J/ApJ/746/88 HST observations of GCs in NGC 1399 (Blakeslee+, 2012)
Optical and infrared photometry of globular clusters in NGC 1399: evidence for
color-metallicity nonlinearity.
Blakeslee J.P., Cho H., Peng E.W., Ferrarese L., Jordan A., Martel A.R.
<Astrophys. J., 746, 88 (2012)>
=2012ApJ...746...88B 2012ApJ...746...88B
ADC_Keywords: Photometry, HST ; Clusters, globular ; Galaxies, IR
Keywords: galaxies: elliptical and lenticular, cD - globular clusters: general -
galaxies: individual (NGC 1399) - galaxies: star clusters: general
Abstract:
We combine new Wide Field Camera 3 IR Channel (WFC3/IR) F160W (H160)
imaging data for NGC 1399, the central galaxy in the Fornax cluster,
with archival F475W (g475), F606W (V606), F814W (I814), and
F850LP (z 850) optical data from the Advanced Camera for Surveys
(ACS). The purely optical g475-I814, V606-I814, and
g475-z850colors of NGC 1399's rich globular cluster (GC) system
exhibit clear bimodality, at least for magnitudes I814>21.5. The
optical-IR I814-H160 color distribution appears unimodal, and this
impression is confirmed by mixture modeling analysis. The
V606-H160 colors show marginal evidence for bimodality, consistent
with bimodality in V606-I814 and unimodality in I814-H160.
Description:
NGC 1399 was observed for one orbit in the F110W and F160W bandpasses
of WFC3/IR in 2009 December as part of HST program GO-11712. The
results presented here are derived from images retrieved from STScI in
2011 January.
NGC 1399 has been observed many times before with HST, including
several times with the ACS/WFC, allowing us to investigate the
optical-IR colors of its GCs. Calibrated observations in F606W from
GO-10129 in 2004 Nov and 2005 Apr (PI: Puzia) and F475W + F814W from
GO-10911 in 2006 August (PI: Blakeslee) were retrieved from the STScI
archive. NGC 1399 was also observed in F475W and F850LP as part of HST
program GO-10217 in 2004 Sept (Jordan et al., 2007, Cat. J/ApJS/169/213).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 76 401 Matched WFC3/IR and ACS photometry for globular
cluster candidates
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJ/736/90 : Chandra X-ray sources of NGC 1399 (Paolillo+, 2011)
J/A+A/513/A52 : Velocities of NGC 1399 globular clusters (Schuberth+, 2010)
J/A+A/477/L9 : Globular clusters around NGC 1399 (Schuberth+, 2008)
J/MNRAS/389/1924 : Old stellar systems (globulars-ellipticals) (Forbes+, 2008)
J/MNRAS/382/1342 : Compact stellar systems around NGC 1399 (Firth+, 2007)
J/MNRAS/382/1947 : CT1 photometry in NGC 1399 and NGC 4486 (Forte+, 2007)
J/A+A/464/L21 : Velocities of globular clusters in Fornax (Bergond+, 2007)
J/AJ/127/2114 : Globular clusters around NGC 1399 (Dirsch+, 2004)
J/AJ/105/1762 : Globular clusters around NGC 1399 (Ostrov+ 1993)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [14/4422] Candidate identification number
6- 14 F9.6 deg RAdeg [54.60/54.65] Right Ascension (J2000)
16- 25 F10.6 deg DEdeg [-35.47/-35.43] Declination (J2000)
27- 32 F6.3 mag Imag [19.6/23.5] SExtractor HST/WFC3 F814W image
magnitude corrected for Galactic extinction
34- 38 F5.3 mag e_Imag [0.009/0.08] Uncertainty in Imag
40- 44 F5.3 mag (g-I) [0.64/1.52] (F475W-F814W) color index (1)
46- 50 F5.3 mag e_(g-I) [0.03/0.15] Uncertainty in (g-I)
52- 57 F6.3 mag (I-H) [-0.23/1.36] The (F814W-F160W) color index (1)
59- 63 F5.3 mag e_(I-H) [0.01/0.2] Uncertainty in (I-H)
65- 69 F5.3 mag (g-I)c [0.66/1.54] Corrected (F475W-F814W) color
index (2)
71- 76 F6.3 mag (I-H)c [-0.25/1.34] Corrected (F814W-F160W) color (2)
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Note (1): Within a 3-pixel radius. Corrected for Galactic extinction.
Note (2): Corrected for differential aperture effects, assuming the corrections
for a typical GC, as given in Section 3 and for Galactic extinction.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Aug-2013