Galactic Dynamics


When viewed in other galaxies, planetary nebulae are essentially monochromatic stars:  they are as bright as stars at the tip of the AGB, but over 10% of their energy comes out in a single emission line of doubly-ionized oxygen at 5007 Å.   Thus, measuring their precise radial velocities is easy, and astronomers can use them to trace galactic gravitational potentials.

Planetary nebulae have been used to discover the (lack of) dark matter around many elliptical galaxies, and to measure the total mass density of galactic disks. 

Publications

Foster, C., Lux, H., Romanowsky, A.J., Martinez-Delgado, D., Zibetti, S., Arnold, J.A., Brodie, J.P., Ciardullo, R., GaBany, R.J., Merrifield, M.R., Singh, N., & Strader, J. 2014, "Kinematics and Simulations of the Stellar Stream in the Halo of the Umbrella Galaxy," M.N.R.A.S., 442, 3544 [ADS Entry]

Herrmann, K.A., & Ciardullo, R. 2009, "Planetary Nebulae in Face-On Spiral Galaxies. III. Planetary Nebula Kinematics and Disk Mass", Ap. J., 705, 1686 [ADS Entry]

Herrmann, K.A., & Ciardullo, R. 2009, "Planetary Nebulae in Face-On Spiral Galaxies. II. Planetary Nebula Spectroscopy," Ap. J., 703, 894 [ADS Entry]

Herrmann, K.A., Ciardullo, R., & Sigurdsson, S. 2009, "Kinematic Evidence for Halo Substructure in Spiral Galaxies," Ap. J. (Letters), 693, L19 [ADS Entry]

Doherty, M., Arnaboldi, M., Das, P., Gerhard, O., Aguerri, J.A.L., Ciardullo, R, Feldmeier, J.J., Freeman, K.C., Jacoby, G.H., & Murante, G. 2009, "The edge of the M 87 halo and the kinematics of the diffuse light in the Virgo cluster core," Astr. Ap., 502, 771 [ADS Entry]

Ciardullo, R., Durrell, P.R., Laychak, M.B., Herrmann, K.A., Moody, K., Jacoby, G.H., & Feldmeier, J.J. 2003, "The Planetary Nebula System of M33," Ap. J., 614, 167 [ADS Entry]

Durrell, P.R., Mihos, J.C., Feldmeier, J.J., Jacoby, G.H., & Ciardullo, R. 2002, "Kinematics of Planetary Nebulae in M51's Tidal Debris," Ap. J., 582, 570 [ADS Entry]

Arnaboldi, M., Freeman, K.C., Mendez, R.H., Capaccioli, M., Ciardullo, R., Ford, H., Gerhard, O., Hui, X., Jacoby, G.H., Kudritzki, R.P., & Quinn, P.J. 1996, "The Kinematics of the Planetary Nebulae in the Outer Regions of NGC 4406," Ap. J., 472, 145 [ADS Entry]

Ciardullo, R., Jacoby, G.H., & Dejonghe, H.B. 1993, "The Radial Velocities of Planetary Nebulae in NGC 3379," Ap. J., 414, 454 [ADS Entry]