxy's inner regions to M/L_V ~2.0 at ~9 kpc. Models in which the dark matter is distributed in the plane of the galaxy are excluded by our data. (abridged)

Affiliated with

Also associated with

No associations

Rating

The Planetary Nebula System of M33 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Planetary Nebula System of M33, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Planetary Nebula System of M33 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-57100