| 1. |
- Stanke, T., et al.
(författare)
-
The APEX Large CO Heterodyne Orion Legacy Survey (ALCOHOLS): I. Survey overview
- 2022
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 658
-
Tidskriftsartikel (refereegranskat)abstract
- Context. The Orion molecular cloud complex harbours the nearest Giant Molecular Clouds (GMCs) and the nearest site of high-mass star formation. Its young star and protostar populations are thoroughly characterized. The region is therefore a prime target for the study of star formation. Aims. Here, we verify the performance of the SuperCAM 64 pixel heterodyne array on the Atacama Pathfinder Experiment (APEX). We give a descriptive overview of a set of wide-field CO(32) spectral line cubes obtained towards the Orion GMC complex, aimed at characterizing the dynamics and structure of the extended molecular gas in diverse regions of the clouds, ranging from very active sites of clustered star formation in Orion B to comparatively quiet regions in southern Orion A. In a future publication, we will characterize the full population of protostellar outflows and their feedback over an entire GMC. Methods. We present a 2.7 square degree (130 pc2) mapping survey in the 12CO(32) transition, obtained using SuperCAM on APEX at an angular resolution of 19 (7600 AU or 0.037 pc at a distance of 400 pc), covering the main sites of star formation in the Orion B cloud (L 1622, NGC 2071, NGC 2068, Ori B9, NGC 2024, and NGC 2023), and a large patch in the southern part of the L 1641 cloud in Orion A. Results. We describe CO integrated line emission and line moment maps and position-velocity diagrams for all survey fields and discuss a few sub-regions in some detail. Evidence for expanding bubbles is seen with lines splitting into double components, often in areas of optical nebulosities, most prominently in the NGC 2024 H II region, where we argue that the bulk of the molecular gas is in the foreground of the H II region. High CO(32)/CO(10) line ratios reveal warm CO along the western edge of the Orion B cloud in the NGC 2023 & NGC 2024 region facing the IC 434 H II region. We see multiple, well separated radial velocity cloud components towards several fields and propose that L 1641-S consists of a sequence of clouds at increasingly larger distances. We find a small, seemingly spherical cloud, which we term Cow Nebula globule, north of NGC 2071. We confirm that we can trace high velocity line wings out to the extremely high velocity regime in protostellar molecular outflows for the NGC 2071-IR outflow and the NGC 2024 CO jet, and identify the protostellar dust core FIR4 (rather than FIR5) as the true driving source of the NGC 2024 monopolar outflow.
|
|
| 2. |
- Walker, Christopher K., et al.
(författare)
-
Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS): “Following water from galaxies, through protostellar systems, to oceans”
- 2021
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 11820
-
Konferensbidrag (refereegranskat)abstract
- Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS) is a space-based, MIDEX-class mission concept that employs a 17-meter diameter inflatable aperture with cryogenic heterodyne receivers, enabling high sensitivity and high spectral resolution (resolving power >106) observations at terahertz frequencies. OASIS science is targeting submillimeter and far-infrared transitions of H2O and its isotopologues, as well as deuterated molecular hydrogen (HD) and other molecular species from 660 to 80 µm, which are inaccessible to ground-based telescopes due to the opacity of Earth’s atmosphere. OASIS will have >20x the collecting area and ~5x the angular resolution of Herschel, and it complements the shorter wavelength capabilities of the James Webb Space Telescope. With its large collecting area and suite of terahertz heterodyne receivers, OASIS will have the sensitivity to follow the water trail from galaxies to oceans, as well as directly measure gas mass in a wide variety of astrophysical objects from observations of the ground-state HD line. OASIS will operate in a Sun-Earth L1 halo orbit that enables observations of large numbers of galaxies, protoplanetary systems, and solar system objects during the course of its 1-year baseline mission. OASIS embraces an overarching science theme of “following water from galaxies, through protostellar systems, to oceans.” This theme resonates with the NASA Astrophysics Roadmap and the 2010 Astrophysics Decadal Survey, and it is also highly complementary to the proposed Origins Space Telescope’s objectives.
|
|
