Star formation at high angular resolution

Abstract The role of the SKA in high resolution observations of the formation of low and high mass stars in the Galaxy is examined. The large collecting area will have a large impact on dynamical studies at high resolution using spectral lines. The SKA will allow dramatic progress in the investigation of the ionised, atomic and molecular phases over a range of evolutionary stages. Attention is focused here on the potential of radio recombination lines, the H I 21 cm line and molecular Zeeman measurements. This combination will unveil the physical processes that drive jets and winds from young stars. Other important areas such as pre-biotic molecules, disc ablation in OB clusters and massive star formation in nearby galaxies are also briefly discussed.

[1]  Philip Crowther,et al.  Hot Star Workshop III: The Earliest Stages of Massive Star Birth , 2002 .

[2]  S. Lumsden,et al.  Molecular and ionized gas motions in the compact H ii region G 29.96-0.02 , 1999, astro-ph/9901196.

[3]  G. Anglada,et al.  The Nature of the Radio Continuum Sources Embedded in the HH 7-11 Region and Its Surroundings , 1999 .

[4]  I. Mirabel,et al.  VLA observations of high-velocity H I associated with the Herbig-Haro objects 7-11 , 1990 .

[5]  H. R. Dickel,et al.  The NGC 7538 IRS 1 region of star formation: Observations of the H66 alpha recombination line with a spatial resolution of 300 AU , 1995 .

[6]  J. Franco,et al.  On the massive star-forming capacity of molecular clouds , 1994 .

[7]  W. Langer,et al.  Measuring the Magnetic Field Strength in L1498 with Zeeman-splitting Observations of CCS , 2001 .

[8]  B. Reipurth,et al.  New VLA Observations of the HH 1-2 Region: Evidence for Density Enhancements Moving along the Axis of the VLA 1 Radio Jet , 2000 .

[9]  T. Henning,et al.  Transport processes and chemical evolution in steady accretion disk flows , 2004 .

[10]  Usa,et al.  OUTFLOW COLLIMATION IN YOUNG STELLAR OBJECTS , 1997, astro-ph/9710255.

[11]  Charles J. Lada,et al.  The Origin of Stars and Planetary Systems , 1999 .

[12]  C. Heiles,et al.  Neutral stellar winds that drive bipolar outflows in low-mass protostars , 1988 .

[13]  R. Pudritz,et al.  Numerical Simulations of Astrophysical Jets from Keplerian Disks. I. Stationary Models , 1997 .

[14]  Astronomy,et al.  MERLIN Radio Detection of an Interaction Zone within a Binary Orion Proplyd System , 2002, astro-ph/0201087.

[15]  W. Goss,et al.  Broad Radio Recombination Lines from Hypercompact H II Regions , 2004 .

[16]  P. Andre',et al.  Submillimeter Continuum Observations of rho Ophiuchi A: The Candidate Protostar VLA 1623 and Prestellar Clumps , 1993 .

[17]  Janet E. Drew,et al.  A radiation-driven disc wind model for massive young stellar objects , 1998 .

[18]  E. Feigelson,et al.  Circularly Polarized Radio Emission from an X-Ray Protostar , 1998 .

[19]  W. Goss,et al.  Broad Recombination Line Objects in W49 North on 600 AU Scales , 2003, astro-ph/0311417.

[20]  K. Johnston,et al.  Simulated Ratio Recombination Line Emission at 1.3 Centimeters toward MWC 349 , 1993 .

[21]  L. Dessart,et al.  Stellar and wind properties of LMC WC4 stars A metallicity dependence for Wolf-Rayet mass-loss rates ? , 2002, astro-ph/0206233.

[22]  C. Lada,et al.  Sequential formation of subgroups in OB associations , 1977 .

[23]  M. Mccaughrean,et al.  Discovery of a Molecular Hydrogen Jet near IC 348 , 1994 .

[24]  J. Drew,et al.  MAPPING THE RADIO EMISSION FROM MASSIVE YOUNG STELLAR OBJECTS , 1994 .

[25]  Compact continuum radio sources in the Orion Nebula , 1987 .

[26]  R. Sorochenko,et al.  Radio Recombination Lines: Their Physics and Astronomical Applications , 2002 .

[27]  Z. Wen,et al.  Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk , 1994 .

[28]  C. Giovanardi,et al.  Very Large Array Observations of High-Velocity H I in L1551 , 2000 .

[29]  D. Jaffe,et al.  Low-Velocity Ionized Winds from Regions around Young O Stars , 1999, astro-ph/9902345.

[30]  T. Ray,et al.  Observations of Shocked H2 and Entrained CO in Outflows from Luminous Young Stars , 1998 .

[31]  Richard M. Crutcher,et al.  Detection of the CN Zeeman Effect in Molecular Clouds , 1999 .

[32]  H. Zinnecker.  Star Formation at High Angular Resolution: Summary and Outlook , 2004 .

[33]  A. Taylor,et al.  Radio emission from the stars and the sun , 1995 .

[34]  B. Reipurth,et al.  Herbig-Haro flows and the birth of low mass stars : proceedings of the 182nd Symposium of the International Astronomical Union, held in Chamonix, France, 20-26 January 1997 , 1997 .

[35]  F. Shu,et al.  Heating and Ionization of X-Winds , 2001, astro-ph/0110539.

[36]  F. Shu,et al.  The Origin of Chondrules and Refractory Inclusions in Chondritic Meteorites , 2001 .

[37]  T. Ray,et al.  Hubble Space Telescope/STIS Spectroscopy of the Optical Outflow from DG Tauri: Indications for Rotation in the Initial Jet Channel* , 2002, astro-ph/0206175.

[38]  W. Welch,et al.  Line broadening in the W3(OH) champagne flow , 1995 .

[39]  N. Evans,et al.  Neutral winds from protostars , 1992 .

[40]  A. Boss,et al.  Protostars and Planets VI , 2000 .

[41]  B. Reipurth,et al.  HH 80-81: A Highly collimated Herbig-Haro complex powered by a massive young star , 1993 .

[42]  G. Garay,et al.  Cepheus A HW2: A powerful thermal radio jet , 1994 .