1,131 datasets found

The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project....

We present projected rotational velocities for 20 early-type (B8-A9) and 74 late-type (F2-M8) members of the ~5 Myr old Upper Scorpius OB Association derived from...

Classical Be stars are known to occasionally transition from having a gaseous circumstellar disk ("Be phase") to a state in which all observational evidence for the presence of...

We surveyed the Hubble Space Telescope UV spectra of 49 low-redshift quasars for z<1 CIV candidates, relying solely on the characteristic wavelength separation of the...

We present spectra of six metal-poor stars in two of the ultra-faint dwarf galaxies orbiting the Milky Way (MW), Ursa Major II, and Coma Berenices obtained with the Keck/High...

In a sample of 114 diffuse cloud sightlines spanning a wide range of interstellar environments, we find the equivalent widths of the diffuse interstellar bands (DIBs)...

We present high-resolution spectroscopic measurements of the abundances of the {alpha} element titanium (Ti) and s-process elements yttrium (Y) and lanthanum (La) for 59...

As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey, we present 123 spectra of faint emission-line galaxies, selected to focus on intermediate redshift...

A sample of 69 galaxies with radial velocities of less than 2500km/s was selected from the HI Parkes All-Sky Survey (HIPASS, Cat. ) and imaged in broadband B and R and...

We present the results of a search for variability in the equivalent widths (EWs) of narrow, associated (|{Delta}v|<=5000km/s) absorption lines found in the UV spectra of...

We report the abundance analysis of new high signal-to-noise ratio (S/N) spectra of the most metal-poor ([Fe/H]=-2.95) star currently known to be a member of a dwarf galaxy, the...

We present H{alpha}-derived star formation rates (SFRs) for the galaxy cluster Cl J0023+0423B at z=0.845. Our 3{sigma} flux limits correspond to an SFR of...

A statistical study is presented of (1) the frequency of narrow C IV {lambda}1549 absorption lines in 1.5<=z<~3.6 radio-quiet and radio-loud quasars and (2) the UV and...

Galaxy-galaxy interactions rearrange the baryons in galaxies and trigger substantial star formation; the aggregate effects of these interactions on the evolutionary histories of...

Red supergiants (RSGs) are evolved massive stars that represent extremes, in both their physical sizes and their cool temperatures, of the massive star population. The effective...

We have derived relations between FWHMs and equivalent widths of metallic absorption lines in the spectra of RR Lyrae stars to estimate new upper limits on the axial equatorial...

To improve the census of the Upper Sco association (~11 Myr, ~145 pc), we have identified candidate members using parallaxes, proper motions, and color-magnitude diagrams from...

We have performed a survey for new members of the Upper Sco association that have circumstellar disks using mid-infrared photometry from the Wide-field Infrared Survey Explorer...

This paper presents the results of 4 years of high-resolution spectral observations of 69 emission-line stars, 54 of them being newly discovered sources. We classified the stars...

We have conducted a novel search of most of the southern sky for nearby red dwarfs having low proper motions, with specific emphasis on those with {mu}<0.18"/yr, the lower...