Protoplanetary Disks around Sun-like Stars Appear to Live Longer When the Metallicity is Low

Bibliographic Details
Title: Protoplanetary Disks around Sun-like Stars Appear to Live Longer When the Metallicity is Low
Authors: Guido De Marchi, Giovanna Giardino, Katia Biazzo, Nino Panagia, Elena Sabbi, Tracy L. Beck, Massimo Robberto, Peter Zeidler, Olivia C. Jones, Margaret Meixner, Katja Fahrion, Nolan Habel, Conor Nally, Alec S. Hirschauer, David R. Soderblom, Omnarayani Nayak, Laura Lenkić, Ciaran Rogers, Bernhard Brandl, Charles D. Keyes
Source: The Astrophysical Journal, Vol 977, Iss 2, p 214 (2024)
Publisher Information: IOP Publishing, 2024.
Publication Year: 2024
Collection: LCC:Astrophysics
Subject Terms: Star formation, Pre-main sequence stars, Stellar accretion, Young star clusters, Small Magellanic Cloud, Spectroscopy, Astrophysics, QB460-466
More Details: Previous Hubble Space Telescope observations of the star-forming cluster NGC 346 in the Small Magellanic Cloud (SMC) revealed a large population of pre-main-sequence (PMS) candidates, characterized by H α excess emission in their photometry. However, without access to spectroscopy, the nature of these objects remained unclear. Using the NIRSpec instrument on board JWST, we studied a sample of these stars, with masses in the range of ∼0.9−1.8 M _⊙ , effective temperatures ( T _eff ) in the range of 4500−8000 K, and PMS ages between ∼0.1 and 30 Myr. Here, we present the first spectra of solar-mass PMS stars in the metal-poor SMC ( Z = 1/8 Z _⊙ ) and discuss the physical properties of 10 representative sources with good signal-to-noise ratio. The observations indicate that even the oldest of these PMS candidates are still accreting gas with typical rates of ∼10 ^−8 M _⊙ yr ^−1 for stars older than ∼10 Myr, confirming their PMS nature. The spectra also reveal near-infrared excess and molecular hydrogen excitation lines consistent with the presence of disks around these stars. These findings suggest that in a low-metallicity environment, circumstellar disks can live longer than previously thought.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1538-4357
Relation: https://doaj.org/toc/1538-4357
DOI: 10.3847/1538-4357/ad7a63
Access URL: https://doaj.org/article/3dcf234b96b5490fa54f83cb3181afc4
Accession Number: edsdoj.3dcf234b96b5490fa54f83cb3181afc4
Database: Directory of Open Access Journals
More Details
ISSN:15384357
DOI:10.3847/1538-4357/ad7a63
Published in:The Astrophysical Journal
Language:English