Deep Hα Imaging Survey of IC 348 with the Hubble Space Telescope: I. Accretion Properties of Stellar and Substellar Objects
Abstract
Accretion governs the growth of young stars and the early evolution of their circumstellar disks, yet population-level measurements of accretion are often hampered by heterogeneous diagnostics and by samples preferentially selected toward disk-bearing or accreting objects. This can impact the mass accretion rate-stellar mass (Ṁ-M⋆) relation, particularly at substellar masses. We present a uniform analysis of accretion in the ∼2 Myr-old star-forming cluster IC 348 based on deep Hubble Space Telescope F656N imaging. Using Hα excess as a single, homogeneous accretion tracer, we derive accretion rates and robust upper limits for 200 cluster members spanning the stellar to substellar mass regime (3 M⊙ to 4 MJup). Accretion is detected in 37±3% of the sample, with fractions of 34±4% among stellar members and 46±6% among substellar objects. For accretors alone, the inferred Ṁ-M⋆ relation is consistent with those measured in similarly aged regions such as Lupus. In contrast, including weak accretors and non-detections increases the scatter and flattens the slope while lowering the intercept, demonstrating the strong influence of the low-accretion tail on population-level accretion relations. For free-floating planetary-mass objects in IC 348, extrapolating the accretors-only fit overpredicts Ṁ by approximately an order of magnitude compared to the fit that includes upper limits, which instead implies mass accretion rates of <10−12 M⊙ yr−1. These results show that sample selection, specifically whether the sample is restricted to disk-bearing or accreting targets, or instead is drawn from a complete membership census, is a dominant factor shaping population-level accretion relations across a wide dynamic range in stellar mass.
Versions
Related
- Extragalactic Multi-Band Exploration of Red Supergiants (EMBERS): Pipeline, Source Classification, and Bolometric Properties of 101,219 Red Supergiants from James Webb Space Telescope Imaging
- 3D simulations of magnetospheric accretion in T Tauri stars I. Disk truncation, stellar torques, and application to observations
- Searching for substellar companion candidates with Gaia. V. M dwarfs within 15 pc studied with absolute astrometry, radial velocities, and direct imaging
- A Simple Miniaturized Stellar Interferometer: Measuring the Angular Diameter of Venus with a Masked Telescope
- The Dyn-Atmo Survey: High-contrast Imaging Spectroscopy of the Substellar Companion HD 13724 B with the JWST NIRSpec IFU
BibTeX
@misc{jiang2026deep,
title = {{Deep H$α$ Imaging Survey of IC 348 with the Hubble Space Telescope: I. Accretion Properties of Stellar and Substellar Objects}},
author = {Lillian Yushu Jiang and Brendan P. Bowler and Yifan Zhou and Adam L. Kraus and Sean M. Andrews and Lynne A. Hillenbrand and Michael J. Ireland and Zhaohuan Zhu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.05620},
eprint = {2609.05620},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.05620},
}
RIS
TY - UNPB
TI - Deep Hα Imaging Survey of IC 348 with the Hubble Space Telescope: I. Accretion Properties of Stellar and Substellar Objects
AU - Lillian Yushu Jiang
AU - Brendan P. Bowler
AU - Yifan Zhou
AU - Adam L. Kraus
AU - Sean M. Andrews
AU - Lynne A. Hillenbrand
AU - Michael J. Ireland
AU - Zhaohuan Zhu
PY - 2026
DA - 2026/09/04
PB - arXiv
DO - 10.48550/arxiv.2609.05620
UR - https://arxiv.org/abs/2609.05620
AB - Accretion governs the growth of young stars and the early evolution of their circumstellar disks, yet population-level measurements of accretion are often hampered by heterogeneous diagnostics and by samples preferentially selected toward disk-bearing or accreting objects. This can impact the mass accretion rate-stellar mass (Ṁ-M_⋆) relation, particularly at substellar masses. We present a uniform analysis of accretion in the ∼2 Myr-old star-forming cluster IC 348 based on deep Hubble Space Telescope F656N imaging. Using Hα excess as a single, homogeneous accretion tracer, we derive accretion rates and robust upper limits for 200 cluster members spanning the stellar to substellar mass regime (3 M_⊙ to 4 M_Jup). Accretion is detected in 37±3% of the sample, with fractions of 34±4% among stellar members and 46±6% among substellar objects. For accretors alone, the inferred Ṁ-M_⋆ relation is consistent with those measured in similarly aged regions such as Lupus. In contrast, including weak accretors and non-detections increases the scatter and flattens the slope while lowering the intercept, demonstrating the strong influence of the low-accretion tail on population-level accretion relations. For free-floating planetary-mass objects in IC 348, extrapolating the accretors-only fit overpredicts Ṁ by approximately an order of magnitude compared to the fit that includes upper limits, which instead implies mass accretion rates of <10^−12 M_⊙ yr^−1. These results show that sample selection, specifically whether the sample is restricted to disk-bearing or accreting targets, or instead is drawn from a complete membership census, is a dominant factor shaping population-level accretion relations across a wide dynamic range in stellar mass.
ER -