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Class I Methanol Masers and Molecular Outflows at 7mm Arturo I. Gómez-Ruiz * MPIfR * Member of the International Max-Planck Research School for Astronomy.

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Presentation on theme: "Class I Methanol Masers and Molecular Outflows at 7mm Arturo I. Gómez-Ruiz * MPIfR * Member of the International Max-Planck Research School for Astronomy."— Presentation transcript:

1 Class I Methanol Masers and Molecular Outflows at 7mm Arturo I. Gómez-Ruiz * MPIfR * Member of the International Max-Planck Research School for Astronomy and Astrophysics CollaboratorsMPIfR:CRyA-UNAM:New Mex Tech: Karl MentenStan KurtzPeter Hofner Friedrich WyrowskiLaurent LoinardEsteban Araya Antoine GusdorfASIAA-Taiwan: Peter Schilke (U. Koeln)Naomi Hirano Science at Q Band

2 Outline Two examples for science at 7mm Two examples for science at 7mm Class I methanol masers at 7mm with VLA Class I methanol masers at 7mm with VLA SiO emission from outflows in SF SiO emission from outflows in SF Possible improvements from ALMA/EVLA at Q band Possible improvements from ALMA/EVLA at Q band SiO outflows & 44 GHz CH3OH masers SiO outflows & 44 GHz CH3OH masers

3 Methanol masers Interstellar masers Interstellar masers Maser lines are probes of hot and dense regions: Methanol Masers Methanol Masers Class I: Offset from UC HII regions and OH/H2O masers, but related with shock regions in outflows. Collisional pumping. Strongest transition at 44 GHz Class II: Near UC HII regions and OH/H2O masers, tracing envelopes of UC HII regions. Radiative pumping Menten, 1996

4 Interferometric survey of Class I CH3OH masers VLA in D configuration (2007 & 2008) VLA in D configuration (2007 & 2008) Sample of High Mass Protostellar Objects (HMPO): Molinari et al. (1994) & Sridharan et al. (2002) Sample of High Mass Protostellar Objects (HMPO): Molinari et al. (1994) & Sridharan et al. (2002) 7 mm observations of class I methanol maser at 44 GHz + Continuum 7 mm observations of class I methanol maser at 44 GHz + Continuum Velocity coverage of 21 km/s, spectral resolution of 0.17 km/s Velocity coverage of 21 km/s, spectral resolution of 0.17 km/s Primary beam ~ 60”; synthesized beam ~ 2” Primary beam ~ 60”; synthesized beam ~ 2” Typical rms of 50 mJy per channel Typical rms of 50 mJy per channel

5 Masers in HMPO & UC HII  Class I methanol masers are more common toward the more evolved objects of the sample Same tendency found for H 2 O & OH masers (Palla et al., 1991; Edris et al., 2007) [Detection rate of 55 % in Sridharan sample] Detection rates (Molinari sample): HMPO: 16/45 (~35 %) UC HII: 13/22 (~59 %)

6 Distance from ionized gas 0.01 pc < d < 0.6 pc 0.01 pc < d < 0.6 pc 4 sources present masers projected on the UC HII region 4 sources present masers projected on the UC HII region 67 of the 69 sources observed by Molinari et al. (1998) with VLA at 2 and 6 cm continuum 68% of the regions with masers also present HII regions Number of masers Distance from HII region (pc)

7 UC HII – CH 3 OH Mol 74 Mol 81 Mol 78

8 Relation with molecular outflows D C A B E DEC (J2000) RA (J2000) IRAS Blue-red: 12 CO(1-0) Grey: 4.5 μm + : CH 3 OH :outflow axis 12 CO and arrows from Shepherd et al IRAS Contours: SiO(2-1); Grey: 2.1 μm (Cesaroni et al. 1997) Δ : H 2 O masers (Tofani et al. 1995) + : CH 3 OH masers Correlation with molecular outflows Correlation with molecular outflows Some cases suggest that only outflows with specific physical parameters allow the class I methanol maser emission Some cases suggest that only outflows with specific physical parameters allow the class I methanol maser emission

9 Comparison with IRAC/Spitzer IRAC bands used to look for outflows IRAC bands used to look for outflows An excess in the [4.5] band respect the [5.8] & [8.0] bands indicates the presence of shocked gas in outflows An excess in the [4.5] band respect the [5.8] & [8.0] bands indicates the presence of shocked gas in outflows In most of the regions with detection we found a coincidence between masers and regions with an excess in the [4.5] band In most of the regions with detection we found a coincidence between masers and regions with an excess in the [4.5] band

10 IRAC/Spitzer Green: 4.5 μm Red: 5.8 μm Blue: 8.0 μm Gomez-Ruiz et al. in prep

11 Maser velocity range |V sys – V maser | ~ 7.6 km/s Velocity interval of class I methanol masers < than the typical velocity of bow shocks (tip) in molecular outflows (~ 20 km/s) V sys – V maser (km/s) Number of maser components

12 A relation with bow shock wing? Molecular outflows consist of swept-up material + jet component Molecular outflows consist of swept-up material + jet component Bow-shock (swept-up gas) = bow-shock tip + bow-shock wing Bow-shock (swept-up gas) = bow-shock tip + bow-shock wing Class I methanol masers tracing bow- shock wings? Class I methanol masers tracing bow- shock wings? Lee et al. 2000

13 Summary Class I CH3OH masers a) Survey shows that although class I methanol masers are present in the earliest phases of HMSF, they are common toward more evolved regions (i.e UC HII regions) a) Survey shows that although class I methanol masers are present in the earliest phases of HMSF, they are common toward more evolved regions (i.e UC HII regions) b) There is evidence of the physical connection between masers and the post-shock region in outflows b) There is evidence of the physical connection between masers and the post-shock region in outflows c) Class I methanol masers might indicate an specific phase of outflow evolution c) Class I methanol masers might indicate an specific phase of outflow evolution

14 SiO emission in outflows SiO is the most specific shock tracer SiO is the most specific shock tracer Exclusive presence in shock regions due to peculiar processing of dust and following gas-phase chemistry (Gusdorf et al. 2008) Exclusive presence in shock regions due to peculiar processing of dust and following gas-phase chemistry (Gusdorf et al. 2008) Simultaneous modeling of H2 & SiO constrain parameters such as Shock type, pre-shock density, magnetic field, or shock velocity and age Simultaneous modeling of H2 & SiO constrain parameters such as Shock type, pre-shock density, magnetic field, or shock velocity and age L1157 Red & Blue: SiO (5-4) White: SiO (2-1) Gomez-Ruiz, Hirano, et al. in prep

15 Outflow bullets and Bow shocks High-J SiO emission tracing high velocity bullets close to protostar, probably related with primary jet (e.g. HH212: SiO 8-7) High-J SiO emission tracing high velocity bullets close to protostar, probably related with primary jet (e.g. HH212: SiO 8-7) SiO emission in bow shocks: high angular resolution observations (sub-arsec) needed to resolve bow width. BUT some times SiO is weaker at bow shock compared to inner bullets (low-J SiO transitions are betters tracers) SiO emission in bow shocks: high angular resolution observations (sub-arsec) needed to resolve bow width. BUT some times SiO is weaker at bow shock compared to inner bullets (low-J SiO transitions are betters tracers) HH 212 Lee et al. 2007

16 ALMA/EVLA High spatial and high sensitivity observations to properly locate class I methanol masers (outflow-maser relation) + polarimetry observations High spatial and high sensitivity observations to properly locate class I methanol masers (outflow-maser relation) + polarimetry observations Sub-arcsec resolution SiO (1-0) observations to resolve bow shock structures as input for 3-D modeling: energy transfer, shock parameters, testing influence of inclusion of state of art dust process in shock models Sub-arcsec resolution SiO (1-0) observations to resolve bow shock structures as input for 3-D modeling: energy transfer, shock parameters, testing influence of inclusion of state of art dust process in shock models


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