Massive star formation occurs in Giant Molecular Clouds (GMCs); an understanding of the evolution of GMCs is a prerequisite to develop theories of star formation and galaxy evolution. We report the highest-fidelity observations of the grand-design spiral galaxy M51 in carbon monoxide (CO) emission, revealing the evolution of GMCs vis-a-vis the large-scale galactic structure and dynamics. The most massive GMCs (Giant Molecular Associations -GMAs) are first assembled and then broken up as the gas flow through the spiral arms. The GMAs and their H 2 molecules are not fully dissociated into atomic gas as predicted in stellar feedback scenarios, but are fragmented into smaller GMCs upon leaving the spiral arms. The remnants of GMAs are detected as the chains of GMCs that emerge from the spiral arms into interarm regions. The kinematic shear within the spiral arms is sufficient to unbind the GMAs against self-gravity. We conclude that the evolution of GMCs is driven by largescale galactic dynamics -their coagulation into GMAs is due to spiral arm streaming motions upon entering the arms, followed by fragmentation due to shear as they leave the arms on the downstream side. In M51, the majority of the gas remains molecular from arm entry through the inter-arm region and into the next spiral arm passage.

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Context. Identifying the most likely sources for high-energy neutrino emission has been one of the main topics in high-energy astrophysics ever since the first observation of high-energy neutrinos by the IceCube Neutrino Observatory. Active galactic nuclei with relativistic jets, blazars, have been considered to be one of the main candidates due to their ability to accelerate particles to high energies.Aims. We study the connection between radio emission and IceCube neutrino events using data from the Owens Valley Radio Observatory and Metsähovi Radio Observatory blazar monitoring programs. Methods. We identify sources in our radio monitoring sample, which are positionally consistent with IceCube high-energy neutrino events. We estimate their mean flux density and variability amplitudes around the neutrino arrival time, and compare these with values from random samples to establish the significance of our results. Results. We find radio source associations within our samples with 16 high-energy neutrino events detected by IceCube. Nearly half of the associated sources are not detected in the γ-ray energies, but their radio variability properties and Doppler boosting factors are similar to the γ-ray detected objects in our sample so that they could still be potential neutrino emitters. We find that the number of strongly flaring objects in our samples is unlikely to occur due to a random coincidence (at 2σ level), and in the case of OVRO samples, the sample of associated sources is on average at an active state compared to random samples. Conclusions. Based on our results we conclude that although it is clear that not all neutrino events are associated with strong radio flaring blazars, when we see large amplitude radio flares in a blazar at the same time as a neutrino event, it is unlikely to happen by random coincidence.

We present resolved images of the dust continuum emission from the debris disk around the young (80-200 Myr) solar-type star HD 107146 with CARMA at λ1.3 mm and the CSO at λ350 µm. Both images show that the dust emission extends over an ∼10 diameter region. The high resolution (3 ) CARMA image further reveals that the dust is distributed in a partial ring with significant decrease in flux inward of 97 AU. Two prominent emission peaks appear within the ring separated by ∼140 • in position angle. The morphology of the dust emission is suggestive of dust captured into a mean motion resonance, which would imply the presence of a planet at an orbital radius of ∼45-75 AU.

We report the detection of CO(2r1) emission from the ultraluminous infrared galaxy (ULIRG) GOODS z p 1.2 J123634.53ϩ621241.3 (also known as the submillimeter galaxy GN 26). These observations represent the first discovery of high-redshift CO emission using the new Combined Array for Research in Millimeter-Wave Astronomy (CARMA). Of all high-redshift ( ) galaxies within the GOODS-North field, this source has the z 1 1 largest far-infrared (FIR) flux observed in the Spitzer 70 and 160 mm bands. The CO redshift confirms the optical identification of the source, and the bright CO(2r1) line suggests the presence of a large molecular gas reservoir of about . The infrared-to-CO luminosity ratio ofis slightly smaller than the average ratio found in local ULIRGs and high-redshift submillimeter galaxies. The short star formation timescale of about 70 Myr is consistent with a starburst associated with the merger event and is much shorter than the timescales for spiral galaxies and estimates made for high-redshift galaxies selected on the basis of their and colors. B Ϫ z zϪ K