J/A+A/517/A81 2nd and 3d parameters of HB of globular clusters (Gratton+, 2010)
The second and third parameters of the horizontal branch of globular clusters.
Gratton R.G., Carretta E., Bragaglia A., Lucatello S., S'Orazii V.
<Astron. Astrophys. 517, A81 (2010)>
=2010A&A...517A..81G 2010A&A...517A..81G
ADC_Keywords: Clusters, globular ; Abundances ; Stars, horizontal branch
Keywords: globular cluster: general - stars: abundances
Abstract:
The second parameter (the first being metallicity) defining the
distribution of stars on the horizontal branch (HB) of globular
clusters (GCs) has long been one of the major open issues in our
understanding of the evolution of normal stars. Large photometric and
spectroscopic databases are now available: they include large and
homogeneous sets of colour-magnitude diagrams, cluster ages, and
homogeneous data about chemical compositions from our FLAMES survey.
We use these databases to re-examine this issue. Methods. We use the
photometric data to derive median and extreme (i.e., the values
including 90% of the distribution) colours and magnitudes of stars
along the HB for about a hundred GCs. We transform these into median
and extreme masses of stars on the HB, using the models developed by
the Pisa group, and taking into account evolutionary effects. We
compare these masses with those expected at the tip of the red giant
branch (RGB) to derive the total mass lost by the stars.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 98 94 Basic parameters for globular clusters considered
in this paper
table2.dat 108 74 Photometric data from the HST-snapshot
(Piotto et al., 2002, Cat. J/A+A/391/945)
table3.dat 108 49 Photometric data from ground-based data (Rosenberg
et al. 2000, Cat. J/A+AS/144/5 and J/A+AS/145/451)
table4.dat 57 74 Intrinsic HB photometric parameters for GCs
with HST data
table5.dat 57 49 Intrinsic HB photometric parameters for GCs
with ground-based data
table6.dat 61 74 Masses on HB for GCs with HST data
table7.dat 61 49 Masses on HB for GCs with ground-based data
table8.dat 73 66 Properties of the RR Lyrae variables for each cluster
table10.dat 40 94 Clusters ages from main sequence fitting and
from HB both for HST and ground based data-set
table11.dat 61 94 R' parameter as derived from both HST and
ground based data
table12.dat 55 64 Spread in He and mass required explaining the HB
--------------------------------------------------------------------------------
See also:
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
J/A+A/391/945 : HST photometry of 74 galactic globular clusters (Piotto+ 2002)
J/A+AS/144/5 : Nearby globular clusters photometric catalog (Rosenberg+ 2000)
J/A+AS/145/451 : Nearby globular clusters photometric catalog (Rosenberg+ 2000)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
10- 16 A7 --- Name Other name
17- 22 F6.2 [Sun] [Fe/H] Metallicity
23- 29 F7.2 mag (m-M)V Distance modulus calculated from V magnitude
30- 36 F7.2 mag E(B-V) Redenning
37- 43 F7.2 mag VMAG Absolute V magnitude
44- 51 F8.2 --- HBR ? Horizontal-branch ratio = (B-R)/(B+V+R)
52- 58 F7.2 Gyr Age ? Estimated cluster age
59- 66 F8.3 solMass M(TO) ? Mass at turn-off
67- 74 F8.3 solMass M(RGB) ? Mass at the tip of the red-giant branch
75- 81 F7.3 --- IQR1 ? Interquartile of the [Na/O]
(anti-)correlations
82- 89 F8.3 --- IQR2 ? Interquartile of the [Mg/Al]
(anti-)correlations
90- 98 F9.3 [K] T(HB) ? Horizontal-branch effective temperature
(log scale)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
9- 12 I4 --- n(HB) Number of Horizon Branch stars
14- 16 I3 --- n(fld) [0/125] Number of field stars (G1)
20- 25 F6.3 mag F555 Median F555W magnitude
28- 32 F5.3 mag e_F555 rms uncertainty on F555
34- 39 F6.3 mag 439-555 Median F439W-F555W colour index
42- 46 F5.3 mag e_439-555 rms uncertainty on F439-F555
49- 54 F6.3 mag F555m Minimum F555W magnitude
57- 61 F5.3 mag e_F555m rms uncertainty on F555m
63- 68 F6.3 mag 439-555m Minimum F439W-F555W colour index
71- 75 F5.3 mag e_439-555m rms uncertainty on (F439-F555)m
77- 82 F6.3 mag 439-555M Maximum F439W-F555W colour index
85- 89 F5.3 mag e_439-555M rms uncertainty on (F439-F555)M
91- 94 I4 --- n(RGB) Number of RGB stars
96-101 F6.3 mag 439-555G F439W-F555W colour index for RGB
104-108 F5.3 mag e_439-555G rms uncertainty on (F439-F555)RGB
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
8- 11 I4 --- n(HB) Number of HB stars in the cluster
13- 15 I3 --- n(fld) [0/47] Number of field stars (G1)
20- 25 F6.3 mag Vmag Median V magnitude
28- 32 F5.3 mag e_Vmag rms uncertainty on
34- 39 F6.3 mag V-I Median V-I colour index
42- 46 F5.3 mag e_V-I rms uncertainty on V-I
49- 54 F6.3 mag Vmagm Minimum V magnitude
57- 61 F5.3 mag e_Vmagm rms uncertainty on
63- 68 F6.3 mag (V-I)m Minimum V magnitude
71- 75 F5.3 mag e_(V-I)m rms uncertainty on (V-I)m
77- 82 F6.3 mag (V-I)M Maximum V-I colour index
85- 89 F5.3 mag e_(V-I)M rms uncertainty on (V-I)M
91- 94 I4 --- n(RGB) Number of RGB stars
96-101 F6.3 mag (V-I)G V-I colour index for RGB
104-108 F5.3 mag e_(V-I)G rms uncertainty on (V-I)RGB
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
11- 15 F5.3 mag (B-V)0G Intrinsic B-V colour index value, for RGB
19- 24 F6.3 mag (B-V)0m Minimim B-V colour index value
28- 33 F6.3 mag (B-V)0 Median B-V colour index value
36- 41 F6.3 mag (B-V)0M Maximum B-V colour index value
45- 49 F5.3 mag VMAGM Maximum absolute V magnitude
53- 57 F5.3 mag VMAG Median absolute V magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
10- 15 F6.3 mag (V-I)0G Intrinsic V-I colour index value, for RGB
19- 24 F6.3 mag (V-I)0m Mimimum V-I colour index value
28- 33 F6.3 mag (V-I)0 Median V-I colour index value
36- 41 F6.3 mag (V-I)0M Maximum V-I colour index value
45- 49 F5.3 mag VMAGM Maximum absolute V magnitude
53- 57 F5.3 mag VMAG Median absolute V magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
11- 15 F5.3 solMass Mmin Mimimum mass
18- 22 F5.3 solMass e_Mmin ? rms uncertainty on Mmin
26- 30 F5.3 solMass Mmed Median mass
33- 37 F5.3 solMass e_Mmed ? rms uncertainty on Mmed
41- 45 F5.3 solMass Mmax ? Maximum mass
49- 53 F5.3 solMass e_Mmax ? rms uncertainty on Mmax
57- 61 F5.3 solMass dMmed ? Difference between median and minimum masses
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
10- 14 F5.1 --- S(RR) ? RR Lyrae richness parameter (Harris, 1996,
Cat. VII/195) (1)
18- 19 I2 --- n(RR)H ? Number of RR Lyrae stars for HST sample
27- 30 F4.2 --- f(RR)H ? Fraction of RR Lyrae stars for HST sample
37- 39 I3 --- n(RR)g ? Number of RR Lyrae for ground-based sample
48- 51 F4.2 --- f(RR)g ? Fraction of RR Lyrae for ground-based sample
56- 59 F4.2 --- f(RR) ? Fraction of RR Lyrae stars
62- 66 F5.3 d <Pab> ? Mean period
70- 73 I4 --- n(Pab) ? Number of stars used to determine the period
--------------------------------------------------------------------------------
Note (1): Number of RR Lyrae per unit cluster luminosity
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
10- 16 F7.2 Gyr Age ? Age from main-sequence fitting
17- 24 F8.3 Gyr Age(HB)H ? Age from horizontal branch fitting,
for HST data-set
25- 32 F8.3 Gyr Age(HB)g ? Age from horizontal branch fitting,
for ground-based data-set
33- 40 F8.3 Gyr Age(Y) ? Age value, determined with Ymed
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
8- 14 F7.2 --- R'(HST) ? R' parameter as derived from HST data (1)
15- 20 F6.2 --- e_R'(HST) ? rms uncertainty on R'(HST)
21- 27 F7.2 --- R'(GR) ? R' parameter as derived from ground-based
data (1)
28- 33 F6.2 --- e_R'(GR) ? rms uncertainty on R'(GR)
34- 40 F7.2 --- <R'> ? Mean R' parameter (1) (2)
41- 46 F6.2 --- e_<R'> ? rms uncertainty on <R'>
47- 54 F8.3 --- Y(<R'>) ? He abundance for R'=<R'>
55- 61 F7.3 --- e_Y(<R'>) ? rms uncertainty on Y(<R'>)
--------------------------------------------------------------------------------
Note (1): R' = NHB/N'RGB, where N'RGB is the number of stars on the
RGB brighter than V(HB)+1.
Note (2): Final adopted value <R'> is the weighted average between the two
estimates, when available.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table12.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC/IC Cluster name
8- 15 F8.3 solMass dM(Y) Spread in mass δM(Y)
16- 23 F8.3 --- Ymed Median He abundance value
24- 31 F8.3 --- Ymax Maximum He abundance value
32- 39 F8.3 --- dY Difference between maximum and median Y values
40- 47 F8.3 mag d(B-V) Colour spread in δ(B-V)
48- 55 F8.3 mag d(V-I) Colour spread in δ(V-I)
--------------------------------------------------------------------------------
Global Notes:
Note (G1): this number is an estimation of those field stars expected to
fall within the region of the color-magnitude diagram that we
identified with the HB and the RGB, based on the galactic model
TRILEGAL (Girardi et al. 2005A&A...436..895G 2005A&A...436..895G; Vanhollebeke et al.
2009A&A...498...95V 2009A&A...498...95V).
--------------------------------------------------------------------------------
Acknowledgements:
Raffaele Gratton, raffaele.gratton(at)oapd.inaf.it
(End) Raffaele Gratton [INAF-OAPD, Italy], Patricia Vannier [CDS] 11-May-2010