arXiv subjects

Li-Nuo Yang

Publications and source records attributed to Li-Nuo Yang.

2 recordsLinked to original sources

arXiv2026

GeV {\gamma}-ray emission in the star-forming region S140

We report the detection of a GeV {\gamma}-ray source in the S140 HII region using 17.75 years of Fermi-LAT data, with a source-detection significance of ~32.1{\sigma} in the 0.1-500 GeV energy band. The emission is significantly extended (AIC evidence ratio above 1 GeV is 2x10^9) and is therefore designated as 4FGL J2220.8+6319e. The {\gamma}-ray emission coincides spatially with a molecular cloud that hosts the massive young stellar object S140 IRS1. Its spectrum is best fitted by a log-parabolic spectrum (TS_cur(LP) = 104.1) and can be reproduced by both hadronic and leptonic models. The jet driven by S140 IRS1 offers a viable particle acceleration site, yielding injection timescales and maximum particle energies consistent with theoretical expectations, whereas stellar winds are energetically disfavored.

astro-ph.HE↗

arXiv2026

GeV {\gamma}-ray emission in the low-mass star-forming region AFGL 490

We report the discovery of an extended GeV {\gamma}-ray source, 4FGL J0330.7+5845e, associated with the star-forming region AFGL 490 using 17 years of Fermi-LAT data. The emission is spatially coincident with a dense molecular cloud and centered near the massive protostar AFGL 490. Its spectral energy distribution shows a distinct high-energy cutoff. Both leptonic and hadronic models can fit the {\gamma}-ray spectrum, but energetic arguments rule out stellar winds as the primary accelerator. Instead, the protostellar jet driven by AFGL 490 is identified as a plausible site for particle acceleration, and the derived timescales and maximum particle energies are consistent with theoretical predictions for such jets.

astro-ph.HE↗