KVN

Sept. 22, 2011

Se-Hyung Cho

Observational Studies from AGB to Post-AGB

Stars Using the KVN Telescope

KVN

◆ Key Issues ◆ KVN Single Dish Survey and Monitoring Obs.: Overview and Some Results

○ Two Color Diagram of SiO/H2O Observed Stars etc. ◆ VLBI Observations for Dynamical Evolutionary Studies from AGB to Post-AGB Stars/PPN ○ Asymmetry at AGB Stage ◆ Related VLBI Case Studies of AGB Stars ◆ VLBI Study of Known Water Fountain Sources ◆ Candidate Sources for KVN+VERA Obs.

Coworkers: Jaeheon Kim (Sang-Jun Kim, Kyunghee Univ.), Dong-Hwan Yun (Yong-Sun Park, SNU), Chi-Young Cho (Seong-En Kim, Sejong Univ.), & Youngjoo Yun (KASI)

Contents

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Observational Studies from AGB to Post-AGB Stars Using the KVN : Key Issues

◈ How appears an dynamical evolutionary process from AGB to post-AGB stars/PPN in both maser emission ?

■ Dynamical effect from SiO to H2O maser regions due to stellar pulsation with relations of mass loss mechanism ~ Propagation of pulsation : photosphere – molecular layer – SiO maser

region – dust formation region – 22 GHz H2O maser region ● Kinematics of maser spots ~ inward/outward motion, rotation, proper motion etc.

■ Dynamical evolution from AGB stars to post-AGB/PN : Aspherical morphology, development of bipolarity, jets

■ Spatial structure and mutual relation of SiO and H2O maser emission

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Energy Level Diagrams of H2O and SiO Molecules

KVN : H2O 616-523 22 GHz SiO J=1-0 43 GHz J=2-1 86 GHZ J=3-2 129 GHz

SiO Energy Levels

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KVN Single Dish Survey: Simultaneous Observations of SiO/H2O

H2O 616-523 (22 GHz ) SiO28 v=1, J=1-0 (43 GHz) v=2, J=1-0 SiO29 v=0, J=1-0 ■ AGB stars (2009-2010)

○ Known both SiO and H2O maser sources (166) : Obs. in 2009 (KVN_Yonsei Tel) ▶ J. Kim et al. (2010 ApJS) ○ Known SiO-only maser sources (83) : Obs. in 2009-2010 (KVN_Yonsei & Tamna) ▶ S.-H. Cho et al. (2011 ApJS, in prep.) ○ Known H2O-only maser sources (152) : Obs. in 2009-2010 (KVN_Yonsei & Tamna) ▶ J. Kim et al. (2011 ApJS, in prep.) ○ Statistical analyses ▶ J. Kim et al. (2011, in prep.) ■ Post-AGB stars (2010-2011) (KVN_Yonsei & Tamna) ▶ D.-H. Yun ○ Spectroscopic post-AGB (Suarez et al. 2008): 50/66 sources ▶ 2 detected ○ IRAS, OH/IR post-AGB candidates: 18/168 sources ▶ 3 detected (Ramos-Larios et al. 2009, Sevenster 2002, Nyman et al. 1998 etc.) ■ AKARI/FIS sources (1st 111): post-AGB or proto-stars ? – SiO/H2O (KVN) ▶ 36/111 H2O-only detected – CO (TRAO) ▶ 36/36 detected → Proto-stars, Star Forming Regions

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Time Monitoring Observations Using KVN Single Dish: Relatively Strong SiO/H2O Maser Sources (2009-2011)

■ AGB stars (SRs, Miras, OH/IR stars: about 30-50 sources) ○ Known both SiO and H2O maser sources (~30) ○ Known SiO-only/H2O-only maser sources ○ New interesting SiO/H2O maser sources ■ Bipolar outflow or multiple H2O sources (about 30 sources) ○ WX Psc, BW Cam, V2108 Oph, V1366 Aql, NML Cyg, NV Aur, OH358.23+0.11, IRAS 19069+0916 et al. ■ Water fountain sources (about 10 sources) ■ Post-AGB stars/PPN (about 5 candidate sources) ■ Symbiotic stars (about 6 sources) ◈ Monitoring time intervals : Irregular, 1-3 months etc. ▶ Single dish studies and basic data for VLBI observations ◈ Maser models based on KVN SD and VLBI data (KVN+VERA) ▶ Y. Yun

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● Regions IV&V : PPNs, No 45 : QX Pup (PPN) IIIb : young PPN can be distributed ● LI&RI : associated with post-AGB stars ● Bipolar structure can start already in AGB stage

(Zijlstra 2001)

W43A ◈

W43A

124

117

QX Pup (PPN)

27

113

45

Jaeheon Kim, Se-Hyung Cho, Chung Sik Oh, & Do-Young Byun ApJS, 188, 209, 2010 (KVN_Yonsei Tel)

● SiO/H2O det. ● SiO-only det. ▲ H2O-only det.

Two Color Diagram of both SiO/H2O Maser Sources (166) : Dynamical Evolution & Maser Chronology from AGB to Post-AGB Stars

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Two Color Diagram of SiO-only & H2O-only Maser Sources: Dynamical Evolution & Maser Chronology from AGB to Post-AGB Stars

83 observed stars for SiO-only sources 152 observed stars for H2O-only

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Survey: Post-AGB Stars and AKARI/FIS Sources Dong-Hwan Yun et al.

Known water fountain sources: IRAS 16552-3050

Newly detected post-AGB ?

CO J=1-0, TRAO 14m

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SiO J=2-1 & J=3-2 obs. with 14m tel. (Cho et al. 1998, 2009, Kang et al. 2006)

Time Monitoring Observations: AGB Stars

Semi-regular pulsating star

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Mira variable star

Time Monitoring Observations: AGB Stars

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Time Monitoring Observations: Water fountain sources (Stellar H2O maser jets)

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■ AGB stars ○ SRs, Miras, IRAS sources etc. ○ OH/IR stars ■ Post-AGB stars ○ IRAS, OH/IR, AKARI etc. post-AGB candidates ▶ Expanded SiO/H2O maser survey, monitoring interesting sources ■ AKARI/FIS sources (1st 111) – Specified sources: CH3OH, SiO (v=0) survey

Single Dish Survey: 2011 Oct. -2012 June

Time Monitoring Observations: 2011 Oct. -2012 June

■ AGB stars (SRs, Miras, OH/IR stars) ■ Bipolar or multiple H2O sources ■ Water fountain sources ■ Post-AGB stars/PPN ■ Symbiotic stars ▶ Continue monitoring

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Bipolar outflow source

Asymmetry starts from Mira variable stars

VLBI Observations for Dynamical Evolutionary Studies from AGB to Post-AGB Stars/PPN

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W Hya Semi regular variable: P~360d Distance ~90 pc Bright maser source: OH, H2O, SiO Elongation of the radio Photosphere

Radio photosphere and SiO maser emission

Green filled ellipses: 43 GHz radio continuum, yellow contour: SiO maser, grey scale: H2O maser, using VLA (Reid & Menten 2007)

Green filled ellipses: radio continuum, contour and grey scale: SiO maser, red filled circles: stellar size

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Multi-epoch Obs. of SiO/H2O Masers:

Related Case Studies

0.3″

■ Annual parallax → distance 1.15 kpc ► Proper motion ► Modeling for the kinematics of 3 dimensional circumstellar envelope

Red Supergiant VY CMa with VERA (Choi et al. 2008, PhD thesis)

◈ We expect to trace the development of outward motion from spherical symmetry in SiO maser regions to asymmetric morphology in H2O regions using KVN+VERA

■ Model of molecular outflow superimposed on HST IR image (Ziurys et al. 2007)

SiO

H2O

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SiO Maser Asymmetric Miras : IK Tauri using VLBA, Cotton et al. 2010

SiO v=2 (left), v=1 (right), J=1-0 2004 Nov. 8 (stellar phase 0.53) 2005 Oct. 23 (stellar phase 1.27) 2006 Feb. 3 (stellar phase 1.49)

KVN Monitoring

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Multi-epoch Obs. of SiO/H2O Masers: Bipolar Outflow from the WX Pisces

NIR 1.24 µm (J band), Hofmann et al. 2001

Ring-like distributions of SiO v=1, 2, J=1-0 by VLBA, Soria-Ruiz et al. 2005

By KVN

◈ Bipolar outflow triggered at a late stage of AGB winds ● Symmetry breaking in the evolution from AGB to planetary nebula ? ● Precursor of water fountain ? Vinkovic et al. 2004

Biconically expanding flow model based on H2O maser by JVN, Inomata et al. 2007

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Time Monitoring Observations Using KVN SD:

water fountain sources

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Parameters of Known Water Fountain Sources

Imai 2007

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Vinkovic et al. 2004

(WX Psc)

MSX Color-Color Diagram of Known Water Fountain Sources & IRAS 19069+0916

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JVN, Imai et al. 2008

NRO 45m, Deguchi et al. 2007

VLBI Observations of Water Fountain Sources

OH 12.8-0.9, Boboltz 2005

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Double-jet model based on VLBA obs. Yung et al. 2011

IRAS 18286-0959

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IRAS 19134+2131, VLBA (Imai 2007)

IRAS 16552-3050, VLA (Suarez 2008)

-23 ~ -10 km s-1 -121~ -117 km s-1

HST image by R. Sahai : Optically visible ▶ Pre-Planetary Nebulae phase Dynamical age ~ 50 yrs

VLBI Observations of Water Fountain Sources

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IRAS 16342-3814, Claussen et al. 2009

VLBI Observations of Water Fountain Sources

VLBA

VLA

HST F814W

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Post-AGB Star, W43A : The H2O masers exist in a precessing jet

SiO v=1, J=1-0 Imai et al. 2005,

VLBA, Imai et al. 2002

Vlemmings et al. 2006

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Candidate Sources for KVN (+VERA) Obs. of SiO & H2O Masers

Based on KVN single dish survey and monitoring observations ■ SR, Mira, SG: RT Vir, IK Tau, W Hya, RR Aql, R UMa, V1111 Oph, NV Aur (O), WX Psc (D: BO), NML Cyg (D: BO), V438 Sct (D), V4201 Sgr (M), V2108 Oph (D/M), OH358.23+0.11 (M) et al. * According to H2O line profiles; O ► One-way, D: BO ► Double peaks: Bipolar Outflow, M ► broad Multiple H2O sources ■ Symbiotic stars: V407 Cyg, V627 Cas ■ Water fountain sources/PPN: IRAS 19069+0916, OH9.1-0.4, W43A ?