Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-01-21
Astrophys.J. 625 (2005) 156-166
Astronomy and Astrophysics
Astrophysics
27 pages, including 7 figures, accepted for publication in ApJ, minor corrections in Sect.3.1.6. and Fig.4
Scientific paper
10.1086/429534
We present a reanalysis of far-ultraviolet (FUV) observations of the globular cluster NGC 2808 obtained with the Hubble Space Telescope. These data were first analyzed by Brown and coworkers, with an emphasis on the bright, blue horizontal branch (HB) stars in this cluster. Here, our focus is on the population of fainter FUV sources, which include white dwarfs (WDs), blue stragglers (BSs) and cataclysmic variables (CVs). We have therefore constructed the deepest FUV-NUV colour-magnitude diagram of NGC 2808 and also searched for variability among our FUV sources. Overall, we have found approx. 40 WD, approx. 60 BS and approx. 60 CV candidates; three of the BSs and two of the CV candidates are variable. We have also recovered a known RR Lyrae star in the core of NGC 2808, which exhibits massive (approx. 4 mag) FUV variability. We have investigated the radial distribution and found that our CV and BS candidates are more centrally concentrated than the HBs and WD candidates. This might be an effect of mass segregation, but could as well be due to the preferential formation of such dynamically-formed objects in the dense cluster core. For one of our CV candidates we found a counterpart in WFPC2 optical data published by Piotto and coworkers.
Dieball Andrea
Knigge Christian
Long Knox S.
Shara Michael M.
Zurek David R.
No associations
LandOfFree
Far-Ultraviolet Observations of the Globular Cluster NGC 2808 Revisited: Blue Stragglers, White Dwarfs and Cataclysmic Variables 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 Far-Ultraviolet Observations of the Globular Cluster NGC 2808 Revisited: Blue Stragglers, White Dwarfs and Cataclysmic Variables, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Far-Ultraviolet Observations of the Globular Cluster NGC 2808 Revisited: Blue Stragglers, White Dwarfs and Cataclysmic Variables will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-279485