相关论文: DI in the outer Galaxy

The Lyman decrement associated with the cumulative effect of HI in QSO absorption systems along the line of sight provides a distinctive feature for identifying galaxies at z>2.5. The Hubble Deep Field (HDF) observations offer the…

We present results from 12 km/s resolution echelle spectroscopy of the bright $z=4.694$ QSO BR1202-0725. A preliminary analysis shows that high metallicity narrow line absorption clouds are present up to the redshift of the quasar. A damped…

We present near-infrared (IR) spectra of two planetary nebula (PN) candidates in close lines of sight toward the Galactic center (GC) using the Gemini Near-Infrared Spectrograph (GNIRS) at Gemini North. High-resolution images from radio…

We present an analysis of the HI absorption in a sample of 101 flux-selected radio AGN (S_1.4 GHz > 50 mJy) observed with the Westerbork Synthesis Radio Telescope (WSRT). HI absorption is detected in 32 galaxies, showing a broad variety of…

Where dust and gas are uniformly mixed, atomic hydrogen can be traced through the detection of far-infrared (FIR) or UV emission of dust. We considered, for the origin of discrepancies observed between various direct and indirect tracers of…

Perhaps as many as 10% of high redshift radio galaxy (HzRG; z > 2) candidates that are selected using an Ultra Steep radio Spectrum (USS) criterion fail to show optical emission (continuum, lines) in deep Keck exposures. Their parent…

We report on a survey of \nh2d towards protostellar cores in low-mass star formation and quiescent regions in the Galaxy. Twenty-three out of thirty-two observed sources have significant ($\gsim 5\sigma$) \nh2d emission. Ion-molecule…

We report statistically significant detection of H I 21-cm emission from intermediate-redshift ($z\approx0.2$-0.6) galaxies. By leveraging multi-sightline galaxy survey data from the Cosmic Ultraviolet Baryon Survey (CUBS) and deep radio…

We report a $\approx 400$-hour Giant Metrewave Radio Telescope (GMRT) search for HI 21 cm emission from star-forming galaxies at $z = 1.18-1.39$ in seven fields of the DEEP2 Galaxy Survey. Including data from an earlier 60-hour GMRT…

We present NOT optical observations of a clump (l = 127.9435 deg, b = +1.8298 deg), embedded in an extended, irregularly shaped, diffuse optical nebula. This condensation shows an emission-line spectrum typical of classic HII regions.…

We report high precision spectrophotometric observations of four planetary transits of HD 209458, in the region of the sodium resonance doublet at 589.3 nm. We find that the photometric dimming during transit in a bandpass centered on the…

We present a detailed analysis of the H_2 and HD absorption lines detected in the Damped Lyman-alpha (DLA) system at z_abs=2.3377 towards the quasar Q1232+082. We show that this intervening cloud has a covering factor smaller than unity and…

The Westerbork Synthesis Radio Telescope finds a weak 21cm line emission feature at the coordinates (RA-Dec-velocity) of the sub-Damped Lyman-alpha absorber observed at z_abs=0.00632 in the spectrum of PG1216+069. The emission feature,…

We report the first $5\sigma$ detection of HI 21 cm emission from a star-forming galaxy at redshift $z\sim1.3$ (nearly 9 billion years ago) using upgraded Giant Metrewave Radio Telescope (uGMRT). This is the highest redshift HI detection in…

The 692 GHz para ground-state line of D2H+ has been detected at the Caltech Submillimeter Observatory towards the pre-stellar core 16293E. The derived D2H+ abundance is comparable to that of H2D+, as determined by observations of the 372…

The diatomic free radical methylidyne (CH) is an important tracer of the interstellar medium and the study of it was critical to our earliest understanding of star formation. Although it is detectable across the electromagnetic spectrum,…

We present a new measurement of the deuterium-to-hydrogen ratio (D/H) in the Lyman limit absorption system at $z = 3.572$ towards Q1937--1009. We use an improved method to measure D/H in QSO absorption systems, which includes extra…

We present the results of a systematic search for gravitationally-lensed continuum Lyman break `drop-outs' beyond a redshift 7 conducted via very deep imaging through six foreground clusters undertaken with the Hubble and Spitzer Space…

We present an analysis of interstellar absorption along the line of sight to the nearby white dwarf star HZ43A. The distance to this star is 68+/-13 pc, and the line of sight extends toward the north Galactic pole. Column densities of OI,…

As the Galaxy evolves, the abundance of deuterium in the interstellar medium (ISM) decreases from its primordial value: deuterium is "astrated". The deuterium astration factor, f_D, the ratio of the primordial D abundance (the D to H ratio…