The Reservoir of the Per-emb-2 Streamer

• Published in: The Astrophysical journal 2024-04, Vol.965 (2), p.162
• Main Authors: Taniguchi, Kotomi, Pineda, Jaime E., Caselli, Paola, Shimoikura, Tomomi, Friesen, Rachel K., Segura-Cox, Dominique M., Schmiedeke, Anika
• Format: Article
• Language: English
• Subjects: Astrochemistry; Chemical composition; Low mass stars; Low temperature; Planet formation; Protoplanetary disks; Protostars; Radio telescopes; Reservoirs; Star formation; Young stellar objects
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ad2fa1

Streamers bring gas from outer regions to protostellar systems and could change the chemical composition around protostars and protoplanetary disks. We have carried out mapping observations of carbon-chain species (HC 3 N, HC 5 N, CCH, and CCS) in the 3 mm and 7 mm bands toward the streamer flowing to the Class 0 young stellar object (YSO) Per-emb-2 with the Nobeyama 45 m radio telescope. A region with a diameter of ∼0.04 pc is located to the north at a distance of ∼20,500 au from the YSO. The streamer connects to this northern region, which is its origin. The reservoir has high density and low temperature ( n H 2 ≈ 1.9 × 10 4 cm −3 , T kin = 10 K), which are similar to those of early-stage starless cores. By comparison of the observed abundance ratios of CCS/HC 3 N to the chemical simulations, the reservoir and streamer are found to be chemically young. The total mass available for the streamer is derived to be 24–34 M ⊙ . It has been estimated that, if all of the gas in the reservoir were to accrete onto the Per-emb-2 protostellar system, the lifetime of the streamer would be (1.1–3.2) × 10 5 yr, suggesting that the mass accretion via the streamer would continue until the end of the Class I stage.