相关论文: Ionization of large-scale absorbing haloes and fee…

Recent studies have shown that K-luminous galaxies at 2<z<2.5 have high Halpha line widths and high [NII]/Halpha ratios. If these lines arise from photo-ionization by massive stars in HII regions these results imply that massive, metal rich…

We conducted a HI 21cm absorption study of a sample of 147 nearby (z < 0.1) low-power radio sources with $10\,\mathrm{mJy} < S_{1.4\,\mathrm{GHz}} < 30\,\mathrm{mJy}$ and $\log(P_{1.4\,\mathrm{GHz}}/\mathrm{W\,Hz^{-1}}) = 20.5-23.7$, using…

The temporal evolution of the ionizing UV background radiation field at high redshift provides a probe of the evolution of the early star formation rate. By comparing the observed levels of absorption in the highest redshift quasar spectra…

To gain insight into four highly ionized high-velocity clouds (HVCs) discovered by Sembach et al. (1999), we have analyzed data from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) for the PKS 2155-304 and…

Far-ultraviolet spectra obtained with $FUSE$ show that the strong $CII\lambda$1036 interstellar absorption-line is essentially black in five of the UV-brightest local starburst galaxies. Since the opacity of the neutral ISM below the…

We have imaged the H92alpha and H75alpha radio recombination line (RRL) emissions from the starburst galaxy NGC 253 with a resolution of ~4 pc. The peak of the RRL emission at both frequencies coincides with the unresolved radio nucleus.…

We analyze a sample of 25 [Ne V] $\lambda$3426 emission-line galaxies at $1.4<z<2.3$ using Hubble Space Telescope/Wide Field Camera 3 G102 and G141 grism observations from the CANDELS Lyman-$\alpha$ Emission at Reionization (CLEAR) survey.…

To investigate the impact of radio jets during the formation epoch of their massive host galaxies, we present an analysis of two massive, log(M_stel/ M_sun)~10.6 and 11.3, compact radio galaxies at z=3.5, TNJ0205+2242 and TNJ0121+1320.…

We compare high-resolution optical and radio imaging of 12 luminous submm galaxies at z=2.2+/-0.2 observed with HST and the MERLIN and VLA at comparable spatial resolution, 0.3" (2kpc). The radio emission traces the likely far-infrared…

We analyse the ro-vibrational absorption bands of various molecular cations (HCO$^+$, HCNH$^+$, and N$_2$H$^+$) and neutral species (HCN, HNC, and HC$_3$N) detected in the \textit{James Webb Space Telescope}/Mid-Infrared Instrument Medium…

We study the effect of H I ionizing photons escaping from high-redshift (high-z) galaxies have on the He II ionizing ultraviolet background (UVB) radiation. While these photons do not directly interact with He II ions, we show that they…

We analyse the formation of broad absorption troughs in the spectra of high-redshift sources in the redshift range $5 \le z \le 15$ for two observationally motivated reionization histories inferred from distant galaxy spectra and CMB…

In Keck HIRES spectra of 9 QSOs we identify a sample of 908 CIV absorber components in 188 systems outside the Lyman forest in the redshift range 1.6 < z < 4.4, with related lines of SiIV, CII, SiII and NV. The properties of the CIV…

We report a Chandra observation of the z=3.395 radio galaxy B2 0902+343. The unresolved X-ray source is centred on the active nucleus. The spectrum is well fit by a flat power law of photon index of Gamma~1.1 with intrinsic absorption of…

We study the molecular and the ionized gas in a possible precursor of an UC HII region to contribute to the understanding of how high-mass stars build-up their masses once they have reached the zero-age main secuence. We carried out…

We present Plateau de Bure Interferometer observations of far infra-red emission lines in BRI 0952-0115, a lensed quasar at z=4.4 powered by a super-massive black hole (M_BH=2x10^9 M_sun). In this source, the resolved map of the [CII]…

We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft…

Neutral atomic hydrogen and molecular gas in the host galaxies of radio active galactic nuclei (AGN) can be traced using H I 21-cm and OH-1667 MHz absorption lines to understand the fueling and feedback processes. We present the results of…

We report the detection of a zabs=0.3654 associated absorption-line system in the UV spectrum of the CSS quasar 3C48. The absorbing material is blue shifted with respect to the quasar emission-line redshift, zem=0.3700, suggesting an…

We present 92cm observations of the high-redshift galaxy B2 0902+343 (z=3.40) with the Westerbork Synthesis Radio Telescope (WSRT). Twenty-one cm HI is detected in absorption, at a depth of 15.9 mJy (=~6\sigma) and rest frame velocity width…