J/ApJ/613/312 Synthetic Lick indices of alpha-enhanced stars (Franchini+, 2004)
Synthetic Lick indices and detection of α-enhanced stars.
II. F, G, and K stars in the -1.0 < [Fe/H] < +0.50 range.
Franchini M., Morossi C., Di Marcantonio P., Malagnini M.L., Chavez M.,
Rodriguez-Merino L.
<Astrophys. J., 613, 312-321 (2004)>
=2004ApJ...613..312F 2004ApJ...613..312F
ADC_Keywords: Abundances, [Fe/H] ; Stars, late-type
Keywords: Galaxy: stellar content - stars: abundances - stars: kinematics -
stars: late-type
Abstract:
We present an analysis of 402 F, G, and K solar neighborhood stars,
with accurate estimates of [Fe/H] in the range -1.0 to +0.5dex, aimed
at the detection of α-enhanced stars and at the investigation of
their kinematical properties. The analysis is based on the comparison
of 571 sets of spectral indices in the Lick/IDS system, coming from
four different observational data sets, with synthetic indices
computed with solar-scaled abundances and with α-element
enhancement. We use selected combinations of indices to single out
α-enhanced stars without requiring previous knowledge of their
main atmospheric parameters. By applying this approach to the total
data set, we obtain a list of 60 bona fide α-enhanced stars and
of 146 stars with solar-scaled abundances. The properties of the
detected α-enhanced and solar-scaled abundance stars with
respect to their [Fe/H] values and kinematics are presented. A clear
kinematic distinction between solar-scaled and α-enhanced stars
was found, although a one-to-one correspondence to "thin disk" and
"thick disk" components cannot be supported with the present data.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 53 402 Detection of α-enhanced candidate stars
--------------------------------------------------------------------------------
See also:
J/ApJ/601/485 : Synthetic Lick indices of alpha-enhanced stars (Franchini+,
2004)
J/ApJS/94/687 : Old stellar populations. V. (Worthey+, 1994)
J/PASP/113/1365 : Super-metal-rich stars (Buzzoni+, 2001)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HD The HD number
8- 16 A9 --- SpType SIMBAD MK spectral type
18- 23 F6.3 [Sun] [Fe/H] Log of the Fe/H number abundance
25- 29 F5.3 [Sun] e_[Fe/H] Error in [Fe/H]
31 A1 --- LC [dg]Luminosity code (1)
33- 36 A4 --- Cananea The Cananea classification (2)
38- 41 A4 --- STELIB The STELIB classification (2)
43- 46 A4 --- ELODIE The ELODIE classification (2)
48- 51 A4 --- Worthey The Worthey classification (2)
53 A1 --- Class Star classification with respect to
α-enhancement (3)
--------------------------------------------------------------------------------
Note (1): Type code:
d = dwarf;
g = giant.
Note (2):
In the following 4 character wide columns we indicate the presence of
the star in each data-set and its classification with respect to
α-enhancement in each of the four index-index diagrams. The
capital letter "Y" is used for bona fide α-enhanced candidates
and the capital letter "N" is used for SSA (solar-scaled abundance)
candidates. The stars marked with "////" are too cool to be compared
with our SSA and NSSA (non-SSA) grids; their low temperatures are
inferred from the position of the observed points in the diagrams and
confirmed by looking at data in Taylor (2003, Cat. J/A+A/398/721)
and by using temperature estimates from broad-band photometry.
Note (3): Star classification with respect to α-enhancement as follows:
? = No classification achieved;
S = Classified as SSA (solar-scaled abundance);
A = Classified as α-enhanced;
C = Contradictory case (HD 43318 and HD 198149: it is very likely that
in both cases the discrepancy can be attributed to observational
problems).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 17-Feb-2005