Chuan-Peng Zhang

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I am Chuan-Peng Zhang, an astronomer working at the National Astronomical Observatories, Chinese Academy of Sciences (NAOC) as an associate professor now, and was ever at the Max-Planck-Institut für Astronomie (MPIA) as a postdoc.

About me

Current Work

The FAST All Sky H I Survey (FASHI) conducted with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) has mapped approximately 19,500 square degrees of the sky north of declination -14°, detecting ~156,000 extragalactic H I sources at redshifts z < 0.09 with a median sensitivity of 0.57 mJy per beam at a velocity resolution of 6.4 km/s. The survey achieves unprecedented depth and area coverage, significantly improving upon previous single-dish surveys. Through a detailed completeness analysis that accounts for the survey's non-uniform sensitivity and line-width dependence, we construct a robust H I mass function (HIMF) using a completeness-corrected sample of over 109,000 sources. The HIMF extends to H I masses of approximately 10⁵ solar masses and is best described by a double-Schechter function with characteristic masses log(M_s1 / h₇₀⁻² M_⊙) = 9.85 ± 0.01 and log(M_s2 / h₇₀⁻² M_⊙) = 7.21 ± 0.17. The derived cosmic H I density is Ω_HI = (4.71 ± 0.02) × 10⁻⁴ h₇₀⁻¹. The shallow low-mass slope of the HIMF indicates a scarcity of detectable neutral hydrogen in low-mass dark matter halos at low redshift. FASHI provides the most extensive and sensitive H I catalog to date, establishing a critical benchmark for studies of gas accretion, galaxy evolution, and large-scale structure in the local universe.

Astro links