J/A+A/325/647 High-resolution spectra south of Taurus (Neuhaeuser+ 1997)
Optical high-resolution spectroscopy of ROSAT detected
late-type stars south of the Taurus molecular clouds
Neuhauser R., Torres G., Sterzik M.F., Randich S.
<Astron. Astrophys. 325, 647 (1997)>
=1997A&A...325..647N 1997A&A...325..647N (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Radial velocities ; Rotational velocities
Mission_Name: ROSAT
Keywords: stars: formation - stars: late-type - stars: pre-main sequence -
X-rays: stars
Description:
Listed are results from our high-resolution data for all stars in our
study area which were listed by either Magazzu et al.
(1997A&AS..124..449M 1997A&AS..124..449M) or Alcala et al. (1996A&AS..119....7A 1996A&AS..119....7A), i.e.
T Tauri candidates from the ROSAT All-Sky Survey. In table 1, we list
all stars for which lithium was found either by Magazzu et al.
(1997A&AS..124..449M 1997A&AS..124..449M) or in our CASPEC spectra, as well as two stars
identified as wTTS by Alcala et al. (1996A&AS..119....7A 1996A&AS..119....7A). Listed are
the designation, number of single-order echelle spectra taken,
effective temperatures, projected rotational velocities, mean
heliocentric radial velocities with errors, radial velocities in the
local standard of rest, and remarks on variability in radial velocity
as found in our high-resolution spectra. For comparison, we also list
the results on spectral types of the stars (with `e' for Hα
emission) as found by Magazzu et al. (1997A&AS..124..449M 1997A&AS..124..449M) (or Alcala
et al., 1996A&AS..119....7A 1996A&AS..119....7A) with low- and medium-resolution
spectroscopy. In the last two columns, we list the (NLTE) lithium
abundance (given on a scale where logN(H)=12) and the lithium excess
above the relevant Pleiades upper envelope; upper limits indicate
stars where the Magazzu et al. (1997A&AS..124..449M 1997A&AS..124..449M) spectra suffer
from either low S/N or low resolution. In table 2, we list all stars
where no lithium was detected -- neither by Magazzu et al.
(1997A&AS..124..449M 1997A&AS..124..449M) nor in our CASPEC spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 89 56 High-resolution data for lithium-rich ROSAT
source counterparts
table2 78 55 High-resolution data for ROSAT sources with
undetected lithium
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Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Name of objects (1)
18- 19 I2 --- No Number of high-resolution observations
22- 25 I4 K Teff ? Effective temperature
27- 29 I3 km/s vsini ? Rotational velocity v sin i
32- 36 F5.1 km/s HRV ? Heliocentric radial velocity
39- 42 F4.1 km/s e_HRV ? Error in radial velocity
45- 49 F5.1 km/s RVlsr ? Local-standard-of-rest radial velocity
52- 59 A8 --- Rem Remarks (2)
61- 71 A11 --- M97 Results from Magazzu et al.
(1997A&AS..124..449M 1997A&AS..124..449M) (3)
73- 75 F3.1 [Sun] NLi ? log of Lithium abundance N(Li)
76 A1 --- n_NLi [?] Unknown value
78- 82 F5.2 0.1nm dEW(Li) ? Lithium excess above ZAMS level
83 A1 --- n_dEW(Li) [?] Unknown value
85- 88 F4.2 0.1nm ULdEW(Li) ? Upper limits on Lithium excess above
ZAMS level
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Note (1):
Row 1 to 9: K-type stars with lithium excess south of Taurus:
PMS stars younger than 30 million years
Row 10 to 18: K-type stars located on lambda Ori with lithium excess:
PMS stars younger than 30 million years
Row 19 to 33: F8- to G9-type stars with lithium excess:
ZAMS stars older than 30 million years
Row 34 to 40: Lithium upper limits due to low S/N or low-resolution spectra
Row 41 to 56: Stars with lithium, but without lithium excess:
ZAMS stars older than 100 million years
Note (2): SB 1 or 2: single- or double-lined spectroscopic binaries.
Note (3): (N): Listed as "wTTS" in Neuhaeuser et al. (1995A&A...299L..13N 1995A&A...299L..13N)
(1): Spectral type given by Alcala et al. (1996A&AS..119....7A 1996A&AS..119....7A), who
identified these stars as wTTS.
(2): SB as found in our CASPEC spectrum; components NW and SE are
separated by 14 arcsec (Magazzu et al., 1997A&AS..124..449M 1997A&AS..124..449M)
(3): SB as found by Magazzu et al. (1997A&AS..124..449M 1997A&AS..124..449M), who found
lithium in both components; data given here are for the primary,
which is much brighter.
(4): We have revised EW(Li) down to 0.25 Angstrom from the value given
in Magazzu et al. (1997A&AS..124..449M 1997A&AS..124..449M), which apparently was
too large due to an incorrect assumption on the continuum level.
(5): Classified as a wTTS by N95c, but as a dKe star by Magazzu et al.
(1997A&AS..124..449M 1997A&AS..124..449M); we detect lithium in our CASPEC spectrum
but not in excess of the Pleiades level, and conclude that this
star is a K5 ZAMS star.
(6): Magazzu et al. (1997A&AS..124..449M 1997A&AS..124..449M) detected lithium, but did
not classify this star as `PMS' or `PMS?'.
(7) Lithium data from our high-resolution CASPEC spectra.
(8) Orbit known (Torres et al., in preparation).
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Name of objects
18- 19 I2 --- no Number of high-resolution observations
22- 25 I4 K Teff ? Effective temperature
27- 29 I3 km/s vsini ? Rotational velocity v sin i
31- 33 I3 km/s ULvsini ? Upper limit on v sin i
35- 39 F5.1 km/s HRV ? Heliocentric radial velocity
42- 45 F4.1 km/s e_HRV ? Error in radial velocity
48- 52 F5.1 km/s RVlsr ? Local-standard-of-rest radial velocity
55- 63 A9 --- remarks Remarks (1)
66- 72 A7 --- M97 Results from Magazzu et al.
(1997A&AS..124..449M 1997A&AS..124..449M)
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Note (1): SB 1 or 2: single- or double-lined spectroscopic binaries.
If "orbit" is given, then the orbit is known (Torres et al., in prep.)
(1): Lines in high-resolution spectra are too broad to obtain
reliable data.
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Acknowledgements: Ralph Neuhaeuser
(End) Ralph Neuhaeuser [MPE Garching], Patricia Bauer [CDS] 22-Jul-1997