J/ApJ/810/116 S-type AGB stars in SMC (Boyer+, 2015)
Identification of a class of low-mass asymptotic giant branch stars struggling
to become carbon stars in the Magellanic Clouds.
Boyer M.L., McDonald I., Srinivasan S., Zijlstra A., van Loon J.T.,
Olsen K.A.G., Sonneborn G.
<Astrophys. J., 810, 116 (2015)>
=2015ApJ...810..116B 2015ApJ...810..116B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Magellanic Clouds ; Photometry, UBVRI ;
Photometry, infrared
Keywords: infrared: stars; Magellanic Clouds; stars: AGB and post-AGB;
stars: low-mass; stars: variables: general; stars: winds, outflows
Abstract:
We have identified a new class of Asymptotic Giant Branch (AGB) stars
in the Small and Large Magellanic Clouds (SMC/LMC) using optical to
infrared photometry, light curves, and optical spectroscopy. The
strong dust production and long-period pulsations of these stars
indicate that they are at the very end of their AGB evolution.
Period-mass-radius relations for the fundamental-mode pulsators give
median current stellar masses of 1.14M☉ in the LMC and
0.94M☉ in the SMC (with dispersions of 0.21 and 0.18M☉,
respectively), and models suggest initial masses of <1.5M☉ and
<1.25 M☉, respectively. This new class of stars includes both
O-rich and C-rich chemistries, placing the limit where dredge-up
allows carbon star production below these masses. A high fraction of
the brightest among them should show S star characteristics indicative
of atmospheric C/O∼1, and many will form O-rich dust prior to their
C-rich phase. These stars can be separated from their less-evolved
counterparts by their characteristically red J-[8] colors.
Description:
We use the photometry databases compiled by the Surveying the Agents
of Galaxy Evolution (SAGE) Legacy programs (Meixner et al. 2006,
J/AJ/132/2268; Gordon et al. 2011AJ....142..102G 2011AJ....142..102G), which includes
photometry from the Magellanic Clouds Photometric Survey (MCPS, UBVI;
Zaritsky et al. 2002, J/AJ/123/855), 2MASS (JHKs; Skrutskie et al.
2006, VII/233), and Spitzer (3.6, 4.5, 5.8, 8.0, and 24um) photometry.
To this, we add available archival and literature photometry from the
Wide-field Infrared Survey Explorer (WISE: 3.4, 4.6, 11.6, and 22um;
Wright et al. 2010AJ....140.1868W 2010AJ....140.1868W) and the AKARI targeted surveys of
the SMC and LMC (3.2, 4.1, 7, 11, 15, and 24um; Ita et al. 2010,
J/PASJ/62/273; Kato et al. 2012, J/AJ/144/179).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 176 23 Spectroscopically-identified S-type stars in the SMC
--------------------------------------------------------------------------------
See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/MNRAS/451/3504 : Classification of IRS sources in the SMC (Ruffle+, 2015)
J/MNRAS/449/639 : VMC survey. XIV. SFR in SMC (Rubele+, 2015)
J/MNRAS/440/631 : IR photometry of LMC O-rich evolved stars (Jones+, 2014)
J/MNRAS/439/2211 : Post-AGB/RGB and YSOs in SMC (Kamath+, 2014)
J/A+A/562/A125 : OGLE-III SMC massive stars VI LCs (Kourniotis+, 2014)
J/AJ/144/179 : AKARI-LMC Point-source catalog (Kato+, 2012)
J/ApJ/753/71 : Mass-loss return from LMC evolved stars. VI. (Riebel+, 2012)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/A+A/536/A60 : EROS-2 Long Period Variables in LMC (Spano+, 2011)
J/AJ/142/103 : Cool evolved stars in SAGE-SMC (Boyer+, 2011)
J/AcA/61/217 : VI LCs of SMC long-period variables (Soszynski+, 2011)
J/MNRAS/411/1597 : LMC point source classification in SAGE-Spec (Woods+, 2011)
J/PASP/122/683 : SAGE-Spec Spitzer legacy program (Kemper+, 2010)
J/PASJ/62/273 : AKARI SMC photometry (Ita+, 2010)
J/AJ/140/416 : IR photometry of massive stars in the SMC (Bonanos+, 2010)
J/A+A/506/1277 : Magellanic Cloud C/O stars modelisation (Groenewegen+, 2009)
J/AJ/137/4810 : LMC-SAGE AGB star candidates (Srinivasan+, 2009)
J/A+A/488/675 : IR photometry of mass-losing AGB stars (Guandalini+, 2008)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/A+A/448/181 : IR colours of AGB and post-AGB stars (Groenewegen+, 2006)
J/MNRAS/353/705 : OGLE Variables in Magellanic Clouds (Ita+, 2004)
J/AJ/127/1531 : Star formation history of SMC (Harris+, 2004)
J/AJ/123/855 : Magellanic Clouds Photometric Survey: SMC (Zaritsky+, 2002)
J/A+AS/125/419 : Obscured AGB in Magellanic Clouds. I. (Loup+ 1997)
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Seq Running sequence number
4- 13 A10 --- --- [SSTISAGEMA]
15- 33 A19 --- Name Designation
( in Simbad)
35- 39 F5.2 mag Umag [19/]?=99.99 MCPS U band magnitude (1)
41- 45 F5.2 mag e_Umag [0.09/]?=99.99 Uncertainty in Umag
47- 51 F5.2 mag Bmag [17.85/19.7] MCPS B band magnitude (1)
53- 56 F4.2 mag e_Bmag [0.03/0.2] Uncertainty in Bmag
58- 62 F5.2 mag Vmag [15.7/17.6] MCPS V band magnitude (1)
64- 67 F4.2 mag e_Vmag [0.02/0.3] Uncertainty in Vmag
69- 73 F5.2 mag Imag [13.4/15.7] MCPS I band magnitude (1)
75- 78 F4.2 mag e_Imag [0.02/0.3] Uncertainty in Imag
80- 84 F5.2 mag Jmag [12/14] 2MASS J band magnitude
86- 89 F4.2 mag e_Jmag [0.02/0.03] Uncertainty in Jmag
91- 95 F5.2 mag Hmag [11.2/13] 2MASS H band magnitude
97-100 F4.2 mag e_Hmag [0.02/0.03] Uncertainty in Hmag
102-106 F5.2 mag Ksmag [10.9/12.7] 2MASS KS band magnitude
108-111 F4.2 mag e_Ksmag [0.02/0.03] Uncertainty in Ksmag
113-117 F5.2 mag 3.6mag [10.6/12.5] Spitzer/IRAC 3.6 micron band
magnitude from SAGE
119-122 F4.2 mag e_3.6mag [0.01/0.03] Uncertainty in 3.6mag
124-128 F5.2 mag 4.5mag [10.7/12.5] Spitzer/IRAC 4.5 micron band
magnitude from SAGE
130-133 F4.2 mag e_4.5mag [0.01/0.03] Uncertainty in 4.5mag
135-139 F5.2 mag 5.8mag [10.6/12.4] Spitzer/IRAC 5.8 micron band
magnitude from SAGE
141-144 F4.2 mag e_5.8mag [0.01/0.04] Uncertainty in 5.8mag
146-150 F5.2 mag 8.0mag [10.5/12.2] Spitzer/IRAC 8.0 micron band
magnitude from SAGE
152-155 F4.2 mag e_8.0mag [0.01/0.05] Uncertainty in 8.0mag
157-161 F5.2 mag 24mag [9.6/]?=99.99 Spitzer/MIPS 24um band magnitude
from SAGE
163-167 F5.2 mag e_24mag [0.07/]?=99.99 Uncertainty in 24mag
169-171 I3 d Per [80/685]? OGLE III I band period (2)
173-176 F4.2 mag Amp [0.04/0.2]? OGLE III I band amplitude (2)
--------------------------------------------------------------------------------
Note (1): MCPS: Magellanic Clouds Photometric Survey
(Zaritsky et al. 2002, J/AJ/123/855).
Note (2): OGLE-III: Optical Gravitational Lensing Experiment
(Soszynski et al. 2009, J/AcA/59/239 and 2011, J/AcA/61/217).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Dec-2015