J/MNRAS/522/367 Differential reddening in 21 globular clusters (Legnardi+, 2023)
Differential reddening in the direction of 56 Galactic globular clusters.
Legnardi M.V., Milone A.P., Cordoni G., Lagioia E.P., Dondoglio E.,
Marino A.F., Jang S., Mohandasan A., Ziliotto T.
<Mon. Not. R. Astron. Soc., 522, 367-380 (2023)>
=2023MNRAS.522..367L 2023MNRAS.522..367L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Photometry, HST ; Ultraviolet ; Optical
Keywords: techniques: photometric -
Hertzsprung-Russell and colour-magnitude diagrams -
globular clusters: general
Abstract:
The presence of differential reddening in the direction of Galactic
globular clusters (GCs) has proven to be a serious limitation in the
traditional colour-magnitude diagram (CMD) analysis. Here, we estimate
local reddening variations in the direction of 56 Galactic GCs. To do
that, we use the public catalogues derived as part of the Hubble Space
Telescope UV Legacy Survey of Galactic GCs, which include photometry
in the F275W, F336W, F438W, F606W, and F814W filters. We corrected
photometry for differential reddening and found that for 21 out of 56
GCs the adopted correction procedure significantly improved the CMDs.
Moreover, we measure the reddening law in the direction of these
clusters, finding that RV exhibits a high level of variability
within the Galaxy, ranging from ∼2.0 to ∼4.0. The updated values
of RV have been used to improve the determination of local reddening
variations and derive high-resolution reddening maps in the direction
of the 21 highly-reddened targets within our sample. To compare the
results of the different clusters, we compute the 68th percentile of
the differential-reddening distribution, σΔAF814W. This
quantity ranges from 0.003 to 0.030mag and exhibits a significant
anticorrelation with the absolute module of the Galactic latitude and
a strong correlation with the average reddening in the direction of
each cluster. Therefore, highly-reddened GCs located in the proximity
of the Galactic plane typically show higher differential-reddening
variations across their field of view.
Description:
The present catalogues allow to correct the photometry of 21 Galactic
GCs by Nardiello et al. (2018MNRAS.481.3382N 2018MNRAS.481.3382N,
https://archive.stsci.edu/prepds/hugs/#dataaccess).
Spefically they includes correction for magnitudes in the UVIS/WFC3
F275W, F336W, F438W filters, and ACS/WFC F606W, F814W.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ngc2298.dat 70 22587 NGC 2298 differential reddening corrected catalogue
ngc3201.dat 70 33471 NGC 3201 differential reddening corrected catalogue
ngc5286.dat 70 235916 NGC 5286 differential reddening corrected catalogue
ngc5927.dat 70 113924 NGC 5927 differential reddening corrected catalogue
ngc5986.dat 70 179837 NGC 5986 differential reddening corrected catalogue
ngc6093.dat 70 150647 NGC 6093 differential reddening corrected catalogue
ngc6121.dat 70 12693 NGC 6121 differential reddening corrected catalogue
ngc6144.dat 70 25108 NGC 6144 differential reddening corrected catalogue
ngc6171.dat 70 22456 NGC 6171 differential reddening corrected catalogue
ngc6254.dat 70 64198 NGC 6254 differential reddening corrected catalogue
ngc6304.dat 70 114429 NGC 6304 differential reddening corrected catalogue
ngc6352.dat 70 28852 NGC 6352 differential reddening corrected catalogue
ngc6366.dat 70 8670 NGC 6366 differential reddening corrected catalogue
ngc6388.dat 70 376788 NGC 6388 differential reddening corrected catalogue
ngc6441.dat 70 394280 NGC 6441 differential reddening corrected catalogue
ngc6496.dat 70 34548 NGC 6496 differential reddening corrected catalogue
ngc6535.dat 70 7402 NGC 6535 differential reddening corrected catalogue
ngc6541.dat 70 131110 NGC 6541 differential reddening corrected catalogue
ngc6656.dat 70 108239 NGC 6656 differential reddening corrected catalogue
ngc6779.dat 70 88052 NGC 6779 differential reddening corrected catalogue
ngc6838.dat 70 15710 NGC 6838 differential reddening corrected catalogue
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See also:
https://archive.stsci.edu/prepds/hugs/#dataaccess : HUGS Home Page
Byte-by-byte Description of file: ngc*.dat
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Bytes Format Units Label Explanations
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3- 10 A8 --- ID ID number of the star (from Nardiello et al.,
2018MNRAS.481.3382N 2018MNRAS.481.3382N) (1)
16- 22 F7.4 mag F275Wc ?=99.9999 F275W magnitude corrected for
differential reddening
28- 34 F7.4 mag F336Wc ?=99.9999 F336W magnitude corrected for
differential reddening
40- 46 F7.4 mag F438Wc ?=99.9999 F438W magnitude corrected for
differential reddening
52- 58 F7.4 mag F606Wc ?=99.9999 F606W magnitude corrected for
differential reddening
64- 70 F7.4 mag F814Wc ?=99.9999 F814W magnitude corrected for
differential reddening
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Note (1): available at https://archive.stsci.edu/prepds/hugs/#dataaccess.
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Acknowledgements:
Maria Vittoria Legnardi, mariavittoria.legnardi(at)phd.unipd.it
(End) Maria Vittoria Legnardi [Univ. Padova], Patricia Vannier [CDS] 26-May-2023