J/A+A/566/A50 Classification of stellar spectra 644-681nm (Damiani+, 2014)
Gaia-ESO Survey: Empirical classification of VLT/Giraffe stellar spectra in the
wavelength range 6440-6810Å in the gamma Vel cluster, and calibration of
spectral indices.
Damiani F., Prisinzano L., Micela, G., Randich S., Gilmore G., Drew J.E.,
Jeffries R.D., Fremat Y., Alfaro E.J., Bensby T., Bragaglia A.,
Flaccomio E., Lanzafame A.C., Pancino E., Recio-Blanco A., Sacco G.G.,
Smiljanic R., Jackson R.J., de Laverny P., Morbidelli L., Worley C.C.,
Hourihane A., Costado M.T., Jofre P., Lind K., Maiorca E.
<Astron. Astrophys. 566, A50 (2014)>
=2014A&A...566A..50D 2014A&A...566A..50D
ADC_Keywords: Clusters, open ; Stars, fundamental ; Stars, pre-main sequence ;
MK spectral classification
Keywords: stars: fundamental parameters - stars: pre-main-sequence -
open clusters and associations: individual: gamma2 Velorum
Abstract:
We present a study of spectral diagnostics available from optical
spectra with R=17000 obtained with the VLT/Giraffe HR15n setup, using
observations from the Gaia-ESO Survey, on the γ Vel young cluster,
with the purpose of classifying these stars and finding their
fundamental parameters. We define several spectroscopic indices,
sampling the amplitude of TiO bands, the Hα line core and wings,
and temperature- and gravity-sensitive sets of lines, each useful as a
Teff or logg indicator over a limited range of stellar spectral types.
Hα line indices are also useful as chromospheric activity or
accretion indicators. Furthermore, we use all indices to define
additional global Teff- and logg-sensitive indices τ and γ,
valid for the entire range of types in the observed sample.
Description:
A set of newly-defined spectral indices is presented for all stars in
the field of the γ Vel cluster, observed within the Gaia-ESO
Survey. All indices are based exclusively on the spectral range
6440-6810 Angstroms, corresponding to the VLT/FLAMES Giraffe setup
HR15N. Fundamental stellar parameters can be derived from these
indices as explained in the paper. Stars with either high cluster
membership probability, or/and SB2 binaries, are flagged.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 135 13 Wavelength ranges for definition of spectral
indices
table3.dat 356 1802 Spectral indices for γ Vel dataset
(for 1242 distinct stars)
--------------------------------------------------------------------------------
See also:
J/ApJ/686/1195 : IR photometry in the γ Vel cluster (Hernandez+, 2008)
J/A+A/563/A94 : Kinematics of the Gamma Vel cluster (Jeffries+, 2014)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Index Index name
10 A1 --- n_Index [a] Note on Index (1)
12- 70 A59 --- Arange A wavelength range(s) of the numerator
71 A1 --- n_Arange [b] Note on Arange (1)
73-135 A63 --- Brange B wavelength range(s) of the denominator
--------------------------------------------------------------------------------
Note (1): Notes as follows:
a = The alphaw index must include a correction based on mu, see text
b = The 6489-6492Å range is summed with the main range with relative
weights 1:7
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Nspec [1/1802] Sequential spectrum number
6- 21 A16 --- JName Star name from coordinates (HHMMSSss+DDMMSSs)
23- 33 F11.3 d JD Julian Date of observation
35- 39 F5.2 mag Vmag [12/19] Apparent Johnson V magnitude
41- 44 F4.2 mag V-Ic [0.2/5.0] Johnson-Cousins V-I color index
46- 50 F5.1 --- S/N Signal/noise ratio
52- 60 F9.5 --- mu1 Index µ1
62- 70 F9.6 --- e_mu1 ?=- Error on mu1
72- 78 F7.5 --- mu2 Index µ2
80- 88 F9.6 --- e_mu2 ?=- Error on mu2
90- 95 F6.4 --- mu3 Index µ3
97-105 F9.6 --- e_mu3 ?=- Error on mu3
107-112 F6.4 --- mu4 Index µ4
114-122 F9.6 --- e_mu4 ?=- Error on mu4
124-130 F7.4 --- mu5 Index µ5
132-140 F9.6 --- e_mu5 ?=- Error on mu5
142-147 F6.4 --- mu6 Index µ6
149-157 F9.6 --- e_mu6 ?=- Error on mu6
159-165 F7.4 --- mu7 Index µ7
167-175 F9.6 --- e_mu7 ?=- Error on mu7
177-183 F7.4 --- alphaw Index αw
185-192 F8.6 --- e_alphaw Error on alphaw
194-200 F7.4 --- alphac Index αc
202-210 F9.6 --- e_alphac ?=- Error on alphac
212-218 F7.4 --- betat Index βt
220-228 F9.6 --- e_betat ?=- Error on betat
230-235 F6.4 --- betac Index βc
237-245 F9.6 --- e_betac ?=- Error on betac
247-252 F6.4 --- zeta1 Index ζ1
254-262 F9.6 --- e_zeta1 ?=- Error on zeta1
264-269 F6.4 --- gamma1 Index γ1
271-279 F9.6 --- e_gamma1 ?=- Error on gamma1
281-287 F7.4 --- mu Index µ=0.25(µ1+µ3+µ5+µ7)
289-296 E8.2 --- e_mu Error on mu
298-307 E10.3 --- beta Index β=1-βc/βt
309-317 F9.6 --- e_beta ?=- Error on beta
319-324 F6.4 --- gamma Index γ=β+γ1
326-333 F8.6 --- e_gamma Error on gamma
335-341 F7.3 --- tau Index τ = min(αw,1)
- βt - ζ1 + 3*µ
343-350 F8.5 --- e_tau Error on tau
352-356 A5 --- Notes [M SB2] Membership/binarity flags (1)
--------------------------------------------------------------------------------
Note (1): Membership/binarity flags:
M = putative (candidate) member of the γ Vel cluster
SB2 = spectroscopic binary
--------------------------------------------------------------------------------
Acknowledgements:
Francesco Damiani, damiani(at)astropa.unipa.it,
Loredana Prisinzano, loredana(at)astropa.inaf.it
(End) Francesco Damiani [INAF - OAPA, Italy], Patricia Vannier [CDS] 04-May-2014