メタノール メーザー

v.s. 水 メーザー

メタノール メーザー

v.s. 水 メーザー

今井　裕（鹿児島大学理学部物理科学科宇宙情報講座）

大質量 YSO 水メーザー源研究がやっぱり面白い！

大質量 YSO 水メーザー源研究がやっぱり面白い！

Chronology of YSO masers

Chronology of YSO masers

Reid (2001, IAUS 206) から改変

メタノールメーザー源よりも水メーザー源の方がやや若いメタノールメーザー源よりも水メーザー源の方がやや若い

A&A 434, 613(2005)

水メーザー源研究における重要な発見水メーザー源研究における重要な発見 三次元膨張運動の発見：

統計視差／モデルフィット法による直接距離計測 恒星風／双極流駆動源の有効的な特定法

(Orion IRc2, Genzel et al. 1981; W49N, Gwinn et al. 1992) 回転降着ガスディスク上の水メーザースポット群

(L1287, Fiebig 1997; G192.16-3.84, Shepherd et al. 1999) マイクロジェットの発見： 力学的年齢 100 年未満のジェット

(S106FIR, Furuya et al. 2000) 真円バブルの発見 : 双極流進化に関する新たなパラダイム

(Cep A R5, Torrelles et al. 2001; W75N, Torrelles et al. 2003) 周期的挙動

(Cep A R5, Gallimore et al. 2003; Single dish observations) ゼーマン効果／磁場構造の解明

(W3 IRS5, Sarma et al. 2002; Imai et al. 2003) 高精度アストロメトリ：年周視差及び経年運動の検出

(W3 TW Object, Hachisuka et al. 2005; VERA papers)

三次元膨張運動の発見： 統計視差／モデルフィット法による直接距離計測 恒星風／双極流駆動源の有効的な特定法

(Orion IRc2, Genzel et al. 1981; W49N, Gwinn et al. 1992) 回転降着ガスディスク上の水メーザースポット群

(L1287, Fiebig 1997; G192.16-3.84, Shepherd et al. 1999) マイクロジェットの発見： 力学的年齢 100 年未満のジェット

(S106FIR, Furuya et al. 2000) 真円バブルの発見 : 双極流進化に関する新たなパラダイム

(Cep A R5, Torrelles et al. 2001; W75N, Torrelles et al. 2003) 周期的挙動

(Cep A R5, Gallimore et al. 2003; Single dish observations) ゼーマン効果／磁場構造の解明

(W3 IRS5, Sarma et al. 2002; Imai et al. 2003) 高精度アストロメトリ：年周視差及び経年運動の検出

(W3 TW Object, Hachisuka et al. 2005; VERA papers)

Chronology of H2O maser sources(Genzel & Downes 1977)

Chronology of H2O maser sources(Genzel & Downes 1977)

Time resolution:~103--104 years

Based on single-dish observations Flux density Velocity coverage

Detectable in infall/rotation gas disks?

Quenching with compact HII regions

Time resolution:~103--104 years

Based on single-dish observations Flux density Velocity coverage

Detectable in infall/rotation gas disks?

Quenching with compact HII regions

Multiple outflows traced by maser kinematics: star cluster (<0.01 pc) formation within 105 years

Multiple outflows traced by maser kinematics: star cluster (<0.01 pc) formation within 105 years

• W3 IRS5, Orion KL(?)• Sgr B2N/M/S • W51 W/M/N/S• W75N• Cep A

Much shorter than duration of cluster formation (~106 years)

Variety of maser kinematics:a micro bow shock

(Furuya et al. 2000)

Variety of maser kinematics:a micro bow shock

(Furuya et al. 2000)

Dynamical age ~50 years

A moment of jet creation

Story of the Cep A H2O masers

Story of the Cep A H2O masers

A 50 year old “bubble”(Torrelles et al. 2002)

Periodic shock wave propagation(Gallimore et al. 2003)

原始星の周期的活動性？他の H2O メーザー源では？

最近も VLBI 観測を行っていたはずなのだが… ..

どっちが若い段階？ 真円バブル v.s. 双極流

どっちが若い段階？ 真円バブル v.s. 双極流

Torrelles et al. (2003) Shepherd et al. (2004)

Correlation between L(H2O) and kinetic energy of outflow/radio jets

(Furuya et al. 2003)

Correlation between L(H2O) and kinetic energy of outflow/radio jets

(Furuya et al. 2003)LH2O v.s. L6cm LH2O v.s. Lbol

Supporting H2O maser excitation by shock (Elitzur, Hollenbach & McKee 1989)

Disk with outflowDisk with outflowL1278L1278

With VLA(Fiebig 1997)

With EVN(Imai et al. 2006)

YSO = variable star?YSO = variable star?Shintani & Imai et al. (2008)

YSO = variable star?YSO = variable star?Lekht et al. (2008)

Chronology of H2O maser sources(Genzel & Downes 1977)

Chronology of H2O maser sources(Genzel & Downes 1977)

Pure infall phase: unknown

Stellar core forms and star burns on: 30x104yr

Cocoon begins to expand : 2x104yr

Development of a super-compact HII region

Shell begins to expand; stellar wind phase : 1x104yr

Shell break up

Compact HII region expands : 1x104yr HII region reaches edge of a protostellar cloud:

3x104yr

Pure infall phase: unknown

Stellar core forms and star burns on: 30x104yr

Cocoon begins to expand : 2x104yr

Development of a super-compact HII region

Shell begins to expand; stellar wind phase : 1x104yr

Shell break up

Compact HII region expands : 1x104yr HII region reaches edge of a protostellar cloud:

3x104yr

Chronology of H2O maser sources(2007 November version)

Chronology of H2O maser sources(2007 November version)

Pure infall phase: 10x104 yr No H2O maser is expected. Stellar core forms and star burns on

(MYSOs) :unknownIRDCs? MIR sources identified with SPITZER/AKARI?

“Bubble”(=cocoon) forms: <103yr ? Hyper-compact (<0.001 AU) H II region

invisible/marginally visible e.g. Cep A R5 “Bubble” expands : ~1x104yr?

Hyper-compact H II region visible e.g. W75N VLA2 Development of hot molecular core

Shell begins to expand; stellar wind phase : ~3x104yr? Development of bipolar flow Periodic maser variation e.g. W3 IRS5, Orion IRC2, W49N,…

Shell break up: H2O masers disappear Compact HII region expands : 1x104yr HII region reaches edge of a protostellar cloud:

~3x104yr

Pure infall phase: 10x104 yr No H2O maser is expected. Stellar core forms and star burns on

(MYSOs) :unknownIRDCs? MIR sources identified with SPITZER/AKARI?

“Bubble”(=cocoon) forms: <103yr ? Hyper-compact (<0.001 AU) H II region

invisible/marginally visible e.g. Cep A R5 “Bubble” expands : ~1x104yr?

Hyper-compact H II region visible e.g. W75N VLA2 Development of hot molecular core

Shell begins to expand; stellar wind phase : ~3x104yr? Development of bipolar flow Periodic maser variation e.g. W3 IRS5, Orion IRC2, W49N,…

Shell break up: H2O masers disappear Compact HII region expands : 1x104yr HII region reaches edge of a protostellar cloud:

~3x104yr