ClassClass I Methanol Masers and I Methanol Masers and Molecular Outflows at 7mmMolecular Outflows at 7mm

Arturo I. Gómez-RuizArturo I. Gómez-Ruiz **

MPIfRMPIfR* Member of the International Max-Planck Research School * Member of the International Max-Planck Research School

for Astronomy and Astrophysicsfor Astronomy and Astrophysics

Collaborators MPIfR: CRyA-UNAM: New Mex Tech:

Karl Menten Stan Kurtz Peter Hofner

Friedrich Wyrowski Laurent Loinard Esteban Araya

Antoine Gusdorf ASIAA-Taiwan:

Peter Schilke (U. Koeln) Naomi Hirano

Science at Q Band

OutlineOutline

Two examples for science at 7mmTwo examples for science at 7mm Class I methanol masers at 7mm with Class I methanol masers at 7mm with

VLAVLA SiO emission from outflows in SFSiO emission from outflows in SF

Possible improvements from Possible improvements from ALMA/EVLA at Q bandALMA/EVLA at Q band SiO outflows & 44 GHz CH3OH masersSiO outflows & 44 GHz CH3OH masers

Methanol masersMethanol masers Interstellar masersInterstellar masers

Maser lines are probes of hot and dense regions:Maser lines are probes of hot and dense regions:

Methanol MasersMethanol Masers

Class I: Offset from UC HII regions and OH/H2O masers, but related with Class I: Offset from UC HII regions and OH/H2O masers, but related with shock regions in outflows. Collisional pumping. shock regions in outflows. Collisional pumping. Strongest transition at 44 Strongest transition at 44 GHzGHz

Class II: Near UC HII regions and OH/H2O masers, tracing envelopes of UC HII Class II: Near UC HII regions and OH/H2O masers, tracing envelopes of UC HII regions. Radiative pumpingregions. Radiative pumping

Menten, 1996

Interferometric survey of Class I CH3OH Interferometric survey of Class I CH3OH masersmasers

VLA in D configuration (2007 & 2008)VLA in D configuration (2007 & 2008)

Sample of High Mass Protostellar Objects (HMPO): Molinari et al. (1994) & Sample of High Mass Protostellar Objects (HMPO): Molinari et al. (1994) & Sridharan et al. (2002)Sridharan et al. (2002)

7 mm observations of 7 mm observations of class I methanol maser at 44 GHz + Continuumclass I methanol maser at 44 GHz + Continuum

Velocity coverage of 21 km/s, spectral resolution of 0.17 km/sVelocity 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 channelTypical rms of 50 mJy per channel

Masers in HMPO & UC HIIMasers in HMPO & UC HII

Class I methanol masers are more common toward the Class I methanol masers are more common toward the more evolved objects of the samplemore evolved objects of the sample

Same tendency found for HSame tendency found for H22O & OH masers (Palla et al., O & OH masers (Palla et al., 1991; Edris et al., 2007)1991; Edris et al., 2007)

[Detection rate of 55 % in Sridharan sample][Detection rate of 55 % in Sridharan sample]

Detection rates (Molinari sample):

HMPO: 16/45 (~35 %) HMPO: 16/45 (~35 %)

UC HII: 13/22 (~59 %)UC HII: 13/22 (~59 %)

Distance from ionized gasDistance from ionized gas

0.01 pc < d < 0.6 pc0.01 pc < d < 0.6 pc

4 sources present masers 4 sources present masers projected on the UC HII regionprojected 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

Num

ber

of

mase

rs

Distance from HII region (pc)

UC HII – CHUC HII – CH33OHOH

Mol 74

Mol 81

Mol 78

Relation with molecular outflowsRelation with molecular outflows

D

C

A

B

E

DEC

(J2

00

0)

RA (J2000)

IRAS 18507+0121Blue-red:12CO(1-0)

Grey: 4.5 μm

+ : CH3OH

:outflow axis

12CO and arrows from Shepherd et al. 2007

IRAS 20126+4104

Contours: SiO(2-1); Grey: 2.1 μm (Cesaroni et al. 1997)

Δ : H2O masers (Tofani et al. 1995)

+ : CH3OH masers

Correlation with molecular outflowsCorrelation with molecular outflows

Some cases suggest that only outflows with specific physical Some cases suggest that only outflows with specific physical parameters allow the class I methanol maser emissionparameters allow the class I methanol maser emission

Comparison with IRAC/SpitzerComparison with IRAC/Spitzer

IRAC bands used to look IRAC bands used to look for outflowsfor outflows

An excess in the [4.5] band An excess in the [4.5] band respect the [5.8] & [8.0] respect the [5.8] & [8.0] bands indicates the bands indicates the presence of shocked gas in presence of shocked gas in outflowsoutflows

In most of the regions with In most of the regions with detection we found a detection we found a coincidence between coincidence between masers and regions with masers and regions with an excess in the [4.5] bandan excess in the [4.5] band

IRAC/SpitzerIRAC/Spitzer

Green: 4.5 μm

Red: 5.8 μm

Blue: 8.0 μm

Gomez-Ruiz et al. in prep

Maser velocity rangeMaser velocity range

• |Vsys – Vmaser| ~ 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)

Vsys – Vmaser (km/s)

Num

ber

of

mase

r co

mponents

A relation with bow shock A relation with bow shock wing?wing?

Molecular outflows Molecular outflows consist of consist of swept-up swept-up material + jet material + jet componentcomponent

Bow-shock (swept-Bow-shock (swept-up gas) = up gas) = bow-shock bow-shock tip + bow-shock tip + bow-shock wingwing

Class I methanol Class I methanol masers tracing bow-masers tracing bow-shock wings?shock wings?

Lee et al. 2000

Summary Class I CH3OH Summary Class I CH3OH masers masers

a)a) Survey shows that although class I methanol Survey shows that although class I methanol masers are present in the earliest phases of masers are present in the earliest phases of HMSF, they are common toward more evolved HMSF, they are common toward more evolved regions (i.e UC HII regions) regions (i.e UC HII regions)

b)b) There is evidence of the physical connection There is evidence of the physical connection between masers and the post-shock region in between masers and the post-shock region in outflowsoutflows

c)c) Class I methanol masers might indicate an Class I methanol masers might indicate an

specific phase of outflow evolutionspecific phase of outflow evolution

SiO emission in outflowsSiO emission in outflows

SiO is the most specific SiO is the most specific shock tracershock tracer

Exclusive presence in Exclusive presence in shock regions due to shock regions due to peculiar processing of dust peculiar processing of dust and following gas-phase and following gas-phase chemistry (Gusdorf et al. chemistry (Gusdorf et al. 2008)2008)

Simultaneous modeling of Simultaneous modeling of H2 & SiO constrain H2 & SiO constrain parameters such as Shock parameters such as Shock type, pre-shock density, type, pre-shock density, magnetic field, or shock magnetic field, or shock velocity and agevelocity and age

L1157

Red & Blue: SiO (5-4)

White: SiO (2-1)

Gomez-Ruiz, Hirano, et al. in prep

Outflow bullets and Bow Outflow bullets and Bow shocksshocks

High-J SiO emission tracing High-J SiO emission tracing high velocity bullets close to high velocity bullets close to protostar, probably related protostar, probably related with primary jet (e.g. HH212: with primary jet (e.g. HH212: SiO 8-7)SiO 8-7)

SiO emission in bow shocks: SiO emission in bow shocks: high angular resolution high angular resolution observations (sub-arsec) observations (sub-arsec) needed to resolve bow needed to resolve bow width. BUT some times SiO width. BUT some times SiO is weaker at bow shock is weaker at bow shock compared to inner bullets compared to inner bullets (low-J SiO transitions are (low-J SiO transitions are betters tracers) betters tracers)

HH 212

Lee et al. 2007

ALMA/EVLAALMA/EVLA

High spatial and high sensitivity High spatial and high sensitivity observations to properly locate class I observations to properly locate class I methanol masers (outflow-maser relation) + methanol masers (outflow-maser relation) + polarimetry observationspolarimetry observations

Sub-arcsec resolution SiO (1-0) observations Sub-arcsec resolution SiO (1-0) observations to resolve bow shock structures as input for to resolve bow shock structures as input for 3-D modeling: energy transfer, shock 3-D modeling: energy transfer, shock parameters, testing influence of inclusion of parameters, testing influence of inclusion of state of art dust process in shock models state of art dust process in shock models