J/ApJ/898/85 CII emission-line stars in LMC with MagE spectra (Margon+, 2020)
A survey for C II emission-line stars in the Large Magellanic Cloud.
Margon B., Massey P., Neugent K.F., Morrell N.
<Astrophys. J., 898, 85 (2020)>
=2020ApJ...898...85M 2020ApJ...898...85M
ADC_Keywords: Magellanic Clouds; Stars, Wolf-Rayet; Spectra, infrared; Optical
Keywords: WC stars ; Planetary nebulae nuclei
Abstract:
We present a narrowband imaging survey of the Large Magellanic Cloud
(LMC), designed to isolate the CIIλλ7231,7236 emission
lines in objects as faint as mλ7400∼18. The work is motivated
by the recent serendipitous discovery in the LMC of the first
confirmed extragalactic [WC11] star, whose spectrum is dominated by
CII emission, and the realization that the number of such objects is
currently largely unconstrained. The survey, which imaged ∼50deg2
using on-band and off-band filters, will significantly increase the
total census of these rare stars. In addition, each new LMC [WC] star
has a known luminosity, a quantity quite uncertain in the Galactic
sample. Multiple known CII emitters were easily recovered, validating
the survey design. We find 38 new CII emission candidates;
spectroscopy of the complete sample will be needed to ascertain their
nature. In a preliminary spectroscopic reconnaissance, we observed
three candidates, finding CII emission in each. One is a new [WC11].
Another shows both the narrow CII emission lines characteristic of a
[WC11], but also broad emission of CIV, OV, and HeII characteristic of
a much hotter [WC4] star; we speculate that this is a binary [WC]. The
third object shows weak CII emission, but the spectrum is dominated by
a dense thicket of strong absorption lines, including numerous OII
transitions. We conclude it is likely an unusual hot, hydrogen-poor
post-AGB star, possibly in transition from [WC] to white dwarf. Even
lacking a complete spectroscopic program, we can infer that late [WC]
stars do not dominate the central stars of LMC planetary nebulae, and
that the detected CII emitters are largely of an old population.
Description:
We obtained spectra of three high significance CII emission
candidates, using the MagE spectrograph on the 6.5m Baade Magellan
telescope of the LCO (coverage from 3150Å to ∼10000Å, R∼4100)
on 2020 January 15 and 16.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 186 4 Spectroscopically verified LMC CII emission stars
fits/* . 3 Individual spectrum in FITS format
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See also:
VII/232 : Nebulae in the Magellanic Clouds (Davies+ 1976)
III/85 : Sixth Catalogue of Galactic Wolf-Rayet Stars (van der Hucht+ 1981)
III/211 : Keck/HIRES Sky Line Atlas (Osterbrock+ 1997)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/370 : XMM-OM Serendipitous Source Survey Cat. (XMM-SUSS5.0) (Page+, 2021)
J/MNRAS/234/583 : Abundances in Magellanic Cloud PNe (Monk+ 1988)
J/A+A/403/659 : Classification of WR planetary nebulae (Acker+, 2003)
J/AJ/128/1606 : Magellanic Clouds Photometric Survey: the LMC (Zaritsky+, 2004)
J/A+A/456/451 : Magellanic Clouds PNe abundances (Leisy+, 2006)
J/MNRAS/373/521 : Complete catalog of planetary nebulae in LMC (Reid+, 2006)
J/AJ/138/1003 : IR photometry of massive LMC stars (Bonanos+, 2009)
J/MNRAS/405/1349 : LMC PNe [OIII] 5007Å and Hβ flux (Reid+, 2010)
J/A+A/530/A90 : Optically bright post-AGB population of LMC (van Aarle+, 2011)
J/ApJ/748/96 : Massive binaries in the LMC (Massey+, 2012)
J/ApJ/749/177 : Yellow and red supergiants in the LMC (Neugent+, 2012)
J/ApJS/221/12 : AGNs in the MIR using AllWISE data (Secrest+, 2015)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/ApJ/863/181 : The fifth catalog of LMC Wolf-Rayet stars (Neugent+, 2018)
J/ApJS/236/37 : The Gaia-WISE extragalactic astrometric catalog (Paine+, 2018)
J/AJ/158/192 : HeII emission from WR stars in MW & LMC (Leitherer+, 2019)
J/ApJ/888/54 : Spectra of a rare low-mass WR star in LMC (Margon+, 2020)
J/ApJS/252/21 : Multiwavelength survey of WR stars in LMC (Hung+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ID Identifier of the source
7- 8 I2 h RAh Gaia DR2 hour of right ascension (J2000)
10- 11 I2 min RAm Gaia DR2 minute of right ascension (J2000)
13- 17 F5.2 s RAs Gaia DR2 second of right ascension (J2000)
19 A1 --- DE- Gaia DR2 sign of declination (J2000)
20- 21 I2 deg DEd Gaia DR2 degree of declination (J2000)
23- 24 I2 arcmin DEm Gaia DR2 arcminute of declination (J2000)
26- 29 F4.1 arcsec DEs Gaia DR2 arcsecond of declination (J2000)
31- 34 F4.2 mas/yr pmRA [1.78/1.95] Gaia DR2 proper motion in RA
36- 39 F4.2 mas/yr e_pmRA [0.06/0.16] PmRA uncertainty
41- 45 F5.2 mas/yr pmDE [-0.22/1.03] Gaia DR2 proper motion in DEC
47- 50 F4.2 mas/yr e_pmDE [0.07/0.17] PmDE uncertainty
52- 56 F5.2 mas plx [-0.15/0.09] Gaia DR2 parallax
58- 61 F4.2 mas e_plx [0.03/0.08] Parallax uncertainty
63- 66 F4.1 mag mag [16/17.3] λ7410 magnitude
68- 72 F5.2 mag delmag [-1.68/-0.25] Magnitude difference (Δm),
on-band minus off-band filter
74- 75 I2 --- Sig [10/62] Significance level of detection
(Δm divided by photometric error)
77- 92 A16 --- 2MASS 2MASS name (HHMMSSss+DDMMSSs; J2000)
94- 98 F5.2 mag Vmag [15.37/16.27] Johnson V magnitude (1)
100- 104 F5.2 mag (B-V) [-0.16/0.87] (B-V) color index (1)
106- 110 F5.2 mag (U-B) [-1.09/-0.3] (U-B) color index (1)
112- 116 F5.2 mag Jmag [15.48/16.19] 2MASS J-band magnitude
118- 122 F5.2 mag (J-H) [-0.15/1.41] (J-H) color index
124- 128 F5.2 mag (H-Ks) [-0.35/1] (H-Ks) color index
130- 134 F5.2 mag W2mag [11.12/14.17] WISE W2 (4.6um) band magnitude
136- 140 F5.2 mag (W1-W2) [-0.2/2.03] (W1-W2) color index
142- 145 F4.2 mag (W2-W3) [0.63/6.8] (W2-W3) color index
147- 150 F4.2 mag (W3-W4) [2.56/3.7] (W3-W4) color index
152- 164 A13 --- File Name of the FITS file in subdirectory fits;
column added by CDS
166- 176 A11 "date" Date UT date of the observation;
column added by CDS
178- 181 A4 --- Inst Instrument; column added by CDS (2)
183- 186 I4 s Exp ? Exposure time;
column added by CDS
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Note (1): UBV photometry from Zaritsky+ (2004, J/AJ/128/1606)
Note (2): The MagE spectrograph on the 6.5m Baade Magellan telescope.
MagE provides complete wavelength coverage from 3150 to 10000Å,
at intermediate resolution (resolving power λ/Δλ∼4100).
We used a 1" slit oriented along the parallactic angle.
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History:
From electronic version of the journal
References:
Margon et al. Paper II. 2023ApJ...942...85M 2023ApJ...942...85M Cat. J/ApJ/942/85
(End) Emmanuelle Perret [CDS] 19-Nov-2021