J/A+A/687/A310 NGC 1835 F300X, F606W and F814W photometry (Giusti+, 2024)
Determining the dynamical age of the LMC globular cluster NGC 1835 using
the dynamical clock. Star density profile and blue straggler stars.
Giusti C., Cadelano M., Ferraro F. R., Lanzoni B., Pallanca C.,
Vesperini E., Dalessandro E., Salaris M.
<Astron. Astrophys. 687, A310 (2024)>
=2024A&A...687A.310G 2024A&A...687A.310G (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Clusters, globular ; Photometry, HST
Keywords: blue stragglers - Hertzsprung-Russell and C-M diagrams -
Magellanic Clouds - galaxies: star clusters: general
Abstract:
In the context of the study of the size-age relationship observed in
star clusters in the Large Magellanic Cloud and the investigation of
its origin, here we present the determination of the structural
parameters and the dynamical age of the massive cluster NGC 1835. We
have used a powerful combination of optical and near-ultraviolet
images acquired with the WFC3 onboard the HST to construct the star
density profile from resolved star counts, determining the values of
the core, half-mass and tidal radii through the comparison with the
King model family. The same data also allowed us to evaluate the
dynamical age of the cluster by using the 'dynamical clock'. This is
an empirical method that quantifies the level of central segregation
of blue stragglers stars (BSSs) within the cluster half-mass radius by
means of the A+ parameter, which is defined as the area enclosed
between the cumulative radial distribution of BSSs and that of a
reference (lighter) population. The results confirm that NGC 1835 is a
very compact cluster with a core radius of only 0.84pc. The estimated
value of A+ (0.30_/-0.04) is the largest measured so far in the LMC
clusters, providing evidence of a highly dynamically evolved stellar
system. NGC 1835 nicely fits into the correlation between A+ and the
central relaxation time and in the anti-correlation between A+ and the
core radius defined by the Galactic and the Magellanic Cloud clusters
investigated to date.
Description:
The table contains the catalogue of the Large Magellanic Cloud
globular cluster NGC 1835.
The table includes the stars ID, the right ascension and declination,
the X and Y coordinate of stellar centroid in pixel,
the magnitudes in the F300X, F606W and F814W filters and the relative
errors, the chi square of the fit and the sharpness.
99.999 stands for no measured magnitude.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 108 65586 Catalog of the globular cluster NGC 1835
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See also:
J/AJ/105/527 : Photometry of RR Lyr stars in LMC cluster NGC 1835 (Walker 1993)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [100001/214593] Star ID
8- 17 F10.7 deg RAdeg Right ascension (J2000)
19- 29 F11.7 deg DEdeg Declination (J2000)
31- 38 F8.3 pix Xpos X coordinate of stellar centroid in pixel
40- 47 F8.3 pix Ypos Y coordinate of stellar centroid pixel
49- 55 F7.4 mag F300Xmag ?=99.9990 Magnitude in the F300X filter
57- 62 F6.4 mag e_F300Xmag ?=9.9999 Uncertainty on the F300X mag
64- 69 F6.3 mag F606Wmag ?=99.9990 Magnitude in the F606W Filter
71- 76 F6.4 mag e_F606Wmag ?=9.9999 Uncertainty on the F606W mag
78- 84 F7.4 mag F814Wmag ?=99.9990 Magnitude in F814W filter
86- 91 F6.4 mag e_F814Wmag ?=9.9999 Uncertainty on the F814W mag
93- 99 F7.4 --- chi2 chi square
101-108 F8.4 --- Sharp Sharpness
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Acknowledgements:
Camilla Giusti, camilla.giusti3(at)unibo.it
(End) Patricia Vannier [CDS] 29-May-2024