mass loss from galactic bulge agb stars€¦ · solar neigh. schulteis et al. 2003 . mass loss rate...

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Mass Loss from Galactic Bulge AGB stars Margaret Meixner (STScI/ visiting Scientist at Harvard- Smithsonian CfA) Nimesh Patel, Dave Riebel, Ben Sargent, Sundar Srinivasan, Ken Young

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Page 1: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Mass Loss from Galactic Bulge AGB stars

Margaret Meixner (STScI/ visiting Scientist at Harvard-

Smithsonian CfA) Nimesh Patel, Dave Riebel,

Ben Sargent, Sundar Srinivasan, Ken Young

Page 2: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Why Galactic Bulge?

•  Known Distance: 8 kpc (Reid 1993) •  Extreme environment •  High metallicity: peak at -0.3, but wide range:

-1<[Fe/H]<1 •  ISOGal studies reveal a population of AGB

star candidates suitable for followup (Omont et al.)

•  Prior studies show that all AGB stars in bulge are oxygen rich, with silicate dust features (Blommaert et al.)

Page 3: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

ISOGal sample: spectroscopy of 107 candidate AGB stars

Schulteis et al. 2003

Page 4: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Metallicity of Bulge ISOGal sample

bulge

Solar neigh.

Schulteis et al. 2003

Page 5: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Mass Loss rate from IR

Schulteis et al. 2003

Page 6: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

SMA project:

•  Use SMA to spatially filter the foreground CO cloud emission, and detect the point source AGB molecular winds of Galactic Bulge AGB stars.

•  Use extended SMA configuration, and observe two AGB stars per track.

•  Goal: to measure gas mass-loss rates, compare to dust mass-loss rates and estimate dust to gas mass ratios

•  Data taken last week…

Page 7: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Vexp Vexp V0

V0-Vexp

V0+Vexp

V0 Jy

V0 V0-Vexp V0+Vexp

Vexp

Vexp

Page 8: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Mass Loss rates from CO

Knapp & Morris (1985) Ramstedt et al. (2008)

Velocity integrated intensity CO abundance

Distance

Beam size

Page 9: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Prior work: CO detected in Galactic AGB stars/ OH-IR stars:

Winnberg et al. 2009

Page 10: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

CO detected in Galactic AGB stars/ OH-IR stars: OH0.3-0.2

Winnberg et al. 2009

Page 11: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

CO detected in Galactic AGB stars/ OH-IR stars: OH 359.762

Winnberg et al. 2009

Page 12: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Our SMA sample

Schulteis name log Mdot (IR) Type

Vstar (km/s)

Del-V (km/s)

A12 -4.65 OH 359.77+0.08 107.60 30A51 -4.73 OH 359.681-0.095 -98.70 20A10 -4.75 OH 359.598+0.00 -73.30 40A27 -4.78 AGB ? ?

Page 13: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Galactic Bulge: A12, OH 359.77+0.08

Page 14: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Galactic Bulge: A12, OH 359.77+0.08

Page 15: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Galactic Bulge: A51, OH 359.681-0.095

Page 16: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Galactic Bulge: A51, OH 359.681-0.095

Page 17: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Preliminary results from SMA sample

Schulteis name Comment

line flux (JyXkm/s) Mdot

A12 detected 42.5 8.3x10^-4A51 detected 32 6.24x10^-4A10 confused … ?A27 3 potential … ?

Page 18: Mass Loss from Galactic Bulge AGB stars€¦ · Solar neigh. Schulteis et al. 2003 . Mass Loss rate from IR Schulteis et al. 2003 . SMA project: • Use SMA to spatially filter the

Future Prospects

•  Continue this galactic bulge project to collect larger numbers and statistics

•  This project demonstrates an approach that could be used for LMC and SMC AGB samples, but with ALMA