APEX-CHAMP+ high-J CO observations of low-mass young stellar objects. III. NGC 1333 IRAS 4A/4B envelope, outflow, and ultraviolet heating
Abstract
Context. The
Aims: The aim is to characterize the warmer parts of the protostellar envelope using the new generation of submillimeter instruments. This will allow us to quantify the feedback of the protostars on their surroundings in terms of shocks, ultraviolet (UV) heating, photodissociation, and outflow dispersal.
Methods: The dual frequency 2 × 7 pixel 650/850 GHz array receiver CHAMP+ mounted on APEX was used to obtain a fully sampled, large-scale ~4' × 4' map at 9″ resolution of the
Results: Broad CO emission-line profiles trace entrained shocked gas along the outflow walls, which have an average temperature of ~100 K. At other positions surrounding the outflow and the protostar, the 6-5 line profiles are narrow indicating UV excitation. The narrow 13CO 6-5 data directly reveal the UV heated gas distribution for the first time. The amount of UV-photon-heated gas and outflowing gas are quantified from the combined 12CO and 13CO 6-5 maps and found to be comparable within a 20″ radius around
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 2012
- DOI:
- 10.1051/0004-6361/201118368
- arXiv:
- arXiv:1203.2965
- Bibcode:
- 2012A&A...542A..86Y
- Keywords:
-
- astrochemistry;
- stars: formation;
- stars: pre-main sequence;
- ISM: individual objects:NGC 1333 IRAS 4A;
- ISM: individual objects:NGC 1333 IRAS 4B;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 20 pages, 22 figures, Accepted by A&