A5053744979- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
Polar Research Institute of China
2018
University of Chinese Academy of Sciences
2015-2016
Shanghai Astronomical Observatory
2015-2016
We investigate the UV continuum slope $\alpha$ of a large quasar sample from SDSS DR7. By using specific windows, we build two samples at lower ($0.71<z<1.19$) and higher ($1.90<z<3.15$) redshifts, which correspond to slopes longer (NUV) shorter (FUV) rest wavelength ranges respectively. Overall, average are $-0.36$ $-0.51$ for $\alpha_{\rm NUV}$ FUV}$ with similar dispersions $\sigma_{\alpha} \sim 0.5$. For both samples, confirm luminosity dependence slope, i.e., fainter quasars have redder...
We investigate the luminosity and redshift dependence of quasar continuum by means composite spectrum using a large non-BAL radio-quiet sample drawn from Sloan Digital Sky Survey. Quasar slopes in UV-Opt band are measured at two different wavelength ranges, i.e., αν12 (1000 ∼ 2000 Å) αν24 (2000 4000 derived power-law fitting. Generally, UV spectra slope becomes harder (higher αν) toward higher bolometric luminosity. On other hand, when quasars further grouped into bins, we find that both...
In this paper, we present an intercomparison study of two quasars, SDSS J145618.32+340037.2 and J215331.50-025514.1, which have proximate damped Lya systems (PDLAs) with residual flux upon the absorption trough. Though they both as luminous $10^{43}erg/s$, their PDLAs are quite different in, e.g., HI column density, metal line strength, high-ionization lines well strength. For J1456, density is $20.6\pm0.2$, za=2.3138, nearly identical to quasar redshift (z=2.3142) determined from [OIII]...
We identified a peculiar proximate subdamped Lyα absorption system (sub-DLA) at z = 3.234 with neutral hydrogen column density of toward the quasar SDSS J125903.26+621211.5 in two epoch optical spectra Sloan Digital Sky Survey. detected residue sub-DLA trough >8σ level. To our surprise, significant (>4σ) extreme ultraviolet (EUV) continuum emission was corresponding Lyman limit edge both FUV and NUV bands by Galaxy Evolution Explorer. The high should allow negligible transmission line...