J/ApJ/505/793 New WR star in M33 (Massey+, 1998)
Evolved massive stars in the local group. II. A new survey for Wolf-Rayet stars
in M33 and its implications for massive star evolution:
evidence of the ``Conti scenario'' in action.
Massey P., Johnson O.
<Astrophys. J. 505, 793 (1998)>
=1998ApJ...505..793M 1998ApJ...505..793M
ADC_Keywords: Stars, Wolf-Rayet ; Photometry
Keywords: galaxies: stellar content - galaxies: Local Group - stars: evolution -
stars: supergiants - stars: Wolf-Rayet
Abstract:
We expect the evolution of massive stars to be strongly influenced by
mass loss and hence to be sensitive to metallicity. It should be
possible to test this "Conti scenario" be comparing the populations of
evolved massive stars among the Local Group galaxies, but such
investigations have been hampered by incompleteness. In a previous
paper, we presented results of a new survey for red supergiants (RSGs)
in selected regions of the Local Group galaxies M33, M31, and NGC
6822. In the present paper, we survey eight fields in M33 for
Wolf-Rayet stars (WRs), using interference-filter imaging with a CCD
to select candidates. Follow-up spectroscopy is used to confirm 22
newly found WR stars, 21 of WN type. We establish that our survey
would readily detect WRs as weak-lined as any known, and we conclude
that our survey is essentially complete.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 155 146 WR candidates in M33
table9.dat 134 161 Wolf-Rayet stars in M33
table10.dat 88 54 Wolf-Rayet stars in M31
table11.dat 97 5 Wolf-Rayet stars in NGC 6822 AND IC 1613
table12.dat 74 17 Wolf-Rayet stars in IC 10
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See also:
J/AJ/110/2715 : UBV photometry in NGC 6822, M31 and M33 (Massey+ 1995)
Table 1: Survey fields
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Field RA (2000) DE OB associations Comments
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M33-A 01 35 01.3 +30 41 48 OB 88, 89 RSG survey
M33-B 01 33 51.3 +30 45 14 OB 65-68 RSG survey
M33-C 01 33 32.1 +30 40 50 OB 55-58, 61-63 NGC 595; contains AM 85
field 2
M33-D 01 32 55.6 +30 35 30 OB 20-22, 24 RSG survey
M33-E 01 33 10.9 +30 29 50 OB 17, 115, 127, 128 RSG survey
M33-F 01 33 40.3 +30 20 44 OB 110, 112 RSG survey
M33-G 01 33 44.5 +30 33 22 OB 3, 6-14, 49-51 RSG survey; slight overlap
with AM 85 field 1
M33-X 01 33 56.8 +30 38 25 OB 96, 142, 143 Includes nucleus
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OB associations are from Humphreys & Sandage, 1980ApJS...44..319H 1980ApJS...44..319H.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Field Field designation
7- 14 A8 --- Name Star designation in the field,
new designation, [MJ98] in Simbad (1)
16 I1 --- No [1/2] Number of set of images that identified
the star as WR candidate
17 A1 --- n_No [f] f: Star is within field of view of only
one set of images
19- 20 I2 h RAh Right ascension (J2000)
22- 23 I2 min RAm Right ascension (J2000)
25- 29 F5.2 s RAs Right ascension (J2000)
31 A1 --- DE- Declination sign (J2000)
32- 33 I2 deg DEd Declination (J2000)
35- 36 I2 arcmin DEm Declination (J2000)
38- 41 F4.1 arcsec DEs Declination (J2000)
43- 46 F4.2 --- rho Distance from the nucleus within
the plane of M33 (2)
48- 51 F4.1 mag WC-CT ? WC-CT colour index (3)
53- 57 F5.1 --- sWC-CT ? WC-CT significant level (3)
59- 62 F4.1 mag WN-CT ? WN-CT colour index (3)
64- 67 F4.1 --- sWN-CT ? WN-CT significant level (3)
69- 72 F4.1 mag WC-WN WC-WN colour index (3)
74- 78 F5.1 --- sWC-WN WC-WN significant level (3)
80- 83 F4.1 mag CTmag ? CT magnitude (3)
85- 87 A3 --- SpType Predicted spectral type
89-113 A25 --- SpTypea Actual spectral type (4)
115-156 A42 --- Com Comments (5)
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Note (1): Names use the following nomenclature:
AM: from Armandroff & Massey (1985ApJ...291..685A 1985ApJ...291..685A),
AM NN = [AM85] M 33 NN in Simbad
MC: from Massey & Conti (1983ApJ...273..576M 1983ApJ...273..576M),
MC NN = [MC83] NN in Simbad
MCA: from MCA87, Massey et al. (1987AJ.....94.1538M 1987AJ.....94.1538M)
(OB NN-NN = [MAP95] M 33 OBNN NN, W91-129 = [W91b] Star 129 in Simbad)
all others are new from the present study.
Note (2): We have assumed RAcenter=01:31:01.2, DEcenter=+30:24:27 (1950),
an inclination of 57°, and position of the major axis of 20°,
and normalized the distance to a Holmberg radius of 25', following
Kwitter & Aller (1981MNRAS.195..939K 1981MNRAS.195..939K).
Note (3): Filters are centered at the following wavelength:
WC filter: λ4650Å
WN filter: λ4686Å
CT filter: λ4752Å
Note (4): Spectral types for previously known WR stars are from
Massey & Conti, (1983ApJ...273..576M 1983ApJ...273..576M), MAC87, Massey et al.
(1987AJ.....94.1538M 1987AJ.....94.1538M), or Armandroff & Massey (1991AJ....102..927A 1991AJ....102..927A).
Note (5): The following abbreviations are used:
Isolated: no stars within 1" as judged from HST WFPC2 images
comp: companion
brt: bright
fnt: faint
v.: very
UIT: UV-bright source identified by Massey et al. (1996, in
Wolf-Rayet Stars in the Framework of Stellar Evolution,
ed. J.M. Vreux, A. Detal, D. Frainpont-Caro, D. Gosset &
G. Rauw (Liege: Institut d'Astrophysique), 39
HS: blue star designation from Humphreys & Sandage (1980ApJS...44..319H 1980ApJS...44..319H)
ob: blue star identified by Massey et al. (1995, Cat. J/AJ/110/2715)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1 A1 --- Note [CR] C: Spectroscopically Confirmed M33 Stars
R: Remaining candidates
3- 4 A2 --- --- [WR]
6- 9 A4 --- WR WR designation (new designation, [MJ98] in
Simbad)
11- 20 A10 --- Name Previous name (1)
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 32 F5.2 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 44 F4.1 arcsec DEs Declination (J2000)
46- 49 F4.2 --- rho Distance from the nucleus within the
plane of M33 (2)
51- 54 F4.1 mag CTmag ? CT (λ4752) magnitude
55- 56 A2 --- u_CTmag [: ] Uncertainty flag on CTmag
58- 63 A6 --- OB OB association designation (3)
64 A1 --- u_OB [)] Uncertainty flag on OB
66- 79 A14 --- SpType Spectral type
80- 85 A6 --- r_SpType References for spectral type (4)
87-134 A48 --- Com Comments
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Note (1): Names use the following nomenclature:
AM: Armandroff & Massey, 1985ApJ...291..685A 1985ApJ...291..685A ([AM85] M 33 NN)
MC: Massey & Conti, 1983ApJ...273..576M 1983ApJ...273..576M ([MC83] NN)
W&C: Wray & Corso, 1972ApJ...172..577W 1972ApJ...172..577W ([WC72] NN)
MCA: Massey et al., 1987AJ.....94.1538M 1987AJ.....94.1538M (MCA NN)
OB: Massey et al., 1995, Cat. J/AJ/110/2715 ([MAP95] M 33 OBNN NN)
UIT: Massey et al., 1996, in Wolf-Rayet Stars in the Framework of
Stellar Evolution, ed. J.M. Vreux, A. Detal, D. Frainpont-Caro,
D. Gosset & G. Rauw (Liege: Institut d'Astrophysique) 39 ([MBH96] NNN)
W91: see Massey et al., 1995, Cat. J/AJ/110/2715 and present text
("W91 129" = [W91b] Star 129)
CM: Conti & Massey, 1981ApJ...249..471C 1981ApJ...249..471C ([CM81] NN)
HS B: Humphreys & Sandage (1980ApJS...44..319H 1980ApJS...44..319H) blue star
NGC 595 and NGC 604 are WR candidates from the Drissen et al.
(1993AJ....105.1400D 1993AJ....105.1400D) survey with HST.
MJ ANN = [MJ98] ANN, this paper
Note (2): We have assumed RAcenter=01:31:01.2, DEcenter=+30:24:27 (1950),
an inclination of 57°, and position of the major axis of 20°,
and normalized the distance to a Holmberg radius of 25', following
Kwitter & Aller (1981MNRAS.195..939K 1981MNRAS.195..939K).
Note (3): OB association designations from Humphreys & Sandage
(1980ApJS...44..319H 1980ApJS...44..319H).
Note (4): Reference numbers are as follows:
1: MCA87, Massey et al., 1987AJ.....94.1538M 1987AJ.....94.1538M
2: Willis et al., 1992A&A...261..419W 1992A&A...261..419W
3: Smith et al., 1995A&A...302..830S 1995A&A...302..830S
4: Massey et al., 1996, in Wolf-Rayet Stars in the Framework of
Stellar Evolution, ed. J.M. Vreux, A. Detal, D. Frainpont-Caro,
D. Gosset & G. Rauw (Liege: Institut d'Astrophysique), 39
5: AM91, Armandroff & Massey, 1991AJ....102..927A 1991AJ....102..927A
6: Massey et al., 1995, Cat. J/AJ/110/2715
7: this paper
8: Schild et al. 1990A&A...237..169S 1990A&A...237..169S
9: Conti & Massey, 1981ApJ...249..471C 1981ApJ...249..471C
10: Massey & Conti, 1983ApJ...273..576M 1983ApJ...273..576M
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Byte-by-byte Description of file: table1?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Note [CR] C: Spectroscopically Confirmed M33 Stars
R: Remaining candidates
3- 13 A11 --- Name Name (1)
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 25 F5.2 s RAs Right ascension (J2000)
27 A1 --- DE- Declination sign (J2000)
28- 29 I2 deg DEd Declination (J2000)
31- 32 I2 arcmin DEm Declination (J2000)
34- 37 F4.1 arcsec DEs Declination (J2000)
39- 42 F4.2 --- rho ? Distance from the nucleus
43 A1 --- l_CTmag Limit flag on CTmag
44- 47 F4.1 mag CTmag ? CT (λ4752) magnitude
48 A1 --- u_CTmag Uncertainty flag on CTmag
49- 52 A4 --- OB OB association designation (2)
53 A1 --- u_OB [)] Uncertainty flag on OB
55- 63 A9 --- SpType Spectral type
65- 69 A5 --- r_SpType References for spectral type (3)
71- 97 A27 --- Com Comments
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Note (1): In table10.dat, identification are from
ob: Massey et al., 1995, Cat. J/AJ/110/2715
MS: Moffat & Shara, 1983ApJ...273..544M 1983ApJ...273..544M
IT: Moffat & Shara, 1987ApJ...320..266M 1987ApJ...320..266M
In table11.dat, identifications are from AM85, Armandroff & Massey,
1985ApJ...291..685A 1985ApJ...291..685A.
In table12.dat: identifications are from Massey et al., 1992AJ....103.1159M 1992AJ....103.1159M
Note (2): the nomenclature is:
table10.dat: OB association designations from van den Bergh,
1964ApJS....9...65V 1964ApJS....9...65V. We have assumed that OB 75 is the
small, unlabeled association direction north of OB 80
table11.dat: OB association numbers for NGC 6822 are from Hodge,
1977ApJS...33...69H 1977ApJS...33...69H. The IC 1613 WR star falls within
H II Region No. 3 catalogued by Sandage, 1971ApJ...166...13S 1971ApJ...166...13S
Note (3): References are numbered as follows:
1: Moffat & Shara, 1983ApJ...273..544M 1983ApJ...273..544M
2: AM91, Armandroff & Massey, 199AJ....102..927A
3: Schild et al. 1990A&A...237..169S 1990A&A...237..169S
4: Willis et al., 1992A&A...261..419W 1992A&A...261..419W
5: Massey et al., 1995, Cat. J/AJ/110/2715
6: MCA87, Massey et al., 1987AJ.....94.1538M 1987AJ.....94.1538M
7: Massey et al., 1986AJ.....92.1303M 1986AJ.....92.1303M
8: Massey 1998, in Stellar Astrophysics for the Local Group: A First
step to the Universe, Proc. 8th Canary Island Winter School, ed.
A. Herraro & A. Aparico (Cambridge: Cambridge Univ. Press.), in press.
9: Moffat & Shara, 1987ApJ...320..266M 1987ApJ...320..266M
10: Westerlund et al., 1983A&A...123..159W 1983A&A...123..159W
11: Massey & Armandroff, 1995AJ....109.2470M 1995AJ....109.2470M
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History: From ApJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 08-Dec-1998