The Infrared Properties and Period-Luminosity Relations of Red Supergiant Stars in the Magellanic Clouds Ming Yang Biwei Jiang Jan / 16 / 2013
Outlines Introduction Sample Selection and Data Analysis Period-Luminosity Relation Pulsation mode
Outlines Introduction Sample Selection and Data Analysis Period-Luminosity Relation Pulsation mode
Introduction Red Supergiant stars (RSGs) are massive evolved, He-burning, extreme Population I stars with mass range roughly between 9-30 M. Relative cool effective temperatures about 3450 4100K (belonging to spectral type late-k M) Enormous radii which could up to 1500R High luminosities that about 2000 30000 L Large mass loss rate (MLR): some RSGs stars could reach 10 6 to 10 4 M yr 1.
Introduction Red Supergiant stars (RSGs) are massive evolved, He-burning, extreme Population I stars with mass range roughly between 9-30 M. Relative cool effective temperatures about 3450 4100K (belonging to spectral type late-k M) Enormous radii which could up to 1500R High luminosities that about 2000 30000 L Large mass loss rate (MLR): Some RSGs stars could reach 10 6 to 10 4 M yr 1.
RSGs have long been known for their hundreds days of semi-regular photometric variation (belong to SRc in General Catalogue of Variable Stars (GCVS) ) It may due to the radial pulsation at fundamental, first or even possibly second overtone mode The inexplicable long term scale variability which could up to 4000 days or more so called Long Secondary Period (LSP) The source of LSP still not quite sure.
The irregular photometric variation (belong to Lc in GCVS) It may caused by the large convective cells in the surface of the star and some recent simulation works have proofed it
The period-luminosity (P-L) relation Cepheid P-L relation There still does need a variety of independent methods which could be used to verified. RSGs P-L relation
Outlines Introduction Sample Selection and Data Analysis Period-Luminosity Relation Pulsation mode
Contamination Sample selection Foreground red dwarf ~ B-V vs. V-R (B band is sensitive to the surface gravity) Red giants in the halo of the Milky Way ~ kinematic analysis AGBs
LMC Total: 191 candidates Feast et al. 1980 ~ 21 Pierce et al. 2000 ~ 10 Kastner et al. 2008 ~ 25 Massey et al. 2003 ~ 135 SMC Total :140 candidates Catchpole et al. 1981 ~ 20 Wood et al. 1983 ~ 6 Massey et al. 2003 ~ 101 Levesque et al. 2006 ~ 8 Massey et al. 2007 ~ 1 van Loon et al. 2008 ~ 3 van Loon et al. 2010 ~ 1
Infrared data (1 search radius): SAGE IRAC Catalog SAGE MIPS 24um Catalog Photometry data: All Sky Automated Survey (ASAS) MAssive Compact Halo Objects (MACHO) projects
Spatial distribution Data analysis
Color-Magnitude Diagrams K S vs. J K S * background from Bonanos et al. (2009, 2010); m bol =-7.1 (Wood et al. 1983)
Color-Magnitude Diagrams K S vs. J K S * background from Bonanos et al. (2009, 2010); m bol =-7.1 (Wood et al. 1983); J Ks cuts are from Cioni et al. (2006a, 2006b) (Boyer et al. 2011)
Color-Color Diagrams [3.6] [8.0] vs. [8.0] [24]
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data
Given all these characteristics in color and brightness, the situation is complicate Low luminosity and no much dust to account for the low luminosity [3.6] [8.0] vs. [8.0] [24] Lack bands data Targets are confirmed as RSGs LMC: 185 SMC: 132
Photometric data Light curve morphology The definition of RSGs variables is semi-regular with amplitudes of about 1 mag
Period Determination Phase Dispersion Minimization (PDM) PDM2: improved curve fits, suppressed subharmonics, and beta function statistics
Period04 (Fourier analysis) Top panel is the 10 day-binned light curve with the fitted curve Bottom panels are power spectra
CLEAN From top to bottom: The dirty spectrum clean components residual spectrum clean spectrum
Weighted Wavelet Z- transform (WWZ) From top to bottom: The contour map The time-varying amplitude The time-varying period
LMC SMC
Outlines Introduction Sample Selection and Data Analysis Period-Luminosity Relation Pulsation mode
K S -band P-L relation 47 targets 21 targets
Compare with the P-L relations of RSGs derived by other jobs
Multi-band Infrared P-L relation Near- and Mid-infrared P-L relations of RSGs in SMC and LMC
Multi-band Infrared P-L relation Near- and Mid-infrared P-L relations of RSGs in SMC and LMC
Multi-band Infrared P-L relation Near- and Mid-infrared P-L relations of RSGs in SMC and LMC
* LPV in MCs from Soszynski et al. (2007); Superposed AGB a2 sequence
Outlines Introduction Sample Selection and Data Analysis Period-Luminosity Relation Pulsation mode
Pulsation Mode Comparison with Guo & Li (2002)
Comparison with Guo & Li (2002)
Comparison with Heger et al. (1997)
Publications 1. The Period-Luminosity Relation of Red Supergiant Stars in the Small Magellanic Cloud, Yang, M., Jiang, B. W., 2012, ApJ, accepted 2. Analysis of a Selected Sample of RR Lyrae Stars in LMC from OGLE III, Chen, B. Q., Jiang, B. W., Yang, M., 2012, RAA, submitted 3. Construction of the Database for Pulsating Variable Stars, Chen, B. Q., Yang, M., Jiang, B. W., 2012, ChA&A, 36, 27 4. 脉动变星数据库的建立, 陈丙秋, 杨明, 姜碧沩, 2011, 天文学报, 52, 297 5. Red Supergiant Stars in the Large Magellanic Cloud. I. The Period- Luminosity Relation, Yang, M., Jiang, B. W., 2011, ApJ, 727, 53 6. The Variability Of RSG : HV2576, Yang, M., Jiang, B. W., 2008, IAUS, 252, 267
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