相关论文: A Thin HI Circumnuclear Disk in NGC4261

Recent studies of the circumgalactic gaseous environment of the Milky Way have concentrated on the distribution, chemical composition, and physical properties of the most massive neutral gas clouds and the highly-ionized halo absorbers.…

We present the detection of an enormous disc of cool neutral hydrogen (HI) gas surrounding the S0 galaxy NGC 612, which hosts one of the nearest powerful radio sources (PKS 0131-36). Using the Australia Telescope Compact Array, we detect…

We present here a detailed analysis of an unusual absorption line system in the quasar SDSS J122826.79+100532.2. The absorption lines in the system have a common redshifted velocity structure starting from $v\sim0$ and extending to…

Narrow Line Seyfert 1 galaxies are generally accreting at high fractions of the Eddington limit. They can show complex X-ray spectra, with a strong `soft excess' below 2 keV and a sharp drop at ~7 keV. There is strong evidence linking the…

We have observed the massive protostar AFGL 2136 IRS 1 in multiple wavelength windows in the near-to-mid-infrared at high ($\sim3$ km s$^{-1}$) spectral resolution using VLT+CRIRES, SOFIA+EXES, and Gemini North+TEXES. There is an abundance…

Neutral gas is commonly believed to dominate over stars in the outskirts of galaxies, and investigations of the disk-halo interface are generally considered to be in the domain of radio astronomy. This may simply be a consequence of the…

We report the discovery of extremely broad 21-cm HI absorption (FWZI ~1600 km/s) detected with the Westerbork Synthesis Radio Telescope in the radio source 4C37.11 (B2 0402+379). This object has been claimed to host a super-massive binary…

We have searched for HI 21cm absorption toward the two brightest radio AGN at high redshift, J0924--2201 at $z = 5.20$, and J0913+5919 at $z=5.11$, using the Giant Meter Wave Radio Telescope (GMRT). These data set a 3$\sigma$ upper limit to…

We report the detection of HI absorption towards the inner double of the double-double radio galaxy (DDRG) J1247+6723 with the Giant Metrewave Radio Telescope (GMRT). The inner double is a Giga-hertz peaked spectrum (GPS) source with a…

Observations of extragalactic objects need to be corrected for Galactic absorption and this is often accomplished by using the measured 21 cm HI column. However, within the beam of the radio telescope there are variations in the HI column…

We present 1.4 GHz HI absorption line observations towards the starburst in NGC2146, made with the VLA and MERLIN. The HI absorption has a regular spatial and regular velocity distribution, and does not reveal any anomaly as a sign of an…

Low-luminosity radio-loud active galactic nuclei (AGN) are of importance in studies concerning feedback from radio AGN since a dominant fraction of AGN belong to this class. We report high-resolution Very Large Array (VLA) and European VLBI…

By combining the data from surveys for HI 21-cm absorption at various impact parameters in near-by galaxies, we report an anti-correlation between the 21-cm absorption strength (velocity integrated optical depth) and the impact parameter.…

We present the Spectral Energy Distribution of HR 4049 based on literature data and new continuum measurements at 850 micron. The SED shows variable absorption in the UV, and a large IR excess, both caused by circumstellar dust. The shape…

We present results of VLA and VLBA observations of the 1.420 GHz neutral hydrogen absorption associated with the Compact Symmetric Object 1946+708 (z=0.101). We find significant structure in the gas on parsec scales. The peak column density…

We report on the discovery of HI in absorption toward the gigamaser galaxy TXS2226-184 using the VLA. The absorption appears to consist of two components -- one with a width of 125 km/s, and one broader (420 km/s), both toward the compact…

We present the results of a VLA and WSRT search for HI emission from the vicinity of seven nearby clouds, which were observed in Lya absorption with HST toward Mrk335, Mrk501 and PKS2155-304. We searched a volume of 40' x 40' x 1000 km/s.…

High resolution X-ray spectroscopy of the warm absorber in the nearby X-ray bright Seyfert 1 galaxy, Mrk 1040 is presented. The observations were carried out in the 2013-2014 timeframe using the Chandra High Energy Transmission Grating with…

We studied the absorption features of CO lines against the continuum originating from the heated dust in the obscuring tori around active galactic nuclei (AGNs). We investigated the formation of absorption lines corresponding to the CO…

During the past decade or so, measurements of Galactic HI absorption using VLBI against extra-galactic sources, as well as multi-epoch observatios in pulsar directions, have detected small-scale transverse variations corresponding to tens…