Oral Presentation
Exploring the ISM near and far with the SMA
Presenter: Charles Law (Center for Astrophysics | Harvard & Smithsonian)
The SMA has enabled sensitive studies of the ISM across a wide range of physical scales and in diverse types of sources from circumstellar disks to high-mass star-forming regions and even in nearby galaxies. Here, we report on several recent SMA studies probing the molecular gas and dust content in such sources. Continuum observations in the form of a pilot survey of protoplanetary disks in the densely-clustered Serpens star-forming region found no evidence of diminished dust disk masses relative to those in the similarly-aged but lower density Taurus region. These observations provide important constraints on disk dispersal mechanisms, dissipation timescales, and the frequency and strength of disk tidal interactions in dense star-forming regions. On larger scales, observations of CO 2-1 line emission throughout the interacting galaxy NGC 3627 allowed us to connect the small-scale physics of the ISM and star formation to galaxy-wide processes that drive galactic evolution. In particular, we constrained gas excitation conditions and hydrogen number density at molecular-cloud scales across the entire galaxy and identified an intriguing but tentative correlation between star formation efficiency and kinetic gas temperature. Utilizing the SMA’s expanded bandwidth, we present new high-spatial and spectral resolution observations of a sample of ultra compact H II regions, offering a window into the chemical and kinematic complexity of massive star formation. In combination with on-going complementary ALMA programs, these observations are crucial in furthering our understanding of the physics and chemistry of the star and planet formation process.
asiaa.sinica.edu.tw