Related papers: Absorption Line Search Through Three Local Group D…
We present new H I 21 cm absorption data and ultraviolet spectroscopy from HST/STIS of the QSO/galaxy pair 3C 232/NGC 3067. The QSO sightline lies near the minor axis and 1.8 arcmin (11 kpc) above the plane of NGC 3067, a nearby luminous…
We present analysis on three intervening H I-C IV absorption systems tracing gas within galaxy group/cluster environments, identified in the $HST$/COS far-UV spectra of the background quasars PG $1148+549$ ($z_{abs}=0.00346$),…
With the Chandra X-ray Telescope we have detected a zero-redshift OVII He-alpha absorption line along the sight line toward 3C 273. This line detection is highly significant, with a signal-to-noise ratio (S/N) of 6.4. We explore two models,…
Absorption-line spectroscopy of 23 background QSOs and numerous background galaxies has let us measure the spatial distribution of metals and neutral hydrogen around 1044 UV-selected galaxies at redshifts 1.8<z<3.3. The typical galaxy is…
The hot gas in galaxy halos may account for a significant fraction of missing baryons in galaxies, and some of these gases can be traced by high ionization absorption systems in QSO UV spectra. Using high S/N ratio $ HST$/COS spectra, we…
The gas content of the complete compilation of Local Group dwarf galaxies (119 within 2 Mpc) is presented using HI survey data. Within the virial radius of the Milky Way (224 kpc here), 53 of 55 dwarf galaxies are devoid of gas to limits of…
The circumgalactic medium (CGM) around galaxies is believed to record various forms of galaxy feedback and contain a significant portion of the "missing baryons" of individual dark matter halos. However, clear observational evidence for the…
Observations of UV metal absorption lines have provided insight into the structure and composition of the circumgalactic medium (CGM) around galaxies. We compare these observations with the low-redshift ($z \leq 0.3$) CGM around dwarf…
We present a UV absorption-line analysis of the circumgalactic medium (CGM) of Sextans B, a dwarf irregular galaxy at 1.3 Mpc distance on the outer frontier of the Local Group. Using HST/COS spectroscopy of two AGN sightlines passing…
Dwarf galaxies are found to have lost most of their metals via feedback processes; however, there still lacks consistent assessment on the retention rate of metals in their circumgalactic medium (CGM). Here we investigate the metal content…
(Abridged) A large fraction of the gas in galactic haloes has temperatures between 10^4.5 and 10^7 K. At these temperatures, cooling is dominated by metal-line emission if the metallicity Z>~0.1 Zsun. We explore the detectability of several…
Using Hubble Space Telescope Cosmic Origins Spectrograph observations of 89 QSO sightlines through the Sloan Digital Sky Survey footprint, we study the relationships between C IV absorption systems and the properties of nearby galaxies as…
As part of the Deciphering the Interplay between the Interstellar medium, Stars, and the Circumgalactic medium (DIISC) survey, we present the UV metal absorption features in the Circumgalactic Medium (CGM) near the H I gas disk…
We carried out a Subaru and UKIRT near infrared imaging survey for H-alpha emitting galaxies around two pair quasar systems (Q0301-005/Q0302-003 and Q2343+125/Q2344+125), and a triple quasar system (KP76/KP77/KP78). Narrow band near…
We examine the HI content and environment of all of the Local Group dwarf galaxies (M_tot < 10^10 M_solar), including the numerous newly discovered satellites of the Milky Way and M31. All of the new dwarfs, with the exception of Leo T,…
(abridged) We searched for evidence of soft X-ray absorption by hot gas in the vicinity of the Galaxy in a small sample of fifteen type I AGN observed with the high resolution X-ray gratings on board Chandra. We find that around half of the…
We have recently identified several high velocity (V < -100 km/s) clouds in the directions of Mrk 509 and PKS 2155-304 that have unusual ionization properties. The clouds exhibit strong C IV absorption with little or no detectable low ion…
About 30-50% of the baryons in the local Universe are unaccounted for and are likely in a hot phase, 10^5.5-10^8 K. A hot halo (10^6.3 K) is detected around the Milky Way through the O VII and O VIII resonance absorption and emission lines…
Far Ultraviolet Spectroscopic Explorer spectra of 22 Galactic halo stars are studied to determine the amount of O VI in the Galactic halo between ~0.3 and \~10 kpc from the Galactic mid-plane. Strong O VI 1031.93 A absorption was detected…
We study the physical conditions of the circum-galactic medium (CGM) around z=0.25 galaxies as traced by HI and metal line absorption, using cosmological hydrodynamic simulations that include galactic outflows. Using lines of sight targeted…