J/A+AS/132/173 New weak-line T Tauri stars in Taurus-Auriga (Li+ 1998)
Newly discovered candidate weak-line T Tauri stars in the
surrounding area of the Taurus-Auriga region
Li J.Z., Hu J.Y.
<Astron. Astrophys. Suppl. Ser. 132, 173 (1998)>
=1998A&AS..132..173L 1998A&AS..132..173L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; X-ray sources
Keywords: stars: formation - stars: pre-main sequence - X-rays: stars - surveys
Abstract:
We present results of an extensive search for weak-line T Tauri stars
(WTTS) in the outskirts of the Taurus-Auriga molecular cloud on the
basis of the ROSAT All-Sky Survey Bright Source Catalog
(Cat. IX/10). Our surveyed region extends from 2h 40m to 5h 40m in
right ascension and from 10deg to 40deg in declination, with the
central part of Taurus-Auriga(4h<α<5h, 15deg<δ<34deg),
accomplished by Wichmann et al. (1996, Cat. J/A+A/312/439),
excluded. Within a sky coverage of about 10$^{3}$ square degrees,
219 X-ray sources fullfill the criteria for selecting program sources
suggested by Neuhauser et al. (1995A&A...295L...5N 1995A&A...295L...5N) and 164 of these
X-ray sources were found to have at least one optical counterpart with
E magnitude brighter than 16. Low-resolution spectroscopic observation
has been carried out in order to discard early type stars and galaxies
from the sample, additional intermediate-resolution spectra of a
sub-sample of 156 late type optical counterparts were obtained for
spectral classification and for the calculation of the equivalent
width of Hα emission and LiI line absorption at 6707Å.
Excluding 2 previously identified WTTS, a total of 75 new candidate
WTTS and one possible classical T Tauri star have been discovered in
our study. The majority of the newly found Li-rich optical
counterparts are believed to b e PMS stars rather than ZAMS stars as
those of the Pleiades.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 102 74 Optical data of the newly discovered candidate WTTS
table3.dat 82 3 Optical data of the possible CTTS discovered and
the two previously found WTTS candidates
table4.dat 84 24 Optical data of the probable cloud members of
Taurus-Aurigae
table5.dat 90 54 Optical data of the possible optical counterparts
to the RASS sources
tables.ps 72 629 PostScript version of the tables
tables.tex 211 261 LaTeX version of the tables
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See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1996)
J/A+A/312/439 : New T Tauri stars in Taurus-Auriga (Wichmann+, 1996)
J/A+A/297/391 : T Tauri stars ROSAT survey (Neuhaeuser+, 1995)
Byte-by-byte Description of file: table?.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- No Number
4 A1 --- m_No [s] Multiplicity index on No
6- 26 A21 --- 1RXS RASS (Cat. IX/10) designation
28 I1 h RAh Right Ascension for equinox J2000.0
30- 31 I2 min RAm Right Ascension for equinox J2000.0
33- 36 F4.1 s RAs Right Ascension for equinox J2000.0
38 A1 --- DE- Declination sign
39- 40 I2 deg DEd Declination for equinox J2000.0
42- 43 I2 arcmin DEm Declination for equinox J2000.0
45- 48 F4.1 arcsec DEs Declination for equinox J2000.0
50- 53 F4.1 mag Vmag ? Visual magnitude of the optical counterpart
55 A1 --- n_Vmag [V?] ? for unknown value
57- 61 F5.2 0.1nm EW(Ha) ? Equivalent width for Hα (1)
63- 67 F5.2 0.1nm EW(LiI) ? Equivalent width for LiI absorption line (1)
69- 72 A4 --- SpType Spectral type (2)
74- 92 A19 --- Name Catalog identifier
94-102 A9 --- Com comments on optical position
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Note (1): These data are not in table5.dat
Note (2): >M0V represents spectral type later than M0V, and so forth.
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Acknowledgements: Jinzeng LI
(End) Patricia Bauer [CDS] 24-Apr-1998