IPA: Class 0 Protostars Viewed in CO Emission Using JWST
Abstract We investigate the bright CO fundamental emission in the central regions of five protostars in their primary mass assembly phase using new observations from JWST’s Near-Infrared Spectrograph and Mid-Infrared Instrument. CO line emission images and fluxes are extracted for a forest of ∼150 rovibrational transitions from two vibrational bands, v = 1−0 and v = 2−1. However, 13 CO is undetected, indicating that 12 CO emission is optically thin. We use H 2 emission lines to correct fluxes for extinction and then construct rotation diagrams for the CO lines with the highest spectral resolution and sensitivity to estimate rotational temperatures and numbers of CO molecules. Two distinct rotational temperature components are required for v = 1 (∼600 to 1000 K and 2000 to ∼10 4 K), while one hotter component is required for v = 2 (≳3500 K). 13 CO is depleted compared to the abundances found in the interstellar medium, indicating selective UV photodissociation of 13 CO; therefore, UV radiative pumping may explain the higher rotational temperatures in v = 2. The average vibrational temperature is ∼1000 K for our sources and is similar to the lowest rotational temperature components. Using the measured rotational and vibrational temperatures to infer a total number of CO molecules, we find that the total gas masses range from lower limits of ∼10 22 g for the lowest mass protostars to ∼10 26 g for the highest mass protostars. Our gas mass lower limits are compatible with those in more evolved systems, which suggest the lowest rotational temperature component comes from the inner disk, scattered into our line of sight, but we also cannot exclude the contribution to the CO emission from disk winds for higher mass targets.
Authors
- Pooneh Nazari (ORCID: https://orcid.org/0000-0002-4448-3871)
- John Tobin (ORCID: https://orcid.org/0000-0002-6195-0152)
- Joel D. Green (ORCID: https://orcid.org/0000-0003-1665-5709)
- Robert Gutermuth (ORCID: https://orcid.org/0000-0002-6447-899X)
- Samuel Federman (ORCID: https://orcid.org/0000-0002-6136-5578)
- P. Manoj (ORCID: https://orcid.org/0000-0002-3530-304X)
- S. J. Wolk (ORCID: https://orcid.org/0000-0002-0826-9261)
- A. Caratti o Garatti (ORCID: https://orcid.org/0000-0001-8876-6614)
- H. Linz (ORCID: https://orcid.org/0000-0002-8115-8437)
- Nashanty G. C. Brunken (ORCID: https://orcid.org/0000-0001-7826-7934)
- Tyler L. Bourke (ORCID: https://orcid.org/0000-0001-7491-0048)
- Thomas Stanke (ORCID: https://orcid.org/0000-0002-5812-9232)
- S. T. Megeath (ORCID: https://orcid.org/0000-0001-7629-3573)
- Pamela Klaassen (ORCID: https://orcid.org/0000-0001-9443-0463)
- Yao-Lun Yang (ORCID: https://orcid.org/0000-0001-8227-2816)
- Mayank Narang (ORCID: https://orcid.org/0000-0002-0554-1151)
- Adam E. Rubinstein (ORCID: https://orcid.org/0000-0001-8790-9484)
- E. F. van Dishoeck (ORCID: https://orcid.org/0000-0001-7591-1907)
- Lee Hartmann (ORCID: https://orcid.org/0000-0003-1430-8519)
- Leslie W. Looney (ORCID: https://orcid.org/0000-0002-4540-6587)
- D. M. Watson (ORCID: https://orcid.org/0000-0001-8302-0530)
- H. Beuther (ORCID: https://orcid.org/0000-0002-1700-090X)
- W. R. M. Rocha (ORCID: https://orcid.org/0000-0001-6144-4113)
- K. Slavicinska (ORCID: https://orcid.org/0000-0002-7433-1035)
- Neal J. Evans (ORCID: https://orcid.org/0000-0001-5175-1777)
- Himanshu Tyagi (ORCID: https://orcid.org/0000-0002-9497-8856)
- James Muzerolle
Institutions
- Tata Institute of Fundamental Research (IN)
- Leiden University (NL)
- Space Telescope Science Institute (US)
- Dublin Institute For Advanced Studies (IE)
- Institute of Astronomy and Astrophysics, Academia Sinica (TW)
- European Southern Observatory (DE)
- University of Illinois Urbana-Champaign (US)
- University of Massachusetts Amherst (US)
- National Radio Astronomy Observatory (US)
- University of Michigan (US)
- Max Planck Institute for Extraterrestrial Physics (DE)
- Royal Observatory (GB)
- SKA Observatory (GB)
- Max Planck Institute for Astronomy (DE)
- RIKEN (JP)
- Center for Astrophysics Harvard & Smithsonian (US)
- UK Astronomy Technology Centre (GB)
- University of Rochester (US)
- Friedrich Schiller University Jena (DE)
- The University of Texas at Austin (US)
- University of Toledo (US)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-10-01
- DOI
- https://doi.org/10.3847/1538-4357/ad6b92
- Citations
- 14
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 4.64
Funders
- National Aeronautics and Space Administration
- Space Telescope Science Institute
- National Research Foundation
- Danmarks Grundforskningsfond
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek
- National Institute of Standards and Technology