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J/AJ/107/2067           Fabry-Perot measurements of M15        (Gebhardt+, 1994)

Fabry-Perot measurements of the dynamics of globular cluster cores: M15 (NGC 7078) Gebhardt K., Pryor C., Williams T.B., Hesser J.E. <Astron. J. 107, 2067 (1994)> =1994AJ....107.2067G (SIMBAD/NED Reference)
ADC_Keywords: Clusters, globular ; Radial velocities Abstract: We report the first use of the Rutgers Imaging Fabry-Perot Spectrophotometer to study the dynamics of the cores of globular clusters. We have obtained velocities for cluster stars by tuning the Fabry-Perot to take a series of narrowband (0.8A FWHM at 5890A) images at different wavelengths across one of the Na D (5890A) absorption lines. Measuring the flux in every frame yields a short portion of the spectrum for each star simultaneously. This proves to be a very efficient method for obtaining accurate stellar velocities; in crowded regions we are able to measure hundreds of velocities in 3-4h of observing time. We have measured velocities with uncertainties of less than 5km/s for 216 stars within 1.5' of the center of the globular cluster M15 (NGC 7078). The velocity dispersion profile shows a sharp rise from 7 to 12km/s at 0.6' (1.8parsec), and then appears to flatten into our innermost point at 0.1'. A rotation amplitude of 1.4±0.8km/s is detected. The rotation has been measured at a radius of 0.6' using stellar velocities and at 0.2' using the integrated light profile. The amplitude and position angle are the same at both radii, indicating a constant rotation profile in this region. Combining our two epochs of Fabry-Perot observation with published measurements, we have repeat velocity measurements for 67 stars. We calculate a binary fraction of about 7% for binary periods between 0.2 and 20 years and mass ratios larger than 0.22, which is in agreement with measurements for other globular clusters. Objects: --------------------------------------------------- RA (2000) DE Designation(s) --------------------------------------------------- 21 29 58.2 +12 10 02 M 15 = NGC 7078 = C 2127+119 --------------------------------------------------- Addresses: Gebhardt K. , Pryor C. , Williams T.B. Department of Physics and Astronomy, Rutgers, The State University, Box 0849, Piscataway, New Jersey 08855-0849 Hesser J.E. Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 W. Saanich Road, R.R.5, Victoria, B.C., V8X 4M6, Canada File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1 62 480 M15 stars table1.tex 93 507 LaTeX version of Table 1
See also: J/AJ/106/154 : HST Observations in inner region of M15 (Ferraro+ 1993) J/AJ/107/1745 : HST UVI photometry of M15. II. (Yanny+, 1994) J/AJ/110/704 : RR Lyrae in M15 (Silbermann+ 1995) J/ApJ/347/251 : Dynamics of Globular Cluster M15 (Peterson+ 1989) Byte-by-byte Description of file: table1
Bytes Format Units Label Explanations
1- 6 A6 --- ID Star ID, blank indicates continuations (1) 8- 13 F6.1 arcsec Xoff X offset from cluster center (2) 16- 21 F6.1 arcsec Yoff Y offset from cluster center (2) 24- 27 F4.1 mag FPVmag Fabry-Perot V magnitude 30- 35 F6.1 km/s RVel Velocity (3) 38- 40 F3.1 km/s e_RVel Error in velocity 43- 46 A4 --- r_RVel Source for velocity (4) 49- 52 F4.2 --- ChiSq []? Chi-square for multiple measurements (5) 53- 62 A10 --- Note Notes (6)
Note (1): ID is taken from Kuestner, F. 1921, Veroeff. Sternw. Bonn., No. 15 =1921VeUSB..15....1K or Auriere, M., & Cordoni, J.P. 1981, =1981A&AS...46..347A if the star has been previously studied, or an FP number if it has not. Note (2): The center of the cluster was taken to be 21h27m33.3s, +11d56m49s (1950), as measured by HST (Lauer, T.R. et al. =1991ApJ...369L..45L) Note (3): When there are multiple velocity measurements for the same star, the first line for that star lists the average velocity calculated from all of the measurements weighted by their uncertainties and the following lines are the individual measurements. Note (4): Source of velocity measurement. All the measurements from Peterson R.C., Seitzer P. & Cudworth K.M. (1989ApJ...347..251P) (PSC) are included. Other sources are listed as FP91 or FP92 for the authors 1991 or 1992 Fabry-Perot observations. Note (5): Probability of chi-square for multiple measurements being drawn from the same velocity. Note (6): Notes include code numbers, as follows: 1: Binary star candidates 2: Not used in dynamics due to radical FP bias 3: Not used in dynamics due to severe contamination 4: PSC has 33 measurements for this star Other notes include additional ID's for stars, as follows: V: Variable star number (Sawyer-Hogg, H. 1973, Publ. David Dunlap Obs., 3, No. 6) S: Sandage, A. (1970ApJ...162..841S) I-V: Roman numerals from Arp, H.C. (1955AJ.....60..317A)
Origin: AAS CD-ROM series, Volume 3, 1995
(End) Lee Brotzman [ADS] 16-Aug-1994, Patricia Bauer [CDS] 15-Feb-1995
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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