J/MNRAS/454/1468 LMC post-AGB, post-RGB star and YSOs (Kamath+, 2015)
Optically visible post-AGB stars, post-RGB stars and young stellar objects in
the Large Magellanic Cloud.
Kamath D., Wood P.R., Van Winckel H.
<Mon. Not. R. Astron. Soc. 454, 1468 (2015)>
=2015MNRAS.454.1468K 2015MNRAS.454.1468K (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; YSOs ; Stars, horizontal branch ;
Planetary nebulae ; Photometry ; Radial velocities
Keywords: techniques: photometric - techniques: spectroscopic -
stars: AGB and post-AGB - stars: fundamental parameters -
planetary nebulae: general - Magellanic Clouds
Abstract:
We have carried out a search for optically visible post-Asymptotic
Giant Branch (post- AGB) stars in the Large Magellanic Cloud (LMC).
First, we selected candidates with a mid-IR excess and then obtained
their optical spectra. We disentangled contaminants with unique
spectra such as M-stars, C-stars, planetary nebulae, quasi-stellar
objects and background galaxies. Subsequently, we performed a detailed
spectroscopic analysis of the remaining candidates to estimate their
stellar parameters such as effective temperature, surface gravity
(logg), metallicity ([Fe/H]), reddening and their luminosities. This
resulted in a sample of 35 likely post-AGB candidates with late-G to
late-A spectral types, low logg, and [Fe/H]←0.5. Furthermore,
our study con- firmed the existence of the dusty post-Red Giant Branch
(post-RGB) stars, discovered previously in our SMC survey, by
revealing 119 such objects in the LMC. These objects have mid-IR
excesses and stellar parameters (Teff, logg, [Fe/H]) similar to
those of post-AGB stars except that their luminosities (<2500L☉),
and hence masses and radii, are lower. These post-RGB stars are likely
to be products of binary interaction on the RGB. The post-AGB and
post-RGB objects show SED properties similar to the Galactic post-AGB
stars, where some have a surrounding circumstellar shell, while some
others have a surrounding stable disc similar to the Galactic post-AGB
binaries. This study also resulted in a new sample of 162 young
stellar objects, identified based on a robust logg criterion. Other
interesting outcomes include objects with an UV continuum and an
emission line spectrum; luminous supergiants; hot main-sequence stars;
and 15 B[e] star candidates, 12 of which are newly discovered in this
study.
Description:
To obtain an initial sample selection for our spectroscopic survey, we
adopted the sample selected by van Aarle et al. (2011A&A...530A..90V 2011A&A...530A..90V,
Cat. J/A+A/530/A90), who identified optically visible post-AGB star
candidates in the LMC based on photometry.
We obtained low-resolution spectra of stars selected from the initial
sample of objects. The spectra were taken using the AAOmega
double-beam multi-fibre spectrograph mounted on the 3.9m Anglo
Australian Telescope (AAT) at Siding Spring Observatory (SSO). AAOmega
allows for the simultaneous observation of 392 targets (including
science objects, sky-positions, and fiducial guide stars) over a 2
degree field using the 2dF fibre positioner.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 188 2106 *Photometric data for the 2102 unique candidates
for which spectra were obtained
table4.dat 158 35 The observational and stellar parameters for
the post-AGB candidates
table5.dat 158 119 The observational and stellar parameters for
the post-RGB candidates
table6.dat 150 162 The observational and stellar parameters for
the YSO candidates
tablea1.dat 19 55 C-stars in our sample
tablea2.dat 19 382 M-stars in our sample
tablea3.dat 64 123 The new planetary nebula candidates and
previously known planetary nebulae in our sample
tableb1.dat 56 85 The observational and stellar parameters for the
85 objects without B and V magnitudes
refs.dat 193 31 References
fig/* . 316 Individual PDF SED for objects in tables 4-6
sed/* . 316 Individual PDF spectra for objects in tables 4-6
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Note on table2.dat: see Section 3 of the paper for details.
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See also:
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
II/236 : UBVR CCD survey of the Magellanic clouds (Massey+, 2002)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/AJ/128/1606 : Magellanic Clouds Photometric Survey: the LMC (Zaritsky+, 2004)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name Name (JHHMMSS.ss+DDMMSS.s)
21- 30 F10.6 deg RAdeg Right ascension (J2000)
32- 41 F10.6 deg DEdeg Declination (J2000)
43- 48 F6.3 mag Umag ?=99.999 U magnitude (1)
50- 55 F6.3 mag Bmag ?=99.999 B magnitude (1)
57- 62 F6.3 mag Vmag ?=99.999 V magnitude (1)
64- 69 F6.3 mag Rmag ?=99.999 R magnitude (1)
71- 76 F6.3 mag Imag ?=99.999 I magnitude (1)
78- 83 F6.3 mag Jmag ?=99.999 J magnitude (1)
85- 90 F6.3 mag Hmag ?=99.999 H magnitude (1)
92- 97 F6.3 mag Kmag ?=99.999 K magnitude (1)
99-104 F6.3 mag W1mag ?=99.999 WISE W1 magnitude (3)
106-111 F6.3 mag [3.6]mag ?=99.999 IRAC 3.6um magnitude (2)
113-118 F6.3 mag [4.5]mag ?=99.999 IRAC 4.5um magnitude (2)
120-125 F6.3 mag W2mag ?=99.999 WISE W2 magnitude (3)
127-132 F6.3 mag [5.8] ?=99.999 IRAC 5.8um magnitude (2)
134-139 F6.3 mag [8.0] ?=99.999 IRAC 8.0um magnitude (2)
141-146 F6.3 mag W3mag ?=99.999 WISE W4 magnitude (3)
148-153 F6.3 mag W4mag ?=99.999 WISE W3 magnitude (3)
155-160 F6.3 mag [24] ?=99.999 MIPS 24um magnitude (2)
162-167 F6.3 mag [70] ?=99.999 MIPS 70um magnitude (2)
169-174 F6.3 mag [160] ?=99.999 MIPS 160um magnitude (2)
176-182 I7 Lsun Lobs Observed luminosity (4)
184-188 I5 K Teff Photometric temperature, Teff,sed (5)
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Note (1): Photometry in the U, V, B, R and I bands were added from either
Massey U, B, V, R CCD survey of the Magellanic Clouds (Massey,
2002ApJS..141...81M 2002ApJS..141...81M, Cat. II/236), the LMC stellar catalogue (Zaritsky et al.,
2004, Cat. J/AJ/128/1606), or the Guide Star Catalogue Version 2.3.2
(Lasker et al., 2008AJ....136..735L 2008AJ....136..735L, Cat. I/305).
Note (2): The SAGE-LMC survey covers the IRAC (3.6, 4.5, 5.8, and 8um) and the
MIPS (24.0, 70.0, and 160.0um) bands. The Spitzer sources have been merged
with the Two Micron All Sky Survey (2MASS) J, H, and K bands (1.24, 1.66 and
2.16um, Skrutskie et al., 2006AJ....131.1163S 2006AJ....131.1163S, Cat. VII/233).
Note (3): We also added WISE photometry in the 3.4, 4.6, 12, and 22um bands
W1, W2, W3, and W4, respectively (Wright et al.. 2010AJ....140.1868W 2010AJ....140.1868W,
Cat. II/311/).
Note (4): Observed luminosity obtained by integrating under the SED defined by
all the photometric bands after correcting for the effects of Galactic and
LMC reddening.
Note (5): Photometric temperature obtained by fitting ATLAS9 atmosphere models
(Castelli & Kurucz, 2003, IAU Symp., 201, 10) to the B,V,I, and J bands
corrected for foreground extinction.
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Byte-by-byte Description of file: table[456].dat
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Bytes Format Units Label Explanations
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1 A1 --- Case [AB] A: Candidates with [Fe/H] estimates from
spectra, B: Candidates with [Fe/H]=-0.50
3- 21 A19 --- Name Name (JHHMMSS.ss+DDMMSS.s)
22 A1 --- n_Name [abc+pd] Note on Name (1)
24- 28 I5 K Teff Effective temperature
30- 32 F3.1 [cm/s2] logg Surface gravity
34- 37 F4.1 [-] [Fe/H] Metallicity
39- 43 F5.2 mag E(B-V) B-V colour index
45- 49 I5 Lsun Lobs Observation luminosity corrected for
foreground extinction
51- 55 I5 Lsun Lph Photospheric luminosity of the central star
57- 60 F4.1 mag Vmag Optical V-band magnitude
62- 64 I3 km/s RV Radial velocity
66- 67 I2 km/s e_RV rms uncertainty on RV
69- 72 F4.2 Msun Mass ? Derived mass of the post-AGB candidate
(not for table6)
74- 78 A5 --- SED SED type of the object
(not for table6)
80- 82 A3 --- Ha [a,e -] Nature of the Hα line
at 6562.8Å (2)
84- 87 F4.1 km/s FWHM ?=- Full width at half maximum of the
Hα line
89- 91 A3 --- [OIII] [a,e- ] Nature of the [OIII] at 5001Å (2)
93-158 A66 --- Com Previous identifications (G1)
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Note (1): Notes as follows:
a = value used to estimate E(B-V) is increased by 250K
+ = based based on their spectra, J053116.74-690104.1 and
J054218.24-695249.4 are likely symbiotic objects
b = value used to estimate E(B-V) is increased by 500K
p = J050504.15-684440.8 , J052245.11-713610.2, J052834.16-715558.1 and
J053130.65-714448.2 show FeII emission line features similar to that
of B[e] stars
c = value used to estimate E(B-V) is increased by 250K
d = Based on the spectra of J050830.51-692237.4, it is likely a YSO
candidate with a C-star in the line-of-sight
Note (2): Nature of the lines as follows:
e = emission
a = absorption
e,a = dominant emission with an absorption component
a,e = dominant absorption with an emission component
- = indicates no detection
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Byte-by-byte Description of file: tablea1.dat tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name Name (JHHMMSS.ss+DDMMSS.s)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1 A1 --- Code [UP] Uncatalogued or Previously identified
planetary nebulae
3- 21 A19 --- Name Name (JHHMMSS.ss+DDMMSS.s)
23- 64 A42 --- Com Previous Identification (G1)
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Case [AB] A: Candidates with [Fe/H] estimates from
spectra, B: Candidates with [Fe/H]=-0.50
3- 21 A19 --- Name Name (JHHMMSS.ss+DDMMSS.s)
23- 27 I5 K Teff Effective temperature, estimated using the STP
29- 32 F4.2 [cm/s2] logg Surface gravity, estimated using the STP
34- 38 F5.2 [-] [Fe/H] Metallicity, estimated using the STP
40- 44 F5.2 mag Vmag ?=99.99 Optical V-band magnitude
46- 49 I4 Lsun Lobs Observation luminosity corrected for
foreground extinction
51- 53 I3 km/s HRV Estimated heliocentric radial velocity
55- 56 I2 km/s e_HRV rms uncertainty on HRV
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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 number
4- 22 A19 --- BibCode BibCode
24- 46 A23 --- Aut Author's name
48-193 A146 --- Com Comments
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Global notes:
Note (G1): Result of a positional cross-matching that was done with the
catalogues in refs.dat file.
Catalogue identifications:
OSARG-AGB = OGLE small amplitude red giant - AGB star
OSARG-RGB = OGLE small amplitude red giant - RGB star
LPV = long period variable
O-AGB = oxygen-rich AGB
YSO-hp = high probability YSO candidate
pagb-disc = post-AGB with disc-type SED
pagb-shell = post-AGB with shell-type SED
pagb-uncer = post-AGB with uncertain-type SED
YSO = young stellar object
YSO-P = YSO with PAH emission features
Evolved = evolved object
CEP = Cepheid variable
RVT = RV-Tauri
O-PAGB = oxygen-rich post-AGB
PAGB-s = s-process enriched post-AGB star
PN = planetary nebula
SRV-AGB = semi-regular variable AGB star
SRV-RGB = semi-regular variable RGB star
EB = eclipsing binary
RCB = R Coronae Borealis star.
G = background galaxy
QSO = quasi-stellar object
C-PPNe = carbon-rich proto-planetary nebula
RRLab - RR Lyrae
C-PAGB = carbon-rich post-AGB
AGN = active galactic nuclei
WVir = W Virginis star
HII = HII region
Be = Be star
red = stars with red spectra
C = C-star
YSO-PE = YSO with PAH emission features and fine-structure lines
C-PN = carbon-rich PN
O-PN = oxygen-rich PN
LPV/HII = long period variable/HII region
EclBin = eclipsing binary
Symb = Symbiotic
UNK = object of unknown type
See catalogued references for full details of the individual object
identification.
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Acknowledgements:
Devika Kamath, devika.kamath(at)ster.kuleuven.be
(End) Patricia Vannier [CDS] 18-Jun-2015