Purpose of the Program

The Orion Molecular cloud was mapped in [CII] using the upGREAT Low Frequency Array. The final map covers approximately one square degree and comprises over two million individual spectra.

Principal Investigator

Xander Tielens (Leiden Observatory and University of Maryland)

Proposal ID and Data Access

04_0066

Proposal Abstract

In this Impact Program, we propose to map the [CII] 158 micron fine-structure line associated with the Orion Molecular cloud over a region ~0.6 sq degrees. The [CII] 158 micron line dominates the cooling of low density (<10^4 cm-3) and low UV field (<10^4 Habings) photodissociation regions (PDRs) and is the dominant emission line in the IR spectrum of galaxies. This line is widely used to determine the physical conditions in PDRs and as a tracer of star formation in nearby normal and starburst galaxies. With the advent of ALMA, the use of this line as a measure of the star formation rate is now routinely extended to the high redshift universe. Yet, the validity of these methods is not well established observationally and theoretical not well understood. The high sensitivity of the multi-beam upGREAT instrument coupled with rapid mapping techniques enabled by the nimble SOFIA observatory allow us to map in 75 hours an area of more than 20 times larger than HIFI/Herschel. We will compare the [CII] line profiles with those of our CO J=2-1 map over the same region to determine the molecular cloud components contributing to the emission and with existing Herschel and Spitzer far- and mid-IR maps. The measured CII/CO, CII/IR, and CII/PAH emission will allow us to quantitatively determine the relationship of these different emission components. This will allow us to determine the use of the [CII] line as a star formation rate indicator, measure the amount of molecular cloud mass not measured by CO (so-called "CO-dark" gas), semi-empirically determine the photo-electric heating efficiency over a wide range in incident UV fields. We will make available fully reduced, velocity resolved, [CII] 158 micron maps.


The 78 tiles indicated were used to construct the Orion A [C II] map. The yellow contours correspond to an approximated far-ultraviolet radiation field of G0 = 50 (in Habing units). The color of each tile indicates its corresponding OFF position: blue tiles use the COFF-SE1 position, red tiles use COFF-OFF1 and green tiles use COFF-C. Each square tile has a side length of 436 arcsec. The black box at the center indicates the region mapped by the single-pixel Herschel/HIFI instrument in 9 h55. The total observing time for the SOFIA/upGREAT map was 42 h. (from Pabst et al 2019 supplementary material). Click on image for a larger version.

Publications

Ü. Kavak, J. Bally, J. R. Goicoechea, C. H. M. Pabst, F. F. S. van der Tak, and A. G. G. M. Tielens, Dents in the Veil: protostellar feedback in Orion. Astronomy and Astrophysics 663, A117 (2022).

Ü. Kavak, J. R. Goicoechea, C. H. M. Pabst, J. Bally, F. F. S. van der Tak, and A. G. G. M. Tielens, Breaking Orion's Veil with fossil outflows. Astronomy and Astrophysics 660, A109 (2022).

C. H. M. Pabst, J. R. Goicoechea, A. Hacar, D. Teyssier, O. Berné, M. G. Wolfire, R. D. Higgins, E. T. Chambers, S. Kabanovic, R. Güsten, J. Stutzki, C. Kramer, and A. G. G. M. Tielens, [C II] 158 μm line emission from Orion A. II. Photodissociation region physics. Astronomy and Astrophysics 658, A98 (2022).

S. T. Megeath, R. A. Gutermuth, and M. A. Kounkel, Low Mass Stars as Tracers of Star and Cluster Formation. Publications of the Astronomical Society of the Pacific 134, 042001 (2022).

R. Higgins, S. Kabanovic, C. Pabst, D. Teyssier, J. R. Goicoechea, O. Berne, E. Chambers, M. Wolfire, S. T. Suri, C. Buchbender, Y. Okada, M. Mertens, A. Parikka, R. Aladro, H. Richter, R. Güsten, J. Stutzki, and A. G. G. M. Tielens, Observation and calibration strategies for large-scale multi-beam velocity-resolved mapping of the [CII] emission in the Orion molecular cloud. Astronomy and Astrophysics 652, A77 (2021).

C. H. M. Pabst, A. Hacar, J. R. Goicoechea, D. Teyssier, O. Berné, M. G. Wolfire, R. D. Higgins, E. T. Chambers, S. Kabanovic, R. Güsten, J. Stutzki, C. Kramer, and A. G. G. M. Tielens, [C II] 158 μm line emission from Orion A I. A template for extragalactic studies?. Astronomy and Astrophysics 651, A111 (2021).

R. Higgins, S. Kabanovic, C. Pabst, D. Teyssier, J. R. Goicoechea, O. Berne, E. Chambers, M. Wolfire, S. T. Suri, C. Buchbender, Y. Okada, M. Mertens, A. Parikka, R. Aladro, H. Richter, R. Guesten, J. Stutzki, and A. G. G. M. Tielens, VizieR Online Data Catalog: Large scale [CII] emission from the OMC (Higgins+, 2021). VizieR Online Data Catalog J/A+A/652/A77 (2021).

W. Lim, F. Nakamura, B. Wu, T. G. Bisbas, J. C. Tan, E. Chambers, J. Bally, S. Kong, P. McGehee, D. C. Lis, V. Ossenkopf-Okada, and Á. Sánchez-Monge, Star cluster formation in Orion A. Publications of the Astronomical Society of Japan 73, S239-S255 (2021).

J. R. Goicoechea, C. H. M. Pabst, S. Kabanovic, M. G. Santa-Maria, N. Marcelino, A. G. G. M. Tielens, A. Hacar, O. Berné, C. Buchbender, S. Cuadrado, R. Higgins, C. Kramer, J. Stutzki, S. Suri, D. Teyssier, and M. Wolfire, Molecular globules in the Veil bubble of Orion. IRAM 30 m 12CO, 13CO, and C18O (2-1) expanded maps of Orion A. Astronomy and Astrophysics 639, A1 (2020).

C. H. M. Pabst, J. R. Goicoechea, D. Teyssier, O. Berné, R. D. Higgins, E. T. Chambers, S. Kabanovic, R. Güsten, J. Stutzki, and A. G. G. M. Tielens, Expanding bubbles in Orion A: [C II] observations of M 42, M 43, and NGC 1977. Astronomy and Astrophysics 639, A2 (2020).

C. Pabst, R. Higgins, J. R. Goicoechea, D. Teyssier, O. Berne, E. Chambers, M. Wolfire, S. T. Suri, R. Guesten, J. Stutzki, U. U. Graf, C. Risacher, and A. G. G. M. Tielens, Disruption of the Orion molecular core 1 by wind from the massive star θ 1 Orionis C. Nature 565, 618-621 (2019).