Related papers: Does the Milky Way Produce a Nuclear Galactic Wind…

Galactic winds are a prime suspect for the metal enrichment of the intergalactic medium and may have a strong influence on the chemical evolution of galaxies and the nature of QSO absorption line systems. We use a sample of 1406 galaxy…

Active galactic nucleus (AGN) feedback is the process by which supermassive black holes in the centres of galaxies may moderate the growth of their hosts. Gas outflows from supermassive black holes release huge quantities of energy into the…

Winds from massive stars supply ~ 10^{-3} solar masss/year of gas to the central parsec of the Galactic Center. Spherically symmetric hydrodynamic calculations show that ~ 1 % of this gas, or ~ 10^{-5} solar masses/year, flows in towards…

Supermassive black holes in galaxies spend majority of their lifetime in the low-luminosity regime, powered by hot accretion flow. Strong winds launched from the hot accretion flow have the potential to play an important role in active…

We report the discovery of eleven high-velocity HI clouds at Galactic latitudes of 25-30 degrees, likely embedded in the Milky Way's nuclear wind. The clouds are detected with deep Green Bank Telescope 21 cm observations of a $3.2^\circ…

We present WSRT, VLA and VLBI observations of the HI absorption in the radio galaxy NGC 315. The main result is that two HI absorbing systems are detected against the central region. In addition to the known highly redshifted, very narrow…

The bulk flow velocity for the cluster of interstellar cloudlets within about 30 pc of the Sun is determined from optical and ultraviolet absorption line data, after omitting from the sample stars with circumstellar disks or variable…

High-velocity atomic clouds in the Galactic center have attracted significant attention due to their enigmatic formation process, which is potentially linked to the starburst or supermassive black hole activities in the region. Further, the…

Hypervelocity stars (HVSs) are stars ejected from the Galactic Centre (GC) through tidal interactions with the central supermassive black hole. Formed in the immediate vicinity of Sgr~A$^\ast$, these stars are accelerated to velocities high…

We have carried out a sensitive high-latitude (|b| > 15deg.) HI 21cm-line absorption survey towards 102 sources using the GMRT. With a 3-sigma detection limit in optical depth of ~0.01, this is the most sensitive HI absorption survey. We…

Aims. We aim to investigate the ionisation conditions and distances of Galactic high-velocity clouds (HVCs) in the Galactic halo and beyond in the direction of the Local Group (LG) barycentre and anti-barycentre, by studying spectral data…

We present a 21-cm emission-absorption study towards extragalactic sources in the Canadian Galactic Plane Survey (CGPS). We have analyzed HI spectra towards 437 sources with S > 150 mJy, giving us a source density of 0.6 sources per square…

Spectra of the archetypal Type II Seyfert galaxy NGC 1068 in a narrow wavelength interval near 3.7 microns have revealed a weak absorption feature due to two lines of the molecular ion H3+. The observed wavelength of the feature corresponds…

Spectra of the He I 10830 Angstrom line were obtained with NIRSPEC on the Keck 2 telescope for metal-deficient field giant stars. This line is ubiquitous in stars with T_eff greater than 4500K and M_V fainter than -1.5. Fast outflows are…

We present new calculations of the mass inflow and outflow rates around the Milky Way, derived from a catalog of ultraviolet metal-line high velocity clouds (HVCs). These calculations are conducted by transforming the HVC velocities into…

We investigate the supernova-driven galactic wind of the barred spiral galaxy NGC 7552, using both ground-based optical nebular emission lines and far-ultraviolet absorption lines measured with the Hubble Space Telescope Cosmic Origins…

The hot gaseous halos of galaxies likely contain a large amount of mass and are an integral part of galaxy formation and evolution. The Milky Way has a 2e6 K halo that is detected in emission and by absorption in the OVII resonance line…

Projected quasar galaxy pairs provide powerful means to study the circumgalactic medium (CGM) that maintains the relics of galactic feedback and the accreted gas from the intergalactic medium. Here, we study the nature of a Lyman Limit…

We report the first detections of associated H{\sc i} 21\,cm absorption in Gigahertz-peaked-spectrum (GPS) sources at high redshifts, $z > 1$, using the Giant Metrewave Radio Telescope (GMRT). Our GMRT search for associated H{\sc i} 21\,cm…

We obtained medium-resolution ultraviolet (UV) spectra between 1150 and 1450 Angstroms of the four UV-bright, infrared (IR)-luminous starburst galaxies IRAS F08339+6517, NGC 3256, NGC 6090, and NGC 7552 using the Cosmic Origins Spectrograph…