科学研究
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2024.12.23
Studying cosmology and astrophysics by the synergy of RSD and kSZ effects
As one main target of cosmological surveys, the galaxy peculiar velocity field encodes information about the cosmic structure growth history and significantly contributes to the study of dark energy and dark matter. Its detection is typically made by the redshift space distortion (RSD) and kinetic Sunyaev-Zel’dovich (kSZ) effects in cosmology. In this talk, I will present high signal-to-noise ...
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2024.12.09
Discussion on DESI Y1 results [EN]
Since DESI has released their cosmological constraints from BAO and Full-shape Analysis with DESI Y1 data in April and November respectively, in the seminar next week, Siyi Zhao and Wenshuo Xu (both are 4th year graduate students) are going to briefly present and discuss DESI Y1 results, including a general introduction to DESI project, methodology and their key cosmological constraints. Welcom...
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2024.11.29
Emulating Extended Lyman Alpha Halos Around Star-Forming Galaxies [EN]
The detection of the extended Lyman-alpha emission (or Lyman-alpha halos) around star-forming galaxies opens a new window for probing the circum-galactic medium (CGM) at high redshifts. With IFU observations (e.g., through MUSE), we are already capable of measuring the spatially resolved Lya spectra around individual galaxies, revealing a diverse population of the Lya emission. However, interpr...
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2024.11.25
Five parameters are all you need [EN]
The standard cosmological model (ΛCDM) relies on six free parameters, five of which have direct cosmological origins, while the sixth, the optical depth (τ), is an ad hoc parameter used to model the scattering effects experienced by cosmic microwave background (CMB) photons. CMB photons decoupled from the primordial plasma at z ~ 1100 when neutral hydrogen formed, reducing the abundance of fr...
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2024.11.18
Estimating and Studying Dust Attenuation From Galactic Spectra [EN]
In the past few years, we develop a method to estimate the dust attenuation curve of galaxies from full optical spectral fitting. One important advantage of this method is that the estimated dust attenuation curve is independent of the shape of theoretical dust attenuation curves. Based on the method, we investigate the dust attenuation in both stellar populations and ionized gas in kpc-scale r...
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