J/ApJS/194/6 Candidate X-ray emitting OB stars in Carina (Povich+, 2011)
Candidate X-ray-emitting OB stars in the Carina nebula identified via infrared
spectral energy distributions.
Povich M.S., Townsley L.K., Broos P.S., Gagne M., Babler B.L.,
Indebetouw R., Majewski S.R., Meade M.R., Getman K.V., Robitaille T.P.,
Townsend R.H.D.
<Astrophys. J. Suppl. Ser., 194, 6 (2011)>
=2011ApJS..194....6P 2011ApJS..194....6P
ADC_Keywords: Stars, OB ; Extinction ; Photometry, infrared ; X-ray sources
Cross identifications
Keywords: infrared: stars - ISM: individual objects (NGC 3372) -
methods: data analysis - stars: early-type - X-rays: stars
Abstract:
We report the results of a new survey of massive, OB stars throughout
the Carina Nebula using the X-ray point source catalog provided by the
Chandra Carina Complex Project (CCCP) in conjunction with infrared
(IR) photometry from the Two Micron All-Sky Survey and the Spitzer
Space Telescope Vela-Carina survey. Mid-IR photometry is relatively
unaffected by extinction, hence it provides strong constraints on the
luminosities of OB stars, assuming that their association with the
Carina Nebula, and hence their distance, is confirmed. We fit model
stellar atmospheres to the optical (UBV) and IR spectral energy
distributions (SEDs) of 182 OB stars with known spectral types and
measure the bolometric luminosity and extinction for each star. Using
X-ray emission as a strong indicator of association with Carina, we
identify 94 candidate OB stars with Lbol≳104L☉ by fitting
their IR SEDs. If the candidate OB stars are eventually confirmed by
follow-up spectroscopic observations, the number of cataloged OB stars
in the Carina Nebula will increase by ∼50%.
Description:
We used data products from the Chandra Carina Complex Project (CCCP;
Townsley et al. 2011ApJS..194....1T 2011ApJS..194....1T), Two-Micron All Sky Survey
(2MASS; Skrutskie et al. 2006, Cat. VII/233), and the Spitzer
Vela-Carina Survey (PI: S. R. Majewski), as described in Povich et al.
2011, Cat. J/ApJS/194/14.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 97 182 Validation sample of cataloged Carina OB stars:
SED-fitting results and IR photometry
table3.dat 120 94 Candidate X-ray-emitting OB stars
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
III/182 : HDE Charts: positions, proper motions (Nesterov+ 1995)
J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)
J/ApJS/194/5 : Carina OB stars in the CCCP catalog (Gagne+, 2011)
J/ApJS/194/14 : Pan-Carina young stellar object catalog (Povich+, 2011)
J/A+A/477/593 : X-ray properties of Carina OB1 association (Antokhin+, 2008)
J/ApJ/667/963 : Near-infrared photometry of Carina nebula (Sanchawala+, 2007)
J/ApJ/589/509 : Chandra observations of Trumpler 14 and 16 (Evans+, 2003)
J/AJ/105/1822 : Open clusters near eta Car (Cudworth+ 1993)
J/AJ/105/980 : Stellar content of Tr 14 and Tr 16 (Massey+ 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Star name from Gagne, 2011, Cat. J/ApJS/194/5
13- 16 F4.2 mag AvBV ? BV Extinction from Gagne 2011,
Cat. J/ApJS/194/5
18- 21 F4.1 kK Teff Effective temperature (1)
23- 26 F4.2 [Lsun] logLbol Bolometric luminosity
28- 31 F4.2 mag Av Extinction from SED fitting
33- 49 A17 --- SSTGLMA SSTGLMA name (GLLL.llll+BB.bbbb) (G1)
51- 55 F5.2 mag Jmag ? 2MASS J-band magnitude
57- 61 F5.2 mag Hmag ? 2MASS H-band magnitude
63- 67 F5.2 mag Ksmag ? 2MASS Ks-band magnitude
69- 73 F5.2 mag [3.6] ? Spitzer/IRAC 3.6um band magnitude
75- 79 F5.2 mag [4.5] ? Spitzer/IRAC 4.5um band magnitude
81- 85 F5.2 mag [5.8] ? Spitzer/IRAC 5.8um band magnitude
87- 91 F5.2 mag [8.0] ? Spitzer/IRAC 8.0um band magnitude
93- 97 A5 --- IREx IR excess emission? (2)
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Note (1): From the Martins et al. (2005A&A...436.1049M 2005A&A...436.1049M) calibrations of
Teff vs. spectral type for O stars, extended to early B stars by
Crowther (2005IAUS..227..389C 2005IAUS..227..389C). Spectral types were compiled from
various sources by Gagne, 2011, Cat. J/ApJS/194/5.
Note (2): Source exhibits marginal IR excess emission in the specified IRAC
band(s) are indicated with I2=4.5um, I3=5.8um, I4=8.0um.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq OB candidate number
3 A1 --- f_Seq [f] X-ray flare for candidate 41 (1)
5- 22 A18 --- CXOGNC CXOGNC designation (HHMMSS.ss+DDMMSS.s; J2000)(2)
24- 27 F4.1 kK Teff Effective temperature (3)
29- 31 F3.1 [Lsun] logLbol Bolometric luminosity (3)
33- 36 F4.1 mag Av Extinction (3)
38- 54 A17 --- SSTGLMA SSTGLMA name (GLLL.llll+BB.bbbb) (G1)
56- 60 F5.2 mag Jmag ? 2MASS J-band magnitude
62- 66 F5.2 mag Hmag ? 2MASS H-band magnitude
68- 72 F5.2 mag Ksmag 2MASS Ks-band magnitude
74- 78 F5.2 mag [3.6] ? Spitzer/IRAC 3.6um band magnitude
80- 84 F5.2 mag [4.5] ? Spitzer/IRAC 4.5um band magnitude
86- 90 F5.2 mag [5.8] ? Spitzer/IRAC 5.8um band magnitude
92- 96 F5.2 mag [8.0] ? Spitzer/IRAC 8.0um band magnitude
98-120 A23 --- Note Previous identification(s); spectral types or
IR excess (4)
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Note (1): the OB candidate 41 appears to be responsible for the spectacular
X-ray flare discovered by Townsley et al. (2011ApJS..194....1T 2011ApJS..194....1T).
Note (2): CCCP Catalog identifier (Broos et al. 2011, Cat. J/ApJS/194/2)
Note (3): Values in Columns 3-5 were derived from SED fitting under the
assumption of single massive stars on the theoretical zero-age main
sequence (see the text). Formally, TMSeff, LMSbol, and
AMSV reported here are upper limits and should be used only for
comparison purposes among this sample.
Note (4): Abbreviations for previous star identifications are:
HD = Nesterov et al. (1995, Cat. III/182);
Y = Cudworth et al. (1993, Cat. J/AJ/105/1822; <Cl* Trumpler 14 Y NNN> in
Simbad);
Cr 228 = Collinder 228: Feinstein et al. (1976A&AS...24..389F 1976A&AS...24..389F;
<Cl Collinder 228 NN> in Simbad) or The et al. (1980A&AS...41...93T 1980A&AS...41...93T);
IRS = Smith (1987MNRAS.227..943S 1987MNRAS.227..943S; <[S87b] IRS NNa> in Simbad);
MJ = Massey & Johnson (1993, Cat. J/AJ/105/980; <Cl* Trumpler 1[46] MJ NNN>
in Simbad);
XMM = Antokhin et al. (2008, Cat. J/A+A/477/593; <[ARV2008] NNN> in Simbad)
Bo 11 = Bochum 11: Fitzgerald & Mehta (1987MNRAS.228..545F 1987MNRAS.228..545F);
LS = Stephenson & Sanduleak (1971PW&SO...1a...1S 1971PW&SO...1a...1S).
OB = Candidate massive stars (Evans et al. 2003, Cat. J/ApJ/589/509)
PMS = Candidate low-mass PMS stars (Sanchawala et al. 2007,
Cat. J/ApJ/667/963)
NOP = Star was not found in any of optical photometric catalogs listed by
VizieR (Ochsenbein et al. 2000A&AS..143...23O 2000A&AS..143...23O).
PFD = Candidate OB star is also consistent with a foreground MS
classification.
I3 = Source exhibits marginal IR excess emission in the IRAC 5.8um band.
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Global notes:
Note (G1): Spitzer Vela-Carina Point Source Archive identification
(described in Povich et al. 2011, Cat. J/ApJS/194/14).
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History:
From electronic version of the journal
References:
Townsley et al. CCCP introduction 2011ApJS..194....1T 2011ApJS..194....1T
Broos et al. CCCP catalog Cat. J/ApJS/194/2
Getman et al. Contamination in X-ray studies 2011ApJS..194....3G 2011ApJS..194....3G
Broos et al. Source classifier Cat. J/ApJS/194/4
Gagne et al. O and B stars Cat. J/ApJS/194/5
Povich et al. Cand. X-ray emitting OB stars Cat. J/ApJS/194/6
Naze et al. O and B stars X-ray properties Cat. J/ApJS/194/7
Parkin et al. QZ Car (HD 93206) 2011ApJS..194....8P 2011ApJS..194....8P
Feigelson et al. X-ray star clusters Cat. J/ApJS/194/9
Preibisch et al. NIR properties of YSO Cat. J/ApJS/194/10
Wang et al. Trumpler 15 Cat. J/ApJS/194/11
Wolk et al. Trumpler 16 Cat. J/ApJS/194/12
Povich et al. Pan-Carina YSO catalog Cat. J/ApJS/194/14
Evans et al. Companions of B stars in Tr 16 2011ApJS..194...13E 2011ApJS..194...13E
Townsley et al. Diffuse X-ray emission Cat. J/ApJS/194/15
Townsley et al. Comparison of diffuse emission 2011ApJS..194...16T 2011ApJS..194...16T
(End) Emmanuelle Perret [CDS] 25-May-2011