J/A+A/666/A99 Globular clusters in PGC 087327 (Hazra+, 2022)
A study of globular clusters in a lenticular galaxy in Hydra I from
deep HST/ACS photometry.
Hazra N., Cantiello M., Raimondo G., Mirabile M., Blakeslee J.P.,
Branchesi M., Brocato E.
<Astron. Astrophys., 666, A99 (2022)>
=2022A&A...666A..99H 2022A&A...666A..99H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Clusters, globular ; Photometry, HST ; Optical
Keywords: galaxies: individual: PGC 087327
Abstract:
We take advantage of exquisitely deep optical imaging data from the
Hubble Space Telescope's Advanced Camera for Surveys (HST/ACS) in the
F475W (gF475W) and F606W (VF606W) bands to study the properties of
the globular cluster (GC) population in the intermediate-mass
lenticular galaxy PGC 087327 in the Hydra I galaxy cluster.
We inspected the photometric (magnitudes and colour) and morphometric
(compactness, elongation, etc.) properties of sources lying in an area
of ∼19x19kpc centred on PGC 087327 and compared them with four
neighbouring fields over the same HST/ACS mosaic. This allowed us to
identify a list of GC candidates and to inspect their properties using
a background decontamination method.
Relative to four comparison fields, PGC 087327 shows a robust
overdensity of GCs, NGC=82±9. At the estimated magnitude of the
galaxy, this number implies a specific frequency of SN=1.8±0.7. In
spite of the short wavelength interval available with the gF475W and
VF606W passbands, the colour distribution shows a clear bimodality
with a blue peak at <gF475W-VF606W≥0.47±0.05mag and a red peak
at <gF475W-VF606W≥0.62±0.03mag. We also observe the typical
steeper slope of the radial distribution of red GCs relative to blue
ones. Thanks to the unique depth of the available data, we
characterise the GC luminosity function (GCLF) well beyond the
expected GCLF turnover. We find gTOMF475W=26.54±0.10mag and
VTOMF606W=26.08±0.09mag, which after calibration yields a
distance of DGCLF=56.7±4.3(statistical)±5.2(systematic)Mpc.
Description:
We benefited from extremely deep images in the HST/ACS gF475W and
VF606W bands to characterise the GC population around PGC 087327.
The full catalogue of GC candidates identified in the galaxy field is
available in Table A.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea2.dat 78 102 Globular cluster catalog
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number
4 A1 --- n_Seq [*] Note on Seq (1)
6- 14 F9.5 deg RAdeg Right ascension (J2000)
16- 24 F9.5 deg DEdeg Declination (J2000)
26- 31 F6.3 mag gF475W HST F475W (g) aperture and extinction
corrected magnitude
33- 37 F5.3 mag e_gF475W HST F475W (g) aperture and extinction
corrected magnitude error
39- 44 F6.3 mag VF606W HST F606W (V) aperture and extinction
corrected magnitude
46- 50 F5.3 mag e_VF606W HST F606W (V) aperture and extinction
corrected magnitude error
52- 56 F5.3 mag gF475W-VF606W HST F475W-F606W (g-V) colour index
58- 62 F5.3 pix FradF475W Flux radius (half-light radius from
SExtractor) in F475W (g) band
64- 67 F4.2 pix FWHMF475W FWHM in F475W (g) band
69- 73 F5.3 pix FradF606W Flux radius (half-light radius from
SExtractor) in F606W (B) band
75- 78 F4.2 pix FWHMF606W FWHM in F606W (V) band
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Note (1): * for "faint fuzzies" candidates.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 20-Feb-2023