Starless clumps and the earliest phases of high-mass star formation in the Milky Way
Brian Svoboda, NRAO Jansky Fellow
High-mass stars are key to regulating the interstellar medium, star formation activity, and overall evolution of galaxies, but their formation remains an open problem in astrophysics. In order to understand the physical conditions during the earliest phases of high-mass star formation, I will present observational studies we have carried out on dense starless clump candidates (SCCs) that show no signatures of star formation activity. We identify 2223 SCCs from the 1.1 mm Bolocam Galactic Plane Survey, systematically analyse their physical properties, and show that the starless phase is not represented by a single timescale, but evolves more rapidly with increasing clump mass. To investigate the sub-structure in SCCs at high spatial resolution, we investigate the 12 most high-mass SCCs within 5 kpc using ALMA. We find previously undetected low-luminosity protostars in 11 out of 12 SCCs, fragmentation equal to the thermal Jeans length of the clump, and no starless cores exceeding 30 solar masses. While uncertainties remain concerning the star formation efficiency in this sample, these observational facts are consistent with models where high-mass stars form from initially low- to intermediate-mass protostars that accrete most of their mass from the surrounding clump. I will also present on-going research studying gas inflow signatures with GBT/Argus and ALMA, and the dense core mass function with the JVLA.
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Revealing reionization with the thermal history of the intergalactic medium
Elisa Boera, SISSA Trieste
The NMSU Department of Astronomy will host a virtual online open house from the Tortugas (A) Mountain Observatory Monday, Dec. 21. This will coincide with a rare conjunction of Jupiter and Saturn, an event when the two planets will be as close together in the sky as they have been for hundreds of years. The virtual event will be held via Zoom videoconferencing and will include a short virtual tour of the recently refurbished Tortugas Mountain Observatory, followed by some remote imaging of Jupiter and Saturn, weather permitting, as well as a short presentation about connection with research on these gas giant planets.
The online event will start at 4:30 p.m. and last until around 6 p.m. Participants will need to download Zoom before joining.
Zoom link: https://nmsu.zoom.us/j/94370800438
However, a password will be required to join the meeting. To receive the password, email firstname.lastname@example.org and we will send you the password before the event. For more information, contact Jon Holtzman at 575-646-4438.