New results on the giant dark silhouette disk dd in the Orion Nebula. Anna Miotello Massimo Robberto August 12 th, 2011 Physics Graduated in Physics at University of Milan, Italy (2011) Astrophysics Doing Master’s degree in Astrophysics at University of Milan, Italy Anna Miotello

Anno accademico Anna Miotello NASA, ESA, M. Robberto (STScI/ESA), HST Orion Treasury Project Team.

Anna Miotello August 12 th, 2011 Massimo Robberto (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 12 th, 2011 Massimo Robberto HST images WFPC2 ACS F435WF555W F775WF658N F820LP F336W 1000AU N W U Hα V Bz I

Anna Miotello August 12 th, 2011 Massimo Robberto 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 AU ★ Anna Miotello August 12 th, 2011 Massimo Robberto i.Disk Structure F658N – F850LP

Anna Miotello August 12 th, 2011 Massimo Robberto ii in its Environment ~ 0.01 pc ~ 0.03 pc EUV flux from θ 1 C

Anna Miotello August 12 th, 2011 Massimo Robberto ii in its Environment (Bally et al. 2000)

Anna Miotello August 12 th, 2011 Massimo Robberto Photoevaporation 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 ~ K o Are not absorbed by atomic hydrogen and easily penetrate to the disk surface FUV Even in the core of the Trapezium Cluster, disk photoevaporation is normally supported by FUV photons (Johnstone et al )

Anna Miotello August 12 th, 2011 Massimo Robberto 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 12 th, 2011 Massimo Robberto 49 X pixel Y pixel

Anna Miotello August 12 th, 2011 Massimo Robberto 49 X pixel Y pixel Pixel Mean Radius Refraction index Pixel [49:93] : a = 0.20 μm m = i0.01 Pixel [49:92] : a = 0.21 μm m = i0.01 Pixel [49:91] : a = 0.36 μm m = i0.01 Pixel [49:90] : a = 0.42 μm m = i0.01 Pixel [49:89] : a = 0.44 μm m = i0.01 Pixel [49:88] : a = 0.48 μm m = i0.01 Pixel [49:87] : a = 0.53 μm m = i0.01 Pixel [49:86] : a = 0.51 μm m = i0.01 Pixel [49:85] : a = 0.53 μm m = i0.01 Pixel [49:84] : a = 0.55 μm m = i0.01 Pixel [49:83] : a = 0.58 μm m = i0.01 Pixel [49:82] : a = 0.59 μm m = i0.01 Pixel [49:81] : a = 0.60 μm m = i0.01 Pixel [49:80] : a = 0.60 μm m = i0.01

Anna Miotello August 12 th, 2011 Massimo Robberto Mass 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 12 th, 2011 Massimo Robberto

Ancillary slides August 12 th, 2011

Sections Anna Miotello August 12 th, 2011 Massimo Robberto  Geometry of the disk  Dust particles sizing  Results and Comments  Observations  Conclusions

Anna Miotello August 12 th, 2011 Massimo Robberto o The largest in ON: D ~ 1000AU. (McCaughrean et al. 1998) o Undetected central star: A v ≥ 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 12 th, 2011 Massimo Robberto i.Disk Structure Tail

Anna Miotello August 12 th, 2011 Massimo Robberto Extinction curve Q ext x Radius of the spherical particle n = 1.3

Anna Miotello August 12 th, 2011 Massimo Robberto Extinction curve Q ext x Radius of the spherical particle Observational data : Q max

Anna Miotello August 12 th, 2011 Massimo Robberto

A nna M iotello Physics Graduated in Physics at University of Milan, Italy (2011) Astrophysics Doing Master’s degree in Astrophysics at University of Milan, Italy Working on protoplanetary disk protoplanetary disk in the Orion Nebula with Dr. Massimo Robberto (SASP STScI)

Anna Miotello August 12 th, 2011 Massimo Robberto

Anna Miotello August 12 th, 2011 Massimo Robberto

Anna Miotello August 12 th, 2011 Massimo Robberto