J/ApJ/863/181 The fifth catalog of LMC Wolf-Rayet stars (Neugent+, 2018)
A modern search for Wolf-Rayet stars in the Magellanic Clouds.
IV. A final census.
Neugent K.F., Massey P., Morrell N.
<Astrophys. J., 863, 181 (2018)>
=2018ApJ...863..181N 2018ApJ...863..181N
ADC_Keywords: Stars, Wolf-Rayet; Magellanic Clouds; Spectral types;
Photometry, UBV; References
Keywords: galaxies: individual (LMC, SMC) ; galaxies: stellar content ;
Local Group ; stars: evolution ; stars: Wolf-Rayet
Abstract:
We summarize the results of our 4yr survey searching for Wolf-Rayet
(WR) stars in the Large Magellanic Cloud (LMC) and Small Magellanic
Cloud. Over the course of this survey we have discovered 15 new WR
stars and 12 Of-type stars. In this last year we discovered two rare
Of-type stars: an O6.5f?p and an O6nfp, in addition to the two new
Of?p stars discovered in our first year and the three Onfp stars
discovered in our second and third years. However, even more exciting
was our discovery of a new type of WR star, ones we are calling
WN3/O3s owing to their spectroscopic signatures. We describe the
completeness limits of our survey and demonstrate that we are
sensitive to weak-lined WRs several magnitudes fainter than any we
have discovered, arguing that there is not a population of fainter WRs
waiting to be discovered. We discuss the nature of the WN3/O3s,
summarizing the results of our extensive spectroscopy and modeling. We
also examine the important claim made by others that the WN3/O3s are
isolated compared to other massive stars. We find that if we use a
more complete sample of reference massive stars, the WN3/O3s show the
same spatial distribution as other early WNs, consistent with a common
origin. Finally, we use this opportunity to present the "Fifth Catalog
of LMC Wolf-Rayet Stars," which includes revised coordinates and
updated spectral types for all 154 known LMC WRs.
Description:
We imaged the optical disk of the LMC and SMC using the Swope 1m
telescope on Las Campanas, Chile. To discover Wolf-Rayet (WR) stars we
observed 537 fields over the course of 38 nights within the 4yr period
of 2013 September 21 to 2017 November 20 (UT). The total area surveyed
was 40.8deg2 of the LMC and 27deg2 of the SMC.
With our WR candidate list in hand, we used the 6.5m Magellan
telescope and the Magellan Echellette (MagE) spectrograph for
spectroscopic confirmation. (We began the project on the Clay
telescope before MagE moved over to the Baade for the following 3yrs).
Over the past 4yr we have had four nights of observing time for
spectroscopic follow-up. For the last and final year of this project
we were awarded two half nights, 2017 February 7 (UT) and 2017
February 8 (UT).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 160 154 The fifth catalog of LMC Wolf-Rayet stars
refs.dat 186 43 References
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See also:
B/mk : Catalogue of Stellar Spectral Classifications (Skiff, 2009- )
III/136 : Optical spectrophotometry of WR C and O Stars (Torres+ 1987)
III/195 : Atlas of Opt. Spectral Classification OB Stars (Walborn+ 1990)
III/215 : 7th Catalog of Galactic Wolf-Rayet stars (van der Hucht, 2001)
III/274 : Galactic O-Star Spectroscopic Survey (GOSSS) (Sota+, 2014)
J/ApJ/505/793 : New WR star in M33 (Massey+, 1998)
J/AJ/118/1684 : UBV photometry of 4 LMC compact OB groups (Walborn+, 1999)
J/AJ/119/2214 : Photometry of Magellanic OB associations (Massey+, 2000)
J/AJ/128/1606 : Magellanic Clouds Photometric Survey: LMC (Zaritsky+, 2004)
J/A+A/458/453 : Annex to 7th Cat. of Galactic WR Stars (van der Hucht, 2006)
J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)
J/AJ/138/510 : Spectral classification of N159/N160 stars (Farina+, 2009)
J/AJ/138/1003 : IR photometry of massive LMC stars (Bonanos+, 2009)
J/A+A/530/A108 : VLT-FLAMES Tarantula Survey (Evans+, 2011)
J/ApJ/733/123 : The Wolf-Rayet content of M33 (NGC 598) (Neugent+, 2011)
J/ApJ/759/11 : Wolf-Rayet content of M31 (Neugent+, 2012)
J/A+A/558/A134 : VLT-FLAMES Tarantula Survey. 30 Dor stars (Doran+, 2013)
J/A+A/565/A27 : Wolf-Rayet stars in Large Magellanic Cloud (Hainich+, 2014)
J/A+A/564/A40 : VFTS. O-type stellar content of 30 Dor (Walborn+, 2014)
J/A+A/584/A5 : Massive LMC stars AAOmega spectroscopy (Evans+, 2015)
J/ApJS/224/4 : GOSSS III. 142 additional O-type syst. (Maiz Apellaniz+, 2016)
J/A+A/598/A85 : Disentangled spectra of R145 (Shenar+, 2017)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/154] Internal index number
5- 6 I2 h RAh [4/5] Hour of Right Ascension (J2000)
8- 9 I2 min RAm [2/59] Minute of Right Ascension (J2000)
11- 16 F6.3 s RAs [0.9/59.89] Second of Right Ascension (J2000)
18 A1 --- DE- Sign of the Declination (J2000)
19- 20 I2 deg DEd [65/71] Degree of Declination (J2000)
22- 23 I2 arcmin DEm [0/59] Arcminute of Declination (J2000)
25- 29 F5.2 arcsec DEs [0.3/59.81] Arcsecond of Declination (J2000)
31- 67 A37 --- Name Preferred name(s) (1)
69- 73 F5.2 mag Vmag [9.3/17.13] V band magnitude
75- 96 A22 --- SpType Spectral type
98-104 A7 --- Ref Reference code(s) (see refs.dat file)
106-108 I3 --- LH [1/116]? OB Association code (2)
110 A1 --- f_LH [n] Flag on LH (3)
112-157 A46 --- Comm Additional comments
158-160 A3 --- f_Comm Flag(s) on Comm (4)
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Note (1): The following stars were included in BAT99 as WRs, but are not
included here as they've been reclassified as O-type stars:
BAT99 6 (now O3f*+O binary, Niemela+ 2001A&A...369..544N 2001A&A...369..544N),
BAT99 107 (now O6.5Iafc+O6Iaf, Walborn+ 2014, J/A+A/564/A40).
Note (2): Lucke-Hodge (LH) OB association numbers are from
Lucke & Hodge (1970AJ.....75..171L 1970AJ.....75..171L) and Lucke (1972PhDT........10L 1972PhDT........10L).
Note that the 30 Dor region corresponds to LH 100 and its extension to
the SW LH 99, while the center of Constellation III is LH 84.
Note (3): Denotes the association if the star is only near the association.
Note (4): Flag as follows:
b = From Foellmi et al. (2003MNRAS.338.1025F 2003MNRAS.338.1025F).
c = Crowded; see finding chart in BAT99 (Breysacher+ 1999A&AS..137..117B 1999A&AS..137..117B).
d = Note that this star is not HD 35517, but rather its south-preceding
companion, RMC 89. See Bidelman & Sanduleak (1987BICDS..33..119B 1987BICDS..33..119B).
e = From Niemela (1991IAUS..143..201N 1991IAUS..143..201N).
f = From Cowley et al. (1984PASP...96..968C 1984PASP...96..968C).
g = We have retained the WN5 classification of BAT99 80 despite the
reclassification by Walborn+ 1999, J/AJ/118/1684 as a O4 If+ based
upon an HST Faint Object Spectrogaph (FOS) spectrum.
Although Walborn+ 1999 were able to separate this star ("5C") in
the tight cluster that contains Brey 65 and numerous other early-type
stars, there are some problems. The ground-based spectrum modeled by
Hainich+ 2014, J/A+A/565/A27 shows N III, N IV, and N V emission of
roughly comparable strength, as well as He II λ5411 emission.
If this is simply due to contamination by Brey 65, though,
where is the N v emission coming from? Brey 65 is a WN7 star, and its
spectrum has strong N III, weak N IV and no N v. So, it is hard to see
how the problem is simply contamination. The HST FOS spectrum is of low
S/N and if N IV and N v were present as shown in the ground-based
spectrum, we doubt that it would appear. A new spectrum taken under
excellent seeing conditions would be useful in resolving this.
h = Crowded; see finding charts in BAT99 (Breysacher+ 1999A&AS..137..117B 1999A&AS..137..117B)
and Massey & Hunter (1998ApJ...493..180M 1998ApJ...493..180M).
i = Described as an SB2 by Sana+ (2013MNRAS.432L..26S 2013MNRAS.432L..26S) but
fit with a single set of parameters by Hainich+ 2014, J/A+A/565/A27
j = From Testor & Niemela 1998A&AS..130..527T 1998A&AS..130..527T
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode of the reference
24- 48 A25 --- Auth First author's name(s)
50-186 A137 --- Comm Comment
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History:
From electronic version of the journal
References:
Massey et al. Paper I. 2014ApJ...788...83M 2014ApJ...788...83M
Massey et al. Paper II. 2015ApJ...807...81M 2015ApJ...807...81M
Massey et al. Paper III. 2017ApJ...837..122M 2017ApJ...837..122M
Neugent et al. Paper IV. 2018ApJ...863..181N 2018ApJ...863..181N This catalog
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Aug-2019