J/AJ/124/3255 UBV photometry in M15 (van der Marel+, 2002)
Hubble Space Telescope evidence for an intermediate-mass black hole in the
globular cluster M15.
I. STIS spectroscopy and WFPC2 photometry.
van der Marel R.P., Gerssen J., Guhathakurta P., Peterson R.C., Gebhardt K.
<Astron. J. 124, 3255 (2002)>
=2002AJ....124.3255V 2002AJ....124.3255V
ADC_Keywords: Clusters, globular ; Photometry, UBV
Keywords: globular clusters: individual (M15) - stars: kinematics
Abstract:
In this series of two papers, we describe a project with the Space
Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope
(HST) to measure the line-of-sight velocities of stars in the central
few arcseconds of the dense globular cluster M15. This first paper
focuses on the observations and reduction of the data. We "scanned"
the central region of M15 spectroscopically by consecutively placing
the 0.1" HST/STIS slit at 18 adjacent positions. The spectral pixel
size exceeds the velocity dispersion of M15. This puts the project at
the limit of what is feasible with STIS, and exceedingly careful and
complicated data reduction and analysis were required.
Description:
WFPC2 images of M15 were obtained on 1994 April 7 in the context of
HST program GO-5324 (PI: Yanny). Results from these observations were
reported in a study led by one of us (Guhathakurta et al.,
1996AJ....111..267G 1996AJ....111..267G, hereafter G96). Data were obtained using the
filters F336W, F439W, and F555W, respectively, which correspond
roughly to the Johnson U, B, and V bands.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 31983 HST/WFPC2 Photometric Catalog of M15
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See also:
J/A+AS/119/307 : Position in M15 (Le Campion+, 1996)
J/ApJ/347/251 : Dynamics of Globular Cluster M15 (Peterson+ 1989)
J/AJ/115/708 : Radial Velocities in the Field of M15 (Drukier+ 1998)
J/A+A/391/945 : HST phot. of 74 galactic globular clusters (Piotto+, 2002)
J/ApJ/602/264 : Proper motions and radial velocities in M15 (Mcnamara+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- VGG ID number of the star, Cl* NGC 7078 VGG NNNNN
7- 14 F8.3 arcsec dRA Right ascension relative to cluster center (1)
16- 23 F8.3 arcsec dDE Declination relative to cluster center (1)
25- 30 F6.3 mag Vmag Johnson V-band magnitude
32- 37 F6.3 mag Bmag Johnson B-band magnitude
39- 44 F6.3 mag Umag Johnson U-band magnitude
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Note (1): The M15 cluster center is adopted from the pixel position
calculated by Guhathakurta, Yanny, Schneider & Bahcall
(1996AJ....111..267G 1996AJ....111..267G) (which has an estimated 1σ
uncertainty of 0.2" in each coordinate). North is to the
top, and east to the left.
The center coordinates, relative to the bright reference star AC 211,
are dRA=0.36"±0.2", dDE=-1.97"±0.2", and AC 211 is at J2000:
21:29:58.29+12:10:02.9 (J2000)
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History:
From electronic version of the journal
References:
Gerssen et al., Paper II 2002AJ....124.3270G 2002AJ....124.3270G
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 06-Feb-2003