J/A+A/686/A283 Differential reddening in globular clusters (Pancino+, 2024)
Differential reddening in 48 globular clusters:
An end to the quest for the intracluster medium.
Pancino E., Zocchi A., Rainer M, Monaci M., Massari D., Monelli M.,
Hunt L.K., Monaco L., Martinez-Vazquez C.E., Sanna N., Bianchi S.,
Stetson P.B.
<Astron. Astrophys. 686, A283 (2024)>
=2024A&A...686A.283P 2024A&A...686A.283P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Interstellar medium ; Photometry ; Optical
Keywords: techniques: photometric - dust, extinction -
globular clusters: general
Abstract:
For decades, it has been theorized that a tenuous but detectable
intracluster medium should be present in globular clusters, which is
continuously replenished by the gas and dust ejected by bright giants
and periodically cleared by interactions with the Galactic disk.
However, dedicated searches, especially in infrared and radio
wavelengths, have returned mostly upper limits, which are lower than
theoretical expectations by several orders of magnitude. We profited
from recent wide-field photometry for 48 Galactic globular clusters to
compute high-resolution maps of differential reddening, which can be
used to correct any photometric catalog in these areas for reddening
variations. Using 3D reddening maps from the literature, we evaluated
the amount of foreground extinction. This allowed us to estimate the
masses of the intracluster medium in our sample clusters, with an
accuracy of one order of magnitude. Our estimates agree with the few
available literature detections and with theoretical expectations.
Because the discrepancy between observations and expectations only
concerns literature upper limits, we explored possible reasons why
they could be underestimated and we show that two recent discoveries
can explain the discrepancy. The first is the recent discovery that
the intracluster medium in 47 Tuc is not centrally concentrated. This
is also supported by our maps, which in the majority of cases do not
show a central reddening concentration. The second is the discovery
that the dust in metal-poor ([Fe/H]≤∼1dex) globular clusters is
dominated by iron grains rather than silicates, which undermines
previous dust mass estimates from observed upper limits. We conclude
that current evidence, including our maps, does not contradict
theoretical expectations and the problem of the missing intracluster
medium is no longer an issue.
Description:
We tabulate the relevant properties and our measurements of
differential reddening and related quantities for the sample of 48
globular clusters, including our estimates of the intracluster medium
masses. We also provide the differential reddening maps for each
cluster, for the stars that were used to create the maps. Finally, we
provide a compilation of literature determinations and upper limits
that we used in the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 555 48 Sample globular clusters and ICM measurements
table2.dat 184 854047 Differential reddening maps
table3.dat 68 44 Compilation of literature estimates
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Cluster Cluster name
11- 18 A8 --- AltName Alternate cluster name
20- 21 I2 h RAh Right ascension (J2000) of cluster center
23- 24 I2 min RAm Right ascension (J2000) of cluster center
26- 30 F5.2 s RAs Right ascension (J2000) of cluster center
32 A1 --- DE- Declination sign (J2000) of cluster center
33- 34 I2 deg DEd Declination (J2000) of cluster center
36- 37 I2 arcmin DEm Declination (J2000) of cluster center
39- 42 F4.1 arcsec DEs Declination (J2000) of cluster center
44- 47 I4 pix X0 X coordinate of cluster center
49- 52 I4 pix Y0 Y coordinate of cluster center
54- 57 F4.1 kpc Dist Distance of the cluster
59- 62 F4.2 arcmin rc Adopted core radius
64- 80 F17.15 arcmin rh Adopted half-light radius
82- 99 F18.14 arcmin rt Adopted truncation (or tidal) radius
101-117 F17.14 arcmin rl Limiting radius of reddening map
119-123 F5.2 [-] [Fe/H] Metallicity from Harris et al. (2010) (1)
125-128 F4.2 mag E(B-V) E(B-V) from Harris et al. (2010) (1)
130-132 I3 --- k Number of neighbors for map smoothing
134-152 F19.17 mag dE(B-V)max Total differential reddening
154-171 F18.16 mag e_dE(B-V)max Uncertainty on d(E-B)Vmax
173-186 A14 --- flag Flag for foreground contamination
188-205 F18.13 --- n-hb Expected number of HB stars
207-224 F18.16 --- e_n-hb Uncertainty on n-hb
226-241 E16.2 yr t-hb Expected HB lifetime
243-247 E5.1 yr e_t-hb Uncertainty on t-hb
249-257 I9 yr tc Time from last disk crossing
259-267 I9 yr e_tc Uncertainty on tc
269-288 E20.18 cm-2 th-nHmin Expected minimum H column density
290-308 E19.17 cm-2 e_th-nHmin Uncertainty on th-nHmin
310-329 E20.18 cm-2 th-nHmax Expected maximum H column density
331-350 E20.18 cm-2 e_th-nHmax Uncertainty on th-nHmax
352-370 F19.14 Msun th-Mgas Expected ICM gas mass
372-390 F19.15 Msun e_th-Mgas Uncertainty on th-Mgas
392-410 F19.17 Msun th-Mdust Expected ICM dust mass
412-431 F20.18 Msun e_th-Mdust Uncertainty on th-Mdust
433-452 E20.16 cm-2 rh-nH ? Estimated H column density
454-473 E20.16 cm-2 e_rh-nH ? Uncertainty on rh-nH
475-493 F19.15 Msun rh-Mgas ? Estimated ICM gas mass
495-513 F19.15 Msun e_rh-Mgas ? Uncertainty on rh-Mgas
515-534 F20.18 Msun rh-Mdust ? Estimated ICM dust mass
536-555 F20.18 Msun e_rh-Mdust ? Uncertainty on rh-Mdust
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Note (1): Harris et al., 2010, A New Catalog of Globular Clusters in the Milky
Way, https://ui.adsabs.harvard.edu/abs/2010arXiv1012.3224H,
accessed: 2020-07-18
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Cluster Cluster Name
9- 14 I6 --- Star Star identifier within the cluster
16- 24 F9.3 pix X X coordinate of the star
26- 34 F9.3 pix Y Y coordinate of the star
36- 37 I2 h RAh Right ascension ICRF
39- 40 I2 min RAm Right ascension ICRF
42- 46 F5.2 s RAs Right ascension ICRF
48 A1 --- DE- Declination sign ICRF
49- 50 I2 deg DEd Declination ICRF
52- 53 I2 arcmin DEm Declination ICRF
55- 58 F4.1 arcsec DEs Declination ICRF
60- 65 F6.3 mag Vmag Johnson V magnitude
67- 75 E9.4 mag e_Vmag Uncertainty in Vmag
77- 98 E22.14 mag dE(B-V)raw Raw color displacement
100-121 E22.14 mag dE(B-V) Differential reddening
123-141 F19.17 mag dE(B-V)mad MAD of dEBV in neighborhood of the stars
143-162 F20.18 mag e_dE(B-V) Statistical error on dE(B-V)
164-181 F18.14 arcsec dE(B-V)res Local spatial resolution
183-184 I2 --- Flag [-1/2] Quality flag on the star
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Cluster Cluster name
10- 17 E8.3 Msun Mass Literature mass estimate
19- 23 F5.2 arcmin FoV ? Typical field of view (when relevant)
25- 29 I5 K Temp ? Adopted temperature (when relevant)
31- 41 A11 --- Meas Either "detection" or "upper limit"
43- 55 A13 --- Type ICM component (dust, gas, etc.)
57- 68 A12 --- Source Literature reference of the source paper (1)
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Note (1): References as follows:
Abbate+18 = Abbate et al. (2018MNRAS.481..627A 2018MNRAS.481..627A)
Barmby+09 = Barmby et al. (2009AJ....137..207B 2009AJ....137..207B)
Boyer+06 = Boyer et al. (2006AJ....132.1415B 2006AJ....132.1415B)
Boyer+08 = Boyer et al. (2008AJ....135.1395B 2008AJ....135.1395B)
Boyer+09 = Boyer et al. (2009ApJ...705..746B 2009ApJ...705..746B)
Evans+03 = Evans et al. (2003A&A...408L...9E 2003A&A...408L...9E)
Faulkner+91 = Faulkner et al. (1991ApJ...374L..45F 1991ApJ...374L..45F)
Forte+92 = Forte et al. (1992ApJ...388..383F 1992ApJ...388..383F)
Knapp+96 = Knapp et al. (1996ApJ...462..231K 1996ApJ...462..231K)
LeonCombes96 = Leon & Combes (1996A&A...309..123L 1996A&A...309..123L)
Matsunaga+08 = Matsunaga et al. (2008PASJ...60S.415M 2008PASJ...60S.415M)
Mendez+89 = Mendez et al. (1989ApJ...338..136M 1989ApJ...338..136M)
Penny+97 = Penny et al. (1997A&A...317..694P 1997A&A...317..694P)
Smith+90 = Smith et al. (1990ApJ...353..168S 1990ApJ...353..168S)
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Acknowledgements:
Elena Pancino, elena.pancino(at)inaf.it
(End) Patricia Vannier [CDS] 09-Apr-2024