A Molecular Inventory of the L1489 IRS Protoplanetary Disk Michiel R. Hogerheijde Christian Brinch...
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Transcript of A Molecular Inventory of the L1489 IRS Protoplanetary Disk Michiel R. Hogerheijde Christian Brinch...
A Molecular Inventory of A Molecular Inventory of the L1489 IRS the L1489 IRS
Protoplanetary DiskProtoplanetary DiskMichiel R. Hogerheijde
Christian BrinchLeiden ObservatoryJes K. Joergensen
CfA
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Origin of Protoplanetary Origin of Protoplanetary DisksDisks
It’s the angular momentum, stupid
Initial distribution of angular momentum– E.g., Goodman et al. 1998; Ohashi et al. 1997; Belloche et al. 2002
Redistribution during collapseFormation of a viscous disk– Mass, size, evolution with time, accretion shock– E.g., Stahler 1994; Velusamy et al. 2002
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
L1489 IRS: A Transitional L1489 IRS: A Transitional Object?Object?
Compact dust continuum– 2000 AU radius– Density: radial power
law with slope 1.8–2.1
– Mass 0.01–0.02 M
– Hogerheijde & Sandell 2000; Joergensen et al. 2002
Neighboring prestellar core
SCUBA 850 and 450 µmobservations from Hogerheijde
& Sandell (2000)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
L1489 IRS: A Transitional L1489 IRS: A Transitional Object?Object?
Single-dish HCO+ lines– infall
Interferometer HCO+ image– Rotation
Hogerheijde (2001)
CO 4.5 µm absorption lines– Inward motions continue
to within 0.1 AU from star
Boogert et al. (2002)
Hogerh
eijd
e
(20
01
)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
L1489 IRS: A Transitional L1489 IRS: A Transitional Object?Object?
Single-dish HCO+ lines– infall
Interferometer HCO+ image– Rotation
Hogerheijde (2001)
CO 4.5 µm absorption lines– Inward motions continue
to within 0.1 AU from star
Boogert et al. (2002)
Hogerh
eijd
e
(20
01
)
HCO+ 3–2 @ 1.1mmBIMA 2000
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
L1489 IRS: A Transitional L1489 IRS: A Transitional Object?Object?
NICMOS scattered light suggests flared disk– Padgett et al. (1998)
Simple model– Flared disk– 10% infall, 90% rotation– Hogerheijde (2001)
Transitional, short-lived (2x104 yr) stage between embedded and T Tauri phase?
NICMOS image from Padgett et al.
(1998)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Molecular Line SurveyMolecular Line SurveySingle-dish molecular line measurements– JCMT, IRAM 30m, and Onsala 20m: 14”–38” = 2000–5500
AU– C17O 1–0, 2–1, 3–2– C18O 1–0, 2–1, 3–2– CS 2–1, 5–4, 7–6– C34S 2–1, 5–4– HCO+ 1–0, 3–2, 4–3– H13CO+ 1–0, 3–2– CN 1–0, 3–2– HCN 1–0, 4–3– H13CN 1–0– HNC 4–3
Aims– More realistic model– Chemical inventory
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Modeling ApproachModeling Approach
Physical model: density– Flattened Plummer sphere
• Consistent with SCUBA data
• p=1.8 (Joergensen et al. 2002)
Brinch, Hogerheijde, & Joergensen (in prep)
(Joergensen et al. 2002)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Modeling ApproachModeling Approach
Physical model: density– Flattened Plummer sphere
• Consistent with SCUBA data
• p=1.8 (Joergensen et al. 2002)
• f>0
Brinch, Hogerheijde, & Joergensen (in prep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Modeling ApproachModeling Approach
Velocity field– Rotation V √M* r-0.5
– Infall Vr √M* r-0.5
Parameterize V-field by– |V|√M* r-0.5
– tg()=Vr/V
Brinch, Hogerheijde, & Joergensen (in prep)
V
V
Vr
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Modeling ApproachModeling Approach2 minimization of synthetic single-dish spectra– Gridded physical model + (constant) abundances– Molecular excitation using Monte Carlo approach– Synthetic spectra, convolved to appropriate resolution
4+n free parameters– Flattening parameter f– Inclination i– Stellar mass M*
– Velocity field direction angle – Molecular Abundances Xi
Brinch, Hogerheijde, & Joergensen (in prep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
ResultsResultsB
rinch
, H
ogerh
eijd
e, &
Joerg
ense
n (
in p
rep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
ResultsResultsB
rinch
, H
ogerh
eijd
e, &
Joerg
ense
n (
in p
rep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
ResultsResultsB
rinch
, H
ogerh
eijd
e, &
Joerg
ense
n (
in p
rep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
ResultsResults
Preliminary values– Stellar mass 1.1 M
– Flattening parameter f=3.0• Equivalent with h/R=0.35
– Inclination 70˚– Velocity field angle =18˚
• Inspiral time approximately 105 yr• Significant fraction of embedded life time
Brinch, Hogerheijde, & Joergensen (in prep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
ResultsResultsAbundances– C18O 4x10-7 (-> 12CO 2x10-4 no depletion)– CS 8x10-9
– SO 8x10-9
– H2CO 1x10-9
– HCO+ 4x10-8
– HCN 4x10-9
– HNC 2x10-9
– CN 2x10-9
Dark cloud values; little depletion; HCO+
increased?Brinch, Hogerheijde, & Joergensen (in prep)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
HCOHCO++ 1–0 Interferometry 1–0 InterferometryObservations Model Prediction
Brinch, Hogerheijde, & Joergensen (in prep)
Surrounding
Surrounding
cloud materia
l
cloud materia
l
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Enhanced-SMA Enhanced-SMA PredictionsPredictions
SMA
CSOJCMT
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
Enhanced-SMA Enhanced-SMA PredictionsPredictions
Brinch, Hogerheijde, & Joergensen (in prep)
HCO+ 4–3 at 0.3” (40 AU)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
A break in the V-field at 300 A break in the V-field at 300 AUAU
Brinch, Hogerheijde, & Joergensen (in prep)
HCO+ 4–3 at 0.3” (40 AU)
Submillimeter Astronomy in the Era of the SMA • June 13–16 2005 • Cambridge MA
ConclusionConclusion
L1489 IRS– Disklike rotating and infalling structure– Lifetime 105 yr, significant fraction of embedded
phase– Chemical abundances
• No evidence for depletion• HCO+ enhanced
Further high-resolution observations with, e.g., enhanced-SMA– Breaks in the velocity field on scales of T Tauri disks– Changes in the chemistry on scales of T Tauri disks