J/AJ/151/6 Spectroscopic and photometric properties of Tombaugh 1 (Sales+, 2016)
Properties of the open cluster Tombaugh 1 from high-resolution spectroscopy
and uvbyCaHβ photometry.
Sales Silva J.V., Carraro G., Anthony-Twarog B.J., Moni Bidin C., Costa E.,
Twarog B.A.
<Astron. J., 151, 6 (2016)>
=2016AJ....151....6S 2016AJ....151....6S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Photometry, uvby, beta ;
Photometry, UBVRI ; Radial velocities ; Spectroscopy ;
Equivalent widths ; Effective temperatures ; Abundances, [Fe/H]
Keywords: open clusters and associations: general -
open clusters and associations: individual: Tombaugh 1 -
stars: abundances - stars: atmospheres
Abstract:
Open clusters can be the key to deepening our knowledge on various
issues involving the structure and evolution of the Galactic disk and
details of stellar evolution because a cluster's properties are
applicable to all its members. However, the number of open clusters
with detailed analysis from high-resolution spectroscopy or precision
photometry imposes severe limitations on studies of these objects. To
expand the number of open clusters with well-defined chemical
abundances and fundamental parameters, we investigate the poorly
studied, anticenter open cluster Tombaugh 1. Using precision
uvbyCaHβ photometry and high-resolution spectroscopy, we derive
the cluster's reddening, obtain photometric metallicity estimates,
and, for the first time, present a detailed abundance analysis of 10
potential cluster stars (nine clump stars and one Cepheid). Using the
radial position from the cluster center and multiple color indices, we
have isolated a sample of unevolved, probable single-star members of
Tombaugh 1. From 51 stars, the cluster reddening is found to be
E(b-y)=0.221±0.006 or E(B-V)=0.303±0.008, where the errors refer
to the internal standard errors of the mean. The weighted photometric
metallicity from m1 and hk is [Fe/H]=-0.10±0.02, while a match to
the Victoria-Regina Stromgren isochrones leads to an age of 0.95±0.10 Gyr
and an apparent modulus of (m-M)=13.10±0.10. Radial velocities identify
six giants as probable cluster members, and the elemental abundances
of Fe, Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Y, Ba, Ce, and Nd have been
derived for both the cluster and the field stars. Tombaugh 1 appears
to be a typical inner thin disk, intermediate-age open cluster of
slightly subsolar metallicity, located just beyond the solar circle,
with solar elemental abundance ratios except for the heavy s-process
elements, which are a factor of two above solar. Its metallicity is
consistent with a steep metallicity gradient in the galactocentric
region between 9.5 and 12 kpc. Our study also shows that Cepheid XZ CMa
is not a member of Tombaugh 1 and reveals that this Cepheid presents
signs of barium enrichment, making it a probable binary star.
Description:
Photometry for Tombaugh 1 was secured in 2010 December during a five-night
run using the Cerro Tololo Inter-American Observatory 1.0 m telescope
operated by the SMARTS consortium (http://www.astro.yale.edu/smarts).
The telescope is equipped with an STA 4064x4064 CCD camera
(http://www.astronomy.ohio-state.edu/Y4KCam/detector) with 15 µm pixels,
yielding a scale of 0.289"/pixel and a field of view (FOV) of 20'x20' at
the Cassegrain focus of the telescope.
Over the night of 2010 January 5, we observed 10 potential cluster
stars (nine clump stars and one Cepheid; see Section 4.1) with the
Inamori-Magellan Areal Camera & Spectrograph (IMACS; Dressler et al.
2006SPIE.6269E..0FD) attached to the Magellan telescope (6.5 m) located
at Las Campanas, Chile. The spectra were obtained using the Multi-Object
Echelle (MOE) mode with two exposures, one of 900 s and the other of
1200 s. Our spectra have a resolution of R∼20000, while the spectral
coverage depends on the location of the star on the multislit mask,
but it generally goes from 4200 to 9100 Å. The detector consists of a
mosaic with eight CCDs with gaps of about 0.93 mm between the CCDs,
causing small gaps in stellar spectra.
Objects:
-----------------------------------------------------
RA (ICRS) DE Designation(s)
-----------------------------------------------------
07 00 29 -20 34.0 Tombaugh 1 = C 0658-204
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 90 11 Excerpt of the Photometric Catalog of Tombaugh 1
table4.dat 88 10 Potential Cluster Stars Observed with IMACS
in the Field of Tombaugh 1
table5.dat 51 82 Observed Fe I and Fe II Lines
table6.dat 51 73 Observed Fe I and Fe II Lines
table7.dat 51 98 Other Lines Studied
table8.dat 51 93 Other Lines Studied
table9.dat 81 10 Atmospheric Parameters from Photometry (ph)
and Spectroscopy (sp)
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See also:
J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003)
J/A+A/421/991 : CT1 photometry in Tombaugh 1 (Piatti+, 2004)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
10- 17 F8.4 deg DEdeg Declination in decimal degrees (J2000)
19- 24 F6.3 mag Vmag [7.179/11.051] V-band magnitude
26- 31 F6.4 mag e_Vmag [0.0016/0.0195] Uncertainty in Vmag
33- 37 F5.3 mag b-y [0.044/1.387] Stromgren b-y color index
39- 44 F6.4 mag e_b-y [0.0023/0.0204] Uncertainty in b-y
46- 50 F5.3 mag hk [0.234/1.976] Stromgren hk index
52- 57 F6.4 mag e_hk [0.0032/0.0213] Uncertainty in hk
59- 63 F5.3 mag Hbmag [2.532/2.915] Stromgren Hβ-band magnitude
65- 70 F6.4 mag e_Hbmag [0.0019/0.0074] Uncertainty in Hbmag
72- 76 F5.3 mag m1 [0.050/0.661] Stromgren m1 index
78- 83 F6.4 mag e_m1 [0.0030/0.0205] Uncertainty in m1
85- 90 F6.3 mag c1 [-0.319/1.012] Stromgren c1 index
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [395/1616] Star identifier
5 A1 --- n_ID [a] Note on ID (1)
7- 8 I2 h RAh Hour of Right Ascension (J2000)
10- 11 I2 min RAm Minute of Right Ascension (J2000)
13- 16 F4.1 s RAs Second of Right Ascension (J2000)
18 A1 --- DE- Sign of the Declination (J2000)
19- 20 I2 deg DEd Degree of Declination (J2000)
22- 23 I2 arcmin DEm Arcminute of Declination (J2000)
25- 28 F4.1 arcsec DEs Arcsecond of Declination (J2000)
30- 34 F5.2 mag Vmag [13.01/14.20] V-band magnitude
36- 39 F4.2 mag b-y [0.51/0.83] Stromgren b-y color index
41- 44 F4.2 mag V-I [1.11/1.32] V-I color index
from Carraro & Patat (1995MNRAS.276..563C 1995MNRAS.276..563C)
46- 50 F5.1 km/s HRV1 [42.7/100.0] Heliocentric radial velocity
at epoch 1
52- 54 F3.1 km/s e_HRV1 [1.4/3.8] Uncertainty in HRV1
56- 59 F4.1 km/s HRV2 [44.8/99.0] Heliocentric radial velocity
at epoch 2
61- 63 F3.1 km/s e_HRV2 [1.3/4.6] Uncertainty in HRV2
65- 68 F4.1 km/s [43.7/99.5] Heliocentric radial velocity mean
value
70- 72 F3.1 km/s e_ [0.0/1.3] Uncertainty in
74 A1 --- l_vsini [<] Limit flag on vsini
75- 77 F3.1 km/s vsini [2.7/6.1]? Projected rotational velocity
(ν sin i)
79- 81 F3.1 km/s e_vsini [0.4/0.9]? Uncertainty in vsini
83- 85 I3 --- S/N [44/110] Spectral signal-to-noise ratio
at 6000Å
87- 88 I2 --- Tab Number of the table containing equivalent
widths for this star
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Note (1): Note as follows:
a = The classical Cepheid XZ CMa.
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Byte-by-byte Description of file: table5.dat table7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- El Element
7- 13 F7.2 0.1nm lambda [4534.78/8736.04] Wavelength λ (Å)
15- 18 F4.2 eV ExPot [0/6.18] Excitation potential
20- 25 F6.3 [-] log(gf) [-5.95/0.514] Log oscillator strength
27- 31 A5 --- Ref Reference (only in table 7) (G1)
33- 35 I3 0.1pm EW-769 [25/158]? Equivalent width for star 769 (mÅ)
37- 39 I3 0.1pm EW-806 [10/152]? Equivalent width for star 806 (mÅ)
41- 43 I3 0.1pm EW-1110 [23/140]? Equivalent width for star 1110 (mÅ)
45- 47 I3 0.1pm EW-1118 [26/155]? Equivalent width for star 1118 (mÅ)
49- 51 I3 0.1pm EW-395 [24/159]? Equivalent width for star 395 (mÅ)
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Byte-by-byte Description of file: table6.dat table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- El Element
7- 13 F7.2 0.1nm lambda [4730.04/8773.91] Wavelength λ (Å)
15- 18 F4.2 eV ExPot [0/6.18] Excitation potential
20- 25 F6.3 [-] log(gf) [-5.79/0.514] Log oscillator strength
27- 31 A5 --- Ref Reference (only in table 8) (G1)
33- 35 I3 0.1pm EW-1534 [21/158]? Equivalent width for star 1534 (mÅ)
37- 39 I3 0.1pm EW-1616 [18/151]? Equivalent width for star 1616 (mÅ)
41- 43 I3 0.1pm EW-1349 [24/156]? Equivalent width for star 1349 (mÅ)
45- 47 I3 0.1pm EW-784 [21/160]? Equivalent width for star 784 (mÅ)
49- 51 I3 0.1pm EW-663 [24/155]? Equivalent width for star 663 (mÅ)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [395/1616] Star identifier
6- 9 I4 K Teffph [4796/6324] Photometric effective temperature
11- 14 F4.2 [cm/s2] loggph [2.53/2.86] Photometric surface gravity (dex)
16- 19 I4 K Teffsp [4900/6000] Spectroscopic effective
temperature
21- 23 F3.1 [cm/s2] loggsp [2.0/3.5] Spectroscopic surface gravity (dex)
25- 27 F3.1 km/s ksi [1.0/4.9] Microturbulent velocity ξ
29- 33 F5.2 [-] [FeI/H] [-0.53/0.10] Abundance ratio [FeI/H]
35- 38 F4.2 [-] e_[FeI/H] [0.12/0.19] Uncertainty in [FeI/H]
40- 41 I2 --- o_[FeI/H] [15/53] Number of FeI lines employed
43- 47 F5.2 [-] [FeII/H] [-0.52/0.08] Abundance ratio [FeII/H]
49- 52 F4.2 [-] e_[FeII/H] [0.09/0.17]? Uncertainty in [FeII/H]
54 I1 --- o_[FeII/H] [2/6] Number of FeII lines employed
56- 81 A26 --- Com Comment
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Global notes:
Note (G1): Reference as follows:
B86 = Blackwell et al. (1986MNRAS.220..289B 1986MNRAS.220..289B);
Ca07 = Carretta et al. (2007A&A...473..129C 2007A&A...473..129C);
D2002 = Depagne et al. (2002A&A...390..187D 2002A&A...390..187D);
DS91 = Drake & Smith (1991MNRAS.250...89D 1991MNRAS.250...89D);
E93 = Edvardsson et al. (1993, J/A+A/275/101);
GS = Gratton & Sneden (1988A&A...204..193G 1988A&A...204..193G);
MFK = Martin et al. (2002, NIST Atomic Spectra Database (Version 2.0;
Gaithersburg, MD: NIST));
MR94 = McWilliam & Rich (1994ApJS...91..749M 1994ApJS...91..749M);
PS = Preston & Sneden (2001AJ....122.1545P 2001AJ....122.1545P);
R03 = Reddy et al. (2003, J/MNRAS/340/304);
R99 = Reddy et al. (1999ApJ...524..831R 1999ApJ...524..831R);
S86 = Not explained in this paper;
WSM = Wiese et al. (1969atp..book.....W 1969atp..book.....W).
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History:
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(End) Tiphaine Pouvreau [CDS] 12-Mar-2018