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August 12 th , 2011. A nna M iotello. Graduated in Physics at University of Milan, Italy (2011). New results on the giant dark silhouette disk dd114-426 in the Orion Nebula. miotello@stsci.edu. Doing Master’s degree in Astrophysics at University of Milan, Italy. Anna Miotello - PowerPoint PPT Presentation
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New results on the giant dark silhouette disk dd114-426 in the Orion Nebula.
Anna MiotelloMassimo Robberto
mio
tello
@st
sci.e
du
August 12th, 2011
Graduated in Physics atUniversity of Milan, Italy(2011)
Doing Master’s degree in Astrophysics at University of Milan, Italy
Anna Miotello
Anno accademico 2009-2010Anna Miotello
114-426
NASA, ESA, M. Robberto (STScI/ESA), HST Orion Treasury Project Team.
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Why is 114-426 important ?
(Ricci et al. 2008)The presence of disks with and without evidence of photoevaporation in the same cluster provides a unique opportunity of understanding how environmental factors may affect the path to planet formation.
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto1. Observations
HST images
WFPC2 ACS ACS ACS ACS ACS
F435W F555W F775WF658N F820LPF336W
1000AU
N
W
U HαVB zI
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto2. Geometry i. Disk Structure
Multiple asymmetry Lobe dimensions Lobe positions Stretched disk’s top
ACS
F820LP
~44°
(Atanassiu L. F. D.)
N
W
210 AU
746 AU 1117.8 AU★
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto2. Geometry i. Disk Structure
F658N – F850LP
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto2. Geometry ii. 114-426 in its Environment
~ 0.01 pc
~ 0.03 pc
117-421
121-434
EUV flux from θ1C
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto2. Geometry ii. 114-426 in its Environment
(Bally et al. 2000)
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Photoevaporation
3. Discussion
EUV photons( hν ≥ 13.6 eV )
FUV photons( 6 eV ≤ hν ≤ 13.6 eV )
o Create a PDR at the disk surface with
T ~ 100 ÷ 1000 K
o Are absorbed early on at a IF in the photoevaporated wind that escapes radially, being ionized and heated to T ~ 10 000 K
o Are not absorbed by atomic hydrogen and easily penetrate to the disk surface
Even in the core of the Trapezium Cluster, disk photoevaporation is normally supported by FUV photons (Johnstone et al. 1998 )
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto4. Results
Mass loss (Adams et al. 2004)
o Chemical composition
o FUV flux coming from the Trapezium and scattered by the nebular wall
Observations
~ 1
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo RobbertoParticle sizing
49 X pixel
80
8584838281
86
8887
89
93929190
Y pixel
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo RobbertoParticle sizing
49 X pixel
80
8584838281
86
8887
89
93929190
Y pixel Pixel Mean Radius Refraction index
Pixel [49:93] : a = 0.20 μm m = 1.3 + i0.01Pixel [49:92] : a = 0.21 μm m = 1.3 + i0.01Pixel [49:91] : a = 0.36 μm m = 1.3 + i0.01Pixel [49:90] : a = 0.42 μm m = 1.3 + i0.01Pixel [49:89] : a = 0.44 μm m = 1.3 + i0.01Pixel [49:88] : a = 0.48 μm m = 1.3 + i0.01Pixel [49:87] : a = 0.53 μm m = 1.3 + i0.01Pixel [49:86] : a = 0.51 μm m = 1.3 + i0.01Pixel [49:85] : a = 0.53 μm m = 1.3 + i0.01Pixel [49:84] : a = 0.55 μm m = 1.3 + i0.01Pixel [49:83] : a = 0.58 μm m = 1.3 + i0.01Pixel [49:82] : a = 0.59 μm m = 1.3 + i0.01Pixel [49:81] : a = 0.60 μm m = 1.3 + i0.01Pixel [49:80] : a = 0.60 μm m = 1.3 + i0.01
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto4. ResultsMass loss (Adams et al. 2004)
Disk Mass (McCaughrean et al. 1998; Mann & Williams 2010)
Time scale for the mass loss of the disk
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Ancillary slides
mio
tello
@st
sci.e
du
August 12th, 2011
Sections
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Geometry of the disk
Dust particles sizing
Results and Comments
Observations
Conclusions
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Why is 114-426 important ?
o The largest in ON: D ~ 1000AU. (McCaughrean et al. 1998)
o Undetected central star: Av ≥ 60 mag of extinction. (McCaughrean et al. 1998)
o Estimation for the disk mass:
(McCaughrean et al. 1998; Mann & Williams 2010)
Previous works
o Properties of disk grains: evidence of chromatic extinction and grain growth (1.9 μm ≤ d ≤ 4 μm).(Throop et al. 2001; Shuping et al. 2003)
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto2. Geometry i. Disk Structure
Tail
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto3. Particle sizingExtinction curve
Qext
x
Radius of the spherical particle
n = 1.3
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto3. Particle sizingExtinction curve
Qext
x
Radius of the spherical particle
Observational data :
Qmax
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Anna Miotello
Academic and personal careerGraduated in Physics atUniversity of Milan, Italy(2011)
Doing Master’s degree in Astrophysics at University of Milan, Italy
Working on 114-426 protoplanetary disk in the Orion Nebula with Dr. Massimo Robberto(SASP 2011 - STScI)
mio
tello
@st
sci.e
du
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
Anna Miotello
August 12th, 2011
mio
tello
@st
sci.e
du
Massimo Robberto
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