J/A+A/507/833 Interstellar CaII lines for 290 stars (Megier+, 2009)
The interstellar CaII distance scale.
Megier A., Strobel A., Galazutdinov G.A., Krelowski J.
<Astron. Astrophys., 507, 833-840 (2009)>
=2009A&A...507..833M 2009A&A...507..833M
ADC_Keywords: Clusters, open ; Stars, early-type ; Equivalent widths ;
Stars, distances
Keywords: ISM: lines and bands - stars: distances - stars: early-type -
open clusters and associations: general
Abstract:
We attempt to extend the relation between the strengths of the
interstellar CaII lines and the distances to early-type stars to
objects beyond 1 kiloparsec, with the line saturation taken into
account.
We measure the CaII K and CaII H equivalent widths, and compute Ca
II column densities for 262 lines of sight towards early-type stars
with available Hipparcos parallaxes (pi). The targets are located
within a few hundred parsecs of the Galactic plane, and span all the
range of Galactic longitudes. We fit the NCaII - parallax relation
with a function of the form pi=1/(a.NCaII+b), using a
maximum-likelihood approach to take account of errors in both
variables. We use the resultant formula to estimate distances to stars
in OB associations and clusters, and compare them to those found in
the literature, usually estimated by spectrophotometric methods.
Description:
Most of the spectra were collected during research projects concerning
diffuse interstellar bands.
The first spectrometer is the MAESTRO fed by the 2-m telescope of the
Observatory at Peak Terskol (TE) in the Northern Caucasus.
The second spectrometer, covering the Southern hemisphere, is the
FEROS spectrograph, fed by the 2.2m ESO telescope.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 113 290 Target stars
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Star name
12- 19 F8.4 deg GLON Galactic longitude (from SIMBAD)
21- 28 F8.4 deg GLAT Galactic latitude (from SIMBAD)
30- 34 F5.2 mas plx ?=- Trigonometric parallax (Hipparcos)
36- 39 F4.2 mas e_plx ?=- rms uncertainty on plx
41- 44 I4 0.1pm EWK Equivalent width of the CaII K line
46- 50 F5.2 0.1pm e_EWK rms uncertainty on EWK
51- 53 I3 0.1pm EWH Equivalent width of the CaII H line
55- 59 F5.2 0.1pm e_EWH rms uncertainty on EWK
61- 65 F5.2 10+12cm-2 NCaII CaII column density
67- 70 F4.2 10+12cm-2 e_NCaII rms uncertainty on NCaII
72- 79 A8 --- Assos Association membership
81- 88 A8 --- r_Assos Reference for association membership (1)
91- 94 I4 pc DH ?=- Association distance from
Humphreys (1978ApJS...38..309H 1978ApJS...38..309H)
96- 99 I4 pc DGS ?=- Association distance from
Garmany & Stencel (1992A&AS...94..211G 1992A&AS...94..211G)
101-103 I3 pc DZ ?=- Association distance from de
Zeeuw et al. (1999, Cat. J/AJ/117/354)
105-108 I4 pc DCaII Distance estimated from formula (3)
110-113 I4 pc e_DCaII ? rms uncertainty pn DCaII
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Note (1): Reference for association membership as follows:
H = Humphreys (1978ApJS...38..309H 1978ApJS...38..309H)
GS = Garmany and Stencel 1992A&AS...94..211G 1992A&AS...94..211G1992)
Z = de Zeeuw et al. (1999, Cat. J/AJ/117/354)
Note (3): The formula for estimating distance is:
DCaII≃77+{2.78+(2.60/[EWK/EWH - 0.932])}*EWH
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History:
* From electronic version of the journal (units of galactic longitude,
latitude, and parallaxes indicated as "mÅ" corrected)
(End) Patricia Vannier [CDS] 02-Mar-2010