J/A+A/601/A56 NGC 6802 dwarf cluster members and non-members (Tang+, 2017)
The Gaia-ESO Survey: the inner disk intermediate-age open cluster NGC 6802.
Tang B., Geisler D., Friel E., Villanova S., Smiljanic R., Casey A.R.,
Randich S., Magrini L., San Roman I., Munoz C., Cohen R.E., Mauro F.,
Bragaglia A., Donati P., Tautvaisiene G., Drazdauskas A., Zenoviene R.,
Snaith O., Sousa S., Adibekyan V., Costado M.T., Blanco-Cuaresma S.,
Jimenez-Esteban F., Carraro G., Zwitter T., Francois P., Jofre P.,
Sordo R., Gilmore G., Flaccomio E., Koposov S., Korn A.J., Lanzafame A.C.,
Pancino E., Bayo A., Damiani F., Franciosini E., Hourihane A., Lardo C.,
Lewis J., Monaco L., Morbidelli L., Prisinzano L., Sacco G., Worley C.C.,
Zaggia S.
<Astron. Astrophys. 601, A56 (2017)>
=2017A&A...601A..56T 2017A&A...601A..56T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Radial velocities
Keywords: open clusters and associations: individual: NGC 6802 -
open clusters and associations: general - star: abundances
Abstract:
Milky Way open clusters are very diverse in terms of age, chemical
composition, and kinematic properties. Intermediate-age and old open
clusters are less common, and it is even harder to find them inside
the solar Galactocentric radius, due to the high mortality rate and
strong extinction inside this region. NGC 6802 is one of the inner
disk open clusters (IOCs) observed by the $Gaia$-ESO survey (GES).
This cluster is an important target for calibrating the abundances
derived in the survey due to the kinematic and chemical homogeneity of
the cluster members in open clusters. Using the measurements from
$Gaia$-ESO internal data release 4 (iDR4), we identify 95 dwarf
main-sequence stars as cluster members from the GIRAFFE target list,
and 8 red giants as cluster members from the UVES target list. The
dwarf cluster members have a median radial velocity of 13.6±1.9km/s,
while the giant cluster members have a median radial velocity of
12.0±0.9km/s and a median [Fe/H] of 0.10±0.02dex. The
color-magnitude diagram of these cluster members suggests an age of
$0.9±0.1Gyr, with (m-M)0=11.4 and E(B-V)=0.86. We perform the
first chemical abundance analysis of NGC 6802, including 27 element
species. To gain a more general picture about IOCs, the measurements
of NGC6802 are compared with those of other IOCs previously studied by
GES, i.e., NGC 4815, Trumpler 20, NGC 6705, and Berkeley 81. NGC 6802
shows similar C, N, Na, and Al abundances as other IOCs. The abundance
versus cluster turn-off mass for these elements in the five GES IOCs
cannot firmly exclude any one of the competing nucleosynthetic models,
including: standard models; models with rotation induced mixing and/or
thermohaline mixing. The five GES IOCs, particularly NGC 6802, seem to
have higher s-process element abundances than that of the inner disk
field stars.
Description:
The dwarf stars in NGC 6802 observed by GIRAFFE spectrograph are
separated into four tables:
1. cluster members in the lower main sequence;
2. cluster members in the upper main sequence;
3. non-member dwarfs in the lower main sequence;
4. non-member dwarfs in the upper main sequence.
The star coordinates, V band magnitude, V-I color, and radial velocity
are given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lms.dat 47 45 Dwarf cluster members in the lower main sequence
ums.dat 47 50 Dwarf cluster members in the upper main sequence
lmsno.dat 47 43 Non-member dwarfs in the lower main sequence
umsno.dat 48 45 Non-member dwarfs in the upper main sequence
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Byte-by-byte Description of file: lms.dat ums.dat lmsno.dat umsno.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Row number
5- 20 A16 --- Name Name (HHMMSSss+DDMMSSs, J2000.0)
22- 27 F6.3 mag Vmag V band magnitude
29- 33 F5.3 mag V-I V-I color index
35- 40 F6.2 km/s RV Radial velocity
42- 46 F5.2 km/s e_RV Error of radial velocity
48 A1 --- sp [Y] Indication of stars belong to the second
peak of the radial velocity distribution
(for umsno.dat only)
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Acknowledgements:
Baitian Tang, tangbaitian(at)gmail.com
(End) Patricia Vannier [CDS] 08-Nov-2016