Other
Scientific paper
May 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993aas...182.1708s&link_type=abstract
American Astronomical Society, 182nd AAS Meeting, #17.08; Bulletin of the American Astronomical Society, Vol. 25, p.818
Other
Scientific paper
Spectra of the two brightest, ``unresolved bluish knots'' surrounding the nucleus of the merger remnant NGC 7252 are presented. Seven of these knots were already found by Schweizer (1982: ApJ, 252, 455), who surmised that the brightest knot might be a galactic foreground star while the other six knots might represent young star clusters formed during the merger. These knots are just the brightest of a population of about 40 blue pointlike objects discovered by Whitmore et al. (this meeting) on frames taken with the Planetary Camera of the Hubble Space Telescope. The spectra were obtained with the Double Spectrograph of the Palomar 5-m telescope and cover lambda lambda 4600--5500 in the blue and lambda lambda 6300--6950 in the red at 2--4 Angstroms resolution. These spectra feature Hα , Hβ , and Mg I absorption lines characteristic of late A-type to mid F-type stars at the redshift of NGC 7252, but no emission lines. Therefore, these spectra show unambiguously that (1) despite its apparent bightness, the brightest knot is a cluster in NGC 7252 rather than a galactic foreground star, and (2) even the two brightest unresolved knots are not H II regions, but have ceased forming stars. The spectra strongly support the notion that these knots are relatively young (<1 Gyr), very luminous (M_V ~ -17 and -15.5 for H_0 = 50 according to Whitmore et al.) clusters of nearly coeval stars. Because these clusters remain barely resolved by HST, they are most likely globular clusters that will fade by 3--7 mag during the next 15 Gyr, depending on their exact present age (Charlot & Bruzual, 1991: ApJ, 367, 126). Both clusters have measured radial velocities within 150 km/s of that of the center of the galaxy.
Schweizer Francois
Seitzer Patrick
No associations
LandOfFree
Spectra of Two Bright Candidate Globular Clusters in the Merger Galaxy NGC 7252 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 Spectra of Two Bright Candidate Globular Clusters in the Merger Galaxy NGC 7252, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectra of Two Bright Candidate Globular Clusters in the Merger Galaxy NGC 7252 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1847701