J/AJ/143/149 NIR spectroscopy of Galactic Wolf-Rayet stars. II. (Shara+, 2012)
A near-infrared survey of the inner Galactic plane for Wolf-Rayet stars.
II. Going fainter: 71 more new W-R stars.
Shara M.M., Faherty J.K., Zurek D., Moffat A.F.J., Gerke J., Doyon R.,
Artigau E., Drissen L.
<Astron. J., 143, 149 (2012)>
=2012AJ....143..149S 2012AJ....143..149S
ADC_Keywords: Stars, Wolf-Rayet ; Photometry, infrared ; Photometry, UBVRI ;
Spectra, infrared ; Equivalent widths ; Spectral types
Keywords: Galaxy: disk - Galaxy: stellar content - infrared: stars -
stars: emission-line, Be - stars: Wolf-Rayet - surveys
Abstract:
We are continuing a J, K and narrowband imaging survey of 300°2
of the plane of the Galaxy, searching for new Wolf-Rayet (W-R) stars.
Our survey spans 150° in Galactic longitude and reaches 1°
above and below the Galactic plane. The survey has a useful limiting
magnitude of K=15 over most of the observed Galactic plane, and K=14
(due to severe crowding) within a few degrees of the Galactic center.
Thousands of emission-line candidates have been detected. In
spectrographic follow-ups of 146 relatively bright W-R star
candidates, we have re-examined 11 previously known WC and WN stars
and discovered 71 new W-R stars, 17 of type WN and 54 of type WC. Our
latest image analysis pipeline now picks out W-R stars with a 57%
success rate. Star subtype assignments have been confirmed with the
K-band spectra and distances approximated using the method of
spectroscopic parallax. Some of the new W-R stars are among the most
distant known in our Galaxy. The distribution of these new W-R stars
is beginning to trace the locations of massive stars along the distant
spiral arms of the Milky Way.
Description:
Near-IR spectra of candidate Wolf-Rayet stars were obtained with
the SpeX spectrograph mounted on the 3m NASA Infrared Telescope
Facility (IRTF) over 11 half-nights in 2009 August. We obtained an
average resolving power of λ/Δλ∼1200. The
near-infrared spectral data spanned 0.8-2.4µm.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 12 *Previously identified Wolf-Rayet stars
table2.dat 86 71 New Wolf-Rayet stars
table3.dat 81 12 Known Wolf-Rayet stars
table4.dat 81 71 New Wolf-Rayet stars
table5.dat 56 17 Equivalent width (Å) measurement for the most
prominent lines of the new WN stars
table6.dat 60 54 Equivalent width (Å) measurement for the most
prominent lines of the new WC stars
table7.dat 58 54 New WC stars organized by subtype
table8.dat 58 17 New WN stars organized by subtype
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Note on table1.dat: previously identified Wolf-Rayet stars from
Shara et al. (Paper I, 2009AJ....138..402S 2009AJ....138..402S ) that were observed using
the SpeX spectrograph. A lack of BVR data implies that the star is
below the 21st magnitude plate limits of the digitized sky surveys.
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
I/297 : NOMAD Catalog (Zacharias+ 2005)
III/215 : 7th Catalog of Galactic Wolf-Rayet stars (van der Hucht, 2001)
III/143 : Spectrophotometry of Wolf-Rayet Stars (Torres-Dodgen+ 1988)
J/ApJ/733/123 : The Wolf-Rayet content of M33 (NGC 598) (Neugent+, 2011)
J/A+A/518/A29 : WR stars distribution in 2 nearby galaxies (Leloudas+, 2010)
J/A+AS/108/669 : IUE spectra of WR stars (Niedzielski+, 1994)
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Wolf-Rayet star name
12- 13 I2 h RAh Hour of Right Ascension (J2000)
15- 16 I2 min RAm Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 35 F5.2 arcsec DEs Arcsecond of Declination (J2000)
37- 42 F6.2 deg GLON Galactic longitude l
44- 48 F5.2 deg GLAT Galactic latitude b
50- 54 F5.2 mag Bmag [15.23/20.75]? NOMAD B band magnitude (from
Cat. I/297)
56- 60 F5.2 mag Vmag [14.49/17.74]? NOMAD V band magnitude (from
Cat I/297)
62- 66 F5.2 mag Rmag [13.31/20.02]? NOMAD R band magnitude (from
Cat. I/297)
68- 73 F6.3 mag Jmag [8.61/18.08] 2MASS J magnitude
75- 80 F6.3 mag Hmag [7.99/15.06] 2MASS H magnitude
82- 86 F5.2 mag Ksmag [7.8/14.37] 2MASS Ks magnitude
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Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Wolf-Rayet star name
12- 13 A2 --- u_SpT [ :] Uncertainty flag on SpT (G1)
14- 35 A22 --- SpT Wolf-Rayet spectral subtype
37- 40 F4.2 mag AKs.J ? Interstellar Ks-band extinction estimated
using the 2MASS J-Ks color and subtype
values provided in
Crowther et al. (2006MNRAS.372.1407C 2006MNRAS.372.1407C)
42- 45 F4.2 mag AKs.H ? Interstellar Ks-band extinction estimated
using the 2MASS H-Ks color and subtype
values provided in
Crowther et al. (2006MNRAS.372.1407C 2006MNRAS.372.1407C)
47- 51 F5.2 mag AKs ? The average of the two values AKs.J and AKs.H
53- 57 F5.2 mag Ksmag 2MASS apparent Ks magnitude
59- 63 F5.2 mag KsMag ? The subtype-specific absolute magnitude
derived for spectral subtypes by
Crowther et al. (2006MNRAS.372.1407C 2006MNRAS.372.1407C)
65- 69 F5.2 mag DM ? Distance modulus
71- 75 F5.2 kpc d ? Heliocentric distance (with typical
uncertainties of 25%)
77- 81 F5.2 kpc RG ? Galactocentric distance RG (with typical
uncertainties of 25%)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Wolf-Rayet star name
<[SFZ2012] FFFF-NNNAA> in Simbad
12 A1 --- f_SpT [:] Uncertainty flag on SpT (G1)
13- 34 A22 --- SpT Wolf-Rayet spectral subtype
36- 37 I2 0.1nm W(2.100) ? Equivalent width of NV 2.100µm
emission line
39- 42 I4 0.1nm W(2.115) Equivalent width of HeI 2.115µm
emission line
44- 46 I3 0.1nm W(2.165) Equivalent width of
HeII+Brγ 2.165µm emission line
48- 51 I4 0.1nm W(2.189) ? Equivalent width of HeII 2.189µm
emission line
53- 56 F4.1 --- Ratio ? ratio of equivalent widths W(2.189/2.165)
used to categorize the WN stars
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Wolf-Rayet star name
<[SFZ2012] FFFF-NNNAA> in Simbad
12 A1 --- f_SpT [:] Uncertainty flag on SpT (G1)
13- 34 A22 --- SpT Wolf-Rayet spectral subtype
36- 39 I4 0.1nm W(2.076) ? Equivalent width of CIV 2.076µm
emission line
40 A1 --- f_W(2.076) [a] Flag on W(2.076) (1)
42- 45 I4 0.1nm W(2.110) ? Equivalent width of HeI+CIII 2.110µm
emission line
46 A1 --- f_W(2.110) [b] Flag on W(2.110) (1)
48- 50 I3 0.1nm W(2.165) ? Equivalent width of HeI 2.165µm
emission line
51 A1 --- f_W(2.165) [c] Flag on W(2.165) (1)
53- 55 I3 0.1nm W(2.189) ? Equivalent width of HeII 2.189µm
emission line
56 A1 --- f_W(2.189) [d] Flag on W(2.189) (1)
58- 60 F3.1 --- Ratio ? ratio of equivalent widths W(2.076/2.110)
used to categorize the WC stars
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Note (1): The Table 6 provides a second value for the equivalent widths of
the Wolf-Rayet star 1669-24L. This second equivalent width is:
a = W(2.076)=-423Å;
b = W(2.110)=-47Å;
c = W(2.165)=-25Å;
d = W(2.189)=-56Å.
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Byte-by-byte Description of file: table[78].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Wolf-Rayet star name
<[SFZ2012] FFFF-NNNAA> in Simbad
12 A1 --- f_SpT [:] Uncertainty flag on SpT (G1)
13- 34 A22 --- SpT Wolf-Rayet spectral subtype
36- 40 F5.2 mag Dm(HeI) ? Difference from the interpolated continum
magnitude for the HeI narrowband filter (2)
42- 46 F5.2 mag Dm(CIV) ? Difference from the interpolated continum
magnitude for the CIV narrowband filter (2)
48- 52 F5.2 mag Dm(Brg) ? Difference from the interpolated continum
magnitude for the Brγ narrowband
filter (2)
54- 58 F5.2 mag Dm(HeII) ? Difference from the interpolated continum
magnitude for the HeII narrowband filter (2)
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Note (2): Negative value indicate emission, positive values indicate
absorption for lines in the narrowband emission-line filter.
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Global notes:
Note (G1):
: = indicates an uncertainty of up to ±2 subtypes (differences among
stars of type WC4-8 are difficult to distinguish from one another).
History:
From electronic version of the journal
References:
Shara et al. Paper I. 2009AJ....138..402S 2009AJ....138..402S
(End) Sylvain Guehenneux [CDS] 22-Jul-2013