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C. A. Pantoja

Publications and source records attributed to C. A. Pantoja.

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A Study of HH 270 with the James Webb Space Telescope

We present a study of the Herbig-Haro object HH 270 based on observations from the James Webb Space Telescope (JWST), Subaru Telescope, and Atacama Large Millimeter/submillimeter Array (ALMA). High-resolution infrared images of H$_2$ and CO were obtained with the NIRCam instrument (JWST) using the F212N (2.12 $μ$m) and F460M (4.60 $μ$m) filters, revealing a previously unseen collimated protostellar jet closer to the source, in addition to the very well defined bipolar cavities carved by the outflow. Newly identified knots associated with the jet were also detected. Ground-based optical images in the H$α$ (660 nm) emission line, alongside millimeter spectral observations of the (2-1) transition of $^{12}$CO, $^{13}$CO, and C$^{18}$O, further enrich the analysis. The Subaru images show a connection between the optical outflow in H$α$ and the protostellar jet observed in the infrared. ALMA CO observations trace the kinematics of the entrained molecular gas in the protostellar outflow and reveal the dense, slow-moving material distributed around the driving source, HH270VLA1. These multi-wavelength observations show evidence of the interaction between the shock-excited jet emission and the molecular outflow seen at optical, infrared and radio wavelengths, which provides a detailed view of the complex structure and dynamics of HH 270.

astro-ph.SR

HH 270/110 as a jet/shear layer interaction

New observations obtained with JWST of the proto-stellar HH~270 jet and the "deflected" HH 110 system, show that HH 110 has a morphology of a series of distorted working surfaces. These working surfaces appear to be "deflected versions" of the heads of the incident, HH 270 jet. We compute a series of 3D numerical simulations, in which we explore the possible parameters of a shearing environment that could give origin to the deflection of HH 270 into the HH 110 flow. We find that we need a quite high sideways velocity for the streaming environment (of ~30km/s) in order to produce the complex structure observed in HH 110. This high velocity would be possible in an environment which has been strongly perturbed by the passage of other outflows.

astro-ph.SR

The Future Of The Arecibo Observatory: The Next Generation Arecibo Telescope

The Arecibo Observatory (AO) is a multidisciplinary research and education facility that is recognized worldwide as a leading facility in astronomy, planetary, and atmospheric and space sciences. AO's cornerstone research instrument was the 305-m William E. Gordon telescope. On December 1, 2020, the 305-m telescope collapsed and was irreparably damaged. In the three weeks following the collapse, AO's scientific and engineering staff and the AO users community initiated extensive discussions on the future of the observatory. The community is in overwhelming agreement that there is a need to build an enhanced, next-generation radar-radio telescope at the AO site. From these discussions, we established the set of science requirements the new facility should enable. These requirements can be summarized briefly as: 5 MW of continuous wave transmitter power at 2 - 6 GHz, 10 MW of peak transmitter power at 430 MHz (also at 220MHz under consideration), zenith angle coverage 0 to 48 deg, frequency coverage 0.2 to 30 GHz and increased Field-of-View. These requirements determine the unique specifications of the proposed new instrument. The telescope design concept we suggest consists of a compact array of fixed dishes on a tiltable, plate-like structure with a collecting area equivalent to a 300m dish. This concept, referred to as the Next Generation Arecibo Telescope (NGAT), meets all of the desired specifications and provides significant new science capabilities to all three research groups at AO. This whitepaper presents a sample of the wide variety of the science that can be achieved with the NGAT, the details of the telescope design concept and the need for the new telescope to be located at the AO site. We also discuss other AO science activities that interlock with the NGAT in the white paper.

astro-ph.IM